Dragstrip results: SRT/10 w/Paxton, heads, 3.55s, DRs, etc.

[treynor]

I just got back from the Sacramento Drags, the first time I'd visited since Dan Cragin installed the Paxton in our SRT/10. The results were promising, but the setup needs a bit of tuning before it'll be turning out awesome numbers.

First off, the digits Best run was 10.9, best MPH was 132, and best 60' was 1.73. Most runs were 11.1 @ 128 as explained below. The Paxton kit functioned flawlessly the entire night; the car drove perfectly and pulled hard and consistently.

Now, the issues. First of all, the combination of 3.55s and 610 ft/lbs was too much for the BFG G-force DRs to handle. My best run involved launching at 1900 RPM (!) and letting the car's torque do the work. Any higher RPMs would make the DRs spin uncontrollably through 1st. I'm considering going with some bigger tires or some shorter gearing.

Speaking of gearing, the other issue was that the SRT/10 ran out of gear about 100' from the end of the track. My one 132 MPH run was actually fairly mellow, and I tagged the rev limiter in 4th *right* as I hit the timing lights. On several other runs I'd hit the rev limiter well before the traps, suggesting that a 134-135 MPH run is only a gearing or tire size change away. The runs where I hit the rev limiter in 4th, the car would coast down to about 128 MPH by the time I cleared the traps. Very frustrating. Shifting to 5th did not seem to improve matters, as there isn't much time for that final shift. Options for this issue are (a) Quaife diff with 3.33 gearing; (b) swap rear gears for 3.33s; (c) go with a slightly larger tire than my current 345/30-18 BFG G-force DRs. Thoughts?

Finally, it was hard to be consistent with shift points. The tach was a bit lazy at times, and I found that I could either short-shift a bit, or occasionally tag the rev limiter. I'm going to put in a shift light before my next trip - any suggestions for favorites?

I'll have a video up tomorrow of my first run - 11.1 @ 128, tagging the rev limiter in 2nd and at the big end.

 

[Snakester]

It was good to see you there Ben. And lucky that you survived the coolant slip-and-slide on your early run!

I was disappointed to only get 3 runs in for the whole night, but it was still a fun event.
The weather cooled down pretty quickly, and I was having a terrible time getting traction. Especially comparing to the last time that I went to Sacramento test-and-tune and was running steady 11s at 5MPH faster, during the day.

Your 10.9 and 132MPH runs show that the Paxton SRT-10 has great potential once everything gets dialed in.

-Dean.

 

[treynor]

Traction was indeed a bear. I don't think they prepped the track as well as normal; I've definitely had much easier times hooking up in the past.

Here's a video of my first run of the evening: http://www.treynor.com/SRT10-Camaro383.wmv

 

[VIPER D]

2 quick questions

1 how on earth did they let you race in ny even when the srt was stock i got booted off the track b/c of soft top?

2 do you have a line lock?


great run 1st time out

what do you think you would of run if you had 308 and more rwtq (680)

vd..

 

[ROCKET62]

Nice first time out. First thing that came to mind - especially after seeing Chad's results with his twin turbo monster was the rear end gearing (wasnt Chad using 2.73 rear gearing). With the SC and the additional HP & Torque - is the 3.55 needed? The stock rear gear may actually allowed you to get better launches. Good luck the next time.

 

[treynor]

> how on earth did they let you race in ny even when the srt was stock i got booted off the track b/c of soft top?

I've got a real rollbar (no sidebar), 5-points, helmet and fire jacket.

> do you have a line lock?

You bet I tried and failed to do good burnout with drag radials without one.

> With the SC and the additional HP & Torque - is the 3.55 needed?

I'm considering that very topic. 3.33 would probably be ideal - the gearing is great for the street, but it _is_ too much for the tires. 3.07 will slow down the launch too much, but with 3.33 I'd have enough legroom in 4th to cross the traps at (?) 135 mph, which is about what the car would run.

 

[SRTRICKY]

Those are some pretty imperssive times even if you were hitting the limiter! Other then the paxton of course what other mods do you have?

 

[treynor]

3.55 gears, mild head port, custom tune by DC Performance - and that's it. The car's got a 10.7 @ 135 in it once I get the gearing fixed

 

[DSR207]

Quote:

"The car's got a 10.7 @ 135 in it once I get the gearing fixed"

Try low 10s @ 139-142...I bet you will with 3.33s

 

[treynor]

That ET seems a touch optimistic - your '04 has similar power numbers to mine, what have you run in it? I was hitting 132 MPH (and the rev limiter) about 3/4 second before reaching the timing lights, so another 3-5 MPH seems reasonable once the gearing is corrected. 3.33s should be good for 140 MPH, which should be just perfect.

 

[DSR207]

Quote{
"your '04 has similar power numbers to mine, what have you run in it?"

No runs yet(No roll bar) even with a $20.00 bribe !!

 

[VIPER D]

> how on earth did they let you race in ny even when the srt was stock i got booted off the track b/c of soft top?

I've got a real rollbar (no sidebar), 5-points, helmet and fire jacket.

> do you have a line lock?

You bet I tried and failed to do good burnout with drag radials without one.

> With the SC and the additional HP & Torque - is the 3.55 needed?

I'm considering that very topic. 3.33 would probably be ideal - the gearing is great for the street, but it _is_ too much for the tires. 3.07 will slow down the launch too much, but with 3.33 I'd have enough legroom in 4th to cross the traps at (?) 135 mph, which is about what the car would run.

what BRAND IS THE ROLL BAR?

