To much Knock

[ttafan]

Ok. I took the TTA for spin today for the first time with the scan tool hooked up. The car is stock except for a drag radials and a chip. The chip is borrowed from a friend that races an 11 sec. GN but swears the chip is a pump gas street chip. After letting the car get up to temp. I hit the gas and kept an eye on the boost and Knock retard. At about 10-11 pounds of boost the knock retard registered 8 deg..... I let out of it fast! I thought I read it wrong. So I tried it again. This time at about 12 pounds it registered 10 deg. wwwoww. I let off again. I am running 93 octane gas with JB octane boost. The car seems to run smooth and fast, but I'm affraid to crack into it because at such a low boost it's already way to much knock. I thought that knock was caused by to much boost. 12 pounds is not alot of boost. Am I missing something? Please help. What could be causing this condition. Thanks.

 

[72firebird]

well it depends on what injectors the chip is made for. I mean if it's made for like 50 lbs injectores the duty cycle on those injectors is going to be much less than lets say 36 lbs in order to supply the same fuel. So the pulse width on the chip is too short for the injectors that you have and not supplying enough fuel thus causing knock. That would be my guess. Does it run fine with the stock chip?

 

[3.8TransAM]

What works on a GN for a chip doesnt quite work the same way on a TTA.

The motors are similair, but not the same.

Even comparing stock to stock binaries there are huge differences. Quite a bit of difference in head flow and chamber design alone.

Just something of note I wanted to pass on.

Find a vendor who deals with the TTA's and work with him.

I would recommend turbotweak aka eric marshall, seems to be a good guy and I've spent some time talking to him about tuning at length.

later
Jeremy

 

[ttafan]

Thanks guys. I'm gonna' dump the chip and run the stock one till I get bigger injectors. Learn something new every day!