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les_garten les_garten is offline
Macht Schnell
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Join Date: Jun 2003
Location: PSL, FL
Posts: 861
Originally Posted by dsiegel360 View Post
Thanks Les. Yesterday I was concerned about cruising at 2500-2800-rpm's with a 14.3-14.8 afr.Thought it was too lean. But at 3000-3500 it was 13.8- 14.1. Which is where I should, so do you think there is a problem with 14.3-14.8 at 2500?......Actually, I see what you are saying. There is no adjustment that will change the 2000-3000 range without changing the 3000-3500 range.
Hi Doug,
The 930 is so low in compression, that if it is not on boost, there is nothing wrong with a perfect mix of 14.7. The issue is when you are boosting and your effective compression ratio increases rapidly to put you in the "Detonation Zone".

Let's say, you took the turbo off. There would be nothing wrong with running that engine at 7000 RPM on pump gas at 14.7 AFR. As long as it would handle acceleration enrichment, and starting enrichment, it would be fine.

Throw in some boost and the scenario changes rapidly...

I have your CD by the way. I'll get it out next week. Thanx for the MUSIC!
---Les Garten---85 930, Andial IC, GHL Headers, Fabspeed Dual, K-27 HF2, 3.4 JE Full Finned 7.5:1 CR, 964 CAM'd, Carerra 3.2 Manifold Cut/Flipped, Tec3r, Siemans 55#, GSF Fuel Rails, Clewett Crank Trigger, Clewett Cam Trigger,Dual Plugged, ARP Head Studs/Rod Bolts, Clewett Wires.Tial 46mm WG, Tial 50mm BOV, WEVO Shifter,934 Boost Gauge, Wideband EGO Sensor/Gauge, C2T Head Gaskets, '88 MB 300TE,BMW R100RT
Old 04-11-2008, 03:32 PM
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