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My 924 Turbo, finally out on the road !
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CÚdric  



Joined: 27 Aug 2004
Posts: 1766
Location: Sweden

PostPosted: Thu Jun 28, 2018 5:34 pm    Post subject: Reply with quote

Fasteddie313 wrote:
CÚdric wrote:

Im not set on the fuel side yet, will see how the AFRs go when i raise the boost, if i get similar problem as carreraRSR and morghen i will have to lean it out in some way, Either by having a boost controller or rpm switching of a solenoid on the WUR line.


I have a US 931 FD I could send you, bolt on..
Add a microsquirt, WB, IAT, MAP, and easily a tach signal, and you should be able to tune your ARFs with tunerstudio via lower/upper chamber differential pressure adjusted by controlling the frequency valve, like CIS-E but works like an EBC externally...
Just leave the WUR alone.. Free FrankenCIS firmware code is all..

It will control your boost for you too, and log for you, and it sounds like you already have the IAT and WB..

Should get you into the high 290's just fine (will pump like 330)..
This is really the next step I should have taken instead of jumping in head over heals for the V8 rig..

If you eventually decide you are satisfied with it I would gladly take a 6.10 housing for it, or maybe we could work out a deal for a euro bumper or something..

That's about as legit "tuning" you can get unless you go for a real CIS-E head of some sort, or EFI.. afaik


Thats a cool idea, hopefully i will be in the ballpark with the current setup, but if I cant get it right, this might be a possibility.

Is the FD controlled by a pure PWM signal? And how much control authority doesn it have? Can it adjust 1% or 25% of the total fueling? That would be nice to know. Why dont more people use that option over there? controlling a PWM is super simple.

I haave non stash of 6.10 housing though
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CÚdric  



Joined: 27 Aug 2004
Posts: 1766
Location: Sweden

PostPosted: Thu Jun 28, 2018 6:01 pm    Post subject: Reply with quote

924-76 wrote:
CÚdric wrote:

I love this graph
Could you add a GT specs turbo "2660 6.10" to this graph at 0.8 and 1 bar?
Thanks


I did a simulation for steve (carrera RSR) a while ago on the 2660 at 1bar. Its a very unhealthy combination and not something i would recommend. You are pushing the compressor to very high turbospeeds and with very bad efficiency. I wouldnt use the 2660 for any more power than the CGT had, im not sure why they chose such a small compressor, probably to maximize low end driveability and get the best fuel consumption.


The map the 2660 is scaled from the 2664 map i did a while ago, i have no data on the 2660, but the design seems similar so a scaling should be good enough.



Turbo speed
[/img][/URL]

Compressor efficiency


2670


2660

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Last edited by CÚdric on Thu Jun 28, 2018 6:48 pm; edited 2 times in total
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1561
Location: MI

PostPosted: Thu Jun 28, 2018 6:28 pm    Post subject: Reply with quote

CÚdric wrote:

Is the FD controlled by a pure PWM signal? And how much control authority doesn it have? Can it adjust 1% or 25% of the total fueling? That would be nice to know. Why dont more people use that option over there? controlling a PWM is super simple.



It's just about changing the duty cycle of the frequency valve..

Fasteddie313 wrote:
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..

......................................


reanimotion wrote:
.....
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



I think their are quite a few 911 guys running this..
You can control the WUR too but it's a course adjustment compared..

Why don't more people do it?
People are lame? CIS tuning is dead? 931 tuning is dead?


That 2670 map is awesome.. I want a turbo like yours..

You have that map running up to about 1.25 bar boost? You think it would stay in the orange up to about 1.75 bar boost?
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CÚdric  



Joined: 27 Aug 2004
Posts: 1766
Location: Sweden

PostPosted: Thu Jun 28, 2018 7:00 pm    Post subject: Reply with quote

Wow, thats a massive adjustability, I cant see why this couldnt be done with a arduino for peanuts, just some fidling to get a good rpm signala. Or if you want tunerstudio and more features use the speeduino platform, which is also very cheap and then you get boost controller and other features awell aswell.

I guess you set it up as a 1 injector engine and go?

/Edit, dont know where my mind was, since its PWM i assume it goes on a boost control outlet or similar..

