I just got my car back from the dealer earlier today. They were fixing a small paint chip. Nothing mechanical. Just a little while ago I was going somewhere and got on it and it felt like it was knocking at wot. I turned my rpd to the ignition screen and tried another 2nd gear and 3rd gear run and im seeing 4 deg on knock at wot. Is this normal? I cant remember having any knock before. The motor was fully warmed up and the intake temp was reading 90 deg (normal for S Fla). I dont remember what the mileage was when i turned it in. Im getting the feeling that they might have "driven it more than needed" and then refilled it to the previous fuel level with regular(87), (I use 93)

Im gonna run through the rest of this gas and then refill it to see if it helps, then disconnect the battery if it doesnt

 

I can't answer your question about the knock retard but take a pic of the mileage anytime you drop the car off anywhere. I always do just incase something like that happens.

 

double post

 

Well I looked at the paper they do when u turn it in and at best theres only like 10 miles unaccounted for. So now Im wondering......Would 4 deg of knock make the car feel like its holding back or bogging? If so, maybe ive had this the whole time.

Also the rpd holds pretty steady at 40deg spark advance at wot. Is that the norm?

 

SS/TC's knock from factory. some have seen as much as 6*

 

40 degress at WOT??

 

is that cause of the stock tune?

 

They might have put 87 in. Fill it back up with 93 and see if the KR disappears.

The advance at WOT is 10* max so the RPD is not correct. 4* is alot of knock when you are running 10* or less of advance. It will loose 20-30 whp because of that.

 

What does knock mean? and knock retard can someone please explain this

 

Hmm...well the advance/retard graphic doesnt show what the unit of measure is. Its just says -60,-40,-20,0,20,40,60. It shows 20-30 at normal acceleration and holds 40 at wot. Also the rpd shows my afr at 14.0 at around 3k rpm and tappers off to about 13.0 by 6k rpm, is that normal? Btw I tried another pull on the way home tonight and the KR was showing about 3-4* at 3500rpm and would tapper off to 0* by the time I got to 6k(its about 6* cooler outside now which may help). No cels

Im thinking its in my head cause im always soo afraid the dealer is gonna screw up my car.

 

And why did they have to drive the car 10 miles for a paint chip??? If I really wanted to I could beat the shi...crap out of a car in 10 miles, that could be 10 miles of NLS's for all you know.

 

I figure I would chime in here. I am in the same boat as the OP. when I accelerate hard (doesn't have to be WOT) I will see knock anywhere from 2* to 8* of knock from my interceptors. Now I never get on my vehicle while it is warming up. I do a lot of highway driving and this all happens on the on ramps and when passing. All when the oil is about 200* and the coolant about 190 or so. I don't have any knock just cruising or ***** footing it. Only when I want to get up and go. I am stock other than a K&N drop in filter and a STS which would have nothing to do with my situation. Any insight as to what to do would be great.

edit: Also I only use 93 oct fuel

 

Yes, my car also knocked HORRIBLY from the factory. I'm talking counts between 6-8* during WOT and 2-4* knock during part throttle acceleration. I had to richen up my AFR and actually pull timing in part throttle area's to help correct it.

 

So is there no way around fixing this without an aftermarket tune?

 

An aftermarket tune probably wont fix this, you need to do a lot of trial and error to get rid of all the knock by playing around with the cam and spark tables.

 

Stock tune is to lean and has too much timing in a couple areas. When I tuned getreadytolose's car he had not one single degree of KR at all in the 30 min we spent logging and pulling the crap out of it. That was on the stock IC in 95* weather with my tune in there.

I have timing tables that have no KR at all on 93 octane or 91 octane. Cam tables dont need to be touched to get rid og the KR. It takes me 5 minutes or less to get rid of all KR on these cars. Most of the KR happens at 2500-4000 rpms because the commanded A/F is 0.95 lambda or 13.96 A/F which is way too lean and causes 90% of the KR issues.

 

This isnt just kr at wot, that is easy to take out, its the part throttle kr that is a pita to take. As soon as you tap the throttle its there, at least on my car, even when it was stock it did that.

 

Mine has no such part throttle KR and even if it did I would just make a histogram of KR vs load and rpm and use that to fix the issue. I see no reason to mess with the stock cam tables as they are far better than the 07 Solstice's cam tables. Messed up fuel trims (or a bad O2 sensor) or a motor not warmed up properly are usually to blame for part throttle KR.

 

I have no part throttle KR. Run it dry and try switching gas stations. You never know


Mine has KR from 3k-5k rpm

 

are kr problems common with these cars? what's the best way to get rid of them, kinda scares me cuz i'm fixin to buy one lol... uh? what's a good A/F ratio for these cars? yea 13 is lean anything over 11 is considered lean isn't it?

 

The KR isnt really a problem longevity wise. It just hinders maximum performance but so does the whole tune that these things come with. Im sure all the aftermarket tunes and probly the mythical stage kit will address this.

 

O... Well that's good to hear I guess, I have no clue of anywhere around me that does tuning on these things... But I'm not gonna get one for a while anyway.

 

Did anyone answer this yet? I too would like to learn some more about this?

 

Just to show that it's common

I had 5-6 degrees of knock on stock tune.

None on stage tune.

 

That is suprising given the fact that the PE lambda table still commands the same A/F as the stock tune and your cylinders are seeing more pressure than they were.