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Naf
February 20th, 2008, 09:18 PM
Good day,

I am going to be swappin my 75mm(Stock) TB for a 90mm. I made the needed adjustment to B4349 but where else should i mod for this upgrade?
Chalky
April 5th, 2008, 03:07 PM
Anyone want this one?
Naf
April 5th, 2008, 06:25 PM
i was hopin for an answer, but no one has one for me
tazinhawaii
April 10th, 2008, 10:44 AM
Take a look at my attached tune. In particular B4403. This is what I changed based on a Holden that comes with a 90mm TB. It worked out great. This is an old tune of mine and has other problems, but B4403 is still the same for my current tune (which I don't have on this computer)...

Derrick
405HP_Z06
May 27th, 2008, 05:18 AM
TTT, I'm installing an LS2 90mm TB soon. How did this work out?
jfpilla
May 27th, 2008, 05:43 AM
TTT, I'm installing an LS2 90mm TB soon. How did this work out?

B4403 applies to cable driven TB's, not to fly by wire.
405HP_Z06
May 29th, 2008, 12:42 PM
Jeff,
Any words of wisdom on the FAST 90 and LS2 90mm TB?

Thanks!
Chalky
May 29th, 2008, 02:10 PM
Jeff,
Any words of wisdom on the FAST 90 and LS2 90mm TB?

Thanks!

Bruce Melton tried a number of settings in B4349 and uses some of the settings in his larger build motors. Just my opinion but I left B4349 alone with my 346 FAST 90 and LS2 TB. So far, so good.
TFZ_Z06
May 29th, 2008, 06:10 PM
i was hopin for an answer, but no one has one for me

I put a ported FAST and ported LS2 TB. I had to make ZERO changes, except for WOT tuning. The car will be tested in about 2 weeks. I expect its going to run 10s around 125-126. There was no bad behavior as a result of the change.

The main thing I did was return top end fuel. I hope to get around to looking closer at light throttle, when I do VE later, but with fuel trims at virtually 0, I'm hard pressed to mess with it.

So, the answer is, there are no big changes.
Bruce Melton
May 30th, 2008, 12:06 AM
The FAST and LS2 TB conversion should be easy IF the FAST seals up ok and does not crack or warp. They seem to always need a little tightening till the worst happens--.
I think the newer ones have brass insets in the fastener lugs which may help.

As far as tuning for idle a quick start is a big B4309 (~.0300) but a stock .0255n and a few RAFIGs should fix idle. The B4307 is all you should need for idle. Don't go nuts changing lotsa settings, cause you will chase your tail. It should settle in with just B4307 correctly. (Read from MAF air flow)
Bruce