 

[treynor]

The rollbar is something Dan Cragin & co cooked up. The track officials were satisfied with it because it has a bar all the way across the top, per NHRA specs.

 

[VIPER D]

Can you post some pics up of the bar?

thanks in advance

vd..

 

[Snakester]

From Ben's previous VCA rollbar post:
http://vca2.viperclub.org/forums/showflat.php?Cat=&Board=UBB21&Number=517080&Forum=All_Forums&Words=732&Match=Username&Searchpage=1&Limit=25&Old=allposts&Main=517080&Search=true#Post517080

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[VIPER D]

nice

 

[Nich0las]

The rollbar is something Dan Cragin & co cooked up. The track officials were satisfied with it because it has a bar all the way across the top, per NHRA specs.

Great news, we just had the same bar installed. Glad to know it was accepted at the strip.

 

[Nich0las]

The rollbar is something Dan Cragin & co cooked up. The track officials were satisfied with it because it has a bar all the way across the top, per NHRA specs.

Great news, we just had the same bar installed. Glad to know it was accepted at the strip.

 

[BigCarrot]

Great news, he just had the same bar installed. He's glad to know it was accepted at the strip.

 

[Wicked]

To be honest, with some of the changes you have mentioned, I would fully expect low 10's/high 9's @ High 130's to low 140's.

The lower gear will not hurt your 60' that much if you were spinning the tires as you say, plus the lower gear will give you more top end.

The 97 Firebird Formula I raced 6-7 years ago ran 11.19's@127 w/ a 3.42....11.19's@125 w/ a 3.73....11.19's@123 w/ a 4.11.(Stick Shift) The car probably only put out about 550rwhp.. yours has MUCH more then that, plus it's lighter. Mine weighted something like 3500lbs+ My car didn't have the torque needed to keep 60's the same with the lower gear, so I lost 60' time with the smaller gear, but I do not see this happening to you.

Then looking at my all out race car (95 Formula) it weighted 3700+ lbs with the cage and everything. Only put out about 625 rwhp or so, but with a TH400 and it ran 10.40-10.50's@127-129. And the TH400's really rob power.

Story short, you have A LOT of potential in your car and with some minor changes and some practice, there is no reason your car shouldn't be running high 9's to low 10's.

 

[Nich0las]

Great news, he just had the same bar installed. He's glad to know it was accepted at the strip.

what????

 

[Y2K5SRT]

I think he is just giving you a hard time as you posted the same thing twice.

 

[Nich0las]

I thought my computer froze

 

[treynor]

Just an update - Ted May @ Valaya has ordered a set of 3.33 gears for the diff, and I've ordered a shift light to take the guesswork out of the critical 3-4 shift. I'm also going to put some VHT on my DRs and see if I can't coax a bit more traction out of them.

> Then looking at my all out race car (95 Formula) it weighted 3700+ lbs with the cage and everything. Only put out about 625 rwhp or so, but with a TH400 and it ran 10.40-10.50's@127-129.

Sure, but with what 60'?? I don't expect better than mid-1.6s with the stock suspension on the SRT. Regardless, I certainly hope the predictions of low 10s are accurate, but I'm going to be realistic and say (without suspension mods, slicks & skinnies, etc.) 10.7 @ 135. I'd love to be wrong in this instance

 

[DSR207]

The 03 didn't have a shift light ?

 

[treynor]

The stock shift light is not suitable for drag racing - it comes on very early (~5500 RPM). On our SRT the peak HP is made at redline, which means the penalty for short-shifting is several MPH.
The 3-4 shift is the most crucial since you're spending the most elapsed time near redline, so I expect to calibrate the shift light to indicate precisely when to make that shift (including reaction time, so probably 5900-6000 RPM)

 

[Y2K5SRT]

Ben -

Not to get off track here (no pun intended), but isn't the SRT your wife's car? I can't wait to hear what kind of times she posts and if she can increase the trap speeds at all...

Chris

 

[Dave T (BADVENM)]

Chris, I was thinking the same thing the other day. I think Ben is ensuring the car is safe at speed (high speed) so when she steps on it nothing goes wrong

I'm sure she'll suprise a few would-be racers at the light!!

 

[treynor]

> Not to get off track here (no pun intended), but isn't the SRT your wife's car?

You laugh, but then again, have you seen my wife?

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[NB - this was *six weeks* after she gave birth to our second child, and she was doing the Russell roadracing class in open-wheelers]

In all fairness, I *did* promise my wife I wouldn't do anything to make her car louder, harder to drive, etc. With the stock exhaust & cats, quiet Novi2K, etc. and DC's tuning, she says she doesn't notice a difference driving around at all. The car really could be a stocker if you don't step on the gas or rev it up over 3000 RPM

 

[Wicked]

Sure, but with what 60'?? I don't expect better than mid-1.6s with the stock suspension on the SRT. Regardless, I certainly hope the predictions of low 10s are accurate, but I'm going to be realistic and say (without suspension mods, slicks & skinnies, etc.) 10.7 @ 135. I'd love to be wrong in this instance

in order of mph.. 1.6s to 1.7s to 1.8s.. My 60's got worse with the smaller gears, but mph went up. The car didn't have the torque needed to maintain low 60's with the lower gear. Also, I never ran skinnies, I did run ET Streets though.