for those of you who have been following my back to the drawing board post, I'm building a new engine which will end up being boosted for my 77 corvette. I'd like to have a streetable car that quarters in 10 seconds, something that is driveable but that I can still take to the track. the time has come to make the decision, EFI or carburetor? since I honestly can't decide, I need some help. I'm looking at efficiency, reliability, performance, cost to build, all of the above. so let the debate begin!

______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

both edelbrock and holley make EFI good kits. I think holley has one that is designed to work with a blower..

carbueration usually has a sweet spot where the air and fuel are balanced and its close but not quite right at all other points.

EFI is always right.

carbueration your are depending on vacuum to pull the air and fuel in. Efi you are pushing the fuel in in the correct amount to match the amount of air than being sucked in.

EFI is better. All other things being equal, as far as I know there is no realistic case where a carb is more efficient or more powerful than EFI.

I agree with Ben. Thats the only way to go if you have the $$ to do it up front. BTW, make sure you make your decision before you sellect your cam.

______________

Brian - NCM Lifetime Member

73 coupe L48, Flat-top pistons, Performer RPM Heads, Crane Cam and roller rockers, Holley 650 vac sec. Performer intake,
3.55 gear BTO 200-4R trans,
Leather seats, Seatbelt Plus 3point seatbelts, Pioneer CD player
Magnaflow Exhuast System

I vote EFI. I want EFI myself but I dont have the moola yet for it.

EFI delivers more even fuel volume the the cylinders than a carb. This is due to injecting fuel right at the intake valves. Fuel is heavier than air and tends to drop out of suspension. So a carb delivers less fuel to cylinders further away, and more to the closer cylinders. One for EFI

Due to the pressures, the spray pattern of fuel into the vacuum causes the fuel to break up better and more completely. Liquid does not burn, only the vapor on the surface. Smaller drops means more surface, better flame propagation, more power and less emissions. Two for EFI

The computer control of the EFI is faster and more responsive then the air and vacuum control of a carb. Therfore it has quicker response. Three for EFI

The effect of the previous three is also better fuel mileage. Four for EFI

Due to the precision, there is less carbon deposits and contaminated blowby than with a carb. This helps keep the oil cleaner, and thats less engine wear. Five for EFI

EFI is more complex and requires sensors and inputs, more wiring, more costly manifolds. It simply is much more expensive. One for Carbs

EFI requires more knowledge and skill to repair and diagnosis than carbs. But anyone who is a good tech and understands both systems can handle either. It depends on knowledge and experience. TIE

EFI requires special diagnosic equipment that is not needed for carbs. Two for carbs.

Score EFI 4, Carb 2, Tie 1 But these are not equals. The benefits of EFI far outweight the benefits of carbs. EFI is a clearly superior choice. If you can afford it.

EXCEPT, when nothing but raw horsepower is whats on tap. If you don't care about idle, tip in, cold operation, or anything but huge amounts of honking horsepower at Wide Open Throttle, the carbs can take over. This is only considered for drag racing, wide open all the time operation. A tall manifold with two four barrels or a couple of Predator carbs and you can dump amazing amounts of fuel and air into a monster motor. Advantage, not streetable carbs. Don't even think about trying to drive this on the street or highway. But if you want 6 or 7 in the 1/4, it's nice.

Still the same thing. How good do you want? How much do you want to spend?

It hit me today that I may have been going about this the wrong way. I think that I should pay less attention to cost, and do what's best for my baby. Therefore, cost is less of a concern, but I still don't want to be spending 16-20 grand on just the engine.

So far, EFI has my attention. The dragging power would be nice, but not in a C3. This C3 would be something I'd take to a drag track a bit, and I'd like to be able to do well in my class, but I could definitely stand being in a slower class...thus, the whole 10-second quarter goal. I've never really raced before, so I want this car to be great for show, very driveable, and still capable of competing on the track, so that I can dabble my fingers in drag racing. If I ever do decide to pursue drag racing more intensely, I will buy a C4 and convert it into a pure drag monster. This C3 I want to be a nice, versatile car that can last me...basically the rest of my life.

One last question...and I'll prolly start another thread for comparison of supercharging and turbocharging so let's not delve into that yet...keep it to just an EFI vs carb thing...sound? I very much value the loud, aggressive sound of my straightpiped C3, and I've been told by countless people that when I slap on those sidepipes, it will be louder and more aggressive. Whatever I do, I don't want to lose that wonderful muscle car sound that catches EVERYONE'S attention as I'm driving down the road. To lose that lovely roar of acceleration, or that beautiful rumbling purr at idle.

