Originally Posted by
Epstein
I wonder about tuning though. NA KA ECU programming jumps to the last column under WOT. It'll fuel correctly, but it'll run the same amount of timing as it would with the crappy stock exhaust. The difference is you'll have much better flow (and therefore higher cylinder pressures) from very much decreased back pressure. Technically you need to run less timing like that, but it's all relative. The stock timing curves are conservative. Run 93 and rock out. Those things have knock sensors for a reason anyways, and they work out to redline unlike the DET ECU tuning.
personal experience,
I was running 93 octane and had my timing pretty much as advanced as you could get it. (it was a pretty healthy/clean engine as I've not been able to get the same results on other engines)
I was getting on it pretty good, not wide open, but still beating on it pretty good, hit a bump and my crap exhaust, broke off. just before the cat. So it was header, down pipe, that's it.
Loud doesn't begin to describe it. It shook the whole car.
From a performance stand point though, it seemed to really take off. It was a significant difference. Comparable to driving with retarded timing, then suddenly switching to advanced. Enough to notice when it happens, but not enough to think your car is faster the next day. Make sense?
Being the dick that I was at the time, I left it like that for a few days. It drove with a little more spirit. Rev matching was much easier as the rpms felt like they "wanted to go up"
Didn't notice any WOT differences. other than the mind melting volume.
I put a tank of gas through it like that, and even though I was beating on it a little bit more than usual, I got the same gas mileage.
I also had full interior in that car and didn't notice the floor board getting any warmer than usual.
Don't know how any of that compares to the "ideal" as far as tuning goes. That was just my personal experience with it.
from that, I would say it might make it a bit easier to drift around on. Like I said, it "felt" like the rpm's "wanted to go higher"
Run 93 octane
with stock timing, you shouldn't have any problems.
If you want to run it advanced, then make sure you're nice and hot, then advance it a little bit at a time. You'll detonate just free revving it before driving on it. When you do, back it down some, and call it even. Not the most precise way of doing it, but it has worked for me so far.
Also, I have taken a big blanket and balled it up in front of the radiator when doing this to get the temp a bit higher than usual, to sort of simulate the higher temps you get when you're beating on it.
It has always worked for me, can't promise it will work for you.