MitsuStyle - View Single Post - 3rd gear knock... I need expert advice PLEASE

Onefast99gsx · 08-04-2005

Hi Shane- First, thanks for the response. To answer your questions.... Makes sense that with each increase in gear, you're in it longer than the previous gear. Heat would be a very likely culprit. I thought for sure that Alky injection would lick the problem. Actually it has done a great deal for me I should say. I couldn't even hardly go over 16psi before on shitty 93 octane without knocking. Now i can go up about 5 more psi from that with pretty good results.

While the weather is cooler out today, i'm gonna back it down to 19-20psi and see what results i get. I using methanol(the stuff the drag and stock car racers use). I have not went negative on the sliders with timing. The only reason is because I hear so many people that can run 19-20psi on 93 octane with no problems. I have my W.I. coming on at about 16psi.

Is going negative on timing sliders necessary a bad thing??? I always thought the more you could advance it the better off you were. I always tried to get as close to 20 degrees as possible. Seems like at about the top of 3rd gear, i'm only getting 13-14* because of the knock. That's gotta provide a power loss. Unfortunately, i'm only reading A/F with dsmlink. I've always strived for 10.8 to 11.3 A/F Ratio. Who knows, maybe my car would like low 10's, something i'll have to try. I don't think the headwork did anything negative. No material was hogged out. The shape and flow characteristics are the same. The rough cast was just cleaned up and polished. The Griffin FMIC could be a possible culprit too. It's 20x10x2.75(core). I'm not sure how efficient they are with a 50 trim and over 20psi of boost.

Thanks.

08-04-2005	#4
Onefast99gsx Join Date: Sep 2004 Location: Wisconsin Posts: 1,411	Re: 3rd gear knock... I need expert advice PLEASE Hi Shane- First, thanks for the response. To answer your questions.... Makes sense that with each increase in gear, you're in it longer than the previous gear. Heat would be a very likely culprit. I thought for sure that Alky injection would lick the problem. Actually it has done a great deal for me I should say. I couldn't even hardly go over 16psi before on shitty 93 octane without knocking. Now i can go up about 5 more psi from that with pretty good results. While the weather is cooler out today, i'm gonna back it down to 19-20psi and see what results i get. I using methanol(the stuff the drag and stock car racers use). I have not went negative on the sliders with timing. The only reason is because I hear so many people that can run 19-20psi on 93 octane with no problems. I have my W.I. coming on at about 16psi. Is going negative on timing sliders necessary a bad thing??? I always thought the more you could advance it the better off you were. I always tried to get as close to 20 degrees as possible. Seems like at about the top of 3rd gear, i'm only getting 13-14* because of the knock. That's gotta provide a power loss. Unfortunately, i'm only reading A/F with dsmlink. I've always strived for 10.8 to 11.3 A/F Ratio. Who knows, maybe my car would like low 10's, something i'll have to try. I don't think the headwork did anything negative. No material was hogged out. The shape and flow characteristics are the same. The rough cast was just cleaned up and polished. The Griffin FMIC could be a possible culprit too. It's 20x10x2.75(core). I'm not sure how efficient they are with a 50 trim and over 20psi of boost. Thanks.