Thanks Knotacare

Louis, you are a "Seriouse Calculating Dude."
I guess your still counting your pennies on Excell to see how much you can spend on your Vette for the month. ...........I just couldn't help myself . Your just too !

Mine came out to be 11.830 seconds?? A bunch of you all got me beat!!

I think the calculations are very generous in regard to E.T. I have not brought this car to the track but I had a 1965 GTO when I was growing up with a 389 tri-power ( wish I still owned it ) that produced 360 hp from the factory. I changed the heads and put headers on and was only able to acheive low-mid 13's. According to the chart I should have been much faster ??
Maybe I just don't know how to drive ??

Measureing HP at the engine is not realistic.  There are huge variables.

If you have a 3:08 rear end you can figure a 15% loss there alone.  Then calculate the loss through the transmission.  My THM400 uses 42 hp.  A THM 350 uses 36 hp.  Manuals are a bit less.

Take you engine, subtract the estimated trans load, and then drop the percentage for the rear end.  It's not real accurate, but it's not a bad guess.

Doing it the other way around, my car dyno run was 206 hp at the rear wheels.  The estimated HP becomes 279 at the flywheel.  According to the calculator this is 14.9 in the 1/4.

If you have around a 4.11 the rear loss is closer to only 10%.  Hypoid gears take a lot of power.

If you just want to give it an average guess, figure 25 to 30% loss between the engine and rear wheels on a rear drive car.

Also keep in mind that if you have a crate engine or one tested on a dyno, the drag of the acessories and belts drops a lot off of that number as well.  The estimate of 279 in my car is including the accessory drag.

Have fun calculating and guessing.

kstyer38750.8255439815

Holey crap...

I'm not sure what my ratio is. Its proba  3.08, or a 3.55 the tranny is a TH350. THe motor was estimated 400BHP and 345HP to the wheels, only calculating tranny loss of about 15%. I guess we'll ahve to wait!

If your rear end is stock it's a 3.08, and the thm350 uses 36. 

So....  400 flywheel est.  And if the engines is rated at gross rather than net, which most are for crate motors and buildups, lose another 15 for accessories.  We start at 385, take away 36 to get 349 out of the trans.  Drop 15% for the rear and get 296 at the wheels.  Figure 3450 lbs of car, and you get 13.2 in the 1/4 mile.

Don't despair young gent.  13.2 is FAST  In today's world there are a lot of unrealistic numbers tossed around.  They give the wrong impression of what actually happens.

Remember,  My car dyno tested at 206 at the rear wheels.  With things missing at the moment, its no more than 3400 lbs.  That puts me at 14.8 by the calculator.   AND last week I whupped a 91 tuned port Z-28. The Z only had a 5.0, but from 65 to 105 mph I totaled 5 car lengths, started out one behind and finished 4 ahead.

Think of what yours will do on the street!     Ahh, make that track, no street racing 

kstyer38752.7774537037

Just beginning to worry that my granddaughter would be able to whupping me with Jim's mini vette ,

 i calculated with that ET program :

250 lbs, 5 hp..... gives 21.459 sec. Oef, i think the C3 does better.. ok , deal goes on....