WAHUSKER

iTrader: (4)

In my on-going quest to go faster I have been modding the car. I have a Predator, so I have been trying to tune it. Most recently I added a Hot Cam (w/H S 1.8 Rockers) and now I installed a Moser 9" with 4.10 gears.

The cam hammered the idle, but James was able to give me a custom tune for that. But now with the cam / gear combo, my A4 wants to shift too soon. It goes into 2nd gear very quickly, & third very soon after that. We're talking by the time I reach th other side of an intersection....like 10-15mph. If I give it more throttle, between 15 & 35% TPS it acts like it's slipping on the 1-2 shift, and usually just falls straight into 3rd.

At very light throttle, 10% & under if feels OK, and over 50% it also feels OK, tho that is hard to tell because I don't have much traction with my street tires with that much gas. It's a good problem, really!

Anyway, James says he has heard this is common with Hot Cams & A4s, but doesn't have a good feel for what needs to be adjusted. So I'm thinking maybe it's time to buy an HP Tuner. My question is, can I fix this with the HP Tuner, and if so, where should I start? (as in adj what table first)

I searched but found no threads about this issue.

A friend with HPT supplied these tables, but he has an M6 & wasn't sure:

A4 SHIFT SPEED
1.shift speed vs %TPS vs Shift
aa. Normal
bb. Cruise
cc. Hot
dd. Performance
2. WOT Shift Speed vs. Shift
aa. Normal
bb. Hot
cc. Performance
3.WOT Shift RPM vs. Shift
aa. Normal
bb. Hot
cc. Performance
4. a) WOT Shift Enable %TPS
5. b) WOT Shift Disable %TPS

Under the "A4 Shift Properties" tab you'll find
1. Force Motor Current vs. Pressure vs. Temp. with
aa. Positive
2. Desired Shift Time vs. Torque
aa. Normal
bb. Performance
3. Base Shift Pressure vs. Torque vs. Gear
aa. Normal
bb. Performance
+ 2 more adjustable's labeled
cc. Brake Shift Pressure vs. Torque vs. Gear
d. Max Line Pressure

The 3rd tab ( A4 TCC ) looks like this

1. TCC Lock During Shift (under this tab you have to choose one of two things)
a. True
b. False
2. TCC Apply/Release Speed vs. %TPS vs. Gear
aa. Normal
bb. Cruise
cc. Performance
dd. Hot
3. TCC Release %TPS vs. Speed
aa. Normal
bb. Cruise
cc. Performance
4. TCC DC vs. Line Press vs. Trans Temp
aa. Base
bb. Offset

Any ideas? Thanks
Mark

foff667

iTrader: (2)

i cant see it not being able to fix it...and alot of those tables will have to be fixed...I'd say find a file of someone that already has 4.10s and go from there otherwise thats alot of back and forth work & calculations to get it right...even trying to get my shifts perfect with my 2.73's took several wot runs and i was only a few mph off from the base stock tune.

stevebSS

I have the same problem. I'm running 4.10's and a 231/237. At wot it shifts fine but when cruising around town it instantly makes the 3-4 shift. Theres no holding period unless the car is under quite a bit of throttle.

marc_w

Yes, that can be tuned out in HPT.

I have my "regular" shifts set to shift nice and early, and lockup at a low RPM. When I click the Tow/Haul button, I programmed my shifts draw out a lot more RPM before bumping up the next gear. (Similar to the stock Tow/Haul settings but not as "tow" oriented).

Under the "A4 Shift Speed" tab, is the, "Shift Speed vs %TPS vs Shift" table. Everything is in there.

FWIW though, my 4.10, 31.5-inch-tire vehicle grabs third by the time I cross intersections.

WAHUSKER

iTrader: (4)

My buddy doens't have this issue with his 231/237. (he has an M6 )

I looked in the bin file list, but didn't see one that covered this. I guess I need to sift thru it more thouroughly. I am assuming mine shifts fine @ WOT. Like I said, it's hard to tell with no traction. I will find out this weekend when I go to the track & make some passes with my Hoosiers. I can shift in manually on the street to make it work right. The wife on the other hand.... But I don't want to do that at the track. I tend ot over-rev it or shift into 2nd too soon. I haven't quite figured out the PCM delay thingie.

I think we have actually made this kind of issue worse ourselves. We are all so focused on the WOT performance, we tend to overlook the daily driving stuff, which comprises over 95% of the mileage.

WAHUSKER

iTrader: (4)

Tow haul? Oh great, so I need to install a bumper hitch on my TA to make this go away?

j/k Thanks!

marc_w

You can have mine!

foff667

iTrader: (2)

with real tires on a track your wot shift points should be different then around town...at least mine are...factor in growth for tires blah blah blah my 2-3 shift rpm is like 300rpm different from my street tune.

WAHUSKER

iTrader: (4)

Good point. So far I have not been able to play with them. My tires are smoking so I can't really tell when & where it's shifting. Hopefully I'll get enough time trials to dial it in before eliminations.