16v turbo dyno testing
11-13-2010, 01:51 PM
#61
Nordschleife Master
11-13-2010, 02:45 PM
#62
Formula One Spin Doctor
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11-13-2010, 03:16 PM
#63
Race Car
When I was messing with my old Ford 2.3 turbo, I was able to squeeze a lot more out of it by leaning it out from around 10.0:1 to 12.0:1. I had a HUGE intercooler on it, and never had my intake temps exceed ambient so long as I wasn't idling. One big advantage of the XR, though, was that I was able to put that intercooler in there. But I also didn't have the feedback you have. I was messing withe the Ford PCM (though I had done a MAF conversion).
Of course, I killled the turbine housing in about a year. But it was a fun year!
Of course, I killled the turbine housing in about a year. But it was a fun year!
11-13-2010, 06:16 PM
#64
Nordschleife Master
Haha I'm sorry if it seems like it. I'm definately not question anything, I'm just interested in this stuff myself and there's so few in the 944 world to discuss tuning with.
I've run my car in WOT conditions with IAT ranging from 3 deg C to +50 deg C and have been adjusting IAT correction a lot.
I find it most important to add fuel at lower temps than the other way around since hotter IAT means richer mixture without compensation. For instance I have to add 10% more fuel at 0 deg C than at 30 deg C to avoid a lean condition.
I actually have a 3d IAT correction table to be able to have specific values at low/zero TPS to account for heat soak conditions etc.
I've run my car in WOT conditions with IAT ranging from 3 deg C to +50 deg C and have been adjusting IAT correction a lot.
I find it most important to add fuel at lower temps than the other way around since hotter IAT means richer mixture without compensation. For instance I have to add 10% more fuel at 0 deg C than at 30 deg C to avoid a lean condition.
I actually have a 3d IAT correction table to be able to have specific values at low/zero TPS to account for heat soak conditions etc.
11-13-2010, 06:31 PM
#65
Drifting
well done Chris, they are some great numbers there. Is this a track or street engine? If its a track engine tell the owner to get some footage on track, if there is one thing we are missing on our forums its more footage of our cars on track,in particular the high hp ones
11-13-2010, 08:29 PM
#66
Formula One Spin Doctor
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Haha I'm sorry if it seems like it. I'm definately not question anything, I'm just interested in this stuff myself and there's so few in the 944 world to discuss tuning with.
I've run my car in WOT conditions with IAT ranging from 3 deg C to +50 deg C and have been adjusting IAT correction a lot.
I find it most important to add fuel at lower temps than the other way around since hotter IAT means richer mixture without compensation. For instance I have to add 10% more fuel at 0 deg C than at 30 deg C to avoid a lean condition.
I actually have a 3d IAT correction table to be able to have specific values at low/zero TPS to account for heat soak conditions etc.
I've run my car in WOT conditions with IAT ranging from 3 deg C to +50 deg C and have been adjusting IAT correction a lot.
I find it most important to add fuel at lower temps than the other way around since hotter IAT means richer mixture without compensation. For instance I have to add 10% more fuel at 0 deg C than at 30 deg C to avoid a lean condition.
I actually have a 3d IAT correction table to be able to have specific values at low/zero TPS to account for heat soak conditions etc.
11-14-2010, 07:58 AM
#68
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well done Chris, they are some great numbers there. Is this a track or street engine? If its a track engine tell the owner to get some footage on track, if there is one thing we are missing on our forums its more footage of our cars on track,in particular the high hp ones
11-14-2010, 07:59 AM
#69
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11-14-2010, 08:10 AM
#70
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Haha I'm sorry if it seems like it. I'm definately not question anything, I'm just interested in this stuff myself and there's so few in the 944 world to discuss tuning with.
I've run my car in WOT conditions with IAT ranging from 3 deg C to +50 deg C and have been adjusting IAT correction a lot.
