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

gectek

iTrader: (2)

If you can post the tune and a scan (or email them), I am sure alot of us can figure it out.

Where did they locate the knock sensors at? Can you post a pic of that as well.

skimms98

iTrader: (7)

Maybe seafoam the car and see?

baezi z06

iTrader: (2)

knock sensor are in stock location under the intake

here is the tune...


Baezi

pwrtrip75

iTrader: (8)

Do you have another wideband to check and see if yours is accurate? What wideband? How is it tied into the scanning software?
Were you logging 12.5:1 as it did this? Or are you going off of a previous assumption that the car is still running the same AFR as set prior?

Try giving it a little more fuel and see if it makes it better or worse. Ever look at the plugs?

baezi z06

iTrader: (2)

He has single FAST wideband , and i use HPT logging whith output from the sensor.

And offcourse i assume the AFR readings from the sensor is right, i tried to give it 3% more fuel, and it still saw KR.

but plugs havenīt been looked at, they are new. NGK TR55

Baezi

djjonesivs

iTrader: (2)

Those heads are extremeley efficient at getting air into the cylinder.

With my ls2 I have a very similar setup.
Etp 215
236/240 110 cam
11.0 or higher cr

At wot I could only get 19-21* timing
Mind you my cam shaft is alot bigger and less efficient then yours, slightly bigger bore then ls1.

If I were you
I would get her on a dyno and tune it.
The dyno numbers and curves will help a ton.

pwrtrip75

iTrader: (8)

Make a run and shut it down immediately, coast and pull over and pull a plug. Thats what I meant by looking at the plugs.... they will tell you if you are lean. Take a pic of the plug and post it if you are unsure how to read them.

Adding 3% fuel is not much. If you are really at like 14.7:1-15:1 (if WB is not right) or around there 3% wont do ****. I would add more.... little at a time and have someone follow you. Richen it up so they can see a little puff of smoke on acceleration or smell it. Know when your rich and you'll have an idea when your lean so you'll know where your at better.

Im just basing my guess off you're info, no power and knocking... usually its lean as hell. Ive had Widebands lie to me so I know its possible,,., And your story sounds very similar to one I have.

gectek

iTrader: (2)

Use TR6 plugs. That will help. OR if he is running the juice, I would use a recommended plug from Harris Speed Works. They have a huge write up on spark plugs for nitrous somewhere on this forum.

Can you post a scan by chance?

gectek

iTrader: (2)

And what injector is he running? And fuel pump?

gectek

iTrader: (2)

I am assuming you are trying to reach 12.57 commanded and are adding fuel in the maf to compensate?

If you can get me a few logs, I can look at it for you

SSpdDmon

iTrader: (10)

You might also have to replace the knock sensors or the knock sensor harness. I've had some go bad and report a lot of false knock.

gectek

iTrader: (2)

Well alot of times the harness gets pinched in between the intake and the back of the head. But that would normally throw a code. I was just wondering if they were put on the side of the block near something noisy or something that makes alot of vibration.

Def go to at least a TR6 plug in that one. That should help a little, but most of it is prob related to what your WOT readings are and if they are consisent. The best way is to get a scan or 2. You are saying they are 12.5, but what wideband and what offset are you running? Or are you running it through an LM-1/LM-2 then into HPT?