need some help figuring out car performance( or lack of)

[GST StreetRacer]

hi guys

this here is my problem, my car:
95 gsx
99k miles
td05-20g
tial 35mm external
full ic piping, NPR FMIC
3" turbo back exhaust
550cc rc inj.
walbro 255lph fp
s-afc

now i thought the compression was messed up because the car was running like complete SHIT, i got pulled on my a freaking neon, enough said, not to mention my best run to date has been 14.3 @ 97 and 14.6 @ 99.

so i do a comp. test and turns out comp. is FINE, now i dont know if tuning could do that big an impact as to turn the car into a low 13, high 12 second car, because i have the mods to run them, so any ideas on what i should check before i take out my chainsaw and start cutting away????

what boost should i run, while fairly tune, for the car to perform like it should with my mods, i'm really having a hard time with this, previosly i had all those mods on my 95 gs-t and i was pulling on the new m3s with ease, and untuned..............please help.

 

[RipperXX]

well i did not look in your profile, but from the mods you have listed.


But I notice you do not have a fuel perssure regulator listed.. a 255lph pump will defently overflow the stock regulator and cause WAY to much fuel to get by, causeing you to run pig rich and a rich mixture dont make big numbers...

also i duno how much HP you are going after but seeing as you have a 20G i would think your injectors are a tad bit small.. i would go with 660's if i were you.. that is if you ever want to run 22 or so psi...

 

[pneumo]

I agree with getting an adjustable FPR, but hold off on any other upgrades until you figure out the tuning.
How much psi are you running?
What gages are you using to tune?
Done any boost leak tests lately?
You already have the mods to do 12's, but there could be so many little things holding you back, like a slipping clutch, worn turbo shaft bearings, etc.

 

[loreak]

ok first off, the walbro has nothing do do with overruning the stock fpr under WOT, it only does it at idle or part throttle, so a afpr is not needed except to improve idle and gas mileage, well its usefull but basically it isnt causing excess richness at wot is what im saying

do you have a datalogger or anything?

i actually had the exact same problem with mine, i have nearly the same setup except supra intercooler instead of fmic and rest is similar

first time at the track i ran a 13.9 @ 99 at 18-19psi.....i was like wtf
then i got to the track again and best trap i could manage was 103-104 and i hit 109 with racegas at 23-24psi and i had it running good according to my datalogger

im going to replace my tb shaft seals and make sure i have no intake leaks, clean out my intake manifold and cylinders with MCCC, and put new spark plugs in and run it on august 16th so ill let you know what happens

so im in the same boat, shit just isnt workin right =*(

although even with it running crappy for a 20g, its still quick enough to beat anything around my area and edge out my friends 02 z28

 

[GST StreetRacer]

hey guys

the car currently has a fidanza flywheel, act 2600 clutch(doubt its slipping) with a street disc

the gauge i use for tuning is a greddy egt, i have a pocketlogger to log runs.

i know that tuning IS important and WILL better the times, but i doubt it'll get me into the 12s.

i am trying to do a boost leak test, i just have to get the tester from my friend, but i doubt i have any.

the 20g is brand new, less than 5000 miles in it, i'm currently runing 17-18psi on 93oct

 

[pneumo]

Tuning and fixing some little things on my car got me from consistant 105 MPH traps to 111 MPH.
Driving is also a factor; what's your 60' time?
What sort of timing are you seeing on the logger? O2 volts? It might help to post a chart with RPM, timing, O2, airflow. Also look for any other parameter that isn't normal, like intake temps, coolant temps, unsteady battery voltage, or?

 

[Mike 99GSX]

post a log of your runs!!

 

[jdmawd]

your probably knocking like a bi***, or simply rich as hell which could= knocking like a bi*** also. use you're logger and tune that car, Also look into a A-FPR.

 

[peregrine]

Originally posted by jdmawd
your probably knocking like a bi***, or simply rich as hell which could= knocking like a bi*** also. use you're logger and tune that car, Also look into a A-FPR.

gonna have to agree with jdm here (unfortunately buy an afpr and get a logger. you should be hitting at least 110 traps with that setup on race gas.

 

[GST StreetRacer]

i trapped 99 untuned, i'm yet to run race gas, i use the pocketlogger to tune, timing gets to 17-18 at top of the gear, but it gets a little shitty at 3000-4000 it gets advanced, pulled, advanced, pulled, also it drops below 10degrees when i step on it, but if i tune it for 10degrees then spool up suffers, i'm going to the track today, i'll see what i come up with.

best 60ft time was 2.3 because i didnt let some preassure out of the tires, and also they are crappy tires, i think i spun half 1st gear

 

[brads]

Originally posted by GST StreetRacer
i trapped 99 untuned, i'm yet to run race gas, i use the pocketlogger to tune, timing gets to 17-18 at top of the gear, but it gets a little shitty at 3000-4000 it gets advanced, pulled, advanced, pulled,

if its going up and down like that, you have knock retard. Is that right around the time your turbo fully spools? I would bet that your boost is spiking right there. Timing will be initially be high if you are cruising and not on the gas. Timing should normally drop as as you get on the gas and your turbo spools up, but once you are at your set boost level, timing should increase to redline.
Check intake air temps too. Making a block off plate to keep the airfilter from getting the hot underhood air helps. This made a big difference for me, Combustion chamber cleaner is a good idea too, as are the plugs if yours are old. The AFPR will help fix some things, but you can probably get the car running quicker and cleaner at WOT with the stuff you already have.
Brad

 

[13secGST]

yeh...tunning it will help you A LOT...also what could help you is turning the boost DOWN...if you turn it down, it shouldn't knock so bad as to keep pulling the timing and you should have consistant timing through till redline which would actually make your car faster. Try leaning it out more down low though if you can...that way it is more responsive and you get quicker spool up...or at least you should.

I'm not sure that you need an AFPR...I think it needs a good tune and tune-up. Are you good at tunning or do you know anyone in your area who could help you tune it for cheap?