in a 3500lb car with a good chasse (1/4mile)

 

More than you have, or ~800 to be more precise.

Rich

 

I don't think you could run high 8s in a 4th gen fbody at 3500#s with 800rwhp supercharged probably 9.1x. I think it would take 850+unless you were using nitrous to assist your car out of the hole then 800rwhp would be damn close if all the planets were aligned just right I'll let you all know how much it really takes by the end of the year.

 

Before at 3400lbs and 780 rwhp and TH400 with my LT1. I went 9.08 @ 159.7mph with very limited traction. On nitrious with a good setup I think you need about 750rwhp provided the car works good ( ie spend the money and set it up properly)!

 

At the same rwhp, I agree you are going to run faster with nitrous. So, the 800rwhp may not be enough for a car 0f that weight with a blower, I agree. However, I stand by my statement "more than you have".

I have a friend with a back halved Mustang with a Procharger running in the 8.7 range with a ~850 rwhp at ~3300lbs.

Rich

 

we had a 68' over 3k pounds.....it went hi 8's and had 840h.p.
another car...73 has a small block 3400 and it makes 800rwhp and runs 9.39 in good air

 

With an A3, I'm gong to agree with 800 rwhp. I've pulled 146 mph at 3700 lb with only 695 rwhp. 146 is good for low 9's if the car launches. I think you need in the 155 range to get in the upper 8's, so 800 should be close.

 

lots of variables have to be considered. The range should be 800-850 depending on type of motor. If it is naturally aspirated or running nitrous there are some low end torque and horse power advantages at lower rpm when they are making 800 horse power as opposed to a fi car that makes low boost at lower rpm so you don't get the elevated torque and hp numbers at lower rpm levels. In my non expert opinion, if you make 1000rwhp then you have lots of room for error and you can still make it in the 8's. Of course you also just spent a s**t load more money and your budget just went out the window.

 

sorry, i should have said turbo RWHP it that mahes much of a diff...

ps: track is 26' above sea level

 

>I'm not to sure about this, but are turbo's better on top end than on a launch?
thought they got quicker down the track than at the lights.

 

With a transbrake and proper suspension, a turbo car can launch extremely well.

 

EngineerMike where you using the T-Trim to hit 695 RWHP???

 

Noooo... The most the T-trim ever made was 550 rwhp. 695 was done with the turbo.

 

In the same vein as ET realted to NA v. SC v. TC v. N2O, etc: a big displacement motor will generally run quicker at the same peak hp and weight than a smaller one. Same reason - "area under the (torque) curve". This difference is minimized with an efficient drivetrain. If the car with the peakier motor has enough gears and the proper rear gear, much of the advantage of the bigger motor will be negated. That does get expensive though.

As an example of the effect of driveline efficency, I have a couple of buddies with blown Mustang Windsor based strokers. Both make rwhp in the mid 600's and weight within 100lbs of the other. One has a 3-speed auto and the other a 4-speed Lenco. The auto car is clearly making more hp to show the same at the rear wheels. The Lenco setup consistently runs 0.2-0.3 seconds quicker and a couple mph faster on the same night at the same track. The 60' times are comparalbe. So, it's clear to me that the difference is hp delivered over time.

Weight is going to be an issue as well. It seems to me that even with the same hp/lb and similar setups, the lighter car will tend to be quicker. I am not sure why this would be so - the added weight would seem to be negated by the added hp. But I have observed it many times. Maybe it's related to aerodynamics with lighter cars tending to be smaller with less frontal area?

If we are talking about 4th gens with LT1's or LS1's, there is little experience to go by as the number solidly in the 8's is damn small.

Rich

 

My car slowed down a consistant 2-3 mph after changing to the LS1 frontend. I attribute it to the more open grill area.