Chasing KR still

SteveZ82

Active Member
I recently just got back from a 600 mile trip in my GN. Car ran fine. No issues. Until I boost. Now, granted we were stuck with 91 octane but I ran some booster to bring it up one night because we were going to do some pulls in our cars. I notice that when I boost, my wideband afr pegs to 10. Scanmaster mvs are 820-850. I was getting 10 degree KR. Now I know I’m super rich so I’ll adjust that, I just can’t solve this issue. Also, I’m not spooling too great. I used to be able to smoke the tires but no more. I'm trying to remember when it started running this rich. It's either after I replaced the O2 sensor with a Bosch (I'm going to throw the old one back on, I replaced this chasing another problem and the O2 wasn't it) or when I bumped up the new FPR to 41 psi line off or after I deleted the Cat. I have a brand new pump in the tank as well with a hotwire kit. Both racetronix parts (240LPH)

One of the guys I was up with brought his 81 twin turbo el camino. He's a master mechanic. That car is insanely fast. Anyway, he gets KR because of a lifter. Now, I have a lifter slightly ticking so not sure if that can be in the same frequency to set off the KR sensor. Also, the turbo shield will rattle when cold. I'll post some numbers I know now.

Boost set to 18 psi
TT 5.6 chip set for 93 octane, 42 lb injectors, 16-18 psi. Default settings.
In boost, between 16-18 psi, 10 degree KR. If I boost it at 14 psi it seems fine (not WOT). At top boost, between 820-850 mv on the Scan master. Pegged at 10 on my AFR wideband gauge.
cc counts are between 5-10 every cycle when cruising. BLMs at 117-120 cruising. Not sure where hey are at on boost.
180 degree thermostat, I run at about 185 all day on cruise in hot weather. I'm debating putting in a 160.

I'm not blowing any black smoke but the tailpipes are black inside. I don't race the car as it's mostly a cruiser but do want to boost every now and then because it's fun. I just want to do so without blowing anything up. Could this KR be caused because it's so rich? I really don't hear detonation but I could be wrong. I wanted to get my AFR up to like 10.8 in boost or like 780mV.

I think this is a matter of just getting the right tune and the right gas but wanted to see what you guys think.
 
I would put a denso in it, as far as KR is concerned thats a tricky one but for what its worth i am going to unplug my knock sensor.
 
I recently just got back from a 600 mile trip in my GN. Car ran fine. No issues. Until I boost. Now, granted we were stuck with 91 octane but I ran some booster to bring it up one night because we were going to do some pulls in our cars. I notice that when I boost, my wideband afr pegs to 10. Scanmaster mvs are 820-850. I was getting 10 degree KR. Now I know I’m super rich so I’ll adjust that, I just can’t solve this issue. Also, I’m not spooling too great. I used to be able to smoke the tires but no more. I'm trying to remember when it started running this rich. It's either after I replaced the O2 sensor with a Bosch (I'm going to throw the old one back on, I replaced this chasing another problem and the O2 wasn't it) or when I bumped up the new FPR to 41 psi line off or after I deleted the Cat. I have a brand new pump in the tank as well with a hotwire kit. Both racetronix parts (240LPH)

One of the guys I was up with brought his 81 twin turbo el camino. He's a master mechanic. That car is insanely fast. Anyway, he gets KR because of a lifter. Now, I have a lifter slightly ticking so not sure if that can be in the same frequency to set off the KR sensor. Also, the turbo shield will rattle when cold. I'll post some numbers I know now.

Boost set to 18 psi
TT 5.6 chip set for 93 octane, 42 lb injectors, 16-18 psi. Default settings.
In boost, between 16-18 psi, 10 degree KR. If I boost it at 14 psi it seems fine (not WOT). At top boost, between 820-850 mv on the Scan master. Pegged at 10 on my AFR wideband gauge.
cc counts are between 5-10 every cycle when cruising. BLMs at 117-120 cruising. Not sure where hey are at on boost.
180 degree thermostat, I run at about 185 all day on cruise in hot weather. I'm debating putting in a 160.

