WOT A4 Shifting Issue
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From: Marysville, WA
WOT A4 Shifting Issue I finally got around to logging a WOT run after my Yank SS3200 install. I only picked up 2/10ths at the track, ALL in the 60', and I lost ~ 2mph. So I knew something was amiss. Anyway, what I found was this:
I have the car set to shift @ 6700, DFCO @ 6800, but the car never hits that target. It shifted at 6500 1-2, and at 6200 2-3. The 1-2 shift hit the MPH limit, so that might explain that (more later) but the 2-3 was 6mph under the shift point, so that one really puzzles me.
At 5600rpm in 1st, the MAF is pulling 35.2 lb & the dyn cyl air is .7 g/cyl. Then both start to fall off up to 6450rpm where everything flattens out until it hits 37mph & shifts at 6500. At that point the MAF is around 38lb but the air is down to ~.65. In 2nd it gets to 6200rpm, the MAF is at 36.4, the cyl air is .68, and the mph is 66.
I wound it out in 3rd & again about 6500 everything started to fall off.
EVERY table is set to make it shift @ 6700rpm, 37mph 1-2 (raising that) & 72mph 2-3. So waht gives? All I can think is that I need to do the SD tuning & re-scale my MAF tables accordingly. (actually, a friend - Racehead - thought that might be my problem).
Any ideas? I need some help if I'm going to hit an 11 sec cam-only 1/4 mile (I'm at 12.29 now)
Thanks!
Mark
I have the car set to shift @ 6700, DFCO @ 6800, but the car never hits that target. It shifted at 6500 1-2, and at 6200 2-3. The 1-2 shift hit the MPH limit, so that might explain that (more later) but the 2-3 was 6mph under the shift point, so that one really puzzles me.
At 5600rpm in 1st, the MAF is pulling 35.2 lb & the dyn cyl air is .7 g/cyl. Then both start to fall off up to 6450rpm where everything flattens out until it hits 37mph & shifts at 6500. At that point the MAF is around 38lb but the air is down to ~.65. In 2nd it gets to 6200rpm, the MAF is at 36.4, the cyl air is .68, and the mph is 66.
I wound it out in 3rd & again about 6500 everything started to fall off.
EVERY table is set to make it shift @ 6700rpm, 37mph 1-2 (raising that) & 72mph 2-3. So waht gives? All I can think is that I need to do the SD tuning & re-scale my MAF tables accordingly. (actually, a friend - Racehead - thought that might be my problem).
Any ideas? I need some help if I'm going to hit an 11 sec cam-only 1/4 mile (I'm at 12.29 now)
Thanks!
Mark
Thread Starter
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From: Marysville, WA
I got it fixed. Well, it worked for 4 whole test runs last night anyway. I fiddled & played & tweaked & finally got the car to shift around 6700rpm. I had to change the tire size (315 Nittos are 1/2" taller than my GSCs) and change the gear ratio from 4.10 to 4.11 (Predator tune entered the 12 bolt ratio). And I had to re-adjust the mph shift points (I guessed at the track what mph coincided with 6700 rpm, and I was a little low).
All that helped a little (shifts went from ~6200 to 6400) The final fix was to set all my shift points @ 7000 rpm, increase the mph accordingly and bump the rev limiter to 7200. Now the car shifts at 6800 1-2 & 6600+ 2-3. (yes, I am moving 1-2 down to 6900)
Kind of a scary way to fix things, but hey, it worked. As long as my motor doesn't try to hit 7k! What this probably means tho is that some parameter in some table (Speedo?) is wrong. If & when I find it, I will let people know.
All that helped a little (shifts went from ~6200 to 6400) The final fix was to set all my shift points @ 7000 rpm, increase the mph accordingly and bump the rev limiter to 7200. Now the car shifts at 6800 1-2 & 6600+ 2-3. (yes, I am moving 1-2 down to 6900)
Kind of a scary way to fix things, but hey, it worked. As long as my motor doesn't try to hit 7k! What this probably means tho is that some parameter in some table (Speedo?) is wrong. If & when I find it, I will let people know.
Thread Starter
10 Second Club
iTrader: (4)
Joined: Feb 2004
Posts: 9,448
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From: Marysville, WA
I may have to do that. I thought about comparing my tune to a stock one I got of Horists site, but I'm not sure I'm smart enough to recognise the problem if I find it. My tranny guy also suggested forcing a full PCM download, reflash?
