pgmfi.org

I'm wondering where that 450 map that comes with ghettodyne came from. Finally got my friend's CRX boosting on the map and got my wideband sensor completed and calibrated.

It seems to me whoever tuned the map did a pretty good job of the mixtures but were using a turbo that didn't spool until about 4200 RPM. We're playing with this CRX with the WG pegged wide open. With this non intercooled setup flooring it we start making a few PSI of boost around 3500 RPM and it's quite lean, 13.5. As soon as it hits 4200 it drops to 11.5. Our safe target AFR will be around 11.0-11.2.

So if we connect the WG actuator we'd be making a few PSI down around 2500-3000 RPM. Make 5 PSI at 3000 RPM and 13.5 AFR it will most likely go kaboom!

I'm thinking of re-engineering the boost code and selling a few of my chips on ebay just to get rid of the OTP ones I accidentally bought, but I thought I'd point out that the stock 450 maps being sold and ebay may be engine killers.

-Michael

I'd personally recommend waiting until a better boost solution is here. The 450 bin for boost that comes with GhettoDyne right now is based off of George's MapHack theory where it scales the MAP sensor output and uses the stock 15x17 maps.

I am working on a complete code overhaul for GhettoDyne right now, and once that is done a better boost solution that doesn't scale the MAP signal at all.

Mike

Yea Xtensive is Right.

Wait For Some Better Code to come out and all the Minor Ignition glitches i have been experiencing (as well as a few others) Come out. If i were You i would also Consult The creator of the GeorgeHack Bin that comes with the Gettodyne for boost Just to Make sure it's OK to sell HIS code. In my Personal opinion i don't think that any of this Code should be SOLD but SHARED instead with the Exception Of donations. Just think of how many people payed 1000 Bucks for Hondata JUST cause someone was Smart and greedy and Didn't want to share their ideas.

Just my .02
Brain

Must make some theoretical remarks here, to spread info.

Detonation usually happens at low RPM's. The reason it happens at high RPM's under boost, is because the fuel mix leans WAY out, like 18:1, and there is not enough fuel to cool the charge. This situation usually only happens to guys who slap a junkyard turbo on without provisions for additional fuel, or an intercooler, and such. 18:1 mix, 7 psi boost, red hot charge because of no intercooling, no spark retard to account for the faster flame propagation, all this makes detonation possible at high RPM.

But if you are intercooled, and you have a NORMAL AF ratio, and are running at least 93 octane, and have your spark retarded at least .5 degree per psi of boost, there is no reason at all to worry about detonation. Just ask guys who have this setup already, and are using GhettoDyne to manage their fuel and ignition, or $ome other fuel and $park management $y$tem.

11:1 AF mix is WAY too rich. All you're accomplishing is to fry your catalytic converter, and blow your fuel out the pipe.

And for what it's worth, I agree that the software should be SHARED. I'm all about Paying it Forward, and I'll help anyone that is interested to get boosted with GhD. Just drop me a line.

One last remark: Heck if your turbo isn't going into boost until 3500 RPM, either your turbo is too big, or you have some serious kinks in your aspiration system, that is choking off the flow through the turbine, or perhaps your compressor and/or turbine wheel have too much clearance between the fin tips and the housing. That can happen if the bearings were shot and later replaced. Worn bearings can allow the wheels to grind against the housing. The clearance shouldn't be more than .020". Heck even that figure is high. Whatever the problem, (or perhaps there is no problem), the right turbo should spool between 2000 and 3000 rpm, and max out quickly, to at least 6 or 7 psi, unless you have the WG set lower.

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EDIT: I am not responsible for damage to your car by utilizing the information below!!!

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Post Edited (08-09-03 20:03)

Heres a program that works really well with the afc hack. The AFC settings are :

1-3.5K= -40%
3-4k= -38%
4.5k= -35%
5k= -35%
5.5-7k= -35%

THese settings are the same for the high and low. This is on a 1990 crx si with 8.7:1 cr, 94 octane fuel, stock fuel pressure, upgraded fuel pump, z6 vtec head. The program pulls ignition timing when it should be coming into boost if you use my afc settings above. This car runs a 60 trim T3 turbo and spools a little before 4000 rpm's. It made 206 hp at on 6 psi of boost and ran low 14's at 103 mph. The ignition base timing is set to 19 degrees base (you read right, it provides good low rpm driveability and brings boost on better). Spark plugs are one heat range colder. It should be a pretty safe tune, it has a good amount of spark retard but still maintains great power and driveability. Drives better than most stock turbo cars.

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Post Edited (08-09-03 20:05)