Quote:
Originally Posted by Barry Bordes
Peter from your data the turbine pressure (17.1psi) is very close to the boost pressure (17.7psi). Is this what you normally find, within a pound difference?
Also your AFRs in the mid -11s at 17 psi is leaner than I would have thought. My EGTs are so high (1000°C) that I have been adding extra fuel trying to cool the temps.
Barry
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Hi Mate,
I have done allot of work on the mixture settings to make good power on that ~1.2kg/cm to 1.3kg/cm boost level, instead of typing it all out here you can have a read of all the tests on Aquamists site >
http://www.aquamist.co.uk/vbulletin/...t=1590&page=10 (spans a few pages back from here).
For the Exhaust manifold pressure to inlet manifold pressure, I currently am at 18.5 to 19 psi inlet boost pressure and the exhaust manifold pressure at 7000rpm in 4th (~125mph) gear is exactly 17.5psi, and this is with ~4.2 psi exhaust system pressure.
*At full boost pressure* The AFR on average is 11.3:1 with the current WI setting, it only goes towards 11.4:1 at revs past 7400rpm to stop the power from falling off where I need to hold rpm to say 8300rpm to save making a gear change be it on a straight or hold out 5th gear for 200+mph top speed as my car is geared for too
. Lower boost pressures (0.5bar to near 1.0bar) the AFR is around ~12.0:1 setting (more so because any more excess fuel is not required, especially with water injection or even without) Anything with more excess fuel really takes away allot of power. My EGT was always around 980 deg C or so with the correct ign timing, this set fuel mixture, and WI rate. Anything outside of these settings results in lower power, too high an EGT, misfire, or and less measured performance (< too over cooled *fuel or combination of fuel and water*, or not enough ignition advance especially) in my standard 90-140kmh testing I do.
Looking towards doing the next level of tests (will pick around 22psi range or 1.5bar gauge boost pressure) and will be *I think* more than happy with that, should be a good compromise between pretty high power level and long term durability, my goal is Ferrari F40 type performance (while still having a catalyst/quiet exhaust and baby bottom smooth motor combination) as you can read in my threads, I am there so far as the USA spec F40 is but a small margin off the European version, another ~40bhp should cover it
My aim: is to do around 127 to 128mph in a standard 400m test on the road in a full road set up, and 0-100kmh range in sub 4 seconds. (60-130mph in about 8 second range) on my set up ~22psi should yield this from where it is now. Should have a honest 480bhp (same as Ferrari F40), not much in this day an age I know, but then again how many
narrow power band 500rwhp cars are about that cant do any of these actual performance measures in road trim on an actual normal road?....... sure you can bolt on slicks, drag radials, semi slicks etc, flat shift it, smash out the windows to save weight, run jet plane loud exhaust, open waste gates, alcohols fuel systems or leaded race fuels, etc etc but its not
a real street car then (please take no offense drag type runners or people with powerful cars).
For people who might be interested in more on factual testing of road cars, power (various measures, engine and rwhp of different systems), actual measured weight: I started this "tested" kerb weight thread and analysis of cars performance to the power they claim to have using well know accepted formula. Its a fair read if your struggling to stimulate your senses with internet posts that are not porn related lol
http://www.ausrotary.com/viewtopic.p...eight&start=80