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14.1 why so slow?

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thumper

20+ Year Contributor
91
0
Jul 17, 2002
Ubly, Michigan
This maybe doesn't belong here, but it has to do with my track results. This last season I got the Talon to run a best of 14.1 @ ~99 mph. I don't think that all of this is my driving skills. I've gained quite a bit in the three years I've been racing the talon. My 60' ranges from 1.8 to 2.0 I'm still working on that. I've got some new tires that I hope will help. I have been running stock sized coopers they are just a mileage tire(the same for 3 years).

91 Tsi AWD

mod list
mbc @ 16 psi
home made 3" intake pipe
K&N w/ hacked air can
ngk's one range colder than stock
walbro 190 ( i installed this before my afpr now I have a 255 to swap in)
bushur AFPR running stock fuel pressure
full 3" turbo back w/ test pipe RNR (wish i had a new o2 housing)
Ported 14b that fixed my boost creep
ACT 2600
rebulit shep trans
shift bushings
pilot short throw shifter

I attached my logs. I'm using data logger. I know I'm getting knock and that's retarding my timing, but where is that coming from. The knock is shooting up before the injector is maxed out. Is the knock from the exhaust being loud? it's a flow through w/ no cat. Is part of the problem from the O2 maybe. In one of the runs it looks like it is slow to react. Any help would be appreciated.

Grant
 

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How much boost are you running? And Im assuming that you are running the stock smic, right? The 14b can heatsoak the stock smic easily with boost over 14psi(less than that actually) and that is probably why you are getting knock. You can thow all the fuel you want at it but it wont help knock if your turbo is just blowing hot air into the engine.

Another problem could be too high of base timing. Set base timing to 5*btdc and no higher until you get rid of knock and get a good tune.
 
only running 15-16 psi, and my intercooler isn't heat soaked. I never run back to back and my intercooler is always air temp to the touch before i make another run. also i have done boost checks and there are two leaks in my system which i thought were rather small at my boost level but large at 20 psi and better, but unfixable with current funds. one at the ic elbow to hose and the other is the TB. Could this be a large part of my problem?
 
it seems to me that u have knock in every gear from what those graphs show. and your 02 is way low. i would go ahead and up your fp to possibly 44psi and try again. your intercooler will defintly heat soak. i would run the 14b at 15psi and by 4th gear it was all knock. and those boost leaks can still cause a problem whether they are small or not. last i would check your spark plugs and make sure they arent overgapped. goodluck!! :talon:
 
i check my plugs every run, they are always in spec. what about base timing? can anyone explain that too me, maybe explain some more tuning stuff. I'd love to talk tuning so if someone had the knowledge and the time.

Thanks
Grant
 
The plugs don't lie. Your car is fine, your MPH is on par. The Only thing holding you back is your 60fts. You have mid 13 potential with that MPH.
 
your 60ft time with a shep racing tranny should be better.
what grade gas are you running?
with that trap speed you should be in the 13seconds, driving has alot to do with it.
at what rpm are you shifting?
 
I don't think your time or trap speed is too slow considering your mods. Run better fuel for less knock maybe, perhaps a better launch and quicker shifting or something, and you'd be in the 13's. That's pretty respectable considering your mods.

A lot of people think that with an AWD car the best launch means bring the rpm up to 5k and just drop the clutch. Not so.
 
Rev to 5.5k, quick slip the clutch half way and give it 100% throttle, when the nose of the car is in the air, let loose the rest of the clutch. Since you have a shep trans, you should even try this method at 6k.

Put your 255 in and raise fuel pressure 1psi. Log a third gear pull and see if that cures your knock problem. If not, raise fuel pressure 1 more psi. Log again. Dont push this too far. If your IDC's dont go down a little, i think its time for some 550cc injectors.
 
I run 93 octane all the time. On a race day I might get the 94. My intentions are not to run anything i wouldn't run any day of the week on the street. I got the car with the intention of being able to drop it against big ego'd camaro's and mustang's by me that aren't even running 13's. I have a huge problem with knock and that's what is concerning me. I've since swapped in a new O2 sensor. It cut knock numbers in half. I still have about 23 counts. I am wondering if this is from my exhaust. If i gently pull through the rpm range I will get to fuel cut with no knock. My boost creep has come back. I'm not sure how that is even possible. It was gone at the track, and then a couple weeks ago i was trying to log some runs and noticed the boost was taking off on me again. I'm looking to get a Evo O2 housing and try it again. I'm picking up some Falken 512's 225/50/16 today. The other tires were part of the problem. I usually rev to 4.5k then slip it trying not to bog. I tried it at 5 and 5.5k my tires just let loose they were the weak link. I sometimes have a little stick when shifting. I think i need to drop the tranny put in a aluminum flywheel, and shim the pivot ball on the clutch fork.
 
i would make sure you are lookin at the octane grade on the gas pump, just because you push the 93 doesn't mean thats what you are getting. alot of gas stations get low grade, so thats why you see the black hand writing on the side that says +or-.

as for boost creep what mbc are you using? if your tranny was build by shep racing i would think that it should shift like a dream.
 
Looks like you don't have an upgraded intercooler. The 14B at 16 psi can easily heaksoak the stocker. I think with a better launch you can get into the high 13's.
 
You should crank the boost to 18 psi with a FMIC. You will easily trap 105-109mph.
 
I'm running a Hallman Pro mbc. That would explain some of my problems maybe. My boost creeps now and before it would drop. When I ran the 14.1 I had just finished my porting and the boost would run to 16 hold strong till about 5400ish then drop to 14 or so. I would shift as soon as i saw the boost start to drop. The boost doesn't just go out of control right away though. It stops at what i have it set at then proceeds to creep after 5000 rpm's. I suspect the O2 housing. I want to put on an evoIII O2 housing. Will that be enough, or should I port it?

Can anyone tell me about base timing? How do you change this?
 
your creep is from your exhaust for sure. i have the rnr 3inch and i had massive creep issues. I did a full port job to the o2 housing, and made a notch in between the exhaust side and wastegate side. it made all the difference. i start at 18psi and slowly fall to almost 16psi by redline. look into porting some more or get a new 02 housing.
 
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