Tuning For 427/L76/90mm TB?

[VortechC5]

My 427 is finally getting installed next week. I know that I will need to modify the IFR for the new injectors and bump the cylinder volume up for the cid increase from 347 to 427.

I Autotuned my current VE table for my current combo. Should I my current VE table up by 24% (to account for the displacement increase) and Autotune from there?

How about idle (and other) tuning specifically for the 90mm throttle body? Is there anything special that I need to do? Any tips are appreciated.

The 427 specs are in my sig.

[tazinhawaii]

I too have a 427. The things I learned when tuning it are :

Don't increase the VE's just because it's a 427. Ve's are a percentage efficiency. All you need to do is tell the computer the new cylinder volume which is used in the equation with the VE value to determine the air going into the motor. You will though probably have to change the VE table a bunch due to the new setup.

For me, the 90mm TB was the hardest part of the tuning.. Until someone mentioned a Holden came with a 90mm TB from the factory. I found that tune (from the site that has all the holden tunes on it - can't remember where now) and copied the MAF calibration from it. That solve about half of my drivability problems.

A recent tune for my setup is attached for you to use as you deem necessary, but mine is for a twin turbo setup and COS 3 version.

Derrick

[VortechC5]

Thanks! You don't remember which Holden file you used do you? Did you get it from holdencrazy.com?

Mark

[tazinhawaii]

I'm pretty sure it was holdencrazy.com. I don't remember which tune it was though. I found the info on here though, so you may be able to do a search and find the info.

Derrick