Oh yes and everyone is saying that EFI is so pricey...does anyone have price estimate on building an EFI engine and getting it to work in my vette?

and again, do these EFI kits work with blowers? I was under the impression that they did not.

|UPDATED|11/4/2004 6:01:47 PM (AZT)|/UPDATED|


______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

I've been doing a little research on a EFI system that suits my needs. And I have looked at Edelbrock, Holley, etc. I've decided that I'm going to aquire piece by piece everything needed to utilize a GM Tuned Port Injection system. And with a little help and wiring from Howell Engineering, I can have a system specifically done for my car for under $2000. And maybe even add a Paxton centrifugal supercharger down the road. That's my .02 cents
Sarge

______________

GEN III 5.7L "LS6" Engine swap
TKO500 5 spd.

hrm...Holley's kit, $1400...no manifolds...

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1527&prmenbr=361

compatible with a blower?

and why do I need a kit if I'm building a brand new engine...

______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

check out holleys multiport fuel injection kits here:http://www.holley.com/HiOctn/ProdLine/Products/C950/C950MPFI/MPFIS.html#1 You need to give them a call for price but I should guess that the 800hp kit is around $3000-$3500. This is the one that is for forced induction applications. They say only for up to 14.7 psi but that is more than enough boost for your 427 stroker small block to make 700 to 800 hp and buckets of torque.

|UPDATED|11/4/2004 6:20:40 PM (AZT)|/UPDATED|

go with that holley kit and use this vortech kit for the super charger. It says the supercharger kit is intended for a holley 4150 carb but I dont think it would be hard to modify it for the fuel injection kit's throttle body that uses a 4150 carb mounting flange. check it out:http://store.summitracing.com/default.asp?target=esearch.asp&N=100&Ntk=PartSearch&Ntt=vor-4gp218-018s&x=14&y=12

I think maybe you should rethink this.
Running 10's at the drags would be great but with a 3600lb car and looking for gas milage and driveability
-you can't have both.
If you want a fun ride,and not break things every time
you punch it,I would suggest looking into a small blower like the B+M. This can give you a real 500hp on a 350
for reasonable money with a 4 BBL carb.
Steve

about whether there is a fuel injection blower kit..

ask aftershark....

I could have sworn there was a weiand kit for this..

anyway.. Matt... where are you ??

I think if you want to convert the roots type supercharger kit to EFI then It would not be hard if they dont sell one already. All you pretty much need to do is buy the universal mulipoint holly kit and add 50-55ppl injectors and get a MAP that can read positive boost up to 14.7 psi. Then have a machine shop weld in the injector bosses and bore them out for your injectors and run your fuel rails to them. Bolt the throttle body to the top of the roots as if its the holley carb it was designed for. You got to figure out the best place to put the MAP so that it can read the air pressure and flow. Probably somewhere under the roots blower.

Yes, it can be done. There are production cars that do just that.

Streetable and 10 sec 1/4 mile? Those thing don't go along with each other. Anything that goes 10 is not very street friendly.

But if you are not used to racing, it may amaze you how fast 13 is. The old muscle cars from the 60's did 14 and 13. And they were FAST! Don't let the numbers and the magazines fool you.

I'm with Ken on that one. A 10 second car is not one you would want to drive on the street too much.
I think my car runs in the 13's because I pulled on a friends car that I know runs in the 13's. It's got way enough for me in my old age.....I never know which way the ass end will end up facing.
Good luck with whatever you end up doing.

What do you know - something I can actually comment on with decent knowledge (strange for a newcomer). Anyway - I've been building turbocharged imports for the past 8 years, but grew up working on SBCs.

As for Carb vs EFI - neither one will make more power than the other. A very common misconception from the importers is that their FI makes them more powerful. What FI will do for you is increase the margin of safety you can run in the engine. It all deals with the finite control that FI has over Carbs. Carbs can move air and suck fuel just fine, but are a REAL pain to tune over the whole rpm range (as mentioned before). FI makes a computer essentially "re-jet" the intake at different RPMs. One major area that gets overlooked more often than is reasonable is the quality of the controlling computer and associated electronics for a FI system. The old Throttle Body Injection systems were no better than a carb in actual performance. For FI to have a difference it MUST be injected as close to the intake valve as possible, and aimed as close to the point where the stem blends into the head when the valve is closed. Also, keep in mind that it takes approximately 5-8psi of fuel pressure to overcome each lb of boost (as a rule of thumb). So if you want to run 10lbs of boost, make sure your pump can support the injectors. If you use one of those injector calculators - keep duty cycle under 70% (I used 60% in all my work). It helps the daily driveability by rarely stressing the injectors, even at WOT. Talk to the injector manufacurer about the injectors themselves. Some don't work well with high pressure fuel (found that the hard way).

