Can To Much Meth Cause False Kr

[dvldoc]

I have a Pontiac Grand prix GTP with a DIY alky kit, I run good old windshield washer fluid 90% of the time with 0 to 1 degrees of KR 99% of the time.

Now when I put strait meth in there I see a pound and a half more boost, the car is faster but I get up to 5 degrees of KR. I enriched my 02's to see if it would help but even at 955 I'm still seeing KR with 100% alky. My 02's are normaly 945 with 0kr. (GTP's Run alot different than GN's)

I'm using a M15 nozzle right now, could I be getting to much alky in the system? My plugs are autolite 103's gapped at .035 which is three heat ranges colder than stock GTP plugs.

I'm baffled as to why it runs better on a 50/50 mix than on a 100% mix of alky.

 

[Razor]

Originally posted by dvldoc
I enriched my 02's to see if it would help

This may be your problem as you may be inducing the KR by dropping too much fuel. Remember your shooting a fuel into the motor, you want to lean out the motor not richen it up.

Its like trying to drink a liquid to fast, there comes a point you start choking.. this is whats probably happening to your motor. Drop injector duty cycle, or fuel pressure as temporary fix's.

Another thing to do is increase the turnon point of your system.

HTH

 

[dvldoc]

Makes sense, I'm going to try both of your suggestions because I need to get this thing dialed in. I'm impressed with the power difference with 100% methonol vs a 50/50 mix. 13lbs of boost jumps to 14.70 on the 100% mixture.

I can change my o2's to what ever I like thanks to the mini afc that lets you tune just like the MAFT plus does.

Thanks Razor.

Oh yeah there is no price listed on your webpage for the progressive controler you sell.

 

[Razor]

We've making some changes to the site recently.. guess we forgot to put the price back in.

Its 189.00. Contact me off list for any business related inquiry. Thanks.

I try and keep what I do here separate from my business. Its a fine line sometimes tho.

Post back if the suggestions worked. Also Rob Archer has been having great success.. may try and get ahold of him through the Impalla/GTP boards. As well as Chris Spratt he has also done a lot of playing.

 

[dvldoc]

No luck with either suggestion, when I leaned it out i had even more KR. I moved my turn on point from 3400rpm's to 4200rpms and I went from 3 to 5 degrees of KR to up to a max of 8 degrees.

So leaning it out is not a factor, I taking it back to 940 02s because 900 to 890's were making way more KR.

I'm going to take my spark plug gap back up from . 035 which Is the major thing I changed on the car since the kit. It was at .045.

I'll try .040 and see if this cures the problem plus move the turn on point a bit higher.

Damm I hate tunning. You change something and everything goes to hell.

 

[HellOnWheels]

Originally posted by dvldoc
No luck with either suggestion

I'm going to take my spark plug gap back up from . 035 which Is the major thing I changed on the car since the kit. It was at .045.

I'll try .040 and see if this cures the problem plus move the turn on point a bit higher.



I didn't realize that plug gap could cause knock retard?? Is this a fact, if so how??


HOW

 

[Razor]

Well if the flame gets blown out I can see that inducing KR.

The 03 I did we played with turnon point only. If we turned it on at 3 PSI it would have zero KR but have high consumption. Turning it on at 6 PSI left a small kr spike that would immediately go away. I also noticed it was a bit finiky getting the ramp dialed in. At the end it worked as planned.

I notice your turning it on based on RPM's not boost pressure. Maybe that has bearing on your results. Your SC makes a lot of boost down low, and the higher the turnon the worst it can be.

Dont know if you'll ever get it rite with a window type switch and a fixed pressure system. Also since it makes more boost, it will want to KR more.

You have some work to do. One more thing is to vary pump pressure.

This is why I no longer sell a fixed point controller.

 

[dvldoc]

I guess Grand prixs don't like 100% methonol because as soon as I went back to a 50/50 mix I went back to zero knock.

I left the spark plug gap at .035 and tried the easy stuff first, added fuel, changed turn on to 3600rpm and went to a 50/50 and bamm no knock. Guess I'll just stick with it.

Thanks for the suggestions Razor.

 

[4sfed4]

Originally posted by dvldoc
I guess Grand prixs don't like 100% methonol because as soon as I went back to a 50/50 mix I went back to zero knock.

I left the spark plug gap at .035 and tried the easy stuff first, added fuel, changed turn on to 3600rpm and went to a 50/50 and bamm no knock. Guess I'll just stick with it.

Thanks for the suggestions Razor.

It would be interesting to see how the actual power output changed when you went back to 50/50. Back to back track or dyno runs with the various mixes would be interesting to see!

Even though the KR went away its tough to say if power went up with the switch of mix. I played with a DIY alky system on my car for a bit and found that overdoing it with the alky could get rid of KR and make the car run "smooth", but I lost 6-7 mph of trap speed in the 1/4!

I ditched the DIY setup and went with Razor's progressive kit which I now have about 80% installed. I think its going to be 1000 times easier to tune than my DIY crude setup as all I could do before was turn the system on or off at a set boost pressure. To fuel the car with my setup like this, it would invariably end up being way overfueled down low to be right up top. So, it was more or less useless in my application.

 

[dvldoc]

Believe me a progressive controller is in my near future.