Looking for mid 11's

[michaelpacey]

Alright guys just got done with a testing day today and I'm currently at a tuning wall right now and it's frustrating me.

My Turbo T ran a best of 12.20 at 109 tonight leaving at 10# of boost with the max boost at 21# and the timing progressing down to 26 degrees at WOT. 60 ft. was 1.62 leaving off the transbrake 7.74 at 87 mph in the 1/8. Talking to Steve Hughes and other guys they said I should be able to put the T down in the 10.50's with the setup I have, granted I'm not looking for 10's just mid 11's.

I'm running a Fast B2B setup and my o2 correction is spot on, and my AFR is 11.00 at WOT and 22#. Data log shows no spark knock. What should I be changing in the tune to get that 11.50's? Current setup on the car is as follows:


Stock 3.8 long block
70mm Precision Turbo and I forget the wastegate size.
GN1 Performance Hot side with a cutout
96# injectors
Aeromotive fuel pump
Fuel pressure is 42.5# with the vacuum unhooked
Griffin Aluminum radiator
dual electric fans
Front mount intercooler
FAST B2B programmer

Neal Chance converter
Neal Chance T400 with transbrake

10 bolt 8.5
3.90 gear
Moser axles
Spool

28x10.5x15 slicks with the frame clearance
QA1 Adjustable shocks
Adjustable upper control arms
Lower control arms
Anti-Roll bar

and a few more misc things.

So where do I start guys?

 

[earlbrown]

You've definably got something wrong up top. Leaving at 10#s with a 1.62 with a 7 sex 1/8... You should already be in the 11's on that very pass.



With all those 'cool guy' parts I'm kinda lost as to a best course of action... but when my golf swing went to shit in 10th grade, I got back to basics....

It looks like it might be time to go old school and read some plugs after a pass, and/or start screwing with that WOT A/F number to see what the car likes. I have a feeling a nice even 11:1 isn't what the car really wants. (unless that number can't be trusted due to a slight top end misfire and it's fat while artificially reading lean). Start moving either way and see if the car likes it.

 

[michaelpacey]

See I played around with the launch boost a bit, I was launching at 18# and my 60 was 1.59 7.60 in the 1/8 with a 12.30 at 106. Talking to a couple turbo guys they told me to leave at a lower boost and let the turbo do the work, and even though I lost a little in the 60 and 330, I picked up the top end charge. For running a 12.20 I feel like the mph should be faster, coming off the line, and shifting first to second it pulls like nobodies business then it just seems to flatten out, it doesn't lay over persay just kind seems like it's cruising. Also the cool parts where on when I got the car, it's Kevin Hess' old car that ran 9's but the long block was swapped.

I'm leaving the line between 4,300-4,500 rpm, shift at 6,000 and cross the stripe at 5,700. So are you thinking that it may want to be leaned out a little bit at the top end? Every time I threw boost and timing at it, it was really liking it. Nothing ever showed on the ESC retard on the data log. I didn't get a chance to pull a plug tonight, I honestly didn't even think about it. I'm running the basic Autolites that the GN calls for I think I've got the AP25. Gapped at .035. A guy recommend I go and get another set of plugs that are one step hotter, I tried the AR23's and they were to cold.

At the top end I wasn't hearing any weird sounds, and it didn't act lean, I was actually fighting a bit of an over rich issue with the AFR going in to the 10.75-10.80 range at the top of 3rd. What are you thinking it wants for AFR?

 

[earlbrown]

When 'the guy' recommend you move up a heat range did he actually look at your plug and see that you were too cold?

I'm wondering if you're actually fatter than you think. A misfire will leave unburnt oxygen in the exhaust stream and cause your reading to read leaner than you actually are.


Unlike other people, I never throw out magic numbers. In the case of your car, the best A/F is close to whatever give you the highest trap speed.

 

[Mr.Spool]

bone stock motor and 70mm turbo at low boost shifting 6000/5700 is the issue.airflow through the motor and the fact the stock cam is out of range at 6000rpm.to me the easiest way to get the car to perform would be to put a smaller turbo on it and tighten the converter,or with the 70 heads/ cam upgrade.then there is the converter which is a very important piece of the puzzle.i use gears in mine and love them,try a smaller turbo and shift the car earlier,or turn the boost up on the 70 and shift earlier.

 

[jimmymack87gn]

Yep. Stock cammed engine doesn't need to be spun higher than 5000-5200

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[michaelpacey]

Alright guys sorry it took so long to get back to you, I was just going through my data log and found out that the car was running in the 10.75-10.80 range from the 60 foot to the finish line. Also noticed that the car crosses the stripe around 5,450-5,500 rpm and drops down to 4,700 when I shift. Seeing how rich it is makes since now that with more timing and boost I was running slower in the 1/8 by almost 3 tenths from last year when I had 21 pounds and 21 degrees. So I went into the AFR changed it to 11.2 at the top end and tried the interpolate on the o2 table. I've never used the unterpolate before so we shall see how it will do.

I definatly agree on it needs a tighter converter. But the plan for this winter is girdle the bottom end, new rotating assembly, hydraulic roller cam a set of ported TA heads and opening up the intake a bit. So for now I'm going to leave the converter alone. I've got heads studs on the engine now, once I get the tune right what would you guy feel safe with boost wise? I'd like to turn it up but I don't know what these engines are able to handle in this stock long block form.

Also in reference to the plugs, I totally forgot to pull a plug at the track. I didn't even think about it. I will definatly do it next time I'm out there.

 

[Amelio]

With what you have and what you are about to do....a mid 11sec will be easy with 20 pounds or less..........now the question of how much boost can you run total.....well that depends on how good your tune is. If setup right....30 psi would not be a problem.

With what you have and your upcoming mods......you should have 10 sec power plant.....you will definitely need to get your converter right, a solid tune and Hook!

you have more turbo, intercooler and injector than my car......and I was able to click off an 11.5 on 19 psi......you also have a trans brake which I do not so you should be able to leave hard!

 

[michaelpacey]

Fully spooled on the brake I can leave at 18-18.5 pounds of boost. Believe me if your head isn't on the head rest you feel it LOL. I was just going through my tune right now with my GN guy and we added timing to it, I'll post a picture of the table. This is the spark table we are going to run with 20 pounds of boost with Turbo Blue Xtreme 116 fuel.

 

[20psiofevil]

To me it seems something is going on when the car shifts into 2nd because it is coming out the hole decent and gaining 22mph out the back ( not bad but could be better even with 390 gear). Is the car bogging or loose power any when it shifts into 2nd? How fresh is the trans and converter?

 

[michaelpacey]

I would guess the tranny and converter have maybe a total of 100-150 passes on them. Once it shifts into 3rd it bogs like a extremely over jetted carb would. Consulting with kevin apprently I was way over fueling. Like stupid over fueling on the AFR table. So we leaned it out alot. I was in the 11.00 range from 3,000-6,000 on the target AFR table. I'm thinking that was alot of the issue.