I'm not blowing any black smoke but the tailpipes are black inside. I don't race the car as it's mostly a cruiser but do want to boost every now and then because it's fun. I just want to do so without blowing anything up. Could this KR be caused because it's so rich? I really don't hear detonation but I could be wrong. I wanted to get my AFR up to like 10.8 in boost or like 780mV.

I think this is a matter of just getting the right tune and the right gas but wanted to see what you guys think.
The car is not tuned properly.
It's way rich,
You could be seeing kr from a shift or the downpipe or a host of other things.
10.0 afr at 18psi is going to foul out the plugs not to mention its the wrong target afr.
 
Being way rich with gasoline can cause knock. Get your fuel dialed in first.
Got it. thanks. I saw scooby's youtube on how to do this with the scanmaster. That being said, I think the car was actually better with the stock FPR on it and lower FP. Do you think I need to pull some fuel for 1st and 2nd gear too or just WOT? Seems to be in the 10s there as well. Cruising is fine. Sits right at 14 and 15 there. I put my chip in this thread too. Spoke to Eric on it and it was bought as a kit from cottons with the injectors and the turbo.
 

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Hard to know where you are starting from, but you have to get the basics under control.
Fuel pressure has to be set per Eric's instructions, and also you have to ensure a 1 to 1 rise in fuel pressure for boost pressure increase.
If BLMs are good, then do not tune with fuel pressure, use the fuel adjustment features in Eric's chip.
I would start at the low end of boost for the chip, so 16psi, make sure you have at least 93 octane since you have a 93 chip. Make sure the chip initial settings are also per Eric's recommendation.
A good octane booster will work, like boostane or equivalent.
I would be shooting for 11.5 to 1 AFR at 16 psi of boost, then go from there to optimize.
Everything else has to be in good working order.
You may need to do some searching and studying as what I posted is very simplified summary.
 
Hard to know where you are starting from, but you have to get the basics under control.
Fuel pressure has to be set per Eric's instructions, and also you have to ensure a 1 to 1 rise in fuel pressure for boost pressure increase.
If BLMs are good, then do not tune with fuel pressure, use the fuel adjustment features in Eric's chip.
I would start at the low end of boost for the chip, so 16psi, make sure you have at least 93 octane since you have a 93 chip. Make sure the chip initial settings are also per Eric's recommendation.
A good octane booster will work, like boostane or equivalent.
I would be shooting for 11.5 to 1 AFR at 16 psi of boost, then go from there to optimize.
Everything else has to be in good working order.
You may need to do some searching and studying as what I posted is very simplified summary.
That's great. I spoke to Eric some time ago and said the same thing. I went with everyone's recommendation and put in a new fuel pump, hotwire, and AFPR. Set the baseline stuff to 41 psi line off and about 38 at idle. I was rising 1:1 in boost but will check again. I never tuned the chip so it's Eric's defaults. Like I said, it was bought as a kit but the only changes I made was the AFPR, new fuel pump and converting to vacuum brakes. I have to run through a mix of 91 and 93 right now to get fresh 93 in there. And a good stretch of road to do some testing. Thanks for the help. It's been a learning process with this car for sure.
 
Just an update. Finally got to the garage after speaking with Eric again. He offered to take a look at my chip but kinda wanted to try some things he suggested. I lowered the wot fuel for all gears (parameter 1 in the SM) to 120 as a start. Car is much better. I’m still running some shit gas but my numbers are better. I’m at 800mV with 6 degree KR. Multiband not pegged anymore but at like 10.5 at 16 psi. Still a bit rich but getting there. The plugs look perfect. Seems to be a little rich at idle so I have to adjust iac too. 41 psi line off at the fuel rail and about 35 psi with vacuum. He also suggested I could lower pressure to 38 line off.