If the best compression you can run with a carb was 12:1, with FI you MIGHT be able to take another .5-1 on it (this comes down to other factors also - not just intake). When it comes to boost, FI allows you to run higher, guarenteed. On my old 2.0L it was a rule of thumb that every lb of boost made 10hp.

There is a whole science to FI. To be honest, talk to the shops that work with the importers. Having to deal with computer controlled everything - we have discovered many ways to keep making more power. I had a daily driver 450hp Mitusbishi Eclipse GSX that pulled 11s. It was not cheap, and it broke rather often (what do you expect from 112hp/cylinder in a 4200lb car). My goal was 10s, and like the guys above, discorvered that 10s is not really streetable.

Overall, my vote goes to FI. FI is the third item on my list of work for my car (behind wipers and steering). My goal is to Twin Turbo mine, so FI just makes sense and is no longer the "mysterious beyond" that it was when I first went to the import camp.

I look forward to the super- vs turbo-charging thread later on

|UPDATED|11/5/2004 6:59:15 PM (AZT)|/UPDATED|

You sound like just the person I need to talk to. I have just started my homework to twin turbo my vette in a few years from now. Right now I am saving up to buy a fuel injection kit for my vette and get it in by this coming summer. what is your opinion on the holley 950 commander ecm? Is it worth it to spend the extra money and go with the accel computer instead?

Uggh, this is a tough decision. I didn't go digging really deep - just what I could find in about 30mins of reading.

Holley- Better known for their "old school" products than the newer technologies. They offer the most exact stats for their system, that's a plus. However, it lacks a lot of the controls you are going to need after boost is applied.

Accel- Better known for top end racing parts, always a good thing. Accel is a big vague on the exact parameters of their system so I have to assume a few things. It appears that is a more powerful processing unit, and shows it's Windows based programming utility (a plus) and even notes that it can change on the fly (we found this very useful).

Overall, between the two, I would go with Accel. Honestly, I won't get either one for mine. I'll either be getting AEM or Haltech. A very large portion of professional import racers use the Haltech (E6K is the most common, but soon to be superceded - if not already). A lot of what makes this decision has to go back to a question you put up before - Turbo or Super? It does make a difference in what you need in the ECU.

Turbo- More efficient, no parasitic loss, suffers "lag". Turbos have the POTENTIAL to make more boost - but you have to wait for enough exhaust energy to spool up the turbine. I favor turbo's because of the efficiency. A turbo doesn't heat the air per lb of compression as much as even a centrfigal blower (which is a case all it's own actually). Another major advantage of turbos that goes unnoticed a lot - the "lag" can work to your advantage in a low traction situation (ie any 2WD high power car). Because it doesn't have all of it's power on tap right away, you won't be as likely to break the tires loose. Then once you get moving just a little, the turbos catch up, max out their boost (as you have it set), and you take off.

Blower- Less efficient, easier to setup, lower emissions, causes parasitic loss, generally will be smog legal when added aftermarket. The blower, by nature that it is crankshaft driven, will respond immediately to throttle input, giving you all it's possible power at any given time. Problem being that at RPMs lower than the blower is tuned for, it will actually suck more power than it makes - slowing you down. Due to the fact that the blower does not interface with the exhaust at all, and the air it deals with is prior to being metered by the air sensor (if present) the "smog laws" don't apply in full. The part that is illegal still is all the fuel and ignition mods to make the blower work But the blower itself isn't illegal The main problem a blower faces is that it heats the air radically when it compresses it. So you might have it set to boost 15psi, but once you take charge density (basically accounting for the air temp) into account you end up with about 6-8psi. Most blowers work in the 50% ranges. Most turbos work in the mid-60%s to low-70%s (for the high end pure racing turbos).

Centrifugal Supercharger- Commonly called Paxton style, looks like the front half of a turbo with the back half being belt driven. This is a good attempt at a middle ground between the two. It doesn't cause a large parasitic lag, and doesn't suffer the "lag" of a turbo. It is generally mid-way between the two in efficiency, but leans more towards the turbo efficiency when well tuned. The main problem to running these is Boost Control at high RPMs, and physically mounting it and the hardware.