Are those fuel numbers with the V8 head, seems like a lot of potential fueling?.
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Last edited by CÚdric on Fri Jun 29, 2018 2:09 am; edited 1 time in total
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CÚdric  



Joined: 27 Aug 2004
Posts: 1766
Location: Sweden

PostPosted: Thu Jun 28, 2018 7:29 pm    Post subject: Reply with quote

Its 1bar manifold pressure in all runs, with a rough calibration of the pressure drop over the intake system and CIS plate thats where it ends up PR wise. I ran it at 1.4 bar manifold pressure as weel, compressor was fine there aswell. It seems to work well at higher boost pressures as long as you dont

I used the data from the 2470 924turbo compressor map to calibrate the pressure drop, asuming that the ran 0,7bar manifold as they should.
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1561
Location: MI

PostPosted: Fri Jun 29, 2018 2:50 am    Post subject: Reply with quote

Those numbers are just my OEM 931 fuel distributor, 4 cyl..
I had the plate at 100% travel too and it will flow even more at like 95% travel but went with 100% for repeatability..
Like I said I probably should have just went with that and been happy..
the V8 FD has been an extreme amount of custom (making stuff) work..
Making things from bits of metal laying around gets very time and brain consuming, and imagine if I did all that work and some overlooked aspect made it not work out therefore scrapping all the work I did.. What a relief that it all worked out.. It could have been huge work and $ down the drain if not..

I have not max flow tested the V8 unit yet but will..
I need to ask how hard I can push it for a test without hurting it..

Their is a guy doing it with some sort of $40 DIY (probably arduino) ECU burried in this thread somewhere.. Too DIY for me..

As far as the MS it does use the injector driver but with custom firmware for the MS it removes the RPM aspect from the injector driver and just varies it's duty cycle at a set HZ I believe.. So it's like firing an injector for a set RPM but varying the pulse width/open time and not HZ.. I think.. Something like that..

"INJ2 - also disconnected from RPM/INJ1 and used for the Frequency Valve"
"So essentially the MS2 believes it is operating an EFI system and the new code accepts the control information and quietly translates that to the CIS way of doing things." http://www.frankencis.com/FrankenCIS

Sorry about getting OT in your thread.. If you want to talk electronic CIS tuning maybe bump this thread..
That genius Steve might even respond to it..
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Last edited by Fasteddie313 on Fri Jun 29, 2018 3:40 am; edited 2 times in total
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1561
Location: MI

PostPosted: Fri Jun 29, 2018 2:53 am    Post subject: Reply with quote

CÚdric wrote:
Its 1bar manifold pressure in all runs, with a rough calibration of the pressure drop over the intake system and CIS plate thats where it ends up PR wise. I ran it at 1.4 bar manifold pressure as weel, compressor was fine there aswell. It seems to work well at higher boost pressures as long as you dont

I used the data from the 2470 924turbo compressor map to calibrate the pressure drop, asuming that the ran 0,7bar manifold as they should.


So...
It's showing the compression ratio (more than 1 bar) because you are accounting for a slight vacuum before the compressor due to the airplate?
So it's over 1 bar to get 1 bar because you started with less than atmosphere..
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924-76  



Joined: 05 Jun 2006
Posts: 1359
Location: Ontario, Canada

PostPosted: Fri Jun 29, 2018 3:38 am    Post subject: Reply with quote

Thank you very much

How do I covert the flow to lbs/min or kg/sec?
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CÚdric  



Joined: 27 Aug 2004
Posts: 1766
Location: Sweden

PostPosted: Fri Jun 29, 2018 6:08 am    Post subject: Reply with quote

Fasteddie313 wrote:
CÚdric wrote:
Its 1bar manifold pressure in all runs, with a rough calibration of the pressure drop over the intake system and CIS plate thats where it ends up PR wise. I ran it at 1.4 bar manifold pressure as weel, compressor was fine there aswell. It seems to work well at higher boost pressures as long as you dont

I used the data from the 2470 924turbo compressor map to calibrate the pressure drop, asuming that the ran 0,7bar manifold as they should.


So...
It's showing the compression ratio (more than 1 bar) because you are accounting for a slight vacuum before the compressor due to the airplate?
So it's over 1 bar to get 1 bar because you started with less than atmosphere..


