924Board.org

[morghen]

Are you saying that WUR enriches by restricting the air flow trough the air meter?
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Supercharger and EFI kits
https://www.the924.com

[Fasteddie313]

The results are in..

All of these numbers are with the airplate at 100% travel and full flow, per injector..

103 psi system pressure

Frequency valve full closed/unplugged
76.5 grams in 30 sec

Frequency valve plugged in and running as default (can measure actual duty cycle later)
102.53 grams in 30 sec

Frequency valve full open, +12v constant
163.97 grams in 30 sec

Frequency valve full open, +12v constant @ 89 psi system pressure (removed my bump shim)
159.53 grams in 30 sec


WOW this means a LOT.. The lower chamber pressure adjustable range is HUGE!!
You can DOUBLE the fuel flow between 0% duty cycle and 100% duty cycle!! 100% increase in fuel flow with 100% increase in FV duty cycle..

I almost can't believe that, it is said that our lambda system has very little authority and is only effective at idle and cruise and can only work at all if your tune is already very close..
It looks like the actual capability of the lower chambers far exceeds the capability of the lambda brain..


And that change in system pressure has little to negligible effect only increasing flow by around 3% at a 14% change in pressure..

I expected the system pressure to have all the authority and the lower differential pressure to be a weak modifier, my hypothesis was wrong on that but this is great news for controlling CIS-Lambda via microsquirt, it means microsquirt will have much more fine control that I imagined...

Now if someone can turn those gram/sec numbers into lb/hr and then into HP that would be really cool..

What does 164 grams per 30 seconds of fuel get you as far as HP?
X4 because that's just 1 injector..

This is going to be pretty much the max HP a 931 fuel distributor can support reasonably, without internal modification..

I also found the airplate to have 43mm of maximum travel down from its rest, and that the last 3-4mm had no increase on fuel flow..
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80 Turbo - Slightly Modified

[Fasteddie313]

[reanimotion]

Excellent work Ed thanks

1 CC of fuel is 748.9milligrams

so

164 grams per 30 seconds = 438 cc/min or 41.7 lbs/hr

good for approximately 330HP at 0.5 bsfc
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Steve
www.FrankenCIS.com
1981 928S ROW KE3-Jetronic 4.7 not even remotely stock

[Fasteddie313]

[reanimotion]

Was your 100% travel test full down or at the 37mm max opening point for the metering slits

apparently past 37mm the last few available mm of travel before it bottoms actually starts to close off the slits again, so there may be more flow in the head than you measured if the plate was bottomed out

see http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/665600-information-about-934-cis-injection.html#post6626613
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Steve
www.FrankenCIS.com
1981 928S ROW KE3-Jetronic 4.7 not even remotely stock

[Fasteddie313]

Bottomed out..

The GF held the plate for me.
Though she is a great help, it would have been much more complicated trying to get her to understand exactly what you just said so bottomed out it was..

So there you have it, 1.5 Bar boost it is.. You're not getting there without full control of the lower chamber pressure though..

That lower chamber pressure is the hat trick..
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80 Turbo - Slightly Modified

[reanimotion]

Then thanks to you both!, that's good new data, and there is probably more fuel available than you measured and the 300+ HP should be easy on a stock head.
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Steve
www.FrankenCIS.com
1981 928S ROW KE3-Jetronic 4.7 not even remotely stock

[morghen]

We dont have the freqvency valve in europe, and i got 9AFR at 1.5bar.
1.1bar gives me an AFR of 11 at 5000RPM and above.
_________________
Supercharger and EFI kits
https://www.the924.com

[Fasteddie313]

Ah yes you have a different distributor and it's very possible it could flow a lot more than our US ones..

You could run the test with your metering plate wide open and switch 1 injector into an empty bottle for 30 seconds and see what shey'll really do..

Being so rich up high like that sounds like an excellent built in safety measure to keep you from blowing up your engine..

You would want to map/adjust for higher control pressure up top at that boost:rpm to actually be able to run there not so insanely rich..
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80 Turbo - Slightly Modified

[Fasteddie313]

I got my Merc V8 fuel distributor in yesterday and my first thoughts "wow it's big"... Real big, scary big..

This morning I got a chance to take it to the car to do some eyeballing and by god I think it'll fit in the OEM location between the washer bottle and the RAD, and between the cam pulley and pop up lights bar leaving room for the crank arm swing but it's going to be tight..

If anything I think it may require me to swap to lower profile RAD fans to make room for its 3" air exit (vs 2.5" 931), maybe, maybe not..

Mounts are different, AFM intake is bigger, AFM exit is bigger, injector lines need some crazy plan, supply/return lines need customizing I think etc..
It's going to be a lot of custom but I think I can pull it off

Don't hold your breath, it will be some time. I think I'll get the injector lines situation sorted out first (I have a scheme) and get all the electronics sorted out before I go trying to install it but you never know, I may get a hair up my a** and try some crazy stuff at any time..

I'm running pretty good with a /6 compressor right now so I think I'll enjoy that for a moment before I put the car down for changes again..
I'll snap some pics of this monster sitting next to the original under the hood for you guys when I can get my fingers on the camera today..
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80 Turbo - Slightly Modified

[Fasteddie313]

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80 Turbo - Slightly Modified

[Fasteddie313]

I have recieved my care package from Australia

Everything looks great and very professional.
I was not expecting the connectors but I see they fit the BMW coolant sensors I have so that's really cool.

The instructions folder that came with it is very nice. It shows how to do all the wiring and even detailed instructions on how to set all the settings on the Microsquirt that look simple.





Thanks Steve!
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80 Turbo - Slightly Modified

[morghen]

looks good, lets see what it can do on your car
_________________
Supercharger and EFI kits
https://www.the924.com

[coldwarvet]

...did you ever get the system installed and running?...I have the system installed and am currently doing some tuning ( I didn't get the nice book that you did)...thought you might be able to help...
Hank
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931 S1 roadster...