baezi z06

iTrader: (2)

Hi

my friends Camaro SS

has a strange problem

he bought a rebuilt motor *short block* from a local guy here

built LS1 348ci set up for nitrous
Custom Nitrous Camshaft 228/230 571/573 LSA 114

Rest of the setup
ETP 215 62cc
FAST 102mm
102 bigmouth
headers
11.1 CP
3200stall
3.73 gears

The car is a good daily driver, it's tuned and sound great
and the mid range TQ is huge
But the problem is it doesn't stand timing, it has to be in the 17-18° in timing so it doesnīt sense Knock Retard in WOT and it doesnīt pull jack **** after 4500 rpms
AFR is 12.5 threw the band, but if you give it more timing it just KR, we tryed give it racegas but it didnīt change anything it just KR if we gave it more timing.
I think it isnīt false knock, because i can get KR out by going down in timing.

the car went at the track like this and it went 13.1@105

So the question is
What can be wrong here ?


could it be
1. the Camshaft is built this way
2. the camshaft is degreed wrong
3. something wrong whith tuning
???

Baezi

01ssreda4

iTrader: (96)

This can be a big problem with the auto cars with aftermarket converters. I would think it was something that should be corrected in the tune. Also, the knock sensors have to be torqued properly for them to read right. Those would be the two things I look at first. The tuning info can be found in the PCM section.

macca33

What are the knock sensor sensitivites set at in the tune? I dunno what OS you are using, but perhaps try to find the original settings for that car / model year and reflash those. If they are stock, decreasing sensitivity - to a point - might be the only remedy.

Are you hearing knock - using a stethoscope / earmufffs, or is it simply showing up KR on the tuning logs?

How aggressive are your KR tables for reducing timing?

Have you got enough fuel flow / injector?

Is there some mechanical issue that is causing false knock?

As you suggest, it may be camshaft related, although camshaft timing would not ordinarily cause knock / trigger knock sensors unless it is WAY out, would it?

Sorry if my queries have already been addressed.

FWIW - my car with those heads and a cam that has higher dynamic compression than the cam your mate has (all the mods in my sig), takes just under 25* timing up top.

Good luck with it.

BTW - great choice in the ETP215s!

cheers

baezi z06

iTrader: (2)

i'll post the tune up

thanks
Baezi

01ssreda4

iTrader: (96)

Its the converter dude

hookngo

Try the converter 1

baezi z06

iTrader: (2)

hi how do i check that ??

Baezi

01ssreda4

iTrader: (96)

I don't remember the process for fixing it in the tune. Thats why I said its in the PCM section. You are gonna need to search around that section until you find one of the threads that tells you how to fix it.

5.3LJimmy

iTrader: (10)

The convertor is a good possibility but it could also be a bad harmonic dampener. What pulley is on the car? I have seen some of the cheap underdrive pulleys cause KR and swapping back to stock fixed it.

baezi z06

iTrader: (2)

SLP UD pulley.

there was some problem whith flexplate, but it is fixed now, but still the KR

baezi