Supercharged/Turbo guys!?!?!!?! Question?
Thread Starter
Drifting
Joined: Feb 2013
Posts: 1,465
Likes: 12
21 degrees from 4500 rpm and up.
A couple more degrees down low, but i discovered less timing down low = more power down low, with my afr heads.
Sometimes an extra 1 degree of timing can mean the difference between starting to get knock retard (and sapping the power) or not.
A couple more degrees down low, but i discovered less timing down low = more power down low, with my afr heads.
Sometimes an extra 1 degree of timing can mean the difference between starting to get knock retard (and sapping the power) or not.
I put the car back to NA and took it out for some 7,000 Rpm pulls. I made about 15 pulls in 3rd gear. It never missed a beat, pulled hard all the way to 7 grand!
I think its 100% fuel cut at 10 psi. As I said, I can see the pressure drop off a few points as its reaching the 5k mark and the area where I am having issues., I ordered my new pumps and harnesses today! Hopefully I will have them by the weekend!
I am also going over to a CDI MSD box for a little extra umfph up top! Greg at blowerworks is a awesome guy and highly recommend from me!
Instructor
Joined: Apr 2005
Posts: 228
Likes: 0
From: Göteborg
What are you guys running for a fuel system?
I have a aeromotive 340 pump and 63 lb siemens injectors and I think my car is running out of fuel at 4700 rpm or so!! (10 psi of boost)
I have a built 383 with a D1SC. Im not 100% certain if its fuel or ignition but at 4700 RPM it has a bad studder. My A/f is 11.5 across the board! My fuel gauge is set at 45 psi at idle and under load it goes to 50 psi. at about 4300 rpm my fuel gauge starts to fall off and by 4700 its down to 44 psi I did a datalog and ofcourse it doesnt show me anything.
Kinda stuck at the moment. I dont think its the ignition system...but idk for sure!!!. I have NGK tr6 plugs gapped at 35.
any ideas or help would be great!
I have a aeromotive 340 pump and 63 lb siemens injectors and I think my car is running out of fuel at 4700 rpm or so!! (10 psi of boost)
I have a built 383 with a D1SC. Im not 100% certain if its fuel or ignition but at 4700 RPM it has a bad studder. My A/f is 11.5 across the board! My fuel gauge is set at 45 psi at idle and under load it goes to 50 psi. at about 4300 rpm my fuel gauge starts to fall off and by 4700 its down to 44 psi I did a datalog and ofcourse it doesnt show me anything.
Kinda stuck at the moment. I dont think its the ignition system...but idk for sure!!!. I have NGK tr6 plugs gapped at 35.
any ideas or help would be great!
Thread Starter
Drifting
Joined: Feb 2013
Posts: 1,465
Likes: 12
Melting Slicks
Joined: Oct 2000
Posts: 2,158
Likes: 9
From: N.E. WA
Thread Starter
Drifting
Joined: Feb 2013
Posts: 1,465
Likes: 12
I believe the 340 is in the tank and the 392 is in-line. Greg runs these in series and the two together are supposed to support up to 1000 RWHP supercharged/turbo cars.
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
I have never had an issue with plug gaps being on the tight side and when you are running a car with a power adder the higher cylinder pressures create a higher demand on the ignition system so you have to run a tighter gap. I have seen many blower cars misfire on the dyno with plug gaps at .035 and this problem usually goes away with gaps of .025. My two cents!
Race Director
Joined: Sep 2001
Posts: 14,674
Likes: 751
From: NEwhere Ohio
I have never had an issue with plug gaps being on the tight side and when you are running a car with a power adder the higher cylinder pressures create a higher demand on the ignition system so you have to run a tighter gap. I have seen many blower cars misfire on the dyno with plug gaps at .035 and this problem usually goes away with gaps of .025. My two cents!
but!
Did these cars also run a capacitive discharge box (like MSD-6?). I am running an MSD-6BTM per greg's suggestion (as much as I hate MSD, I have had good luck with this box being reliable).
I agree misfires could be a problem at high rpm, high boost situation.
It was real clear, on the highway, that I was getting misfires in high gear, low rpm with plugs gapped too tight.
The engine seemed like a washing machine out of balance (duh) because cylinders were dropping out and not firing .
Move the gap back to .035"; and no problem.
BTW, this was on NGK TR6 plugs.
Now I have to run Autolite plugs due to my afr 195 heads.
I still use .035ish" with no issues.
Race Director
Joined: Sep 2001
Posts: 14,674
Likes: 751
From: NEwhere Ohio
I had an issue where the tiny electrode fouled, on an iridum plug.
It fouled because of a bad, contaminated o2 sensor (silicone sealer got vaportized and coated it).
It then left me with a no-start condition. The tiny (iridium is expensive, thats why they make it small) electrode was soot covered.
Its my belief a bigger copper electrode would have been more resistant to fouling and was cheaper to boot anyways.
This is what I run now.
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Thread Starter
Drifting
Joined: Feb 2013
Posts: 1,465
Likes: 12
I am not a fan of any of the platinum, iridum plugs.
I had an issue where the tiny electrode fouled, on an iridum plug.
It fouled because of a bad, contaminated o2 sensor (silicone sealer got vaportized and coated it).
It then left me with a no-start condition. The tiny (iridium is expensive, thats why they make it small) electrode was soot covered.
Its my belief a bigger copper electrode would have been more resistant to fouling and was cheaper to boot anyways.
This is what I run now.
I had an issue where the tiny electrode fouled, on an iridum plug.
It fouled because of a bad, contaminated o2 sensor (silicone sealer got vaportized and coated it).
It then left me with a no-start condition. The tiny (iridium is expensive, thats why they make it small) electrode was soot covered.
Its my belief a bigger copper electrode would have been more resistant to fouling and was cheaper to boot anyways.
This is what I run now.