Track results. Need some tuning advice!

[Rich Gio]

Just got back from the track....

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Well, I mixed my 100 Octane fuel, slapped on the Drag radials and headed to Island dragway "fast and furious Fridays".


First run was a baseline, with the scan master set at 0% fuel added, 0% timing advance and 16ish PSI boost 43# fuel line off. I get to the tree and OH crap...it's a pro light. (Insert lame excuse here) Never ran a pro tree, always brackets. Ran a 14.007 @ 99.16mph ...ugh. Didn't have time to get set up at the tree so I left at basically zero boost. Had 1.4 KR and 239 02 at 96 MPH.

Second run Raised WOT fuel to +10% and fuel pressure up to 45# line off.
13.76@ 99.37mph. Zero KR. Time to crank up the boost! crappy 60' 2.134 attributed to pro light and some wheel hop.

Third Run Raised boost to 17ish
Ran my best time so far 13.531 @99.72 blip of KR at 20 mph (wheel hop?)
60' time of 2.015. Here's where it get confusing!

Fourth run
Raised boost again to 18psi, advanced timing 4degrees
Ran a 13.85 @99.35 2.215 60' time had some 4 KR at 96 MPH O2 read 240 at 96 mph. BLM was 124 At WOT

Fifth run
Left boost at 18psi, raised fuel to +12% at WOT and set timing back to 0 advance default. Raised fuel pressure to 48# line off. Ran a 13.797 @ 99.20 2.189 60' time...tons of wheel hop. Zero KR but BLM was 118.

Last run
Same settings...hurried to get one last run in before close.
13.682 @ 98.41 2.038 60' . Had some KR again at 96mph.



Questions: Does this top end seem flat for my set up? Why was my time getting WORSE as the night cooled down? Do you think I'm running it too Rich? What pressures are you guys running your MT drag radials at? I was running at 27#. Last year after I changed my valve springs my best trap speed was 100.70. Why am I failing to break 100MPH trap speed now?


Things I learned: Gotta go next time they run a Bracket tree so that I have time to stage up and bring boost up to 4 pounds for a better launch. I need to heat up the MT drag radials a bit more and remember to inflate the air bag on the passenger side coil spring to cut down on wheel hop before I leave for the track. All in all I'm kind of disappointed.
__________________
'87 GN with 48K miles (Original owner). Stock except for AVC "GNX style" dash,
208/208 cam, adj FP reg, Art Carr shift kit and cold air kit. Car was stored for 16 years and was just pulled out of mothballs. I'm working on getting it back into shape as time and $$ permit.
Completed so far:
6/01/09 Complete "spring cleaning"
8/01/09 Got My NJ Collectors Car inspection decal. No more emissions testing! For 2 years anyways....
8/15/09 Installed Racetronix Walbro 340M pump ,hotwire kit, TT chip and 42# injectors.
9/15/09 DIY Adjustable wastegate Mod. ,Comp 980 Valve springs installed and DS header weld repaired.
4/02/10 Installed Mike's Monte's Headliner.
5/02/10 Installed RJC Powerplate

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[jasjamz]

Too many adjustment at one time sums it up... Here is what I do, other may do it differently.

Set the FP at 43 line off. Leave it there. Add fuel via the chip. Start rich, add 10% and to get the 02s down either turn up the boost until you reach the target psi in two pound increments or trim fuel in 3% increments. You want the O2 in you target range at the finish line. Should be higher that your target and fall as you get closer to the stripe.

Once you have the boost and fuel set, play with 1st/2nd gear timing. Look at the 1/8th mph for gains. No more the 2* at a time. The 60' needs to be pretty consistent to do this. When you see knock in 1st or 2nd, you can back it off a degree or add 2% fuel to the chip. Do this till you see no more MPH gain. Repeat this process for 3rd/4th gear.

Race the car in "D" not "OD"

Widebands help...

 

[theCATman]

Yes... the car certainly is running rich. I'm guessing a TurboTweak chip because of you messing with the fuel & timing?

Personally I'd unplug the battery for a few minutes to reset the chip back to Eric's "stock" settings. Then set the WG rod to achieve 17 PSI and leave it alone 'till you learn to drive the car better. Maybe, maybe, take 10% fuel out of 1-2 gears, but only after you get your driving skills in check.

Next.... I'd work on learning to launch the car. Your 60' times suck (sorry:redface Sounds as if you're leaving at 0 PSI. These cars have to leave on 5+ PSI (or what ever your brakes will hold) to get a good launch and ultimately a good 1/4 mile time.

Don't worry about the tree, the guy in the next lane OR your R/T on the slip. Sit there, build boost, & run your own race. Your not a pro racer & getting paid for winning. You're there for your own enjoyment.

I have M/T DR's and run them at 18-20 lbs on the track & 28 lbs on the street.

 

[Dreamn4GN]

CATman... I new to these cars... Im curious why your running lower boost at the track then on the street? I would thinnk it would be vice versa...Looking for the reason behind this.. thanx..

 

[TurboSpeed]

JuToo many adjustment at one time sums it up... Here is what I do, other may do it differently.

Set the FP at 43 line off. Leave it there. Add fuel via the chip. Start rich, add 10% and to get the 02s down either turn up the boost until you reach the target psi in two pound increments or trim fuel in 3% increments. You want the O2 in you target range at the finish line. Should be higher that your target and fall as you get closer to the stripe.

