Hey Guys,

Is it normal for my car to have more KR with a modded pcm as opposed to a stock one? My car is basically stock except for a ZZP PCM, Gutted airbox w/ K&N filter, 605 plugs and 180 T-stat. The pcm has been on for over a week and I have more KR when I "get on it" than with the stock pcm I have a 3" catless DP coming to me. Hopefully that helps with the KR.

The timing is increased, so i can see this happening. I was not happy with my ZZP PCM. The downpipe will help out a lot. A cone filter will help too.

x2. I've heard bad things about their PCM's. get rid of that ubend and put an open cone to let the motor breathe, it will help alot.

The DP is a catless bolt-on so it will have the ubend deleted. I was "trying" my best to keep this car stock. But I guess I'm just trying to make it more fuel efficient, yeah right!

anything that helps the motor breath, intake or exhaust, increases MPG. the bigger dp and intake will improve MPG.

negative. more air = more fuel = less mpg.

Actually the easier it breathes the more "efficient" the motor is. More bang for the buck. Requires fewer RPMs. My open cone netted me a 2mpg gain.

Theoretically, the high velocity TB I ordered should improve MPG too, right? That's kinda what I was assuming, not that it makes much difference.

easier it breathes the better it is.

Well part of the reason your getting more knock is because the ZZP is tuned for a mildly modded car,for an out of the box pcm ZZP's are not bad but from what most guys say if you have no way of tuning try Overkill's PCM he apparently tunes a little more individual than the others generic type tunes,What specifically did you want tuned out of your stock PCM?

I like the quicker shifts the modded pcm gives..along with the other benefits like speed limiter removal, fan turn-on etc.

my 97 still just flashes 199 (km). so after that I dk how fast i'm going.

You can get PCMs with stock timing.
DP should just about solve your problem, though.

How much louder will that catless DP make my car sound? I still have the stock resonator and mufflers.

Luis

A bit louder. Tone will sound a little more raw. I like the idle much better. I won't even mention full throttle sound since most of us know it sounds crappy.

*update* Installed the 3" catless DP and it's hardly noticeable. Like zuulmusic said, it's more "raw". Sounds nice.

Did the DP help with KR?

Well after a few days of driving with the DP, I've decided to remove the ZZP pcm for the stock one. Not sure why but the DP didn't help much with my KR. I was getting between 4-5*. Took it out for a test with the stock pcm a few times and my car hardly has any KR now. The only drawback is the coolant temps are now a little higher than before.

And here I was thinking that 4-5* KR is acceptable. That being said, I understand any KR is a performance-killer. I, for one, woulda kept the tune, but thats me. Glad you're happy with the exh note, though.

Get's great MPG also.

4-5 degrees on a stock car is fine. When you start dropping pulleys, the knock becomes more of a problem.

4 degrees of knock with a 3.0 pulley is a LOT worse than 4 degrees of knock with a 3.8 pulley