Knock in third only (DSMLink)!

[Nexius]

Ok so I went to the track last saturday and I had severe knock in third gear only. I tuned my car the week before with 0 knock and all of the sudden it started to knock. I'm running 20 PSI, 16G, 680cc injectors, 255hp with rewire, stock sidemount, DSMLink, BPR7ES, 94octane.
Intake temps where around 90F (at the MAS), .96-.98v O2, timing was great in 1,2,4th gear.

Now I started to pull timing to eliminate knock (which wasn't there before) and I'm up to 3 degrees and still some knock.

Any ideas why this is happening ?

Thanks for your help.

 

[QuickerDSM]

Just a guess, but it could be your stock sidemount is getting heat soaked. By third gear it's not able to cool the charge enough, especially at 20psi I'm facing the same problem right now with only 15psi. First and second is perfect, 0 knock w/about 19deg timing. Third gear starts with 3 counts of knock and steadily rises to about 13, pulling timing as it goes......

New piping and fmic is in my future.... Along with a new head gasket and ARP studs ....

Mike

 

[hostile]

Mine did pretty much the same thing, on my 14b I could run as much boost I wanted in first or second gear, but during the last part of the quarter mile knock was everywhere.

Either put in some good gas at the track, turn down the boost, or slap on a supra side mount.

I bought the supra side mount, but I would still like to run the car on race gas next time I goto the track.

 

[kpt4321]

It is likely heat soaking of the SMIC, combined with the higher load in third gear.


....Kyle T.

 

[MaineDSM]

My stock sidemount does the same thing, heatsoaks by the time I reach 3rd gear. I can't explain you not getting knock in 4th, that's just strange.

My car: 2G AWD, T28/28, 20psi, DSMLink, 100octane race gas.

I'm debating on getting a bigger intercooler, getting a bigger turbo, or just waiting and getting both.

Some people don't have these problems. There is one local guy who just ran a 12.3 with a stock 2G sidemount and a 16G. Every car is different, I guess.

 

[Violater101]

I had major issues on my car with a bigger fuel pump before I installed a AFPR (was overunning the stock FPR). Since you said you weren't having these problems before, I doubt that is your problem. 96-.98V's seems to be a bit rich. I think you want to shoot for more around .92. There is no real way of knowing unless you have a wideband O2. WHen you tuned the car before, was it the same temperature outside? How much timing are you getting at the top of 3rd?