Here is a run down of the car..

Evo8
Stock Block
Stock Head (Headbolts)
AMS35
1000ccs
4" IC
HKS280s
34psi pump gas.
Self tuned.

This happens at the track and is killing my MPH. As soon as I shift into 4th, the knock instantly romps up as high as 12 counts all through 4th...

No knock in any of my other gears. 34psi, about 340-360 load, 0 counts of knock AFRS- 11.2-11.3s

I thought at first that it was my fmic, so I upgraded to a garret core. I thought the IC was heatsoaking.

I do not have an IAT sensor.

Another thing that I may be thinking it could be is my Greddy Type S opening up in 4th gear and blowing hot air into my turbo?

I even tried lowering the boost to about 30psi, and it seems like it does the same thing.

Any idea or inputs would be awesome!

 

A log would be helpful

 

if youre tuning for the same timing in 4th as you are in 3rd thats your mistake. 4th gear will use higher load so you can tune 4th gear separately.. and most of the time it will not want the same timing as 3rd gear.

 

I will post a log later on tonight. Work computer FTL

The load in 4th is not that significantly greater then 3rd gear. I have even tried lowering the timing to about 4 degrees up top...

 

Here is one of my logs from the track. My wideband stopped working after my first run.

 

I have this same issue, did u manage to sort it?