ALVAROG1983
EVIL GN
- Joined
- Mar 27, 2007
Cant Figure Out the Knock
- Thread starter GNBeswick
- Start date
ALVAROG1983
EVIL GN
- Joined
- Mar 27, 2007
DailyDrifter
The Slow and the Curious
- Joined
- Dec 5, 2007
I have never seen a Sunoco station in California, I dont think we have them. I only found one place that has race fuel, and they want $100 for 5 gallons of c16. I dont really have the money for that right now.....seems a bit expensive. I looked into finding a station that sells ethanol.......there is apparently one place somewhere in the heart of LA....which is a little ways from me, so I dont know if Ill be able to take that route.
Something that I would like to know is, are there any other symptoms of a bad ECM? Is a bad ECM something that is fairly common in knock issues? What exactly goes wrong in the ECM that causes knock? I can think of very few things besides the ECM and coil pack that can be causing my knock. I feel like Ive covered most everything else save putting race fuel in. I would like to try that, but getting my hands on some is the problem. I had also figured that the alky should pretty have the same affect of race gas.
Also, maybe Boost231 can answer; what does XFI all do that the ECM doesnt? I ask because you said it solved your problems. Im assuming it runs off speed density and that is the main draw of the system as well as adjustability, but is there anything else special?
Something that I would like to know is, are there any other symptoms of a bad ECM? Is a bad ECM something that is fairly common in knock issues? What exactly goes wrong in the ECM that causes knock? I can think of very few things besides the ECM and coil pack that can be causing my knock. I feel like Ive covered most everything else save putting race fuel in. I would like to try that, but getting my hands on some is the problem. I had also figured that the alky should pretty have the same affect of race gas.
Also, maybe Boost231 can answer; what does XFI all do that the ECM doesnt? I ask because you said it solved your problems. Im assuming it runs off speed density and that is the main draw of the system as well as adjustability, but is there anything else special?
Oh, and here's one of the most recent logs Ive taken. As usual I cant make any sense out of it. AF ratio was set to 10:7 and I increased the "initial" knob on my alkycontrol to put more alcohol in and had the blue knob maxed. Did this because Razor said if it knocks, add more alcohol. Knock comes in at 11.2lbs of boost......explain that one. It's like the alky does absolutely nothing.
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
Do yourself a favor and call Julio. He will have better insight on the alky injection situation. Maybe you need to increase the "gain" not how much the blue knob is turned.
I'd make up a batch of homemake race gas with the xylene to test out the knock if you can't find 100 ul. It won't be 100 but better than that 91....
You can do a search for it.
BTW what are you spraying? Straight Meth?
I'd make up a batch of homemake race gas with the xylene to test out the knock if you can't find 100 ul. It won't be 100 but better than that 91....
You can do a search for it.
BTW what are you spraying? Straight Meth?
- Joined
- Feb 18, 2006
Alky does nothing because it's not real detonation.
I have adjusted the "gain", on my PAC controller it's called "Initial". Ill look into the Xylene. I am spraying straight methanol, yes. As for the knock being false.....I had my doubts in the beginning, but now Im positive it's real. I got a torque strap and I know nothing is hitting. I can also 99% of the time hear the knock now.
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
Homebrew Octane Boosters
Here you go.
Here you go.
chrisgarrett
Registered Member
- Joined
- Jun 2, 2004
GNbeswick,
I have a the same issue as you with a similar build. I'm pretty sure the source of my knock issue is my noisy 218/212 roller. How noisy is yours at idle?
I have a the same issue as you with a similar build. I'm pretty sure the source of my knock issue is my noisy 218/212 roller. How noisy is yours at idle?
No...I unfortunately have not. Been waiting to post until I get make some homemade race fuel or get my hands on some. See if it makes any difference. Car is still doing alot of the same things. Knock comes on at 10.5-11 psi every run than fades and comes back in the 12.5psi + range.
My cam is noisy at idle, but I also know my knock is real.
One other thing I forgot to ask about is, what is the acceptable amount of oil in the intake? I took off my up pip and looked into the throttle body and noticed a little bit of oil near the back of the plenum on my rjc powerplate. I dont know what the actual intake looks like because I didnt take the plenum off.
chrisgarrett
Registered Member
- Joined
- Jun 2, 2004
There shouldn't be any oil in the intake. Assuming the uppipe itself is dry, the oil is probably coming through your pcv. Take off the vacuum block on top of the intake and see if it has oil in it.
Of course the oil has nothing to do with your kr.
Of course the oil has nothing to do with your kr.
Jerryl
Tall Unvaccinated Chinese Guy
- Joined
- Dec 14, 2004
No oil in the intake is really accptable, especially when you are chasing KR.
If it is from the PCV, disconnect, clean the intake and run the car to see if there is a KR difference.
Sorry Chris, I have to disagree.
Oil in the intake has a LOT to do with KR - Oil seriously lowers the total octane.
Ya...that why Im asking, I know even just a drop of oil can have a drastic effect. I know there have been some threads on here in the past that have argued about the PCV, but I cant find them. I know the source of the oil is most definitely the PCV, but like I said, I dont know what is acceptable.
My intercooler and up-pipe were sparkling clean.
My intercooler and up-pipe were sparkling clean.
chrisgarrett
Registered Member
- Joined
- Jun 2, 2004
Well I'll defer to you that the oil could be the cause, but I was going on the basis of the appearance of the spark plugs. They didn't seem to be oil fouled.
- Joined
- Feb 18, 2006
Thread soup
Thats what gets me. The plugs tell the story yet no one here knows how to look at the facts. It all a big guessing game. This thread has degraded the credibility of it's posters. Without mentioning names, people still have allot to learn.
If your getting oil in the intake, it's easy enough to unplug/block off the PCV valve and see if the supposed detonation goes away.
When your ready to get to the bottom of all this, eliminate the spark plugs, wires, coil pack, module, crank and cam sensors otherwise this is all just thread soup.
Rick
Thats what gets me. The plugs tell the story yet no one here knows how to look at the facts. It all a big guessing game.
This thread has degraded the credibility of it's posters. Without mentioning names, people still have allot to learn. If your getting oil in the intake, it's easy enough to unplug/block off the PCV valve and see if the supposed detonation goes away.
When your ready to get to the bottom of all this, eliminate the spark plugs, wires, coil pack, module, crank and cam sensors otherwise this is all just thread soup.
Rick
