Fast Burn Tune?
Thread Starter
Burning Brakes
Joined: Nov 1999
Posts: 859
Likes: 17
From: Houston TX
Fast Burn Tune?
Those of you who have Fast Burn Heads, what are your timing tables like?
I am having issues that I cannot seem to resolve and I'm going nuts...
What's wrong with my car???
I can't imagine that my tables could be off enough to cause the headers to glow... but I don't know what else it could be at this point. The chip I ran with L98 113 heads and 9.5:1 compression is causing the same problems as the new one.
Can it be the computer? Everything is working like it should on the Datamaster (except the IAC) yet I'm running out of possibilities.
I am having issues that I cannot seem to resolve and I'm going nuts...
What's wrong with my car???
I can't imagine that my tables could be off enough to cause the headers to glow... but I don't know what else it could be at this point. The chip I ran with L98 113 heads and 9.5:1 compression is causing the same problems as the new one.
Can it be the computer? Everything is working like it should on the Datamaster (except the IAC) yet I'm running out of possibilities.
Thread Starter
Burning Brakes
Joined: Nov 1999
Posts: 859
Likes: 17
From: Houston TX
I thought about that, but the IAC is behind the MAF, so I guess I don't see how it could make the car lean. The air going through the IAC if it were parked open (which it's parked shut because the car won't idle) would still be metered by the MAF.
I've checked for other vac leaks, but haven't found anything.
I've checked for other vac leaks, but haven't found anything.
Melting Slicks
Joined: Dec 2008
Posts: 2,772
Likes: 64
From: Mystic CT
If I follow this correctly they glow red when you run the engine at 3500 rpm with no load for 2 minutes? If that is correct my question is why do you do that it has nothing to do with normal operation or any form of racing for that matter. You have probably fallen off the edge of the timing tables for light loads and high rpm. The 32 degrees of timing is for WOT and has nothing to do with part throttle. When the headers glow red there is either big back pressure typical on a turbo engine under high boost or the timing is retarded and the fuel not finished burning before the exhaust valve opens. You have a loner duration cam and the exhaust opens earlier requiring more timing at low rpm and light loads. You will be hard pressed to get detonation with no load on the engine as the cylinder pressure is low but can get preignition from the egt being so high with the retarded timing. my .02 cents on this anyway..
Thread Starter
Burning Brakes
Joined: Nov 1999
Posts: 859
Likes: 17
From: Houston TX
If I follow this correctly they glow red when you run the engine at 3500 rpm with no load for 2 minutes? If that is correct my question is why do you do that it has nothing to do with normal operation or any form of racing for that matter. You have probably fallen off the edge of the timing tables for light loads and high rpm. The 32 degrees of timing is for WOT and has nothing to do with part throttle. When the headers glow red there is either big back pressure typical on a turbo engine under high boost or the timing is retarded and the fuel not finished burning before the exhaust valve opens. You have a loner duration cam and the exhaust opens earlier requiring more timing at low rpm and light loads. You will be hard pressed to get detonation with no load on the engine as the cylinder pressure is low but can get preignition from the egt being so high with the retarded timing. my .02 cents on this anyway..
I guess I need to put the car back on the street and log some data and see where to go from there. Thanks for the ideas on the glowing headers and the timing!
Burning Brakes
Joined: Aug 2006
Posts: 1,061
Likes: 99
From: Seattle WA
I have 2 suggestions:
1) verify your actual timing with a timing light as best you can. Datamaster is only giving you the commanded timing, but you could have other distributor problems that make your actual timing way off. Being off 4 or 5 degrees from optimal under light load would not produce the symptoms you are seeing.
2) take your car somewhere where you can hook it up to a wideband o2. Again, you think you're fueling X amount because of your injector size and what's in your chip. You could be way off from where you think you are.
I think you have some global problem that's messing up a lot of other stuff.
P.S. - I'm running fastburn heads on my boat and am running about 39 degrees total timing without any knock counts.
1) verify your actual timing with a timing light as best you can. Datamaster is only giving you the commanded timing, but you could have other distributor problems that make your actual timing way off. Being off 4 or 5 degrees from optimal under light load would not produce the symptoms you are seeing.
2) take your car somewhere where you can hook it up to a wideband o2. Again, you think you're fueling X amount because of your injector size and what's in your chip. You could be way off from where you think you are.
I think you have some global problem that's messing up a lot of other stuff.
P.S. - I'm running fastburn heads on my boat and am running about 39 degrees total timing without any knock counts.
