Old TT chip, stk inj, to 42.5#inj and new TT chip - Retard issue ?

[TBlaze]

Hi Guys,


I sent Eric a message last night, however I wanted to see if anyone either might know or what I should be looking for. Car is pretty much stock except has a K&N, 160 stat, no cat, hooker duals and ran great.

No problems with using the stock injectors and TT 5.6 chip. 28# Street 93, 20-18* & 15-17psi. No knock at all, all 0.0 on SM.


Then I changed to the 42.5# inj and a new TT 5.7 chip using 42#inj, street 93, 20-18* & 16-18psi.

Car had knock retard, si I pulled -2.2* from setting 3 + 4 and decreased boost to a confirmed 14.7psi and still have slight knock, 2.1*

02 reading on SM at retard was 815 while adding 10% more fuel at WOT, just to see if that helped.

Open to any suggestions or thoughts.

Thanks guys.

 

[87-WE2]

Hi Guys,

I sent Eric a message last night, however I wanted to see if anyone either might know or what I should be looking for. Car is pretty much stock except has a K&N, 160 stat, no cat, hooker duals and ran great.

No problems with using the stock injectors and TT 5.6 chip. 28# Street 93, 20-18* & 15-17psi. No knock at all, all 0.0 on SM.

Then I changed to the 42.5# inj and a new TT 5.7 chip using 42#inj, street 93, 20-18* & 16-18psi.

Car had knock retard, si I pulled -2.2* from setting 3 + 4 and decreased boost to a confirmed 14.7psi and still have slight knock, 2.1*

02 reading on SM at retard was 815 while adding 10% more fuel at WOT, just to see if that helped.

Open to any suggestions or thoughts.

Thanks guys.

I would wait for a response from eric first.

There is a possibility it could be rich knock. I had the same problem when i got my chip and inj combo from turbotweak. I had never heard of this before, but a well-respected member (might've been Grumpy but not sure) mentioned The possibility of rich knock. Anyway, i started trimming fuel out and the knock eventually disappeared. My O2's at WOT were running around 770's which i thought was a little low, but there was zero KR. I have seen many say that 800 is just a rule of thumb number and not gospel. Be careul about trimming fuel; if you see your kr climb, get outta the gas and put the fuel back in.

I must say i'm no tuning expert, and my experiences may not necessarily be what your car needs. Every one is different. I'm just saying rich knock is a possibility to consider. I fiddled with mine for months and got lost along the way with changing fuel and timing. I ended up starting over completely, left the timing alone and upped the fuel a little at a time. My chip settings finally landed on zero change in either timing setting, and 5.1% (i think) increase in WOT fuel. I evidently had WAY overshot the fuel increase that i needed.