Topic: Engine Torque
in Forum: C3 Engines
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Lifetime MemberHot Springs, AR - USA
Joined: 4/24/2004
Posts: 3236
Vette(s): 69 Conv #'s match 427, TKO-600/.64, 3.36HD-Posi, HT, T/T, PS, PB, PW, SP, Leather, Comp XE264HR & Roller Rockers & Lifters, Air-Gap RPM intake, Holley St Av 770 VS, MSD 6AL+Dist+Blaster SS, K&N, Jet-Hot Hooker Side-Pipes, Steeroids, Al Rad, Spal Fans
can you send me full hyperlinks for the two charts...
anyway... Joel is right, HP is for bragging... torque is for driving...
for a fun drivable car...
you want a torque curve that is very flat during over the reasonable rpm range of the vehicle...
this is how i deisgned mine
the green is torque
the red is HP
notice how it has a mild peak but stays pretty consistent over the range of 2000 to 5000 rpm...
Ramjet 350 is GM's answer to everyone else's crate engine. It's fuel injected, comes with its own computer and you can get them from any Chevy Dealer.....or Jeg's....or Summit Racing....etc....even EBay.
To get the specs, just type in Ramjet 350 in your browser and you'll get all the info you can stand.
It also looks cool as hell.
Former Member
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Yelm, WA - USA
Joined: 7/12/2007
Posts: 356
Vette(s): 1979 L82 4 speed Scat 383 crank 190 cc Procomp Aluminum Heads 202 160 stainless valves GM Powder metal rods Speedpro H860CP Hypereutectic pistons 280 cam hydralic HEI Pro comp 1.6 roller rockers Mighty Demon 750 Sanderson CC1AP Hedders.
I was looking at ram jet last week in a custom and they're not too bad height wise. You might want to think about being able to work on it though. I wouldn't know the first thing about what to do with that setup except to drive it somebody who did and then get out the checkbook
(Stupid question) but wouldn't all your numbers change at the wheel anyways? I know I'd like to take mine down and get it dyno'd when I'm finished just to see what I'm actually producing.
Lifetime MemberHot Springs, AR - USA
Joined: 4/24/2004
Posts: 3236
Vette(s): 69 Conv #'s match 427, TKO-600/.64, 3.36HD-Posi, HT, T/T, PS, PB, PW, SP, Leather, Comp XE264HR & Roller Rockers & Lifters, Air-Gap RPM intake, Holley St Av 770 VS, MSD 6AL+Dist+Blaster SS, K&N, Jet-Hot Hooker Side-Pipes, Steeroids, Al Rad, Spal Fans
[QUOTE=79rebuild]
cthulhu 2008-01-01 22:15:00
I was looking at ram jet last week in a custom and they're not too bad height wise. You might want to think about being able to work on it though. I wouldn't know the first thing about what to do with that setup except to drive it somebody who did and then get out the checkbook
(Stupid question) but wouldn't all your numbers change at the wheel anyways? I know I'd like to take mine down and get it dyno'd when I'm finished just to see what I'm actually producing.
[/QUOTE]
and while youre thinking about changing your rear wheel performance... when you drop this new engine in..... can your transmission handle it ?
I think the rear end can handle it if not it's one more thing for me to do. As for the tranny the car has a automatic right now. I bought a m-22 for a conversion and I think it would be o.k
Lifetime MemberHot Springs, AR - USA
Joined: 4/24/2004
Posts: 3236
Vette(s): 69 Conv #'s match 427, TKO-600/.64, 3.36HD-Posi, HT, T/T, PS, PB, PW, SP, Leather, Comp XE264HR & Roller Rockers & Lifters, Air-Gap RPM intake, Holley St Av 770 VS, MSD 6AL+Dist+Blaster SS, K&N, Jet-Hot Hooker Side-Pipes, Steeroids, Al Rad, Spal Fans
what is your axle code... that will tell us whether it is a HD or not..
the m-22 should be fine for strength of course...
but you may find that for a street car... its not very fun... my car had an m-21 (same ratios as an m-22) and the ratios were just too shallow...
the 2.20:1 first gear is not very steep especially when mated to something like a 3:08 or 3:36 (like mine was)
ideally a 10.0 first gear ratio is loads of fun...
3.08 x 2.20 = 6.776
3.36 x 2.20 = 7.392
3.55 x 2.20 = 7.81
none of these is even close.
youll find yourself dropping the clutch at 3500 just to get it moving good... using the slippage of the disc to make this a better ratio... then you skip 2nd goto straight to third, by the time you hit fourth youre looking for a 5th & 6th that dont exist. dont forget changing the clutch regularly from your 3500 rpm drops.
your th-400 you had in there was 2.48:1 in first gear...
giving you 7.638, 8.332, or 8.804 using the three ratios above...
i hate to say this.... but im betting you will notice a decrease in first gear power with the m-22, even with a stronger engine in the range youre talking about.
as much as I love manual transmissions, id say you really should look at going with a built up 200r4 or a 700r4
700r4 (3.06:1 first) would give you 9.425, 10.282, 10.863
i dont remember what the 200r4 is but i think is around 2.87
to make this math easy... lets assume 100% efficiency in drive train...
an automatic loses 15-20% of its power... a manual loses 10-15%
with a 300 lb-ft engine... and a 3.36 gear ratio..
the effective torque would be
m-22 2217.6
th-400 2499.84
700r4 3084.48
now change the change the engine to 350 lb-ft
m-22 2587.2
th-400 2916.48
700r4 3598.56
see how it takes 50 lb-ft of flywheel torque from your engine just to make up for the poor gearing of the m-22. you add 50 lbs just to get back to where you were with a th-400.... also notice that the 350 lb-ft engine with the th400 doesnt even equal the 300 with the 700r4
in fact a 400 lb-ft engine with a 3.36 and a m-22 yields 2956.8 still hasnt even caught up to the 300 lb-ft with a 700r4.
my advice... save the $500 and whatever you were going to spend to convert an auto to stick and worry about your gearing.
Former Member
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Yelm, WA - USA
Joined: 7/12/2007
Posts: 356
Vette(s): 1979 L82 4 speed Scat 383 crank 190 cc Procomp Aluminum Heads 202 160 stainless valves GM Powder metal rods Speedpro H860CP Hypereutectic pistons 280 cam hydralic HEI Pro comp 1.6 roller rockers Mighty Demon 750 Sanderson CC1AP Hedders.
[QUOTE=ossw1]Hey I saw the ramjet does that fit under the hood?[/QUOTE]
I had a chance to go look at the custom with a brand new RamJet in it, Terry the mechanic building said it's actually about a 1/2" lower than a stock intake and carb. He pooped me up on how it works, pretty cool. It didn't make me want to go out and get one though, I'm just not a huge fan of doing mod's like that, but that's just me.
in Forum: C3 Engines
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