Nuke

Tunes are written by companies or individuals that hold the software license that allows them access to the numerous tables of data our engines today use to run. Based on what mods you have, they'll write your tune for your PCM and mod requirements. Those tunes are either pre-loaded into the handheld or you load them from your computer (you can have your tunes e-mailed to you) into your handheld and then into your PCM. The handheld only allows the owner to change a few basic things beyond those changes from the tune, like tire RPM's, gears, timing, rev limiter, speed limiter and a few others.

It's also good to know that a custom 87 octane tune will usually run circles around a stock 87 tune.

JIM5.0

Good point Nuke. And the 87 octane tune will also in many cases get you a tad bit better avg MPG too, at least from what I observed.

When I ordered 3 tunes with my purchase of a hand-held flash tuner, I made sure to get the street tune in 87 octane for DD, emissions, and fuel economy. The performance increase was only a bonus.
I say you should always have an 87 octane tune just in case. You never know that when you leave your area, if 93 octane will be available. Some states do not even have 93 octane gasolines. (They have a max of 91 octane.) The 87octane tune will help ensure you dont knock your engine like a ball peen hammer.

grnbayfan

my question is what does the tune do to the auto ? how does it change the shift points in it?

daredevil95

I attached a write-up from Pontiac High Performance. I know we are talking about Fords but, the principles are the same. I thought this is an excellent article. If you search the internet you may find application specific trans or maybe someone has a Ford tranny tech manual.

http://www.highperformancepontiac.co...ing/index.html

grnbayfan

awesome. thanks for that. im just wondering how different a tuned auto feels versus a stock tuned one?

daredevil95

It would depend on how "all out race" the tuned auto is? For the most part it's heavy duty parts in the race tranny that could take extreme torture.

The firmness/quickness of the shifts should be similar when comparing your average race track & modified street tranny. The converter stall speeds will be very noticeable....and well worth it on a street tranny....2500rpm seems to work good from the cars I've been in.