Does it work this way
Thread Starter
Racer
Joined: May 2004
Posts: 270
Likes: 0
From: NORFOLK VA.
Does it work this way
1. In the constants table there is mode called Highway mode spark rpm disable thresh,it is set at 6350rpm does this mean at this rpm that ignition spark will be disabled?
2. My tcc force lock speed is set at 109 mph should this be set lower or
higher for a better 1/4 mile time?
This is on a 85 I am using the 1f file. THANKS
2. My tcc force lock speed is set at 109 mph should this be set lower or
higher for a better 1/4 mile time?
This is on a 85 I am using the 1f file. THANKS
Instructor
Joined: Aug 2004
Posts: 108
Likes: 0
I didn't know this feature was available as early as 1985... Anyway, my 91 Vette has highway fuel and spark modes. I suppose yours is similar to mine in that respect.
Fuel: works during crusing conditions. The ECM allows the air/fuel mixtrure to be leaner than 14.7. The result is lower fuel consumption but the price you pay is higher emissions. The three way catalytic converter is of two-bed design where both beds are only working in close vicinity of 14.7. I think EPA stopped this feature so it should be disabled from factory.
Spark: When the engine runs leaner one would also want to increase spark advance a little bit. Spark uses its own set of entry/exit parameters.
Hope this helps!
Fuel: works during crusing conditions. The ECM allows the air/fuel mixtrure to be leaner than 14.7. The result is lower fuel consumption but the price you pay is higher emissions. The three way catalytic converter is of two-bed design where both beds are only working in close vicinity of 14.7. I think EPA stopped this feature so it should be disabled from factory.
Spark: When the engine runs leaner one would also want to increase spark advance a little bit. Spark uses its own set of entry/exit parameters.
Hope this helps!
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by MR.KIDD
1. In the constants table there is mode called Highway mode spark rpm disable thresh,it is set at 6350rpm does this mean at this rpm that ignition spark will be disabled?
2. My tcc force lock speed is set at 109 mph should this be set lower or
higher for a better 1/4 mile time?
This is on a 85 I am using the 1f file. THANKS
2. My tcc force lock speed is set at 109 mph should this be set lower or
higher for a better 1/4 mile time?
This is on a 85 I am using the 1f file. THANKS
As for the forced TCC lock, Corvette0096 has his enabled at 90mph and runs into the high 11's. I have been trying to get him to try running it at a speed where it will not lock up during a dragstrip pass. The reason is that when the TCC Locks up the RPMs falls out of the optimum range, at least that is what I see because I can hear his engine drop RPMs dramtically and out of the power band. In my opinon if the engine is allowed to stay in that region its going to give better pass times. If you can I would just try it both ways. Stock setting is 90 MPH for the TCC Lock and that is where Corvette0096 has his set up. The way I see it, if going into lock up was such a great thing, then all race cars would have it
