• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

What amount of KR is acceptable?

I'll second e85. I had a fully built srt4 on e85 running 38* timing and 30 pounds of boost, shifting at 8000 rpm running 12.6:1 AFRs and never saw a tick of kr. While on pump gas, those numbers would have blown up my car 17 times
 


Max Cook said:
Yeah more mods and boost means KR is more dangerous. 1-2 or less isnt really much to be concerned with on any build. Ideally you want 0 though within reason. If you're getting 2 degrees only at 140MPH thats probably not a concern. At 60MPH it might be a concern (as its probably only going to get worse). A lot of stock cars will have like 5* of KR and be fine because of the low boost levels.

On another note with a 3.1 on a GenV I've hit 6-7 degrees of KR before multiple times without killing my car (asuming there aren't chipped pistons merely hiding away). I really don't reccommend that though.
Click to expand...
I've only seen it at 2* once and its less than 1* only on long hard runs closing in on 100 mph so for daily driving its not a concern at all I guess. I'm new to this stuff so I'm just being cautious. I'm going to reprogram the lights to only come on over 1* on one gauge and over 2* on the second gauge. If I see more than 2* I will take it seriously. Like gtpsleeper said I'm thinking it the .02 amount of KR may be false knock.
 
But whoever posted above is right 1-3 degrees is nothing. To me at least. 4*+ above stock boost and shift points and I started to watch it.
 
I saw 7* on my stock motor.

Now with my Mods, I can see up to 3.5* at times. Yes, the more modded you are, the more "deadly" KR becomes.

If you're seeing .2* you have absolutely nothing to worry about.
 


Getting back to the KR... I just changed the lights to 1 degree on one gauge and 2 degrees on the other. After a few hard runs and no red lights im feeling good about the 3.2.
 
I'm going to go out and say, zero. ZIP. Nada. None. Absolutely no amount is acceptable.
If you're knocking, even a lit bit... there are changes you need to make somewhere.
 


Honesty, I have no clue what my boost level is at WOT because Im always watching my WB, maf hertz and KR but I can look on the way home today. Its probably somewhere in the 11-13 range though depending on the weather. Yes, Im Iced aswell... Also, it might be worth mentioning another perk to E85 is not only less KR obviously but less harmful knock (in a sense). By that I mean 5* of KR on regular fuel is not the same thing as 5* on E85 (for argument sake, anything above 10 would be bad no matter what fuel you run) which makes it way safer in regards to "exploring your tune" due to its forgiveness (I need to find the source my roommate used to write his paper on it for his engineering stuff).

Its nice having a roommate majoring in mechanical engineering and an upstairs neighbor finishing up his masters in aerospace engineering... They are my google half the time...
 
gtpsleeper said:
Honesty, I have no clue what my boost level is at WOT because Im always watching my WB, maf hertz and KR but I can look on the way home today. Its probably somewhere in the 11-13 range though depending on the weather. Yes, Im Iced aswell... Also, it might be worth mentioning another perk to E85 is not only less KR obviously but less harmful knock (in a sense). By that I mean 5* of KR on regular fuel is not the same thing as 5* on E85 (for argument sake, anything above 10 would be bad no matter what fuel you run) which makes it way safer in regards to "exploring your tune" due to its forgiveness (I need to find the source my roommate used to write his paper on it for his engineering stuff).
Its nice having a roommate majoring in mechanical engineering and an upstairs neighbor finishing up his masters in aerospace engineering... They are my google half the time...
Click to expand...

I'd think your over 13 psi boost with a 2.8 and a GenV... I thought every pulley drop size ads about a pound of boost and a GenV adds 2 pounds of boost. Your car must really haul! I'm actually installing 60# injectors, pump and pcm for e85 Saturday. intense sent out the parts and ball park e85 tuned pcm today. I'm going to have the car dialed in with a dyno tune on Tuesday. I've done a lot of research on e85 and the biggest advantage of it is seen in boosted engines. The fuel has a cooling effect similar to water injection and a slower burn rate which decreases cylinder temps and KR. Another cool thing is that 93 is well over $4.00 a gallon and e85 is around $3.10 so even with the decreased gas mileage fuel costs should be about the same. I'm really looking forward to the dyno tune and seeing the exact numbers. I'm sure in Kansas there is no shortage of e85 and in the Detroit Metro area e85 is all over the place too.
 
Boost is all about restriction though. A roots blower gets inefficient with high numbers of boost which is anything really above 14/15 depending. But ya, in Lawrence alone we have I think 6-7 e85 pumps and even 1 e100(98) that has said "temporarily out of order" for the last year and half (due to the drought). Its soooooo painful to see it for this long and not ever get it.... kinda like being friend zoned by the hottest girl on campus...
 
You must log in or register to reply here.
Back
Top