Thought I’d update in case it could help others. After I get some better gas I might lower it more to like 118 or so. Seems a bit much to me but it’s a learning process. I have to quiet up a lifter too (#3). So might get some new springs too while I’m in there.
 
You want zero KR. If those numbers are real knock I wouldn't floor it again until you make some changes. Start by just cruising to burn up the 91, then fill up with fresh 93 octane. Use the chip to back timing off 2 or 3 degrees in 3rd/4th gear. You could add some VP octanium unleaded for insurance if you want. A clean pull from a roll in 3rd with ~10.8 AFR on the wideband and zero knock will get you in the ballpark to fine tune it further.

That tapping #3 lifter isn't going to get quieter. The cam lobe is likely worn and will get worse, throwing metal chips around the motor in the process.
 
I am running a similar setup and was getting some KR. I ended up adding one can of VP Octainium to a tank of fuel and KR went away so I confirmed the KR was not false. I have since discovered that the gas in my area is extremely inconsistent on octane . Some tanks require a booster and some do not. I really don't believe that the octane is being checked at the pump by anyone allowing stations to do what they want. Our cars on boost are really sensitive to the octane. Maybe you have a really low octane tank of gas? Or try a can of VP Octainium.
 
Some tanks require a booster and some do not. I really don't believe that the octane is being checked at the pump by anyone allowing stations to do what they want.
AFAIK, the state does not check octane, but only the accuracy of the pump volume vs the test jug.
 
I am running a similar setup and was getting some KR. I ended up adding one can of VP Octainium to a tank of fuel and KR went away so I confirmed the KR was not false. I have since discovered that the gas in my area is extremely inconsistent on octane . Some tanks require a booster and some do not. I really don't believe that the octane is being checked at the pump by anyone allowing stations to do what they want. Our cars on boost are really sensitive to the octane. Maybe you have a really low octane tank of gas? Or try a can of VP Octainium.
Anything is possible. I have a can of boostane I’m going to try once I get through this tank. My mechanic buddy hears a tiny bit of lifter noise but says it’s nothing to be worried about. Maybe I’m over sensitive on that.

I’ll update this soon.
 
Will do. I was wanting to try .025.
Well I thought I had them at .030 but they are set to .025. Plugs are nice and tan. I remember doing this now. Foggy because of beer involved. Lowered the Wot to 118 on the sm. I’m at like 2 degree KR 770mV wot but if I’m not Wot it’s still rich in the 800s. Like 3/4 throttle in 2nd. I think I’m at the point of fine tuning.

And what I thought was a lifter tick isn’t that. I think it may be the timing chain or a little exhaust leak. I replaced the DS header with a poston and high temp gasket. I never went back and retourqed those nuts/bolts. You can really hear it under the car. Sounds like a sprinkler. Not there when you start the car but gets more prominent as it warms up. Whatever. I don’t think it’s a big deal. I’m pulling about 17in vacuum.

I think I just have little things to attend to. I won’t boost until I get better gas. IM taking about a 1500 mile round trip in a couple weeks so can mess with it more when I’m on some country roads. Chicago streets are limited to just quick bursts.
 
So what's your BLM's in Park with the engine fully warmed up.

Do you have the knobs and switches in the Translator set correctly.

What's the MAF reading at idle.

Jam a Denso 02 sensor in it if you can find one.

Chip is burned for 93...91's gonna knock. Turn the boost down to 14.

What MAF are you using.
 
If this chip is burned for your EXACT combo...then it should run like a top on Erics defaults.
I’ve spoken to Eric. I’m going to send the chip to him when I get a chance to do so. I think the EXACT combo is with the old, stock, fpr.

Stock MAF, BLM at 122 at idle hot, I have a denso to throw on, psi at 16 right now. I think you hit the nail on the head. Bad gas. Or, go back to the basics and put back the stock fpr.
 
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