Should I be faster???

[jonnygsx]

I made a trip up to the drag strip this weekend. I think this was my fourth trip but first one this year.
I am currently running a 16g at 17.5 psi, full i/c piping, supra sidemount, 255lph rewired low pressure pump, turbo xs boost control, 1g crushed bov, 2.5 full exhaust, no cat, ported exhaust manifold, 8mm magnecor wires.

Here is my best timeslip (they were all about the same) and my pocketlogger results from that run.

Timeslip

r/t 1.525
60 2.054
330 6.017
1/8 9.382
mph 72.93
1000 12.196
1/4 14.760
mph 90.76


Pocketlogger
1st
RPM Timing 02-1
4277 6deg .98
4710 6deg .98
4812 9deg .98
4941 9deg .98
5121 10deg .98
5285 11deg .98
5398 11deg .98
5507 12deg .98
5695 12deg .98
6007 15deg .98

2nd
4183 38deg .82
4273 10deg .96
4308 8deg .98
4375 7deg .96
4617 7deg .98
4679 8deg .98
4902 8deg .98
4988 9deg .98
5125 9deg .98
5187 10deg .98
5292 10deg .98
5457 11deg .98
5609 11deg .98
5738 13deg .96
5855 14deg .96
5867 14deg .96

3rd
4414 8deg .98
4625 7deg .96
4796 8deg .96
4886 8deg .96
4980 8deg .96
5089 9deg .96

I am thinking that with my mods I should be running quicker than this. I ran a 14.2 on my old t-25. This is all on a 1998gsx with 46,000miles on it.

The only reasons that I can think of that would cause mt to be running slow are:
1. Bad compression (doubtfull on a 46k mi engine though)
2. Stock clutch

I'm slipping the clutch from 6k, I don't ever notice it slipping but I can smell it after a race. I'm still waiting for my EGT guage from UPS. Otherwise I would have posted my temps too. My next mod will be an ACT 2600lbs but I'm waiting for the $$$.

If you have any thoughts, suggestions that would be helpful please post them.

My elevation is 1180ft.

p.s. I know I had a slow R/T, I was running for ET's not to beat the guy next to me...

Thanks, Jon

 

[ivanr4g63]

well even so your reaction time could be better...

But anyways, yeah... your clutch might be the reason why your ET's are kinda high for your mods...
I think you should be in the mid or even low 13's...

But you can maybe have a leak somewhere... have you checked that lately...?

 

[jonnygsx]

Yeah, i pressure tested everything to 20psi. The only leak is out of the throttle body arm. I'm going to either rebuild the 2g one or put on a 1g TB.

As far as the R/T. I sat at the line till I had the rpm's just right to launch. R/T doesn't affect ET so whats it matter. I "CAN" launch decent from lights when I want to, but right now I was more concerned with good launches than quick ones.

 

[need4speedtsi]

hmm... O2's seem a little rich, but your timing isnt great, I wouldve guessed that thats because your on stock injectors, but the 02's (usually useless) say otherwise... I think timing is one of your problems, dont know what your others are, clutch could be some of it, but your trap seems about right, your 60' foot could be better.. I dont know man.. alls i know is you should be faster...

 

[mattn]

Something is def. wrong with that time... Look at my profile to see that I ran a comparable time with the stock turbo and not nearly the mods you have...

Perhaps you're not shifting correctly?

 

[Mike 99GSX]

If that datalog is from your run down the track then your shifting too early. The 16g makes usable power in the 6000 rpm band. I'd say shift at about 6700. Your timing if probably getting pulled because your most likely running pretty rich. 550s and and AFC and you should be in good shape.

 

[need4speedtsi]

AH, i didnt see that you didnt have AFC, and no FPR! your 255 is probably outrunning your stock fuel pressure regulator, thats why youre running rich I think...

 

[jonnygsx]

I'm sure i am, I am getting an ACT 2600 in a few weeks and then its 550's and afc time.

