I have been running the GT500 t/b for a few months now and you can get by without a retune but it does make some dead spots at times by not having the correct values loaded for it. it's nowhere near the issues others have experienced using aftermarket t/b's but you should still have a retune just to get the correct values loaded.
There is very little to gain on N/A cars with this mod anyway. I imagine a KB,whipple or saleen s/c car would see decent gains making it worth the expense to purchase install and retune for this item.
FYI on a simple at track mod:
Power Steering Delete Belt= No reflash

 

I was just about to ask that very question on a few of those. Thanks for this post - definitly a bookmark.

 

Great write up and info, thanks!

 

Gonna shamelessly bump this back up again.. noticing alot of mis-information running about about tunes and what does and doesn't need them...

 

Do shorty heads need tune?

 

Awesome post. Mentioned some stuff I havent even thought about :P.

 

Bravo! Bravo! Sticky!

 

Repaired a couple of the posts as requested . Seems like something chopped a couple of the topics off, maybe during one of the crashes

 

Nice work GT Bob! I'm curious what the other small things are that a gear change on a manual affects?

 

What about a T/C?