You should shoot for 20-21psi on 93oct for daily driving. As for the stuttering, I'm not sure, but you should probably buy a cheap set of copper NGK BPR7ES plugs ($1.40/each) at your local Autozone or Advanced Auto and slap those in. Go drive around and do some WOT pulls. If the stuttering doesn't go away, then we can do some more troubleshooting.

1) Turn your boost down to 20-21 at WOT in 3rd gear.

2) Try a fresh set of plugs.

 

Also, doesnt the xede prevent knocking? I'm 99% sure it does. I know my car is fast, very fast but I'm sure that I can get a bit more from my mods.

 

Not on 93 and 24psi.

He does not know everything, but he is correct here.
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Part of your problem is that your mods are sporadic and random. Someone needs to take you in and show you the way

There is a staged upgrade list in my sig. I would start by reviewing it. You will find a fuel pressure regulator no where on the list. Follow along the mods list and you will be in good shape.

 

Go one step colder on the plugs for higher boost. 94 oct. I am right cause I have it on my car for 2 years. Repeat 2 yrs. Don't believe all you read here. Ask any reputable tuner

 

Uhm, no. Knock tells the ECU that something bad is happening, which allows it to then pull timing so that you don't destroy your engine. If the Xede "prevented knock," then you'd just blow your engine when running with unsafe conditions. The Xede is a tuning device that allows you to make more power with optimum conditions in the hopes of reducing or eliminating knock, but it doesn't magically prevent knock.

If you are running too much boost on pump gas, then you will cause knock. I don't think you "know" your car is fast or very fast, regardless of how it feels. You would need to get on a dyno and/or go to the drag strip to prove that it's "fast," because the butt dyno is not accurate.

 

Yeah, ok. You obviously don't do your own tuning or logging...

 

So 20-21 for daily but what about when action starts? I changed plugs months ago. This stuttering started last week. I'll change again tomorrow and report. I'm also going to look at my injectors and filter.

 

Did I mention anywhere that I did ? Roll your eyes some where else

 

When the action starts? If you turn up your boost, you will make less power. There is no reason to turn up your boost unless you run race gas or install alcohol injection.

What plugs did you get? Did you make sure they were gapped properly between .24-.26? Did they get fouled already? Copper NGKs only last a short time, so if that's what you got, they may have fouled. There should be no reason to check injectors or "filter."

 

Do you have your ECU xflashed to remove the fuel cut and raise the rev limit? If not, you are going to have issues like you describe. Also if your running an off-the-shelf map from Vishnus' site its not properly tuned for your intake and injectors.

 

There is a good chance your plugs are bad from running 24 psi on the pump gas and detonating. 20 - 21 psi is the range you want to stay in with proper tuning per Warrtalon's recommendation.

 

Agreed!! Most of what I do on my own is guessing. I've about 2-3 years bracket racing behind me. What I've done is set up markers and continue to measure performance using the markers. For instance, I roll of the line and run my full 180kmh speedo abt a sec before the 1/4 marker. LAst year, my speedo was at 172-175 for the same distance. Bush tuning but I'll soon unveil. Till then I'm keeping everything too myself.

By the way, keep your comments coming guys. I'm learning lots here. I'll lower my boost now and go test.

 

I didn't say that you claimed to do your own tuning. My point, which you missed, was that you don't do your own tuning, which means you don't have a clue what you're talking about. You don't know what your AFRs are at WOT in 3rd gear from 4k-7.5k, nor do you know what your timing curve looks like. If you would log your own 24psi WOT pull in 3rd, you'd learn what knock is...

 

wartalon is correct if you use to much boost on pump gas you will stutter and you may ruin your motor, he knows a lot i have read a lot of forums and also what country are you in??
what kind of evo do you have??

 

also does you car throw a cell when it stutters?? you should check that??