I have been trying to troubleshoot some problems with my automatic and today I noticed something strange.

First, the problem.

I cannot get sub 1.999 60' on 13-14 PSI ET streets with my cammed A4. (348 RWHP)
It has 3.23 gears and a 2400 stall. Some people said that this is because of the 3.23s and because the stall is too small and it's just a restalled stocker (SLP) without the STR advantage of more expensive stalls. I still beleive I should be getting a 1.85 or 1.9 60' with this setup.

Looking through some of my logs, I noticed that on all my runs, the throttle percentage gradually gets to 100% up to 20-30 MPH. I looked through other people's logs and they get to 100% TPS right away. (now I know this is normal for a 6 speed but I was in doubt about the automatic)

Here's the weird thing. I always floor it all the way and do so in an instant, not gradually. Could this be the problem of the bad 60's? If so, how can I fix it? (well I have a 4.10 rear in my garage but I doubt that will fix my throttle issue. )

I don't know if this might have anything to do with it, but when I swapped the 94 engine in my 93, the throttle cable had some slack in it and floored all the way, it would only go to about 80% TPS. I replaced the cable with a new one and nothing changed, so I used two large nuts as a "ghetto fix" spacer for the cable. It's kinda hanging when the throttle is depressed but it does go to 100% when pushed in all the way. Could this have anything to do with it?
Thanks!

 

That is odd... when my car only dynoed 260ish rwhp I could run 1.8's in the 60 on street tires...



I don't know what could be causing it to not got WOT right away, that's odd.

 

Hmm, did you change transmissions as well?? The 93 had a tv cable to the trans..and apprently the 94 TB doesnt have a connection for that.. Not trying to question your intelligence..I dont mean it as an insult...

Here is the part number for the cable you should be using 12550676... did you put a 93 cable on to replace the old one ? or a 94~96 style?

 

Hmm...looks like you used the 93 throttle body?? I would check the TPS readings
Could need adjusted or replaced.

 

I think the TPS is fine, and it's doing that mainly because this stall is too low. It just doesn't have enough "free room" to get to 100% before the stall hits.... which also looks like it happens at ~21-2200... the SLP stall sucks.
Time to replace it with a clutch and pressure plate... and a different car to go with it.

PS. I added you to my IM list, but I'm going offline now. We'll talk tomorrow.

 

Alright Will do. Hmm didnt realize a stall could do that to you... I have a 2200rpm stall. I wonder if it is going to be giving me any troubles.

 

I would figure out why it is taking so long to get to 100% throttle, that means the car is not seeing the WOT (PE Tables) and going out. The stall has nothing to do with the TPS but I will say that you will gain a ton if you get a better stall.

Car was stock and pulled 2.0s and if I was lucky 1.9s, rebuilt motor with LT4 stuff and put in a lower cost TC, still pulled 2.0s, I was pissed. Stepped up to a ST3500 and started pulling 1.8s and then got the car down in the 1.7 range with practice and weight reduction. this was with the 3.23s. Later i put in 3.73s and no change in the 60s but top end dropped 3 tenths. So the gear would help.

Then the car went thru changes and now sits with a rebuilt a4 and Vig 3200 and pulled 1.78 on street tires.

With all that said, get a good TC!!

 

It sounds like you have TOO much tire. but its not that bad. (when i bracket raced my car weekly the et streets where too much for my taste at 1.77 sixtys) Went back with BFGs @ 22psi.


I would have to say too that the SLP stall is a waste of time.. look for something with a higher STR like a vigilante or yank. A 2800 vig will probally drive better (won't feel like its slipping so much) than your SLP.

Anthor thing is focus on lifting your *** out of the chair by pressing on the gas so hard also make sure there are no floor mats.


for what its worth I went from a 2400 B&M (cheapo) to a vigiliante 2800 with a set of BFG drag radials. My sixty's went from 1.99 to 1.77 with street tires it would do 1.88's with street tires. 343rwhp 333rtq. Stock 3.23 gear and weight

 

What if you're just sitting with key on, but motor off...can you view the TPS value realtime? If not, try monitoring it with a voltmeter and see if it's instantaneous...mine is on my ScanMaster.

 

OK Thanks for the tips. Did your MPH go up any with the other stall? The car is also down on MPH for some reason. It traps at 106.66 with the current setup (just a hair less with the stall unlocked completely) and I would think it should do 110 at least with 348 RWHP/345 RWTQ. (dyno curves look ideal, torque curve is flat and long)

Oh yea, last time I took it to the track, I ran it 4 times and every single run was a 13.012 Tried experiencing with higher/lower shift points, ET stayed the same.

 

I picked up 3+ MPH with my Yank and would expect the Vig to do the same.

The SLP unit is a stocker restalled, the others are smaller and that helps too!!

 

I woudl say it only picked up a mph or so, you got to figure its making it down the track faster so theres less time for it to pick up speed.

Don't worry about low traps. when my car was an auto about the fastest it ever did was a late 107mph but dynoed 343rwhp. still went a 12.52

I always stress picking up your *** with the gas pedal. Some coaching my girlfriend like that got her stock six speed Z from a 9.0-9.50's to 8.705 pretty consistantly. 2.00 sixtys

 

btw.. heres a timeslip

10/17/02
60' 1.77
330 5.18
1/8et 8.003
1/8mph 87.73
1/4ET 12.54
1/4MPH 107.62

 

It is definetely opening the throttle all the way after I got rid of the slack, and yes, I do run without the floormat.

I'm not that worried really since I built this car just for fun last year, but it looks like I'll be going back to a MAF 6 speed in spring.

 

Here's mine:

60' - 2.020
330 - 5.549
1/8 8.449
MPH 85.67
1000 10.914
1/4 13.012
MPH 106.66

3605#
Temperature 68*
Humidity 31%
Track elevation: 756 ft
Pressure in: 29.97