Well i have been talking to zoomer in detail about timing. He said that 26 degrees is ideal for an L36, after that you do not gain anything. The 95'* run 19 degrees and it has been proven on a L36 that 1 degree of timing is worth 2-3 whp Sooo lol . I want to see your knock after you get a heatsheild on that CAI. I think it will be down around 2ish and throw in that 180 drilled and that might take care of it.

notice that when the air is cold like 60 degrees IAT and the coolant temp around 160 i have no KR .so i know that heat is my problem for KR .so i will do more testing after my intake is sheild and my stat change

well the stat is change to 180 drill and my cai is sheilded and i still have a bit of KR like 2 or 3 degrees if i give it more throttle in high gear . from a dead start i have 0 KR or at the most below 1.is it that hard to get zero KR whit a L36

typically you shouldnt have knock in a L36, but some just do. On a good note before the heatshield and 180 state, i saw as much as 5.4 degrees on your gauge, so at 3 it is much better. A lot of Grand prix guys i talk to see around 2-3 degrees, usually they just do like PEM'* or a DP and it gets rid of it. So i would say next if i was you i would do the front EM, if yours looks anything like mine then that should kill off another degree. Every little bit killed off is more power to the ground. So that would be my next suggestion. Truthfully bud, i would like to see zero all the time before we do that ported LIM. The Ported LIM will increase flow and probably increase knock, so i would really like to see zero first. Like i was telling you, i really wish you would have bought a 2.5 inch DP, instead of just getting the u-bend deleted, a DP will give you much more top end power and would probably kill off alot of knock.

PS- we still have to clean your MAF, and do your plugs, that may kill a little right there.

PSS- After thinking a little, (i dont know much about knock), does anyone know why his car would have zero knock from a dead stop to WOT run, but if he is rolling and punches it, it will spike about 2-3 degrees and then jump around that area?

My understanding and since I'm not an expert and have been wrong before take it for what it'* worth

The reason you are seeing knock in the higher gears is because in first gear the motor is working less than when you stop it in high gear. It takes less effort to move the car. Therefore the load % is lower and knock is at lesser loads.

Has a tank of premium been tried to combat the knock? That will tell you if it'* octane related.. (Sorry..didn't read everything)

I believe he tried 91 octane but i am not 100% sure. Is that right? Maybe try 93 if that is available. Myself, i dont have much knowledge about KR, i know what it is and some ways to lessen it but not alot. I was watching his gauge and to me it was just a little strange. We would be rolling from say 20, and punch it. It would go right to like 4.8-5.4 and it would stay there for about a second then go to like 2.3 then 3.2 then 1.1 and then like 3.5. It was all over the place. But at that time we hadnt finished the heatshield yet. I am going to have to take a look again and see how it is now. I think cleaning the MAF (car has around 70K) and changing the plugs (he is going 1 heat range cooler) may ghet rid of the knock. He is seeing 25.5 degrees of timing which seems a little high. I am unsure of what most cars are seeing but Zoom told me most grand prix gt'* see around 23-24 stock. So maybe with that little extra timing on a mostly stock car it is causing the knock. We are going to clean the MAF and do the plugs and see where we are at that point.

TJ'sblackbonne wrote:
TJ, firebuick:

I found my ported LIM to reduce KR significantly. Here is an excerpt from my ported LIM thread:
http://www.bonnevilleclub.com/forum/...72094&start=40

Here'* some additional analysis at WOT only, comparing the pre-ported to post-ported LIM'*:

Stock LIM at WOT (99%+ TP, 95kPa+ MAF), stock spark table:
Average timing: 12.8 degrees
(Max timing: 13.5 degrees)
Median KR: 4.26
(Max KR: 5.80)

Ported LIM at WOT (99%+ TP, 95kPa+ MAF), tuned spark table:
Average timing: 19.6 degrees
(Max timing: 22.5 degrees)
Median KR: 1.10
(Max KR: 2.72)

By porting the LIM, I was able to advance spark at WOT from the stock 12-13 degrees to 19-20 degrees, while also reducing typical WOT KR values by almost 300%.

Over the whole range, I was able to reduce KR frequency by over 150%, and severity by over 100%.

(With warmer weather coming up, I either need to ease back a degree or two on my timing, or install the front PEM I got in the mail yesterday )


It seems that Regal has a much more agressive stock spark table than my LeSabre had, if WOT timing maxes at 25.5 degrees. It is crying out for a ported LIM .

Well in that case , that is nice to know. He has it in his trunk and it is all ready to go in. So, it looks like a good time to put it in. PM me don and we can get together and do the MAF, plugs, and LIM. Might as well do them at the same time and then we can hit the track. As for his timing, i was surprised to see how aggressive it was. I think 25.5 degrees is quite a bit for a stock car, he was seeing 5 degrees of knock with his exhaust mods (deleted u-bend and resonator), and a CAI. Can you imagine how much knock he was seeing when the car was stock.

Is that ported LIM also "polished" (or at least, "de-roughed") on the inside of the runners? I suspect that has alot more to do with the benefits of the ported LIM than originally thought...

Alot of what I've been researching leads me to believe that much of the KR we see, including the KR induced by rapid changes in engine load (hills, "punching it," even just gear changes) is due to air turbulence being induced throughout the the entire intake stream, from the UIM "horns" all the way down to the valves. Smoothing the ungodly awful rough castings in the LIM intake runners should help alot with that.

Yes, he smoothed them. If he gets on and sees this, maybe he will post some pictures . I am ready to put that LIM on and see what the difference is like. He was telling me how bad the stock LIM was and how the imperfections looked, i laughed and then went and got my stock front manifold. We both had a nice laugh.