Tuesday, August 08, 2006 - 09:40 pm, by: Anish Varsani(Yomama)
I've finally got an M90 setup running 6-7 psi working. I'm at the tuning stage as was after a guide as to how much ignition retard I should expect to run to avoid detonation.
At the moment, I'm running -10 degrees retard using an SMT6 but am still getting detonation at WOT. I'll be running on the road this weekend to try and tune out all detonation.
At the moment, with a reset ECU, the car runs great. Smoking tires all the time. However, at full load and WOT it get detonation and the stock ECU tries to correct without much success. Afterwards, the car runs like a dog due to the excessive longterm timng retard of the stock ECU.
Do any other supercharged V8 soarer owners here have any maps I can use as a guide before getting the car dyno tuned?
Tuesday, August 08, 2006 - 10:07 pm, by: Neil Griffiths(Aussiesc)
I run a stock ECU for about 18 months.Then Harrys next 18 months ( RPM lifted to 8,000 ) I used to get some Det on WOT..just lifted my foot off go pedal ( Sometimes,,heheh )
What you gotta look for is * Longitivity *.. My Soarer has been blown now for 3 years Still going strong.
Don't try and use someone elses setup as a guide, all engines ARE different. You MUST be unique
wow -10 degrees thats massive on mine i setup the microtech to retard 0.5 degrees per pound of boost. No detonation at all. keep in mind mine is intercooled and a centrifugal unit
Wednesday, August 09, 2006 - 01:01 am, by: Cihan Aday(Cihan)
Anish, what AFR are you running with 6psi? I doubt it, but is it intercooled?
You should aim for 11:1 full boost with 1 degree retard for every pound of boost and take it from there. Since its a positive displacement blower and possibly not intercooled, 10 degrees retard is probably lacking at various stages. Average 65% compressor efficiency puts you well over 40+ degrees celsius added to the intake charge at low pressure ratios. You need ignition compensation for that also.
Wednesday, August 09, 2006 - 06:06 am, by: Anish Varsani(Yomama)
M90, non intercooled.
I heard detonation around 4800rpm and WOT then backed of slightly and it stopped. Not sure on the AFR, I don't trust the narrow band reading under 13:1.
The base MAP has +48% fuel in this area but the extra fuel dosn't seem to make a difference. I'm trying to get rid of all detonation before it goes on the dyno so that way there's no excessive long term timing retard otherwise every time the ECU is reset, the car will drive well for the first few hundred K's then sluggish afterwards.
I'll get the dyno operator to work in as much timing as he can after he's set up the fuel map.
Wednesday, August 09, 2006 - 08:19 am, by: Anish Varsani(Yomama)
I'm trying to decide whether to get a MAP sensor or not. I had the car tuned before supercharging. Is it safe to use this map as the base map and use the MAP sensor to sense boost and retard timing accordingly?
Wednesday, August 09, 2006 - 11:10 am, by: Cihan Aday(Cihan)
Try pulling 15 degrees from 4500 to 5000 at 100% tps.
Rule of thumb, for 6psi you will need 40% additional fuel to maintain the same AFR as factory. Since volumetric efficiency doesnt scale linearly, 6psi is more like 5psi which equates to about 35% additional fuel. You then need to pull timing to counter the temperature delta and the boost itself. Since its not intercooled, 15-20degrees boost retard would be my starting point above 3500rpm. You will find that pulling 1-3degrees sometimes has NO effect on power at all. In that case its because it was far to advanced and increasing peak chamber pressures for no reason.
Just keep pulling timing where it knocks Anish. If you have standard injectors, maybe they are maxed out at + 48%? Im not familiar with their capabilities..
Regarding the MAP conversion, it will be hard to do using a piggyback. Anythings possible, but it will definitely cause headaches.
Wednesday, August 09, 2006 - 01:13 pm, by: Anish Varsani(Yomama)
Yes. Malpassi 1.7:1. Base fuel pressure was set at 40 psi. Will have to make sure it hasn't drifted. I've was advised to check it regularly, ie. every oil change. The stock fuel regulator is still in circuit. The malpassi is piped in down stream from the stock reg.
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