If you are going with a regular supercharger, or most centrifugal superchargers, then the Holley/Accel are decent choices. If you want the turbocharger system, you will need the extra mapping and output channels that aren't listed as present on either one of those two. I know this ends up making turbos sound like the hard road, but they really aren't. They are also more flexible than the superchargers. You want more boost? Just restrict the wastegate pressure hose, done. You can build a manual boost controller for a turbo system in about 20minutes for about $30. That can control two turbos from 0-20psi with rock solid accuracy and can be adjusted by turning a knob at anytime. I went with electronic boost controllers on my Eclipse, so I could adjust it from the cabin to exact pressure levels and swap between preset levels at the touch of a button. I ran 12psi on the road while commuting, but hit a button on my dash and it swaps over to 25psi (tried 27psi with well deserved disaster ). The flexibility and efficiency of turbos will always take my vote.

I'm tired, my wife if bugging me to get to bed....I'll answer more questions later

Lots of good info there! I was wondering if you have seen this web site and see what this guy did to his vette. http://www.montygwilliams.com/ Also check out this web site for a whole turn key kit that is very expensive. http://www.bankspower.com/twin-turbo-products.cfm Also I forgot to mention the F.A.S.T. ECM

I have been trying to help out Michael-Jon here with his future project, deciding what route to go. For me personally, I have already made my decision to go with a low boost twin turbo system for a small block. I will be running it under 15lbs of boost. Most likely 6-8 on street and 14 on the track. Aside from the ECM what do you think of the holley stealth ram intake for a future boosted application?

|UPDATED|11/6/2004 10:22:29 AM (AZT)|/UPDATED|

About the Stealth Ram (judging from the pictures) - The Plenum looks a little on the small side. This will mean that maintaining boost levels under increasing throttle will be difficult. The runners are longer than "ye olde" intake, but longer is better for these applications. Hence why you see engines that the plenum feeding the left bank is over the right head with long runners coming across the engine. The longer the better (to a point of course). It would also be a little better if the manifold wasn't split into two throughput sections (two 4bbl type areas). It works a lot better if it was just one open channel to feed all eight runners. That valley between the two tunnel areas would have been better used as more air storage. Overall, it's not a bad design - but it could be better. There are obvious overtones of their heritage as an "old school" designer in the way it's done. For combining max turbo efficiency, with adding FI to the engine, and keeping cost in mind - you probably won't find a better pre-made unit. If you made one by hand (from sheet metal or such), you could get more performance.

As for your desired boost levels - Low boost is generally assumed below 10psi, 12psi max. For a engine that is designed for Normal Aspiration these drop to below 5psi, 8psi max. Yes, the assumed threshholds of what is "low boost" are set rather low. This comes from the fact that most import engines are very high flowing engines to begin with and if you boost much on them you blow heads.

Thanks for the prompt response. My basic game plan for my engine is, I cannot forsee my future financial situation but Right now I have a pretty good normally aspirated small block chevy. I got Aluminum Trickflow heads with 180cc intake runners and they flow very well. My compression ratio is 10.3 and I have forged pistons with a comp cams 270h magnum cam in it that has 224 duration @.050 and .470 lift for both intake and exhaust at 110 lobe sep. I am using 1.6 roller rockers. My power is about 390 hp and 410 ftlbs. I plan on saving my top end for the turbo engine but redoing my short block for lower compression, forged crank, forged connecting rods, and a good cam for turbos. This wont be for another 3 years since I am returning to school in january and will still have 2 years to go for my degree. But like I said I am thinking of buying a EFI kit for the summer enjoyment and improve the overall drivability of the vette.

You think a tuned port manifold would be better for a turbo app? since its got long skinny runners?

You appear to have a very similar set up to mine. I bought my Vette with the engine already set up as a 383 Stroker, so I don't know specifics - but that's pretty close to what the PO claims. You also have a similar plan - use the V8 for the low end, and the turbos for the high end. The problem you run into with this is getting a turbo "mapped" correctly to the flow you are expecting in the engine. This is heading into higher level turbo theory and engineering, so I'd rather not get farther than that right now.

It is a solid plan to use. You do appear to have a engine that is heading towards being prepped for this style of turbo use.

One thing I had forgotten to mention in that long post - you can intercool Turbo's and Centrifugal Blowers but not regular superchargers. Intercooling can add about 10% more efficiency at the expensive of responsiveness and the amount of work being put on the turbo. Theorhetically, a maxed out racing turbo system (ie F1 style, CART, IMSA, etc) will be running in excess of 80% efficiency. Losing 20% of the work put into compressing the intake charge may sound like a lot, but some loss has to be taken since we can't change the laws of physics and not heat air as we squish it

If you want to get deeper into matching turbos and what to look for - start a new thread on it and I'll keep going in there

I do have a grasp of the concepts needed to be done to turbo my engine. I have read the book "maximum boost" by Corky Bell, from that book is what most of my understanding of turbochargers come from in a hotrodders perspective. My degree is in marine engineering, so from that perspective I am learning how to fix and maintain huge ship's diesel turbos. But this is only book knowlege, I have never had the experiance of designing and building an actual turbocharged car. So I hope you will still be in touch in the future for I will have a lot of questions.