I find it most important to add fuel at lower temps than the other way around since hotter IAT means richer mixture without compensation. For instance I have to add 10% more fuel at 0 deg C than at 30 deg C to avoid a lean condition.
I actually have a 3d IAT correction table to be able to have specific values at low/zero TPS to account for heat soak conditions etc.
I've run my car in WOT conditions with IAT ranging from 3 deg C to +50 deg C and have been adjusting IAT correction a lot.
I find it most important to add fuel at lower temps than the other way around since hotter IAT means richer mixture without compensation. For instance I have to add 10% more fuel at 0 deg C than at 30 deg C to avoid a lean condition.
I actually have a 3d IAT correction table to be able to have specific values at low/zero TPS to account for heat soak conditions etc.
11-14-2010, 02:15 PM
#71
Nordschleife Master
11-14-2010, 08:02 PM
#72
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This is interesting.
One thing I always wondered; on a wideband air/fuel ratio meter, does the proper air/fuel ratio get sensed whether the fuel is fully vaporized or just partially vaporized. Another words, theoretically, one can go so rich that not all of the fuel would vaporized, or burn; but would the actual fuel being dumped show up on the wideband?
Last edited by TurboTommy; 11-14-2010 at 11:00 PM.
11-15-2010, 01:06 AM
#73
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This is interesting.
One thing I always wondered; on a wideband air/fuel ratio meter, does the proper air/fuel ratio get sensed whether the fuel is fully vaporized or just partially vaporized. Another words, theoretically, one can go so rich that not all of the fuel would vaporized, or burn; but would the actual fuel being dumped show up on the wideband?
One thing I always wondered; on a wideband air/fuel ratio meter, does the proper air/fuel ratio get sensed whether the fuel is fully vaporized or just partially vaporized. Another words, theoretically, one can go so rich that not all of the fuel would vaporized, or burn; but would the actual fuel being dumped show up on the wideband?
11-15-2010, 03:51 PM
#74
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Chris, nice numbers! 
I especially appreciate that they're done on an engine dyno and with that "modest" boost pressure.
Which turbo do you use?
I especially appreciate that they're done on an engine dyno and with that "modest" boost pressure.
Which turbo do you use?
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Power. Lots is good, more is better, too much is just right...
'87 951, RIP
'00 996 C2 L92U AQ / IXAA IXRB IX54 M96/7.xx G96/7.88 M030 M375 M376 M436 M476 M601 M983 ... + 991 GT3 brakes, 997 GT3 sway bars, fully monoball'd suspension, Bilstein Cup Car coilovers, do88 Big Pack ICs. 10 & 12 x 19" BBS CH-R wheels with 265/30 & 325 /30 -19 MPSC2s.
Pete
Power. Lots is good, more is better, too much is just right...
'87 951, RIP
'00 996 C2 L92U AQ / IXAA IXRB IX54 M96/7.xx G96/7.88 M030 M375 M376 M436 M476 M601 M983 ... + 991 GT3 brakes, 997 GT3 sway bars, fully monoball'd suspension, Bilstein Cup Car coilovers, do88 Big Pack ICs. 10 & 12 x 19" BBS CH-R wheels with 265/30 & 325 /30 -19 MPSC2s.
11-15-2010, 05:30 PM
#75
Rennlist Member
Keep in mind that an O2 sensor does not measure fuel – it measures Oxygen. If there is a misfire it will read the O2 since there is not complete combustion – so incomplete combustion, even if it is very rich, will report back as a lean mixture when it is not really lean.
Is it safe to say that widebands often read leaner than the actual mixture when starting to tune on the rich side? (Even if there aren't any misfires)
For example: cold start on a cold day; I understand that an engine might need as rich as 6 or 7:1 air/fuel to get it started. I can't see a wideband (which is theoretically up to operating temp) giving a proper reading because alot of the fuel wouldn't be vaporized in the exhaust (even if there was no misfire). Is this correct?
If so, it stands to reason that engines often run richer than indicated (when tunning on the rich side to ward off detonation, for example).