I used Craig's software and went for a drive. It works but I have a few questions.

1. All the numbers on the first page seem normal but on pages 2 and 3 some numbers seem wrong like "O2 sensor ready" and "Engine running" are always 0. The O2 sensor value changes though and the engine runs fine.

2. I did a little WOT run and some knock retard showed up. About 2-3d from 2000+ rpm for around 20-23d total advance. I was using 87 octane, would 92 get rid of this and does it affect power much?

3. MAT readings were around 65. I have a K&N right on the TB. What kind of readings do you guys get?

This stuff is really cool and I think I'll start burning my own chips soon. Thanks for any help.

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'90 Red Formula Firebird
305 TPI 5-speed UBC Sports Car Club

[This message has been edited by CheezX (edited July 28, 2001).]

 

I don't know about question 1. Yes, using 92 octane will greatly reduce your knock retard, hence giving more power. My MAT readings are usually just above atmospheric temperature, unless I've been sitting in traffic. Is the 65 in degrees C or F? If F, then that's pretty good for a throttle-body mounted air filter. If C, then that shows you're pulling in a bunch of hot air from your engine compartment, which could be contributing to your knock retard and also costing you power due to the less-dense air.

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Greg Westphal
'87 IROC 355TPI/A4

 

After looking at the data logs again it seems that there are 2 MAT readings. One is always 64 F the other one changes so I assume that is the correct one. It was around 140-150 F. I guess I'll need to make a cold-air intake.

 

I think 2-3 degrees of retard is not much to deal with and I would back out that much in that area when you start doing your own prom. I don't think it'll cost you much in power but by adding the higher octane gas it will cost you more in the wallet. I don't know in your area but around here it's about a $.20 per gallon difference. Besides, higher octane doesn't always mean better gas, but it does mean that it burns slower.

 

I have a cold air intake and my MAT readings are usually around 130 deg. What are others seeing?

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'87 Formula WS6 - ZZ4 Crate TPI, ported heads, LT4 hot cam, 1.6RR, Accel runners, Accel lower, ported plenum, Edelbrock 58mm TB, pulleys, SLP cold air, headers and full exhaust, gutted cat, Walbro 255, Koni yellows, aftermarket panhard & LCA's.

 

Is that with a relocated MAT and is that in Celsius or Fahrenheit?

If is relocated and the temp is *F; you are aware on SD cars that relocating the MAT has a dramatic effect on the MAT Tables (as they are expecting the MAT sensor to be inside the plenum). Your mixture will be too rich and you either will have to readjust the MAT Tables or convert the MAT back to inside the plenum to get the mixture correct.

 

Glenn, I was looking at the wrong column cause the value there went to 0! It's actually 120-130 F during normal driving. I have a T/A hood and cut holes under the louvers. Maybe it helped feed cool air. I'm going to try driving with it covered up and see if it there's a difference. MAT is in stock location.