Good afr still get kr? - Tuning Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Good afr still get kr?
Wednesday, January 11, 2012 1:47 PM
I have a difficult time trying to word this...

Too rich, kr. Too lean, kr. What if afr is good but your iat's are pretty high. Can that cause knock?

Is it possible to get no kr with good afr and still piss off your pistons?

I ask because Id like to run my m45 ld9 at the track. Seeing about 8 maybe 9 psi but I dont have my meth kit on yet. But I wouldnt know if race fuel would cover any bad chances, including the pistons.

Just dont want to go to the track and something happen because my iat's were way high but no kr and afr at mid 11s.




Re: Good afr still get kr?
Wednesday, January 11, 2012 7:12 PM
Yes high iat could cause this. Your iat effects timing along with other things.



Re: Good afr still get kr?
Thursday, January 12, 2012 9:32 AM
Have you pulled timing where it knocks? Is your timing table smooth? Is it false knock? How are your plugs? Need more info or we're just shooting in the dark.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: Good afr still get kr?
Friday, January 13, 2012 3:41 PM
Absolutely, there are many things that can cause knock or preignition too. I would agree, have you tried pulling a few degrees on timing in the spots where you are seeing the kr?



Re: Good afr still get kr?
Friday, January 13, 2012 3:57 PM
In my experience the LD9 is known for false knock. Even in stock form.



FU Tuning



Re: Good afr still get kr?
Tuesday, January 17, 2012 11:56 AM
Good advice Addicted, I have never owned one of these engines , good input!



Re: Good afr still get kr?
Tuesday, January 17, 2012 3:53 PM
Addicted to meth wrote:

In my experience the LD9 is known for false knock. Even in stock form.


To add to this. Regardless of what it is known for, you should always take the right steps to verify if it is real or not.

I have taken as much as 10 degree's away to get no change in KR.

With advise from Ryan I have changed the settings on the knock sensor so it is less sensitive. That has made a nice difference.



FU Tuning



Re: Good afr still get kr?
Monday, January 23, 2012 11:44 AM
Well I got it scanned. Car is not dialed in too accurate probably cuz its a 98 being 1bar tuned. Timing was between 22-29 degrees at WOT lol. I threw in xylene just to be safe. Saw knock but it was at dips or some shifts. Pretty positive false. Plus my IATs were only 164 degrees max with no meth.

I was just wondering this for the track one night. I dont plan to keep running it like this.



Re: Good afr still get kr?
Monday, January 23, 2012 1:02 PM
hmm.. interesting, what are you using to tune hp tuners right?



Re: Good afr still get kr?
Monday, January 23, 2012 2:04 PM
That seems like quite a bit of timing for a boosted car.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: Good afr still get kr?
Monday, January 23, 2012 2:23 PM
Leafy wrote:

That seems like quite a bit of timing for a boosted car.


It sure does, im in the mid to low teens




"Straight roads are for fast cars, turns are for fast drivers"-Colin McRae

Re: Good afr still get kr?
Monday, January 23, 2012 3:26 PM
Leafy wrote:

That seems like quite a bit of timing for a boosted car.


I have to agree for a LD9 that is way too much timing.



FU Tuning



Re: Good afr still get kr?
Monday, January 23, 2012 8:58 PM
So timing should be pulled? Whats a good target for say... 11-13 psi?



Re: Good afr still get kr?
Monday, January 23, 2012 9:22 PM
It all depends on the engine, but I'd be surprised if you see over 22 peak, 20 more likely. Though I'm not terribly familiar with the ld9.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer
Re: Good afr still get kr?
Tuesday, January 24, 2012 1:16 PM
I'm no pro tuner, but that's a tremendous amount of timing advance for a boosted engine, especially one with a GMSC.

I "believe" in stock form the GMSC tune maxes out at 18-20 degrees of timing advance, sorry it's been 6 months since I looked a stock M45 file give or take. The Stock N/A file goes to about 29-30 degrees.

The LD9 does love to create false knock but my first instinct seeing the information you have given is to pull the timing. I always start from a known "safe" constant and even on a 1 bar tune I would start at GM's "safe" tune level and then go from there.

I have found that going even 1 degree higher in timing in certain areas of the map at certain RPM's creates a surprising amount of knock on M45 cars, and it's hard to prove if its false or not. Yes the meth will help you but it is my opinion and experience that 29 degrees of advance on non-intercooled boost is far, far too high.

Also, expect to re-tune for meth. It loves to change your AFR quite a bit.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: Good afr still get kr?
Tuesday, January 24, 2012 6:00 PM
Well that may explain the timing. Remember this is a 98. Couldnt reflash it. Probably adjusted the afr to get it run but never ajusted the timing maybe?

And yes I know meth will richen it up and will have to retune. So we recommened 20 degrees timing max at WOT?



Re: Good afr still get kr?
Tuesday, January 24, 2012 6:09 PM
I would start with like 18 (depending on the pulley).

I'm running 17 max with a 2.5 and overdriven crank pulley and meth.



FU Tuning



Re: Good afr still get kr?
Wednesday, January 25, 2012 9:31 AM
I think a huge help to you would be if somebody could post up screenshots of the GMSC stock timing maps for you to go off of. I apologize I'm not near my laptop or I'd do it for you, but you'll be able to see GM's curve out of boost and in boost as PSI and RPM's increase. It will help you get a good safe base map that you can then start to tune for yourself on your 1 bar setup.

(I have to do this exact same thing for Darren's car this spring. If I'd already have done it I'd just send you the HPT file - sorry man!)

I know John has tuned a few 1 bar GMSC Setups - maybe he can send you the file or post up his timing maps for you to start from?

That's my advice!

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: Good afr still get kr?
Friday, January 27, 2012 11:48 AM
That would be awesome if I could get a file on a 1bar tune. Ill go with what John said at 18 degrees. I didnt want to say this cuz Im sure it would bother some people but I got the prototype m45 on my car, with whatever that pulley is (2.55) and just purchased an OD crank pulley. So thats what Ill be working with, kind of close to Johns setup. Except the prototype part.

Since Ive gotten the afr right to my car it always felt like it was dragging. Like the parking brake partially up. Hopefully it is cuz pf the timing.



Re: Good afr still get kr?
Friday, January 27, 2012 11:51 AM
Craig, is thomas still tuning you?



Re: Good afr still get kr?
Saturday, January 28, 2012 6:59 PM
EvoFire wrote:

Craig, is thomas still tuning you?


Not really. He hasnt since I had first supercharged the car.




Re: Good afr still get kr?
Monday, January 30, 2012 11:10 AM
whose tuning now?



Re: Good afr still get kr?
Monday, January 30, 2012 9:02 PM
EvoFire wrote:

whose tuning now?


No one. Hasnt been tuned since I supercharged the car. Thats why I asked on azgmp of dyno shops. Thomas could still do it but hes out of the game pretty much and I do want dyno numbers.



Re: Good afr still get kr?
Monday, January 30, 2012 9:07 PM
dynocomp uses HPT 190 an hour for dynotune. plus credits and with your good base tune i think an hour is all you would need.



Edited 1 time(s). Last edited Monday, January 30, 2012 9:07 PM


Re: Good afr still get kr?
Saturday, February 04, 2012 5:52 PM
I don't want to thread jack, but I'm having issues with my timing.I there a timing table to start with. I'm using the stock SD timing.
Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search