austin21

i know i am a little late for this conversation but for what it is worth and thats probly not much my very first time at the track i was running consistant 113-114 mph and 114.92 on my last pass of the night .....i just cant drive

david vericker

iTrader: (1)

People on this thread consider that to be an insult "not stock" thanks for being honest. Your driving has very little to do with trap speed,that is is basicly a constant - will only very one or two MPH tops. Now, your ET is a totally different story. ET will suffer big time if driving is a serious issue. This ones on me!

mrr23

iTrader: (3)

and you're back.....

SI (hell stock motor from TB to exhaust manifolds) and 123 mph here.........

then again, i'm not a M6 and the SI list is biased for NA only (bull crap rule, SI is SI). so, i don't count.

Bitemark46

Actually you're wrong. In drag racing the key is to lay down the highest average rwhp during the whole run. If your shifts are slow you are giving up distance the car has to achieve a desired mph. If you shift like grandma your mph will not be as high as if someone would powershift during a run. Remember, it's momentum. If it slows down (aka nose dives during shifts) it has to make up that momentum it lost and make it up in a shorter distance. Plus driving has alot to do with mph. Shift points are key. You shift out of the cars powerband its not gonna make the mph. -Mark

OH and 1-2 mph is a good amount IMO. It is noticeable on the big end when its a close race. Atleast I can tell when I went racing against a GN 2 weeks ago. He was trapping 111mph and I was trapping 113. I could tell I started to pull away.

david vericker

iTrader: (1)

Gee,other than a small cam I'm running SI too. But,I don't pretend to consider my car stock. Spray was put on in eary September with a limited amount of runs - 128.11 best to date. Things will improved greately by the time my Vette hits the strip next spring - forged bottom end and bigger spray.

I have been looking for an old issue of Hot Rod that had the formula for calculating ones HP in relationship to weigh and trap speed. Hopefully, I can find it- think you will be susprised how much HP it takes to trap a 3600# car at 118 MPR.

david vericker

iTrader: (1)

I guess the only thing we can agree apon is to disagree. I was replying to a new drag racer in general terms,however, what you just described is going to effect ones ET much more than MPH. MPH is mostly HP related and a sub par run (poor traction ect,ect) will only scrub off a couple MPR where the ET can be reduced by .50 +. Which would you consider the more important factor - MPR is much more A constant than ET. I base my opinon on hundreds of runs that date back to 1964 - old but not slow.

Thank you for the drag racing insight. No more on this subject - we would only be beating a dead horse.

93_z28

yeah,if your going 2 mph faster then someone its the same as if the are standing still and you are walking away from them

93_z28

it takes 461.64,but as people have repetedly told you in this thread "THESE ARE NOT FULL WEIGHT CARS"

mattf2

"other than a 224/228 cam, 1.85 rockers, Z06 heads (lingenfelter machines these, right?), my car is SI too."

We call that a heads/cam car, and they are in the 450-500 rwhp range. Low 11/mid high 10 car. Add spray, low 10 high 9 car.

Please let us know when you're running 9's, otherwise your car is average for the mods you have.

david vericker

iTrader: (1)

Rule of thumb is .10 ET .75 MPH for every 100# of weight reduction. So a bone strock 3700# F- Body runs approximately 13.30 @ 106 - with bolt ons + 35 rwhp HP gain = 12.95 @ 108. Now reduce the car weight to 3000# (huge weight reduction). Do the rule of thumb calculation - .75 x 6 (600 #) = 4.5 MPR with a gain of .6 ET. That puts the car in a ball park figure of 12.35 ET
@ 112.5.MPR To increase the MPR there needs to be additional HP - THE ET can be improved upon with additional mods to improve traction (launch). Question is were does that additional HP come from to produce 116-118 MPH if the car is SI?

This is just some food for though - your caculation of 461.64 is big HP NO! Now do the caluation on a 3200# car at 118 MPR. Do you think that HP number is realistic for SI cars?

Kent1

My estimated weight car of 3450 pounds runs a 116 MPH with nothing but boltons. These times are achieved by lightweight, light rotational weight, and torque mulptilication. Guess what, with good weather and computer tuning, the car may run faster. Most of them take everything out of their of car for weight savings. I choose to kept my car intact with air conditioning and power steering. Everything is optiumized. For heavens sake, look at the 50 fastest on the SI list.

mattf2

wow! my almost bone stock (lid, k&n, FRA) running 17" 275/40/17 at all 4 corners w/ absolutely no weight reduction car ran 13.01 @ 108 mph in 1800' absolute altitude (hot, muggy July air). Mike Kleman (Rapid Motorsports) saw that happen. Corrected, it was much better.

Must be over 500 HP then.

I'm trying to figure out how an early 60's Vdub that I ran hit 11's at only 110 mph? It couldn't have anything to do w/ 60' and gearing, could it?

mattf2

Merry Christmas, I'll get back to this after Santa makes his visit.

david vericker

iTrader: (1)

Merry Chrisrmas to all. Sorry if I offended anyone. I wasn't very tactful at times - just trying to make a point. Good racing to all in 07 - subject closed!

Kent1

Merry Christmas to everybody!

big dave

FWIW, it seems that production tolerances for GM aren't as close as they may be for other manufacturers. Where my bolt-on car only produced 341 rwhp, others have seen upper 360s and higher with similar mods.

I know it's difficult comparing dynos since there are so many variables that can produce different readings.

A friend has a bolt-on '98 TA that consistently traps 2 mph higher than mine, and has gone as fast as 115 without an ls6 intake. His car is full weight down to the spare and the jack. I would call bs if I didn't know the car...and the driver. He can powershift, I can't.

I do believe 11s are possible with a full weight car. Though mine hasn't come close, I believe that with a better 60' and a better driver, 12.2s would be possible from my car the way it sits. I guess mine probably weighs between 3700 and 3800 lbs with me in it. It does have 135k miles so I'm sure it's lost a little power over the years.

My times are in my sig.

98Z28MASS

iTrader: (6)

Math bench racing for the win!