Hey guys. I got some time today so i took my car to the dragstrip nearby. I was expecting mid 12's and well here are my actual times
60ft--1.906
1/4mile et--13.169
1/4mile speed---103.18
they are not as good as i expected but they were all within 2 tenths of the 13.169
only thing i noticed that may be hurting me is my throttle position. I have a DFI so i can monitor everything and on my last run which was a 13.2XX i only was getting 80% throttle position the whole track! i'm confused if the computer is wrong or if it really is only getting 80% throttle. for what is worth i ran a 13.9NA..... btw i'm running 7lbs of boost on a 12lb pulley

.......at the track there was a 2001 Trans am Ram Air with a procharger, first ls1' i've ever seen supercharged and that flew, he trapped a 120mph but only rain a 12.2 because he couldn't launch without spinning. Very very nice car.

 

no offense or anything man, but either most of you dont know how to tune a motor for max hp or you have MAJOR belt slipping issues

i went from 14.54 @ 93 to 13.1 @ 110

BREAKING MY POSI when 2nd gear hit and i had 2.77 gears

i just dont get why all you other ATI people have such low et/mphs

 

that was kind of rude, if u didn't have any help for me then why did u even say that. and if i'm only getting 80% throttle then there is more in it, i know there is because i've traped 110+ on our local street 1/4 that we measured out, so something was off and i couldnt' figure out what it was, and we arnt' all as foruant as alot of you that have access to dynos. i live in iowa and all i gotta say is good luck finding a dyno around here! as far as belt slip i don't think i have any, i'm getting 7lbs, sure its a 12lb pulley but i have ported heads and intake. and for what is worth to you procharged, i also have 2.77 gears and my tranny is starting shift very slow(transgo going in this week). and a DFI is not that easy to tune with, i shouldn't have bought it but now i am stuck with it so i'm learning on it.

89procharged, this is your DFI system i have

 

Also agree, if you got nothing nice to say or help out constructively, then don't post anything. Garbage in...garbage out..


88IROCZ350 - Verify that you are getting full throttle, visually inspect that the throttle plates are goin' horizontal at WOT.

Can you make the computer relearn closed and open throttle?

BTW, GOOD JOB. You bolted on a power adder and made the car faster. Now to optimize power!!!!

 

i agree check that your actually getting full throttle.make your throttle sensor properly adjusted.another thing im thinking is your supercharger might be running out of steam.u might need to upgrade to a bigger charger.

dave

 

7# on the 12# pulley prbably is belt slip. look for any black dust on the face of the supercharger (dirty). fixing the throttle limitation could fix alot also. as far as local dynos go, see if one of these dynojets knows how to tune DFI, even if they dont, you should still go. I recommend every one go dyno. we got one car about 130 more hp on an "as installed" supercharger kit. remember if you live close to a state border to check the surrounding states for the shortest drive. find a dyno here! http://www.dynojet.com/lauto.shtml

 

sorry, i was in a bad mood that day

btw.......email me your home address. i forgot to send you a part of the DFI separate harness and didn't have your address to send it to you.

Also, i'm 99.9% sure that the throttle percentage thing that you have doesn't matter much. Because it only affects fuel enrichment

verify with another person that your TB is opening fully and dont worry about the percentage

for more detailed answers and tips/tuning hints go to www.turbobuick.com and go to the performance ECM section and do some searches. if you cant find the answers you need, sign up and make a post

sorry for before, just bad mood

 

89procharged... its understandable, i know the feeling of bad moods and stuff.

I checked my throttle blades and they open fully when i go full throttle on the pedal. I'll check the TPS soon but i dont' have a meter, i'll use my mechanics for a quick check some night.

Well i did another run and found something else out that may be causing my slowness, i'm gettin 10.5degrees of retard at 5150RPM!! would the nitrous settings effect that even tho i'm not using it its still in the DFI, i figured it wouldn't affect it unless activated that part somehow, maybe i'm wrong??

B4CTOM... thanks for the links to the dyno site, i forgot the address to it and couldn't figure it out. i live 30 miles from the one in waterloo but it recently closed!! so i gotta find the next closest. There was black on the head unit when i first had it out and only got 5lbs but i tightened it and got 7lbs now but don't think its slipping anymore, i dont' see anymore dust. fwiw.. i have about 1/4in of play on the longest part of the belt.

 

check my post on fixing belt slip: https://www.thirdgen.org/techbb2/sho...485#post641485

 

here is something for belt issues also....

when you have a brand new belt you ARE NOT suppose to tighten the belt fully....you will stretch out the belt too much upon startup and you'll never get the right boost

this is what u are suppose to do:

put the belt on and only tighten the belt SLIGHTLY
start the car and run the belt....but dont rev it
let it idle for a few minutes
turn the car off and re-tighten belt
you should be good to go

 

Hmmm... I dont think that was necessary.

A lot of guys here are just as inexperienced as you were when you first started. Oh... thats right, you were NEVER inexperienced!

DFI's aren't that easy to tune when you've never worked with one (Hell, I've never worked with one either). It's even more difficult when you haven't tuned a base CCC TPI setup!