Maximum Boost is an AWESOME book. It is still regarded as the most cmprehensive guide in turbocharging. I own one also, and reference it greatly. In there you can get through all the turbo mapping and other stuff that I would have gone through - so thanks for saving me from writing all a second time

I will be around for many years now. I'm figuring I'll die before the Vette does and so long as I have the Vette, I'll be here

lemme just interject for a quick moment. if I was going to go EFI, and I said...hey, let's call up Banks Power and order one of their 350 twin turbo crate engines, and drop it in the vette...

http://www.bankspower.com/twin-turbo-products.cfm

What kind of horsepower would I need for high 10s, low 11s. Just so I have an idea the kind of power I should ask for when I call em tomorrow. (also taking into consideration traction loss and driver reaction time)

|UPDATED|11/7/2004 8:32:03 PM (AZT)|/UPDATED|


______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

okay my last post was as I was heading out the door to go to work. the idea that has jumped into my mind is this. buying a 350 twin turbo crate engine from Banks power and having ONLY the plenum chamber and the boost tubes polished and plated, nothing else. I can remove the valve covers and put on some polished Edelbrock covers, maybe a chrome dress-up kit and an air cleaner. (when I had my original price check from Banks, I think they had the entire engine and turbo system polished and plated, and I told them I'd like to be able to switch between premium gas and 100-octane fuel, so I don't know is there was another ECU for the 100-octane, or if they did something with the injectors, so that I could do this, because on the site...I quote..."The fuel injection and engine management system was recalibrated for the octane of the gasoline being used." I figure that between having the entire engine polished and plated and having the 100-octane fuel option, whatever it was, the price of the product was raised.) So...my theory is...get the bare minimum horsepower I need for the time I want...have only the tubes and the chamber polished and plated, then use cheap dress up kits...that way the visible part of the engine looks pretty, who cares about the rest...and forget 100 octane, I'll just run premium gas all the time. Scratched down to that, I'm wondering how much it will cost, and as soon as I wake up, I will call and ask about price, payment options, etc. I'm thinking...maximum boost, 15 psi. I like concept of electronic boost control, push a button on the dash to switch between 5 or 6 psi for street driving and 15 psi for racing. if I can switch between psi, the engine'll be more streetable. I'll look into that later. anyhow, horsepower I'd need to run low 11s, high 10s?

______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

With proper gearing, good traction tires and a good driver reaction time assumed. To move 3600lbs of car and driver down the strip in a comfortable ten seconds, about 650-700 hp is needed. Since it is an automatic maybe 750 hp but you can't misshift an automatic once its set up right. So my guess with the good flowing heads and a proper turbo set up 13-15 lbs of boost is the required amount at the strip. 6-8 lbs is good for street fun for around 450-500 hp. Love the turbos versitality. I still think the cost will be sky high at Banks engineering for the turn key motor. You can save a ton, I think if you handled the actual motor and EFI your self. You can still buy the turbos, exahust manifolds, wastegates, and oil feed plumbing from them. I think they quoted me around $5000-$6000 for those. Looks like we got enough experienced guys here that can help you pick out the rest if you like. But Banks will put a warrenty on there motor and its all done for you already. You just drop it in your car and your done.(at least motor wise) Its your money and your call.

Wow, Looks like I have missed out a bunch during my absence. Sorry I have not been able to join in on the topic here, but I have been at SEMA for the past week.

So Far here is what I see being debated and I would like to offer up some suggestions.

Carbs?
EFI?
Supercharger?
Supercharger EFI?
Turbo?
Turbo EFI?

Let me first say anyone of these combinations can be used on the street and all are currently being used with great success. It all boils down to time and money and working with the right parts and people.

10 Second Quarters only makes your goal more challenging. If you want to run 10's in a C3 you will need 700 RWHP. No if ands or buts about that. In my 8 years working on various projects with many magazines and todays parts 700HP on 91+ octane can now be easier to acheive then ever.\

To name a Couple:
Billet Specialities, Chicayne Built By Troy Trepenier, 1200 HP Twin Turbo EFI. Street Driven

Malitude, Built by Mark Stielow, 1100 HP Twin Turbo

Aftermarket EFI systems like FAST, Accell DFI, Holley Commander 950, Motec, AEM, etc are all fantastic units. Some have so many features you will never use them all and it really makes their units expensive. What you need to remember is the ECU is a brain or if you like think of it as an orchestra condoctor, directing information to the outputs and inputs to the engine so everything runs in harmony. It could care less what type of engine it has been attached too.

