Knock!?

[Zarco]

well, i have done a couple of logs before this one at 15psi on my 16g(stock fuel,91oct.) and i went to take a full pull in 2nd..... i hit 9.6????? i use mmcd....is this counts of knock or voltage? anyone know.......... thanks fellas, and i didnot turn up the boost at all to do this log, it was really wierd that i got knock on this pull.... as i JUST boosted before doing this next pull........... no visable leaks, any suggestions for what may have caused this?.... thanks, marco

[Dallas J]

With a stock IC and injectors i could run 1.3 bar on my 16g, which is about 19psi. The injectors were at 100% duty cycle, then I leaned it out and got it to about 90%, but then their wasnt enough cooling to keep the knock at bay. This was all on 91octane.

What are you logging with? What is you injector duty cycle at?

-Dallas J

[Zarco]

mmcd on a m100, and they are at 66%....i hear 85% is pushing it......the car didnt knock at all on the logs before...kind of weird:(

[Zarco]

o ya... and on this run my boost went down from 15 to 11...... with 8 count/voltage?not sure which it is......i turned up the boost....and i knoecked 9.6....thanks guys im all ears on this one

[Dallas J]

If you fell off at only 15psi then you have to have a major leak somewhere. I held 19psi to redline fine in colorado. 66% seems pretty low to me. I dont think 15psi and 19psi would have that big of a difference between injector pulse width.

Either way, find out why youre falling off.

-Dallas J

[Zarco]

i have a nice size crack in my manifold....could it be from this>? and i didnt switch out the exhaust housing from the turbo when i switched out for the 16g, im sure like most other stock ones its cracked..........could either of these be it? thanks

[Dallas J]

A cracked mani can cause you to run rich cause the o2 sensor see's more air than it normally would, and could slow the spool a little, but thats about all it should effect. YOu shouldnt fall off from 15psi with just a cracked mani unless it was huge. You need to see where you have an intake leak.

On a side note, I have a 2g mani I could sell ya. Contact me off list if youre interested.


-Dallas J