 

[DSMeclipse4G63]

yes you should be much much faster. I can run damn near a tenth slower bone stock i.e no free mods and air filter.

 

[jonnygsx]

Well i agree that i should be faster. What do you think is the culprit though? Clutch, rich condition, bad compression? At least give me some ideas to check out. The only intake leak i have is in the TB which will be either rebuilt or replaced with a 1g. Other than that everything is solid at 20psi.

 

[Mike 99GSX]

Originally posted by jonnygsx
Well i agree that i should be faster. What do you think is the culprit though? Clutch, rich condition, bad compression? At least give me some ideas to check out. The only intake leak i have is in the TB which will be either rebuilt or replaced with a 1g. Other than that everything is solid at 20psi.

The clutch will make a big difference. Its a combination of the clutch and the rich fuel. Also, like I said earlier, you shouldn't be shifting at 5800 rpm with a 16g. Shifting more at 6800 will improve your times.

 

[jonnygsx]

well i'll get the clutch and see how it goes. The AFC will have to wait awhile but hopefully the clutch will improve times quite abit. Thanks for the help everyone...

 

[echo]

get the clutch. then get an afpr to get control of that 255. i'm pretty damn sure that you are overrunning your stock fpr. there is a post in the tuning section on how to build a custom setup with a aeromotive afpr. once all that is taken car of get some 550's and some type of fuel management (s-afc,dsmlink, e-manage). get it tuned properly and your times should be in the 13's. if you are a really good driver, you might even be able to squeeze a 12.

 

[jonnygsx]

About the whole pump thing. It kinda sucks because I did my best to figure out which pump to get that would give me the most flow but not require an AFPR. The general agreement was that the walbro 255lph high pressure pump was to much for the stock fpr, but that the walbro 255lph low pressure pump wouldn't need an AFPR. So i went with the low pressure one. It is really hard to decide what pump to get when so many people say so many different things. Someone needs to put up a sticky that has accurate information on a few of the different pumps.

 

[need4speedtsi]

yeh i heard that both 255 need the AFPR... Only the 190 was good with the stock FPR.. but Im stickin with what I said originally, and what echo said, im pretty sure your overrunnin your stock FPR.. I know theres a LOT of contradictory information out there... kinda sux doesnt it?

 

[pneumo]

Yes it sux, and it sux worse when that contradictory information get perpetuated, like in this thread.

So here's the scoop.

The 255lph and bigger pumps will overrun the stock FPR and lead to a rich condition at idle and low throttle settings. Once you are at WOT there is so much gas going through the injectors that the stock FPR doesn't have to bypass as much fuel, so it's not being overrun anymore. If that's not clear, please ask for clarification. I'm here to help.

The standard Denso upgrade pump flows 150 lph and is good enough for 11's. The stock pump is good enough for 13's.

 

[jonnygsx]

well what do you think then. Should i buy an afpr and use the 255 or should i sell the 255lph and get a 190 or so. My goal is anywhere in the 12s

 

[pneumo]

For now, I'd leave it alone. You can deal with it later. Overrunning the FPR makes the car run rich when you're driving around at slow speeds, so it's not a factor in drag racing. First get the clutch and shift at about 6700 RPM, that should make a big difference.

The rich O2's could be caused by a boost leak, which might also explain why you're down on power.

It's hard to say what would be better; sell the 255 at a loss and buy a 190, or buy an adjustable FPR which would cost even more. Maybe look for someone who is willing to trade a 190 for your 255?

 

[jonnygsx]

The only boost leak I can find is from the throttle body seals, I don't know how much of a loss that is but a leak is a leak. I'm going to attempt a rebuild soon.

 

[fast4g63t]

4183 rpm 38 degree igntion retarding and fuel cuttin .82 sounds like you missed 2nd gear that will severely hurt your times.trust me done it quite a few times with my fwd thats about when my tires break loose i always miss there.

 

[jonnygsx]

No, didn't miss second, must have just been a drop from coming off the throttle... The act 2600 and egt guage go in on friday so hopefully I will have some new times/info soon.