Oft

[John27]

is it okay to run stage 2 uel with catted header ?

[Teseo]

Originally Posted by John27

is it okay to run stage 2 uel with catted header ?

No

[John27]

why not

[Teseo]

Originally Posted by John27

why not

Read
http://www.ft86club.com/forums/showthread.php?t=81493

[Tor]

Originally Posted by John27

is it okay to run stage 2 uel with catted header ?

The only differences are valve timing, ignition timing and MAF scaling. What you really don't want is the ignition timing increase.

If you are willing to put in some work, and assuming your header is an UEL catted header, you could copy the stg 2 UEL AVCS safe tables to your stg 1 tune.

Idealy, you would do Virtual Dyno runs before and after to see if they make a positive difference or not. You would of course need to monitor for knock as well.

If you increase the AVCS Base/Normal/safe Hysteresis to "safe above" 0.9, it will switch from the safe tables to the normal tables in case your IAM drops for a bit of extra safety. So just leave the normal tables as they are.

There is nothing preventing you from using parts of the tables either. Let's say it knocks below 4400 rpm with the stg 2 tables, but not above. Then you could use stg 2 from 4400 rpm and up. Or vice versa. Of course it would need to make sense the way it blends into the table and it should provide a benefit in terms of performance increase.

In either case, you would thereafter concentrate on getting the fueling right and finish of with adjusting ignition timing up as much as you can toward the stg 2 timing.

[steve99]

Or you could ask shiv at openflash for the V3 tunes their is specific tunes for catted header in those they used the ft86speed factory header I believe on the test car

[John27]

okay ty