All of these units will work with a supercharger or turbo system, you just have to set up the initial parameters in the software so it knows it will know the engine is force inductioned. You also need to have the right Map sensor for a boosted type system.

Combining EFI with A Turbo or supercharger can be very costly. So what are some alternatives that I believe you should consider.

First if you are looking for a viable supercharged engine that makes 700 HP then check out the cover of this months (DEC 04) SuperChevy Magazine. This is an engine that I helped put together with Vrbancic Brothers Racing in Ontario California. We chose all off the shelf parts. No custom built parts which make it a very viable option.

You could also do the above engine with EFI on a block through MPI setup or a TPI style intake.

Lastly, and this would be the route I would go would be nitrous Oxide. This will let you build a very streetable 500HP big inch small block, something like a 427 CID. Then when you decided to take it to the strip you could spray 200HP shot into the engine when needed to run 10's.

I think you will find the nitrous much easier to install and maintain then trying to cram a twin turbo, or supercharger system into the engine bay of a C3. That alone would be expensive and costly.

One last thing. Your talking alot about your engine. Don't forget about the rest of your car. If I've seen it once I've seen it a 100 times, with big power comes big breakage. If you ever wanted to find the weak parts in any system, then 700 RWHP will do that for you real quick so be prepeared to spend lots of money now or later to get those systems in order. Those would be Transmission, Drive Axles, Differential, Bearings, U-Joints, ETC. And don't get upset if you start to see stress cracks in the body created by that much power.

You will also need to address the fuel system.

Let me say if you have never driven a car with 700 RWHP then you might be in for a shock. You can make them streetable, but you have to drive them with a very soft foot as it does not take much to send yourself propelling out of control. Been ther done that and to be honest you will get tired of it really quick.

Thats my opinion and some additional food for thought.

______________

i just learned a lot by reading the post by ken, he is a genous. However I am a sheer horsepower man, so my vote is a carb.

______________
-LOUIE

nitrous just...isn't my thing. I like to think that my car can win a race on its own power, without injecting anything...foreign...into the engine. nitrous creates more wear on the engine and fuel lines, and is rather...volatile. if I have turbos and I get into a fairly bad accident, the car could end up fixable. if I have nitrous and get into a the same accident, BOOM. I don't like the thought of driving down the street with a bomb in my car. If I were to buy the turbo system from banks and build the engine myself, EFI, what kind of cost should I expect, estimated? As for drivetrain and what-have-you, I had planned to have everything strengthened before I put the engine in. new suspension, new drivetrain, U-joints, etc...the people here told me that B&M made TH-400 automatic transmission could handle it. stress cracks in the body makes me real scared. how might I alleviate that?

______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

here I go, callin Banks. gonna ask em what the prices for turnkey engines start at, then I'm gonna ask em about the price for a 700 hp engine that rums premium gas, with only the plenum chamber and boost tubes polished and plated, costs...and I'm gonna ask about payment options. wish me luck!

______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

well it's official. Banks doesn't really let you pick the engine you want...the crate engine they have available is 800 HP, and once you've bought it you can upgrade it further...you can't really choose what parts are polished and plated either. 38 thousand dollars, 50% down, the rest after you receive the engine.

I think...I'll build the engine myself, buy the turbos from banks.

______________

Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

every time I think I've figured something out, I doubt my decisions. the army taught me to analyze the situation, develop a plan of action, and execute. It seems that as hard as I try to do that with this engine, I can't. I did it fine with the rest of the car, but the engine doesn't seem to be working out. I've been told superchargers sound nicer than turbos, and like I mentioned earlier I don't want to lose that low rumble at low RPMs, and deep roar at high RPMs. of course I keep reminding myself that it's still gonna be a big engine and an exhaust system with no mufflers, but if only I could hear different options beforehand...supercharged, turbocharged, the same engine EFI and carb...I'm almost certain I want to stick with EFI for the reliability and responsiveness, and the gas mileage. the electronic boost control, switching between max psi sounds like it'd work for my application...run about 5-7 psi max on the street, 14-15 max on the track. 700-750 horsepower at max boost.
I don't suppose you can do electronic boost control with superchargers? and if I had some relative estimates of how expensive it would be to combine EFI engine with forced induction in a C3...it would help a lot. I know that Holley Commander 950 from Jegs was roughly $1400, but it had no intake manifold, no injectors, who knows what else you needed. I look at it straight from Holley,

http://www.holley.com/HiOctn/ProdLine/Products/C950/C950MPFI/MPFIS.html#1

looks like it has everything, a complete stand-alone EFI kit. I'd like to know how much that costs. I'd like to keep the cost of the engine under 20 grand, more preferrably down near 15. I'm gonna take a short break from all this, hopefully I'll get some good opinions when i get back. thanks for the help, guys, I appreciate it.

