robul

iTrader: (1)

I bought this cam a while back when I was spraying my car and it worked great.. Now I have a twin turbo kit on my GTO and I am having a problem with knock. I have taken out all kinds of timing and boost and I still get a tad bit of knock at WOT as well as partial throttle sometimes.. I was told to mabye talk to some turbo cam guru's because my cam may be buidling too much cyl pressure.. I did the math and the cam and If I did it right it should = about -1 overlap . But I am far from a cam expert so please chime in if you have any suggestions..

I do plan on changing the cam out when I build a new low compression motor but hoped this would be fine until then..

Specs on the cam
Comp Xer
220/224 581/581 112 lsa 108 icl

The car makes good power when it doesnt knock. I dynod the car the other day on a dynomite dyno at 9 psi it make 571 rwhp @ 630 tq This is with 12 degrees of timing and about 12.00 a/f accross the board..

Thanks in advance..

DeltaT

iTrader: (5)

No, the cam should be fine. What kind of exhaust manifolds are you running?

12.0 AFR is right on the ragged edge. I'd try some tuning around 11.4 if you are having knock issues.

I would also look to get a meth kit. That should clear up your knock problems and allow you to add back in some timing, if lowering your current AFR doesn't do it first.

Jim

robul

iTrader: (1)

I have a cooling mist meth kit with the vari cool controller sitting here on my shelf.. I will isntall it sometime next week. Its never a ton of knock less than a degree but its something so I need to take care of it.. I will richen it up a tad and see if that helps before I put the meth kit on.. thanks for your input..

I have the Gen TTR twin turbo kit from australia it uses the stock manifolds.. This is on a GTO

cablebandit

iTrader: (37)

that shouldnt knock...still got pcv hooked up like stock?

robul

iTrader: (1)

nope.. its totally blocked off I have a metco breather cap on the valve cover..

RAACCR

That's not a bad turbo cam. Retarding it 2 - 4 degrees would make it even better.

RooRnZ28

iTrader: (14)

thats almost like my turbo cam, but mine is a rear mount...

NA$TY-TA

iTrader: (21)

Damn Robbie i didnt know u were running it that lean..... wish u would of told me that.....
At WOT im never over 11.5:1
Add some fuel in there and let us know what she does...

Kyle

robul

iTrader: (1)

well.. I do normally run it around town on about 11.00-11.50 It was knocking then as well.. I just leaned it out a bit for the dyno.. I went ahead and added fuel to the 110+ KPA ranges on the ve. I also took the timing down to 11 degrees.. I will drive it around later and see if the knock is still there..

Could it be possible that my stock cat back is soo restrictive that could make it knock? I am gonna have a dual 3" fabbed soon the problem is just finding somebody where I live to do a good job.. kyle can attest to that..

SS2win

iTrader: (11)

that engine's fighting to breath with a stock cat back...

EPP

iTrader: (22)

If you're getting oil into the cylinders, it can knock also. It may be your ventilation system. Bob

robul

iTrader: (1)

yeah I defiantly figured that.. but is it possible with all 4 ports block off? is there any other way for it to suck oil into the engine?