I'm pretty sure that you've been on ThirdGen.org longer than I have, and I'm pretty sure that you have asked A LOT of questions in your day. Where do you come off answering that man like that? I can see if he asked something really DUMB, but in my opinion he asked a legit question and needed some real help and advice. He didn't deserve your response.

The day will come when your car is broke again. You're gonna come here and post a technical question. If somebody answers you as rudely as you answered 88IROCZ350, dont get upset, because I WILL throw this post up in your face and remind you of how rude YOU were...

PEACE!!!

 

JayDubb i appreciate your reply but i understood what procharged ment, i am very young(17) and am still learning, but i have figured out why i'm running so damn slow. Where i live the highest octane gas i can get is 89.5 there is 93 45 miles away but its hard to get that all the time, so i'm getting alot of timming retard due to the poor gas, i'm going to get some toulene and mix me a batch of gas and see what happens, should fix that problem, i'll see though. Procharged emailed me and is a very helpful guy, he apologized and i understand, he even offered to help tune the car if we lived closer but 5 hrs is a ways. So hes still a good guy just having a bad day. later

 

maybe you should read the WHOLE THREAD before trying to shoot me down

i already APOLOGIZED and said i was having a bad day.....never happened to you huh?

then i POSTED SUGGESTIONS TO HELP HIM OUT, while you just came here and decided to bash me instead of posting something useful

 

Hey,

I run 107 octane race fuel at the track when racing, and I only take out 1 degree per pound of boost. I run 8` initial timing, and it seems to work great. (no detonation). I've only seen 6lbs of boost so far, although suposedly my pully is a 10 pounder. Every once and a while I jump a rib, so i gotta fix that soon.

I don't really have any times to post, since I blew my clutch apart launching too hard, and am waiting for RAM to finish machining my custom pressure plate..

Anyway, whats the DFI setup you're using?? I'm looking for one, still on a stock chip.

Good luck!

 

Well i've havn't had alot of time to work witht he car this week so i've only driven it tonight to wash it and thats all. I know of a friend that uses 110 octane gas in his 12.1-1 compression ratio car and i was wondering if i could use like 4 gallons of this, and fill the rest up with 91(or close). Would the little bit of lead in that 4 gallons hurt my car? supposivly its unleaded but i thought anything over 104octane was leaded, am i wrong? any help would be good, i wanna try and get some better octane stuff in it this weekend and try to run it again on sunday. Thanks guys

 

The lead destroys the O2 sensor (temp, or perm).

I ran 2 gallons of 110 leaded accidentally (a buddy was filling for me, and forgot I was FI).

My ECM flipped out, it idled irraticly from 500 - 2500 until it was burned through the system, and the O2 sometimes still freaks -- gotta replace it this weekend.

So in turn, dont do it.. 103, 105, 107 is usually available in unleaded.. Unleaded smells better anyway..

-- Joe

 

 

Bs? So you think two cars sitting side by side, one burning unleaded, one burning leaded; both smell the same? I think not.

-- Joe

 

No, leaded gas smells better.

A very subjective topic and my only experience is the Sunoco 100 unleaded compaired to Sunoco 110 leaded. FWIW

 

Haha. A matter of opinion.

-- Joe

 

well i'd have to agree that unleaded smells better. I dont' like the smell of the race gas my friend uses. You can tell its no where near a stock engine when u smell that.

Anyway.... i put some 93 octane in my car today and it did not effect the timming retard at all! if anything its a little worse, whats going on?? i can't believe that with 9.5 compression and only 7lbs of boost i'd need more than 93 octane. Is it possible that my exhaust leak by my cat is causing false knock readings? any ideas u guys have would be great.

 

how old is your knock sensor?

Also what are your 02 voltages?

does that DFI have the wide band o2 sensor?

you can see false knock from a aging sensor, or improper installation, (not torqued)

I still see about 4 degrees of knock retard, when i play around out on the street, and i'm not even getting into drive(3rd gear).
but i still have the original knock sensor that came with the car from the factory. i just replaced my 02 sensor (it was original also), because it wasn't reading correctly.

someday i'll get back to the track, i know the car will be able to hit 12.9x's, i just need the time and most importantly MOOLA!!!

later
larry

 

I'm just wondering what kind of injectors you are using. There is a chart on eather the vortech, or ati site(maybe both) of the size injectors you should use in what hp and blown/non blown applications. You definatelly need larger than stock injectors.

 

alright.... stock knock sensor and stock O2 sensor, my DFI readings are like .735 or somewhere around there. as far as i know the DFI only reads up to .800 for o2 sensor. As far as injectors i'm using 24lb injectors so i got the fuel covered, its getting plenty of fuel no doubt about that, something else is the problem. Unforunatly the DFI i have is not a Wideband.

 

I run leaded race fuel all the time but I have no cats, I replace my O2 but not very often lead contaminates an O2 but it takes a while. it contaminates and can sometimes plug a cat the very first time. the same slow contamination also takes place on wide band O2's even the one on my dynojet. some guys with wideband O2's build a good map and then remove it (run without it) and plug the hole until race days and simply screw it back in and re-establish it in the ECM when they have any trouble or are racing or making combo changes.

 

88IROCZ350-try these guys-the helped tune my DFI-they have what it takes to fix your car.

www.cerraracing.com