Bigger Throttle Body, TPS reference changes!

[yoda69]

Possibly need a longer log to get more detail, as I'm not sure how many hits you have in each cell.
If you look at the the "before" chart at say the 2400 and compare with "after" cells we get something like this start from 0% TPS

TPS%...before.......after
12.5......xx........336
18.75...184.........411
25.......270.........467
31.25...347.........506
37.5.....462........536
43.75...497.........546
50.......530........551
56.25...552........XXX
62.5....556........XXX
100......XX.........568

What this basically shows is that at 2400RPM once the motor reaches ~550mgc that's as much air as the engine can consume regardless of throttlebody size.
The original throttlebody achieved this at around 56% TPS, the larger throttlebody achieves the same airflow at about 44%.
By moving the tables for pressure and shift speeds lower to match will improve, can do by trial and error or lots of logging before and after to figure out some patterns. Biggest problem is that most are based on TPS%, gear change and vehicle speed. The airflow measurements just give you an idea of how big a change the throttlebody has made.
Interesting to note that at 12.5% with the new throttlebody, you nearly have as much air getting into the motor as you did at 31% with the original.

Makes the old hydraulic trans with a simple TCC lockup look easy.

yoda69

[delcowizzid]

you would also have to factor in was the sample airflow on the way past that tps% or was it constant at that tps or was it under decel etc which would scew readings .i just add 2-4 to the upshift and downshift tables to fix it all in one swoop 3rd can do with a bit more added than 1st and 2nd .i just guessed my first tweaks for TB tune i ever tweaked to suit 69mm customer said it drove like stock again and all his problems were fixed so its been my standard mod on every 69mm tune LOL

[The1]

thanks guys, ill do some logging and testing, ive attached some old logs, the tps wasn't quite working properly so replaced and working good now still need to tweak the shift points or pressures.

[The1]

here's something that might float the boat, use slip to tune FM table. Here's a slip history before and after, still need to tweak a bit but looking good and can kind of find where it needs more pressure then, i just guessed for a start by shifting the tables up a notch under 30tps which came close and it's shifting nice now to, i also shifted both up and downshift tables up under 50tps by 4kmh as suggested before i started tuning.
STOCK TB


69MM TB


Stock TB Sample Count
69mm TB Sample Count

FM TABLE used with 69MM TB Results above.

[yoda69]

Looking good.
I think these electronic trannies will be good once you can get your head around how it all works, much like the MAF stuff.
There actually a smart unit, but until you figure out how everything works it's difficult to know what to change.
HAving said that, go back a few years and people were saying that about the MAP based tunes until things like $12P came out, and better defined xdf's.

yoda69

[The1]

i guess at the end of the day you can tune any trans and even if it's old and half worn out there maybe hope!! Im gonna pay the inlaws a visit sometime and do a log on there vs commo, it's totally stock with stock tune but has had the trans rebuilt recently so ill see what the slip is like may help give an idea what it should be.

[The1]

here's the trans settings ive used with the car that has a 69mm TB with a 25mm manifold spacer

[The1]

Right think ive found some Default tables that could make this easier, but obviously need some testing done. Also thanks for Holden202 who made this a hell of alot more easier to find.



The Left one is 4E77 in CKUL N/A and 50C7 in S/C CKUM calc should be X/2.56
The Right one is 4E54 in CKUL N/A and 50A4 in S/C CKUM calc should be X

My Thinking is to scale up the left table so smaller tps % at larger G/S Airflow, this should alter shift times, keep adjusting till shift times are to desired shift times you have set in the High & Low ALT shift time tables, once you get that then you would need to adjust the force motor tables, scales the rows up or increase your lower PSI till you get slip rpm under control.

[gbonola]

Having the same problem with my vu since rebuilding v6 stroker with ported heads, intake manifold and 69mm TB. thought I stuffed the transmission. being playing but not sure where to look, still new at this, got any idears where to look for changes to transmission and also to adjust fuel and timing, tried changing tps and transmission values with no success. be great if you could head me in the right direction, keen to learn. thanks

[The1]

you either need to change the above or change your shift points and shift pressures/force motor table.