Hey guys, I have GM Stage 2, 2.8" pulley, and Injen CAI. I am getting knock at the top of my RPM band. It's about 2-5 degrees when at WOT. Before joining this forum I knew nothing about KR or AFR. I only know a little now. Whats going on with this knock? How can I get rid of it?

Also, I'm always paranoid that I'm running lean, and slowly damaging my car. Would I get a CEL if I was lean? Is there anything I should be worried about?

Thanks for your input

 

Jim I really appreciate your advice. I am running the GM 2 tune. I do not have any tuning available to me, and I can't afford, nor have the knowledge for HP Tuners. I use 93 octane gas only. I think I am going to put my 3.0" pulley back on for now, and deal with this stuff in the spring. I just don't have the $$ right now to buy any more parts.

 

run the 3" for a bit and see if the knock goes away...I'm curious

 

the gm tune is almost being maxed out on the 3 ...there is no way in hell i would run a 2.8 in the winter months

 

how do you know you are getting kr (interceptor??) recommend get a wideband to monitor af ratio.

 

2.8 is pretty small for the 42lb injectors. Some areas people can get away with it others people cant. I would try the 3 or 2.9 and see what happens.

 

Ok so for us guys in Canada, it wouldnt be smart to run with the 2.8 pulley in the winter ?? Or is there something else we can add so that the 2.8 pulley can stay on ???

(bare with me I'm new to this )

 

You can run a 2.8 pulley. However if you are not providing enough fuel and a too aggressive tune that is where your going to run into trouble. Personally I dont like to see people run 2.8's with 42lb injectors. However this has been a never ending debate in here. I like to run a safe tune and not run the tune to the very edge. While yea its more fun at the time in the long run it could mean a empty wallet. Do it once and do it right.

 

oh ok, good to know. Any idea on a rough cost for a set of 60lb injectors?? And will 93 octane fuel be enough ?

 

check that... will 91 octane be enough. Im running that Shell V-Power stuff

 

yea i'm reading the KR from my interceptor. i want an AEM eugo but cant afford one right now

i get an airflow reading from the interceptor... i don't know how accurate or helpful it is though

i will put the 3.0" back on tomorrow and let u guys know if the knock is still there

 

we are ok up hear in calgary at 3500 feet running the 2.8" pulley on the stage II as for the 60# injectors you can't just put them in. You need to get the car tuned.if not the car won't idle then stalls and now it is flooded. without the tune.

 

OHHHH ok thanks! Ya I didnt know that, thanks for the info!
Still learning all this stuff