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As was pointed out to me from a very smart human being(yoda69), when changing throttle bodies on any car there will need to be a lot of tps reference tables changed (especially for transmission as it will be very pronounce), I had a look through the xdf & there A HELL OF A LOT of tables to change!

Is there an easier way of just changing a reference point in the cal file to make it 10% less sensitive for the change of all tps references?

What is a stock VT-VY throttle body? I think 65mm & then they get bored out to 69mm is this right? if so everything would need to be changed by 5,8% by my calculations?

yeh im having similar issues, i have a 69mm TB im trying to tune for, the tps gives out the same voltage at the same TPS % as the stock one, yet im having issues with shift points being so sloppy it slips sometimes, not the case with the old one back on there!

The basic issue, is that for a given amount of throttle (TPS%) the vehicle is now getting more air, and hence more power.
Everything needs to be moved down lower in the TPS readings.
It's actually about a 12.7% difference going from 65 to 69mm, as your interested in the throttlebody area.
((69/2)^2-(65/2)^2)/(65/2)^2, have ignored adding pi in as they all cancel out.

Yes there are a lot of tables (Pressures, gear up/down shift points, TCC lock/unlock points, etc.), and no, unfortunately I don't know any easy way to fix it.
The only good thing in this case, is a lot of the tables have 12.5% increments, so maybe be able to copy the data and move down one line, as this close to the calculated 12.7%.
If you do a histogram of airflow Vs TPS% with the old and new throttle body, may be able to better understand what is going on.

yoda69

AS I said smart bugger, or genius I like to refer!

I thought I was o.k. with maths & just did 69 minus what ever % until it hit 65 & thought that was it! but proven wrong yet again!

Yeah I guess it's not too hard to move them all down 1 line & then make up the % less from the given 2nd line(old 1st line).

But there is a hell of a lot of tables to mod & not just in trans either, thats why I was hoping somewhere in the cal section there may have been a tps reference that could be changed by 12.7%

Thanks!

B.T.W. I should have actually had this in the general tuning topic sorry

easy fix, put a hydraulic auto in it

here's was a screenshot of me playing just after i put it on ages ago, but dont do anything really other than to say yes airflow increased!! lol 18-25% is a problem area with trans stuff for me.

Before


After

I thought you might be interested in this thread the1!

So did you change all of your tps reference tables for both engine & trans?

i havn't touched anything yet, have only tuned the fuel and spark, so it's all running right, the tps has the same voltage at the same opening as the stock TB but i guess it's like yoda said the airflow at the same throttle opening is now larger which upsets some tables. So i guess just gotta figure out what ones it's upsetting, for me it was upshifts slipping so the pressures and shift points are different

raise upshift and downshift mph by around 2-4mph at under 50% TPS normally fixes the shifting side of things 50% upwards can stay the same

thanks delco ill try that, i noticed the issue was around 25% tps, low throttle or 50% up to wot was fine.