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Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

As for boost control - 1) Intake Mounted Supercharger (ie Roots) does not allow boost control beyond setting your pulley diameter for the belt that runs it; 2) Centrifugal Blower (ie Paxton) can be set via the pulley, and fine tuned via a Blow Off Valve (or two) but in general, not a great option; 3) Turbos can be set to exacting boost levels and changed on the fly.

My opinion of Nitrous - totally safe, would use it if all other options were exhausted. Modern Nitrous Systems aren't AS volatile as they used to be about ten years ago. There are also very stringent rules on how your system is set up (determined by the governing body of the racing venue). My old motto on the Eclipse's was "Don't Spray it, Make it Stronger". The one exception to this is the possiblity of rigging the Venom 2000 Nitrous Kit (a computerized Nitrous System) to advance spool the turbos. As of the last time I talked to them, they still didn't have all the kinks worked out - but here's the theory. When boost pressure is below a certain level that you set at various RPM points it sprays the nitrous to keep the turbo spooled. As boost pressure comes up, it tapers off the flow until you are at full boost again and it shuts off. The current program can only inject a certain pulsewidth depending on throttle position and RPM. It would still help some in spooling the really big turbos.

As for the traction and wear on other parts - my vote goes to Turbos again. Visualize the dyno chart with your expected output without forced induction. Now raise it by "X" horsepower (or torque) across the whole band. This is what a supercharger does (in general, so don't blast this to shards). Take that same dyno chart in your mind - a) lower the first 2000rpm power by a little; b) Leave the middle RPM alone; c) Raise the upper half of the RPM range by "2 times X" horsepower (or torque). That delay in power is what's going to reduce a lot of the wear on the rest of the car. The physics of forced induction note that a turbo system will make more power in the upper RPM range, but won't compare at all in the lower. All that power from your supercharged engine has to be slung by the car from a standstill - causing all kinds of drag and inertia loads which is what tweaks everything out of whack and breaks stuff. Let the car get moving a little, then let the rush of power hit it and that load is dramatically reduced. It is simple enough physics that I think everyone can picture it in your head. Downside - you won't get the hole shot or even the 60' most likely. But down the stretch, Turbos just keep on making more power and the supercharger is already maxed out.

I am gonna throw out a good place to check out for your actual shortblock and maybe even the longblock. Check speedomotive's 750hp small block chevy blower motor package. This company has a great reputation and alot of mag's use them to build their project motors. They also offer free shipping. I would consider this engines short block a good foundation for your turbo motor, the long block is perfect except I would ask for a cam set up for turbo rather than a supercharger. Also the cam is solid roller which is great for performance but hydrallic roller does not need relashing every 2000 miles or less, I would ask for them to make it hydrallic roller. They price it for a very reasonable cost considering the parts they use and the amount of labor to build it. here is the link:http://www.speedomotive.com/725_h.htm

I was looking for an engine that wasn't a stroker...specifically because the longevity of strokers is diminished...and I think that Holley EFI kit is meant for 350s. I dunno where to look for 350 short blocks or long blocks I can build up from.

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Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

If the engine is built properly and good components are used, then Its longevity should not be any more effected then the fact its used to make 750 hp. You probably wont get 100,000 miles off a 750 hp motor anyways. But besides you can ask that they use a 3.48" stroke crank if you wanna keep it 350 cubes. Just cause they got a specific package doesn't mean they wont build you what you want. Call em up and ask. These guys custom build engines to the customers specs.
This is there whole selection of packages:http://www.speedomotive.com/TABLE%20OF%20CONTENTS%20FOR%20THE%20SITE.htm

These guys also have good engines:http://www.enginefactory.com/

|UPDATED|11/8/2004 10:07:52 PM (AZT)|/UPDATED|

Check this bad boy out.....

http://www.rebuiltcarengines.com/ce17.html

As I have been told, and I after some more research a 'supercharger' or 'turbo' is nothing more than really addind displacment to your motor. And yes NOS is like a bomb, and does wear down the engine, not to mention for 4 bangers. Without these wonders (NOS, TURBO, and SUPERCHARGERS) 4 bangers would be nothing less or more than an economy car. Yes my friend's srt-4 is fast but thats only because it has a Mitsubishi turbo on it. Without that its a stock PT cruiser 2.4 litre POS

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-LOUIE

new77guy said: Check this bad boy out..... As I have been told, and I after some more research a 'supercharger' or 'turbo' is nothing more than really addind displacment to your motor.

no.. it doesnt add displacement..

it increases your effective compression ratio..