Thats right, pressure ratio is what you use in the compressor maps. It will be very significant if you live at high altitude and want the same boost in the manifold, then you suddenly have 0.8bar into the compressor, which will yield 2.5 pressure ratio instead of 2 if you had an optimal intake at sea level. Henceall modern engines have a calibrated power derate asa a function of altitude. Restrictions such as the plate in the cis acts similarly as the altitude.

Ill revive that thread if i cant get the fuelling sorted in a simple way, sounds like a neat solution.
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 1603
Location: Somerset, UK

PostPosted: Fri Jun 29, 2018 8:25 am    Post subject: Reply with quote

Whilst Cedrics maps says the 2660 is sub optimal at 1.0bar+, those who have ridden in my car can vouch for the fact it does feel strong. But yes, it does lack the legs over 5000rpm. Only wish is that I spec'd the 2664 or 2670 when I rebuilt the turbo. Hindsight is a wonderful once you know what you have already achieved a successful build even with a sub optimal compressor. I am hoping to have a K26/27 hybrid on the car by the end of this year. That will be interesting!!
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1980 931 - forged pistons, Piper cam, CGT turbo, 951 ducted FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife LSD
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CÚdric  



Joined: 27 Aug 2004
Posts: 1766
Location: Sweden

PostPosted: Fri Jun 29, 2018 7:09 pm    Post subject: Reply with quote

Carrera RSR wrote:
Whilst Cedrics maps says the 2660 is sub optimal at 1.0bar+, those who have ridden in my car can vouch for the fact it does feel strong. But yes, it does lack the legs over 5000rpm. Only wish is that I spec'd the 2664 or 2670 when I rebuilt the turbo. Hindsight is a wonderful once you know what you have already achieved a successful build even with a sub optimal compressor. I am hoping to have a K26/27 hybrid on the car by the end of this year. That will be interesting!!


It will absolutely produce alot of power and especially mid range torque. I just dont recommend it as a long term solution since there is risk of short turbo life if you rev it out a lot. I am maybe a bit more picky since this is my profession and i do things like this all the time, i just want to be clear with the recommendations if anyone wants to build and tune their car further on. That doesnt mean you cant push alot of power out of that turbo. If you do a good high speed balancing you increase the chance of it surviving since you put less stress on the bearings system at the high speeds, though the limit will come from fatigue of the wheels themself.

A regular remap that different companies do also often pushes the turbo(among other things)way out of its specified max limit speed, it works for most people anyway since they dont push the car that often (though some get problems with turbo longetivity).
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morghen  



Joined: 21 Jan 2005
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Location: Romania

PostPosted: Fri Jun 29, 2018 7:39 pm    Post subject: Reply with quote

K27 FTW
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924-76  



Joined: 05 Jun 2006
Posts: 1359
Location: Ontario, Canada

PostPosted: Fri Jun 29, 2018 9:38 pm    Post subject: Reply with quote

This is all great info, thank you all for contributing.

I'm still trying to understand the bottom axes of the turbo map, *Reduced Mass Flow Rate [(kg/s)-K*0.5kPa]* what is this unit?
Thanks
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CÚdric  



Joined: 27 Aug 2004
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Location: Sweden

PostPosted: Fri Jun 29, 2018 11:19 pm    Post subject: Reply with quote

Here you have it in lb/min, still corrected flow though, which is what we normally use for compressor maps. The corrected mass flow is there to compensate for the fact that you may not run the compressor at the same conditions as the ones that you measured the map with. I dont want to fill the thread with theory, but google "corrected flow " and you will get a more detailed explanation.




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924-76  



Joined: 05 Jun 2006
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Location: Ontario, Canada

PostPosted: Fri Jun 29, 2018 11:34 pm    Post subject: Reply with quote

CÚdric wrote:
Here you have it in lb/min, still corrected flow though, which is what we normally use for compressor maps. The corrected mass flow is there to compensate for the fact that you may not run the compressor at the same conditions as the ones that you measured the map with. I dont want to fill the thread with theory, but google "corrected flow " and you will get a more detailed explanation.




Thank you very much
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