drag2003 dyno program
Thread Starter
Burning Brakes
Joined: Jul 2006
Posts: 1,108
Likes: 0
From: Sebastian Florida
drag2003 dyno program
What numbers do I have wrong?
I think the horsepower is a little high (I have an L82 with headers, duel exhaust and no cats)
I have no ideal what my frontal area is.
I think the horsepower is a little high (I have an L82 with headers, duel exhaust and no cats)
I have no ideal what my frontal area is.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Yea, e/t is too low by around 5 tenths, and mph is high by 2 or 3. Something not right. Look at your 60 foot times and your low h/p and peak rpm. No way. The 4:11 gears help, but not when shifting at 4,400 rpm.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Off the top of my head, frontal area s/b 19, Aero C/D should probably be about .50 (78 Pace Car aero package is about 15% better than no dam & spoiler, and is supposedly only down to about .43-.44 C/D).
HP is high. I'd say 230 would be closer, and more likely nearer 4500 rpm. TQ curve also looks optimistic on the bottom end for an L82 w/only headers. I'd get some actual numbers from a stock L82, and add about 15% up and down the curve to account for the headers for a better "guestimation". Redline seems low, too.
Make sure to use tread width rather than secton width for your tires. Not familiar with yor specific program, but don't be too optiomistic on traction for street tires, and they aren't going to grow much.
That ought to get your sim tuned a little better, for a start. Just keep in mind, before you spend any money on something you "learn" from modeling, the quality and accuracy of these programs vary widely. The speed shop variety stuff is ball park type entertainment at best, and even Engine Analyzer Pro / Drag Racing Analyzer programs are still just a bunch of formulae (albeit, pretty complicated) some group of guys have been sitting around tweaking on a keyboard.
Hope that helps, a little, anyway.
HP is high. I'd say 230 would be closer, and more likely nearer 4500 rpm. TQ curve also looks optimistic on the bottom end for an L82 w/only headers. I'd get some actual numbers from a stock L82, and add about 15% up and down the curve to account for the headers for a better "guestimation". Redline seems low, too.
Make sure to use tread width rather than secton width for your tires. Not familiar with yor specific program, but don't be too optiomistic on traction for street tires, and they aren't going to grow much.
That ought to get your sim tuned a little better, for a start. Just keep in mind, before you spend any money on something you "learn" from modeling, the quality and accuracy of these programs vary widely. The speed shop variety stuff is ball park type entertainment at best, and even Engine Analyzer Pro / Drag Racing Analyzer programs are still just a bunch of formulae (albeit, pretty complicated) some group of guys have been sitting around tweaking on a keyboard.
Hope that helps, a little, anyway.
Last edited by TheSkunkWorks; Jul 19, 2007 at 10:00 PM.
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Considering the 4.11 gear, the 4400 rpm redline and the 102 mph trap speed, it suggests that the car would be in 4th (.67 overdrive) well before the lights. The performance numbers show it running for 6 seconds in 4th before the end. There is no way that engine could push that car to ET and mph numbers like that, IMO.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
Likes: 4
From: Austin Texas
Well, IMO the 4:11's coupled with the 2.74 1st gear are too short. Compounded by converter slippage, your car is in second gear before you have gone 60 feet! Maybe that fact is throwing a wrench into the mix. weird.