Once you have the boost and fuel set, play with 1st/2nd gear timing. Look at the 1/8th mph for gains. No more the 2* at a time. The 60' needs to be pretty consistent to do this. When you see knock in 1st or 2nd, you can back it off a degree or add 2% fuel to the chip. Do this till you see no more MPH gain. Repeat this process for 3rd/4th gear.

Race the car in "D" not "OD"

Widebands help... st


Yes... the car certainly is running rich. I'm guessing a TurboTweak chip because of you messing with the fuel & timing?

Personally I'd unplug the battery for a few minutes to reset the chip back to Eric's "stock" settings. Then set the WG rod to achieve 17 PSI and leave it alone 'till you learn to drive the car better. Maybe, maybe, take 10% fuel out of 1-2 gears, but only after you get your driving skills in check.

Next.... I'd work on learning to launch the car. Your 60' times suck (sorry) Sounds as if you're leaving at 0 PSI. These cars have to leave on 5+ PSI (or what ever your brakes will hold) to get a good launch and ultimately a good 1/4 mile time.

Don't worry about the tree, the guy in the next lane OR your R/T on the slip. Sit there, build boost, & run your own race. Your not a pro racer & getting paid for winning. You're there for your own enjoyment.

I have M/T DR's and run them at 18-20 lbs on the track & 28 lbs on the street




Took my ride to the track thrusday and ran 13.2 with no boost off the line, just ran one time because i just about lost my t-top,didnt tape them down.but anyways this is some good reading.

 

[Dreamn4GN]

Turbospeed maybe you can help me out a bit... Curious about the reason about the lower boost at the track and higher boost on the street...

 

[gusszgs]

I think Cat was refering the the psi in his drag radials.....not the boost.

 

[Dreamn4GN]

haha wooow.. Im a goof... der...sry guys my fault...Still hung over haha

 

[Timbuick]

Interesting figures, I raced my car a couple of weeks ago for first time. Just for comparison, my state of tune is very similar to yours although I have alky.
I ran from zero boost and only ran 14.s, (2.6 60' ) however all three runs gave 101mph, so you do have more in there i'd say. I had drag radials too and ran 16/17 boost.
My problem was vac brakes and no boost at the tree, but that's another story!

 

[mr go fast]

Tire questions?

What psi?
What size?
New or used?

 

[theCATman]

haha wooow.. Im a goof... der...sry guys my fault...Still hung over haha

Yep... tire PSI, not turbo PSI.

 

[Timbuick]

In my case MT drag radials 26" (235 60 15) barely used. 20psi

 

[Rich Gio]

Thanks for the input, guys.

Yeah, you ain't lyin' my 60' times do suck. I actually had better times on street tires. I was getting psyched out at the tree. The one time I had time to stage properly I left at 5psi and wheel hopped all over the place. (Forgot to inflate my airbag )

Any ideas why my trap speed was 1-2 MPH lower than last year? Only thing I changed was the tires and RJC power plate was added.

I was running at 25# at the track in my drag radials. I'll give 18-20 psi a shot.

 

[TurboDave]

I'm assuming your mph is off because your 60' and ET is off. They all go hand in hand to a degree.
Launching takes tons of practice to get "right".

As for launching on a pro tree it's really not all that difficult at all. Pre stage, get on the brakes hard, start building boost to 0-2#, then ease off the brak just enough to allow the car to nudge forward and reaply, may take a couple "nudges" to get fully staged, now you're already in boost and bringing up to your launch boost will be quick and easy. Once both cars are staged, you should have 2 seconds before the tree flashes.

I have, over the years (yes it takes years to get real good at it), found it easier and much more consistent to launch my car from the sound only. You develope a "feel" or whatevery you want to call it, for how much rpm/boost is equal to how difficlult it is to hold against the brakes. It just takes way too much time and effort to look at gauges and still try to watch the tree. You HAVE TO develope a feel for your car!!!! What the engine sounds like on the foot brake for almost any given amount of boost, etc.. YOU HAVE TO! or your reaction times will forever suck!!
Some tacks display reaction time from a base of .000 and some from a base of .500 (.400 on a pro tree). To consitently win you'll need to be able to get into the .050 range (.550) or a little better. You won't be able to get a whole lot better on a foot brake, no electronics box launch, but an .010-.020 reaction will win you more races than your car will.
Remember, having the quickest or fastest car doesn't always mean a win. First car over the line is the winner.

That's why I love "non electronics" based braket racing so much. It's a driver's race. I absolutey HATE electronics based bracket racing. That's nothing more than a person along for the ride to steer.

All of this of course assumes you've made a couple passes to see what the track and your tires will hold.
Pro trees are actually fun once you get a feel for what's happening. That and the fact that most people just cant get a feel for the pro tree, makes taking home the trophy/cash a little easier.

I may be making it all sound too simple, I suppose because I've been racing the same exact car for over 20 years now.

 

[Pronto]

20lbs in M/Ts seem to work well for me.
If your just learning your car forget the Pro Tree. Just do the regular lights. Don't worry about reaction time. Like Turbo Dave said you kind of have to "learn" the car. I still have lots more set time I need but I am getting the hang of it.:wink:

Leave the fueling at 43lbs line off. Got back to the defaults and start over. Change one thing at a time and WRITE IT DOWN, all your scan #s, chips setting, fuel oct, and air temps. As you work on tuning and learning having everything in a notebook will help you decide where to go with your next change in tune. If the mph goes up then you're heading in the right direction. Watch out for knock!