KR Help!!

[2001GTP]

First off here are my current mods..... 3.4", 180 t-stat, 104s(new), 2.5 catted DP with u-bend and resonator delete, P-log, Custom DHP PCM. Anyways with the "standard" DHP PCM I was hitting as high as 10 degrees of KR. I know!!! So we dropped the timing back to stock. Still seeing as high as 6 degrees of KR. Added 10% more fueling and still getting bad KR. The IPWs are high as hell, 18 to 19 and the IDCs are as high as 90. Basically my injectors are maxed out if not beyond some. I replaced the front O2 to no avail. My LTFTs are around 7 and O2s are 900 to 910. I'm buying a wideband tomorrow and haven't gotten around to check fuel pressure yet. I guess I'm just looking for any ideas on what things to check. Thanks!

[OH4CompG]

Wow, that's a LOT of kr for that setup. Why didn't you get the 3 inch dp? 2.5 are great for n/a. If you can figure it out soon get that pulley off of there until you find out what's going on.

[TheOtherNick]

See what your a/f is with the wideband. You want to shoot for about 11.5. Do you have a mps or press on pulley. I would bump up the pulley size until you can figure out your tune. Also drop some timing out to help take out the knock.

[2001GTP]

Timing is back at stock. Its a press on pulley. I don't think its in the tune because my guy who tunes loaded the fueling tables basically as much as he could. Also it has a brand new fuel filter. I'm just hoping its a tired fuel pump. Also, the car isn't going to be driven until its figured out.

[TheOtherNick]

Pull timing further than stock. If it is still knocking. You pull timing until the car stops knocking. Loading the fuel tables it not the proper way to do it either.

[2001GTP]

I understand pulling the timing even more. I'm just curious as to why with my setup I am getting such bad KR. Is there something I'm missing?

[TheOtherNick]

I am knocking with my mods too. I bet it is something in the tune or there is carbon built up in a cylinder and is creating a hot spot for knock.

[Bio248]

when are you knocking? how far has he pushed the thresholds for the transmission so that it doesnt pull timing (knock) when youre on it hard?

i also believe you need a little more flow action (bigger downpipe).

[a98gtp4u]

get a 3 inch downpipe. 2.5 is basicley stock since the stock downpipes r double walled on the inside at 2.5, even tho u deleted the ubend and res.

[blueguy]

screw that DP story...get headers

[TheOtherNick]

x2 headers FTW

[BoostJunki3]

screw that DP story...get headers

[Lsick7]

screw that DP story...get headers

Agreed. If money is an issue check out ssautochrome headers for $350. Great replicas of slps.

[PonchoDvr4Lfe]

Anyways... now that all of you people plugging headers over his current set-up are done.

Is there anything you can think of that may be giving you false knock?

[FoSHO99]

Anyways... now that all of you people plugging headers over his current set-up are done.

Is there anything you can think of that may be giving you false knock?

Running a 3.4 pulley with a 2.5" dp is going to give you most of the KR he sees, headers are optimal on a 3.4 setup. The other KR is from running a car without much of a tune. Open the exhaust a little more and then get your tune figured out...

[DanGTP]

I'm thinking you have low fuel pressure if you're getting that high of an IDC with a 3.4 pulley.
Your LTFT's should be pretty darn close to 0. That can cause a bit of KR even if the NB fueling looks good.
Check the fuel pressure and let us know what you get?

[blueguy]

Like I had said...it isn't a plug Poncho...7* of KR is no joke. Headers are one of the BEST ways to kill KR. If it is false...it might be the downpipe making contact with the sway bar or the motor mounts might be shot causing the contact.

[PonchoDvr4Lfe]

Running a 3.4 pulley with a 2.5" dp is going to give you most of the KR he sees, headers are optimal on a 3.4 setup. The other KR is from running a car without much of a tune. Open the exhaust a little more and then get your tune figured out...

I agree that he could use headers, but I don't see the point of everytime there is an KR or exhaust question there is one person who says headers and then everyone on the forum smells it and comes along agreeing with the headers. Thats all I am saying...

[2001GTP]

Fuel pressure is 48 with key on. 40 when idling. It built kind of slow with the key on only test. I think I'm gonna get a racetronics pump and new 3" DP.

[Bio248]

you have to see if its dropping on the top end to tell if youre running out of fuel. how are the fuel trims? WHEN is it knocking (top end? mid range? at the shift? etc.)? how much timing do you consider "stock"?

im thinking the culprit is a crappy tune, then the downpipe, then your car being the opposite of a freak.