OK Drag Racers! Riddle me this......

[viperrt96]

I’ll explain in detail below but to save time reading for most of you I’ll just ask the simple question….

How can I run a 11.67 @ 125.05 on all motor and then give the car 150 shot of NOS and it only runs 11.33 @ 134.68

I gained 10 mph but only .3 ET?

The track was pretty good and for the most part I was cutting 1.7 60’ times.

As you can see I just got done installing a NX kit with a FJO mini progressive controller.

Here’s a link to a video of the pass

http://www.indyhpmedia.com/index.php?dir=vids/petsn8k/&file=11.33.wmv

I think it traps pretty good and it was very consistent on the trap speed even though my ET’s were everywhere. I made like 20 passes and even at the end I turned the bottles off (so a friend could witness) and went right back out and then ran a 11.92 @ 125 (Below is that video) Not my best of the day (11.67 on all motor) but to prove my trap speed never changed. It was very consistent but what gives here?

http://www.mr2turbz.com/videos/us41/MOV0B8.wmv

To give some background my car has dynoed 490/510 @ the rear wheels and of coarse I have yet to dyno it under the spray. I’ve ran a little quicker ET on all motor but for the sake of arguing I’ll just stick with what I did that day. I will be going to the dyno before I go back to the track that’s for sure. I just got the install done Friday and went racing Saturday so….. I started out very conservative 100 shot and a light program with the controller (came on 50% @2800rpm and didn’t go 100% until 4500 and it shut off at 5500). The 100 shot didn’t improve my run that much 11.58 @ 129.41 was my best with that set-up. I then changed the jets for 150 shot and I got aggressive with the controller (came on 80% @2800rpm and 100% @ 4500 to 5500-set point). The guy running the tree said when I left he could see a bunch of clutch dust (That’s what he called it) when I left the line.

I guess I want to ask ….

Am I limited to a certain ET by staying with my 3:08’s ? The car obviously makes more ground at the end of the track. My best 1/8th ET and time was 7.58 @ 98.72 and I never trapped once over 100mph in the 1/8th

 

[2001 GTS]

First off...what tires are you running?

With that kind of additional power your should have dropped almost 1 sec off your time.

My car with 472rwhp trapped 11.39@123 then with 100 more hp and a crappier 60ft trapped 10.9@133...

and o yea...nice setup.

You must be registered for see images attach

 

[valentine_viper]

Drag racing is all about the first 1/8th mile, and that's were you are weak for some reason. You should be doing much better than 7.58 @ 98.72 considering your trap speed. To put it in perspective, I ran 10.2 @ 133. My 1/8th mile was 6.5 @ 106. That was with drag radials and high 1.4 second 60' times. Your trap speed was higher than mine, but my car is a beast in the 1/8th, and that makes all the difference.

Your problem could be tires, clutch slippage, gearing, tune or any combination of those things. Driving is the easy part in drag racing. The hard part is finding the right set-up.

 

[viperrt96]

Drag racing is all about the first 1/8th mile, and that's were you are weak for some reason. You should be doing much better than 7.58 @ 98.72 considering your trap speed. To put it in perspective, I ran 10.2 @ 133. My 1/8th mile was 6.5 @ 106. That was with drag radials and high 1.4 second 60' times. Your trap speed was higher than mine, but my car is a beast in the 1/8th, and that makes all the difference.

Your problem could be tires, clutch slippage, gearing, tune or any combination of those things. Driving is the easy part in drag racing. The hard part is finding the right set-up.

Well I'm not running drag radials so that could be a big part of it. I'm running Kumho V700's with about 22psi. My tune has to be pretty good in order for it to run what it did. It sure feels good I agree it is hard to find the right set-up but what I was asking are you both still running the stock 3:08 rear gears or have you upgraded?

 

[2001 GTS]

I'm still running stock gears

 

[-FROG-]

V700's are drag radials. DOT competition tires with a sticky compound. MUCH MUCH softer than Pilots.

Did you get a good burnout? Gotta get out of that hole HARD!

 

[valentine_viper]

V700's are drag radials. DOT competition tires with a sticky compound. MUCH MUCH softer than Pilots.

Did you get a good burnout? Gotta get out of that hole HARD!

Although V700s are definitely sticky, they're not drag radials. They're a road race tire and have much stiffer sidewalls than drag radials. This makes a significant difference in straight line acceleration. With drag rdials or a drag racing slick, 60' times will improve quite a bit over V700s on a high HP car.

 

[-FROG-]

Although V700s are definitely sticky, they're not drag radials. They're a road race tire and have much stiffer sidewalls than drag radials. This makes a significant difference in straight line acceleration. With drag rdials or a drag racing slick, 60' times will improve quite a bit over V700s on a high HP car.

ah, you are correct. I'm wrong. No wrinkle wall...

 

[valentine_viper]

Well I'm not running drag radials so that could be a big part of it. I'm running Kumho V700's with about 22psi. My tune has to be pretty good in order for it to run what it did. It sure feels good I agree it is hard to find the right set-up but what I was asking are you both still running the stock 3:08 rear gears or have you upgraded?

Gearing is definitely an issue and Vipers are not geared for drag racing. The 10.2 I ran was in my Supra with 3:43 gears and an auto trans. This gives me a big advantage since I can leave the line already under boost, but my Supra was making 90 rwhp less than your 650 and it weighs about 100 lbs more than a Viper. This should even the playing field.

I watched the Video and you seem to get off the line well. Your top end charge looks strong too. It seems you are not getting as much punch as you should in your midrange as indicated by your 1/8th mile speed. Drag radials and bringing in the NOS earlier should help that quite a bit. With 134 mph trap speeds, you should be dipping into the 10s with sticky tires.

 

[1TONY1]

Well I'm not running drag radials so that could be a big part of it. I'm running Kumho V700's with about 22psi. My tune has to be pretty good in order for it to run what it did. It sure feels good I agree it is hard to find the right set-up but what I was asking are you both still running the stock 3:08 rear gears or have you upgraded?

It is not your gear.

 

[kwkshift]

The long and short of it, is that you just aren't taking full advantage of all the available power. Generally, the first 1/8th mile will determine your ET and the second 1/8th will determine your trap speed. You need some slicks and once you start cutting low 1.5 or better 60' times, you'll start seeing those 10 second timeslips.

Keep in mind that you ar picking up 36 mph on the big end (2nd 1/8th mile). Most cars will pick up about 30-32mph. That means that there is a lot of unused power laying around.

Go buy some tires and you may also need to upgrade your clutch.

 

[viperrt96]

Thanks for the info guys

What is considered a good clutch upgrade? Or should I ask who's running what?

I'll start looking for a set of extra rims to mount some slicks.

I need some more seat time as well. I did try different launch techniques but I could never overcome one or the other. Too agressive it spun like crazy and not enough made it bog down.

I'm pretty sure it's 20% car and 80% driver! LOL!