Perrin EBCS

[Piper747]

I installed the Perrin 3 port ebcs today. I have some fine tuning to do as AFR is a bit rich and the graph could use some smoothing. The car spools a bit faster and holds boost better in the higher rpm. Here is a log for those who are interested.

[Piper747]

Just tried something new with the rom. 1st gear really hauls now! When the boost first spikes, there is a slight feel and sound of the tires breaking free. Just briefly. That would be nice to have the power to spin all four at will...lol

[Seawolf]

Are you sure about those AFR's? I see values in the 11's which is lean, not rich. No knock though, but I would be worried about exhaust temps being high. Especially at 3,424RPM you have an AFR of 11.89

[Piper747]

I guess I was referring to the 10.55 in the higher rpm. I was under the impression (from the reading I have done here) that AFR in the 11's at peak boost was not too lean. What do you tune your car to?

[RotorGlow]

The lower the number, the more rich it is.

11 lbs. of air vs. 1 lb. of fuel is more rich then...
16 lbs. of air vs. 1 lb. of fuel

[Piper747]

right...lol So you are saying 11.8 at peak boost is lean or not?

[Seawolf]

The lower the number, the more rich it is.

I know how it works

10.5-11.5

In the 3500 RPM Range, your boost is around the max (though your timing is pulled), I would shoot for a lower AFR than 11.89.

[Piper747]

I'll do some more tweaking tonight and post up another log. Why do you think my timing should be pulled?

[Seawolf]

Because it is. To get more boost, you have to decrease the timing and/or richen the fuel to keep knock down. If you look at your knock timing advance in your log and graph it, you'd see the car pulling timing advance when the boost peaks, then gradually adding some back in up to peak RPM's. It is the way of things for a boosted application. Higher octane fuel (read: e85 or racing fuel) would mean you wouldn't have to pull so much timing though.

Sorry, just re-read my post above. I see where the confusion is. You don't have to pull more timing than you have, there is no knock. Actually, if you richen up the mixture a bit, you could play with putting some back in until you get 1-2 knock counts...then back it off 1*.

[Piper747]

Right...I did miss-read. I agree....

[secondchace]

Originally Posted by Seawolf

Are you sure about those AFR's? I see values in the 11's which is lean, not rich. No knock though, but I would be worried about exhaust temps being high. Especially at 3,424RPM you have an AFR of 11.89

11.89 isnt dangerous, if anything, its perfect at a lower rpm, not alot of fuel wasted, and no knock threat.

WOT 5-7000 rpms is where u need to be careful, anything less the 12 is fine

[Piper747]

Thanks for the second opinion.

[Piper747]

I spent some time this evening attempting to lower my afr at peak boost. I had a hard time getting it to run richer. Actually, it seemed to get richer the first log after I changed the fuel map and all following logs seemed to return to the afr it was before I made the adjustment! Does anyone have any idea what may be happening? Any adjustments I make seem to take effect after 3700 rpm or so but I cannot get the afr to be richer than 12.2 or so at around 3300 rpm and 180 - 200 load regardless of the fuel map. I tried to log IPW and it does not seem to work as I get no value at all. Anyone???

[Seawolf]

To enrichen it now, if setting a fuel target doesn't work, is to play with the injector latency setting. Start adding a few milliseconds and it should start to richen up

[Piper747]

I was wondering if this was the next step. Now...should that be the injector base latency map or the injector battery voltage latency compensation map?Thanks for the input. Ill give that a try.