Wow, I'm off for less than one day and missed all this.

But I must agree with AfterShark on every point.
Built stock, or 800 HP will be the same end effect.
If the engine can only handle 500 HP, and you get 600 HP from it, it's going to come apart. If the same engine produces 400 HP, it will stay together.
Nitrous, Turbos, Superchargers, all produce more HP. Can your base engine handle it?
And properly built, there is no reason a stroker won't hold up. The 400 does fine, and that's the crank being used.

Start at the crank and start building.

kstyer said: And properly built, there is no reason a stroker won't hold up. The 400 does fine, and that's the crank being used. Start at the crank and start building.

I hate doing this but I must disagree slightly with you Ken...

long strokes are not good for high RPM applications..

Ben, that's not a disagreement. You are right. They don't work as well for high RPM. But that was not the issue. It was the durability of the engine. It can hold up as well and last as long, provided you don't try to overrev it. No matter what you build, if you try to exceed it limits, it's coming apart. If you don't exceed it's limits, the stroker is as good as the others in terms of use and wear.

https://www.c3sharktank.com/sound/sound4.html

Michael-Jon, Go and click on the last two videos and see what a 9 second quarter looks like. Also the very last one can happen to you if you dont strengthen your drivline properly. LOL

here's a good EFI site http://www.affordable-fuel-injection.com/

so would you all suggest calling speedomotive and telling them I want an EFI engine built that can handle a twin turbo upgrade that brings the horsepower up to 750? or should I try to rebuild the engine that's in there now, bore it out, pick a different crank, etc, build from scratch?

and what EFI system should I be thinking about using? The AFI website intrigues me, but I look at the Holley and I'm wondering if I shouldn't go with that one...if it could handle the power. the Holley's 950 forced induction system can only take a max boost of 14.7 psi...but then how many psi am I going to need to hit 750 hp. I could look for one with a 20 psi max, but that over 6 psi is gonna be another what...100, 150 hp? what am I ever gonna need that for. 10 seconds is very borderline with driveability and necessary reinforcements...I think if I reinforce the drivetrain and everything I need, the car will be perfectly driveable with electronic boost control keeping the turbos at around 5-7 psi on the street, 14-14.5 on the track (no idea what max I should run with that 950, if I should stay with 14 so I have an extra pillow, or push the limit and run 14.5 max). as I drop below 10 seconds and go above 750-800 horsepower, I'm going to lose driveability and need so many more reinforcements...roll cages and such...and it would stress the body even more. it just doesn't seem necessary. anyhow, input please.

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Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

I can tell you that you can get 3 bar map sensors for the commander to run 14.7 to 29.4 psi boost. The issue will be tuning it, you will need a good tuner for the type of engine you will be building. You will also need the Wide Band 02 upgrade kit if you decide to go with the commander. Price wise you the commander has more features dollar for dollar compared to other units on the market, but I'm not here to tell you what to buy. There are other units out on the market that will do just as well.

I know the Acel DFI system has a good database of tuners around the country for their system. Holley does not have much of database, but there are certain tuners we can recommend. Can't tell you if there is one in your area or not.

Something you said needs to be address, about turning up the boost for running on the track. First off you may only get one pass down the track and they you will be banned. Any car that runs quicker then 11's is required to have a roll cage, drive shaft loop, and safety harnesses. So if your planning on adding them later then just to save the hassle at the track you might as well add them now.

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thought 10s only needed bars, not a full cage. yeah they'll be added before the turbos are put on, every reinforcement and safety precaution necessary will be added before the turbos are put on. that's another thing...if I build an engine meant for a twin turbo system, can I put it in and drive for a few months before I put the turbos on? or no.

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Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)

It can work fine normaly asprirated as long as you realize that a low duration cam and low compression will not be very good for power of non boosted applications. You will need have your fuel injection computer calibrated for that and then recalibrate it for the boosted app. but most aftermarket computers will allow you to do it yourself on a laptop. you just need to know what your doing.

anyone happen to know where I can locate a prefit roll cage for my 77? seems it'd be a lot less hassle than trying to make one. I couldn't find too many roll cages using google. also, I looked for some drag rules on www.nhra.com, couldn't find em...so if anyone could point me in the right direction I'd be obliged. and let's not forget my post about where to get the block for this, speedomotive or having my own engine rebuild and bored and a new crank, just by a mechanic around here...and what about the psi for the horsepower I'm wanting.

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Mike

My old Stingray...sure do miss it:


(click image to see a bigger version)