2+2

Dont discount potential cat/piping issues as it can restrict exhaust flow and thus, restrict boost. I am told that if you clamp the signal to the wastegate, you should be able to boost really high unless you are clogged in which case, it will not make a difference. Of course, this should be done very carefully to not overboost.....keep us posted on what you find.... good luck!

alpenweissisnice

Started at idle at about 12.5 to 1; bottomed out rich at to about 10.25:1 at around 3250 and started climbing back up to finish out at 11.5 :1 at redline...Bottom line, I want another dyno run to see what happens...

Ski

That's pretty rich, even at idle - which should be around 14.5 - 14.7-9, sort of dithering in between.

I think if you get that ratio leaned out a bit in the midrange, and try to end up around 12.3 - 12.5-7 at redline, you'll see that hp that is missing.

What fuel pressure are you running? Do you have a 3 bar reg or AFPR or stock?

That is a good point on the exhaust from the above post. This is sort of silly but I have the old factory muffler that I can put on my SFR exhaust on the back (when my wife and I take the car out and it shouldn't be too loud), anyway I've noticed on boost a couple of times that it runs more rich than normal.

alpenweissisnice

Looking at the chart, idle AFM is actually about 13.2:1 on the Steve R chips. On the STOCK chips, it is about 12.5:1...

As for the FPR, I am running stock...Could I have a fuel filter that may be not as efficient as it should be?

toddk911

Weak wastegate and clogged cat make a HUGE difference. I just recently took cat out and put in test pipe. When held to the light I could only see about a 1/2 inch circle of light through it. Most of the insides were clogged bad. That is like puting a cork in your exhaust!!! Heavy back pressure amplifies turbo lag and robs at least 1-2 psi of boost.

Then you add in a weak wastegate and you got an even bigger performance hog. Even shimmed only helps it, does not fix the problem. Get the cat out and new wastegate or GURU now has rebuilt wastegates for a ggod price.

alpenweissisnice

I do have an SFR catback and am considering a test pipe or a high flow sport cat...I don't have to pass emissions here; however, I am open to either based on price and performance. Comments?

Ski

You could take the cat pipe off, get a 31" wrecking(crow) bar, a five pound shop hammer, and then spend about 2hrs beating the guts out of it. The ceramic(or whatever it is) stuff comes out pretty easy; it's getting the steel wool out that is a PITA.

2+2

Alpine...since you already have a 3"catback and you have no emissions test, I would suggest a 3" testpipe...it will get you faster spool up and about 1-2psi of boost......

alpenweissisnice

Since I did a smoke test and all seemed to go fine, I am going to go with the clogged cat theory...Perhaps it is a wastegate issue, but one thing at a time...SO...Let's talk test pipes.

SFR? Been happy with exhaust, so that's my first thought. I know Bursch makes one for less money...Huntley? Comments? Suggestions? Thanks!

Ski

SFR, you did it right the first time on the cat back, do it right the second time around too.

alpenweissisnice

SFR 3" test pipe going on tomorrow...I'll then set up a dyno day and report back. I will report back on how clogged/not clogged my cat is after it comes off. We'll see if that is the culprit. If not, on to a new wastegate...LOL

2+2

Actually, I don't think you can see into the cat....it has a bend so you cant see into it....Just think of it this way....people say that a cat bypass is one of the best upgrades you can make and since you dont have a sniffer test, it was money well spent!!

alpenweissisnice

I was going to sawzall through the old cat and see what I came up with. I'll also post dyno results...Thanks !

Flight_951

I just installed a 3" test pipe with hi-flow cat from SFR this morning. (I have the SFR cat-back already. ) Noticeable difference in performance and sound too. My stock cat was inoperable and partially clogged. On deck: Emissions test... I failed bad a couple weeks ago.

alpenweissisnice

While it was evening traffic and didn't really get a chance to play, the "butt dyno" tells me that the car is definitely quicker with the SFR test pipe. I'm know running three inch stainless from the down pipe to the muffler and out. You can really hear the turbo spool, which is...pretty cool. As for my old cat, I have not started the dissassembly process yet to see what is in there. We'll see..I hope to dyno the car in a week or two...I'll report back. Then on to the wastegate...