Advanced CIS Turbo Tuning Discussion Thread. Ultimate?

[cole930]

Dave,

Gosh don't think I was in any way offended, it's that after I read your post I
went back and read mine. I sounded pretty adamant about the cone
having "NO" effect, when in fact your statement, as to what it did was correct.
I think Keith explained it best, the old toilet bowl vortex deal.
Varying opinions separate the wheat from the chaff and in the end we get,
at least, reasonable assumptions for unanswerable questions.

Cole

[fredmeister]

I think it is important to keep it as light as possible so spinning in aluminum would be ideal.
The metering plate is balanced in the CIS and adding weight to one end of the lever arm will create an imbalance against the piston/plunger end. This will be compensated slightly by increased control pressure but the overall change should be kept minimal.
The big benefit is increased control of the crossectional area that the air must pass thru between the metering plate and inside cone surface of the housing. The cone should also increase total MP travel so that stall and extra plunger movement happens at max air flow rates at high load and rpm.
I would be interested in buying one as long as they are tested by someone on a dyno for results in a controlled back to back test. Someone must measure A/F ratios and hp numbers during the run with and withtout the cone installed.
If you could post verified gains I would bet lots of guys would sign up to buy this thing. I don't buy things like the aftermarket plastic air filter housing because the supplier selling it tells me it makes 15 hp without proving it works with data.
Rarlyl8 does alot of testing and I value his comments, maybe he would be interested in developing this thing? I don't want to speak for him though.

[cole930]

Fred,

The velocity plate is spun aluminum . It can't weigh more than an ounce or so.
The sensor plate that was with it seemed to be heavier than the original. I will
weigh them when I get it back from Steve.

I was wondering if there weren't two objectives here. One being adding
weight, via, heavier sensor plate for more precise balancing of the arm, hence,
reacts faster initially & moves down quicker. Two being the velocity plate on top
of the sensor plate to allow the sensor plate to move further into the venturi
and past the stall point hense allowing full plunger movement and max fuel.

I am not a supplier selling something. I really don't need to have them made
because I already have one. I'm not going to have it Dynoed because the LM1
and the seat of my old a-- will give me enough info to tell if it's worth keeping on
the car or not. I've offered to have some made because I have the only one.
All I ask is help pay for the costs I incur. I would get an estimate for making
them and post it before proceeding if there is interest.

Cole

[jcc911]

Please let me know the cost of the updated plate, thanks.

[JFairman]

If you wanted to experiment with this idea and didn't want to spend alot of money doing it, there's a plethora of polypropylene round food and chemical containers out there in different diameters that you could cut the botton 3/4" off of and fasten it to the top of the sensor plate and try it out...

Polypropylene plastic is untouched by gasoline or oil fumes and it doesn't get very hot there so I don't think melting would be an issue either.
It's the same type of plastic that motor oil, paint remover, and many other nasty chemicals come in these days.

[tarheelturbo]

i'm absolutely no expert here.. but i'm trying to pick up on this and learn fast as i can, as i have interest in seeing how far CIS can be pushed before i look at $$$$ to build a sick EFI motor, anyways ...
i heard someone mention the similarity of the 930 CIS to the Mercedes 6.3 CIS.. except the 930 has 2 of the holes plugged in the fuel head...
so heres the question, why wouldn't we try and fit a 6.3 fuel head to the 930, it would seem like it owuld be the same as drilling out whats on there now??
would that not yield a lot more fuel potential??

[JFairman]

The beautiful old 280SEL 6.3 motor had mechanical fuel injection, but the 450SEL 6.9 was CIS.

I've wondered if the CIS head with 8 threaded banjo fitting ports airflow sensor plate and housing stuck down in between the V of those 4.5, 5.0, and 6.9 CIS motors is the same ones they put on the 930.

Or if different, how different and how much could be interchanged? Being dusty old Mercedes parts they probably wouldn't have the insane Porsche tax added on...

[cole930]

J,

I think if you could chase some of the bosch part numbers you would find which
models are interchangable.

Cole

[cole930]

Tarheel,

930 CIS is good on fuel up to 400-450 HP with not too much work but above
that it gets real tough. Many feel the problem is lack of enough air at these
HP's. Most anyone looking for real HP, EFI is the only alternative.
Do some searches on this forum there is a wealth of info right here.

Cole

[zcoker]

Originally Posted by cole930

Fred,


I am not a supplier selling something. I really don't need to have them made
because I already have one. I'm not going to have it Dynoed because the LM1
and the seat of my old a-- will give me enough info to tell if it's worth keeping on
the car or not. I've offered to have some made because I have the only one.
All I ask is help pay for the costs I incur. I would get an estimate for making
them and post it before proceeding if there is interest.

Cole

Should be proud to be the seller if you see that they work well. Let us know how yours functions and then I'm sure you can sell a lot of them right here which will take care of any cost. It's a simple bolt-on, something that I am interested in. I think we need to see it tested first by you and then report back to us your initial thoughts or seat of the old a--- feelings. After that, I'm sure we can get a group buy going.

[cole930]

Z,

Appreciate your comments. I didn't discover this thing I just happen to have
one.
The original credit goes to Mercedes & Bosch and secondly to the original guys
at Power Haus. We know it was used on Power Haus engines, who made some
of the strongest turbo engines ever built, and some of the guys like Chris Caroll
at Turbo-Kraft are still around.
We all enjoy this site Wayne has created for us and we all have received a
lot of help, support, and friendship. You bums kept me laughing through a lot of
very late nites when I was jonesen through 6 months of Chemo. This time we'll
get this done together and it can be the first mod we have ever gotten that we
didn't have to sell our kids to pay for.

Cole

[mark houghton]

Close, but no cigar. Just needs to be about 115mm in diameter to cover the entire metering plate. The one I've pictured is a bit smaller.
I'm interested in a being part of a group buy, if/when it all comes together.

[cole930]

Mark,

If you look at the pic. I sent of the velocity plate I have you will notice the sensor plate under it extends beyond the velocity plate by 2-3 mm all the way around. If yours is relative close to the outer edge of the sensor plate I would give it a try. Look like the same thing with a different profile.

Cole

[911st]

As the air has to bled off the sides of the metering plate, going to the re-discovered metering plate might help minimize turbulence and creating a low pressure area in the center of the MP. Two birds, one stone.

Are we getting one of these special metering plates on a dyno for a back to back against the stock to verify they help AFR's up top by pushing the metering plate to the end of its range?

[911st]

Originally Posted by mark houghton

Close, but no cigar. Just needs to be about 115mm in diameter to cover the entire metering plate. The one I've pictured is a bit smaller.
I'm interested in a being part of a group buy, if/when it all comes together.

Looks like the bottom of a Bud?

FYI, If you are thinking this device goes on top of your MP, that is not the case.

It is a replacement and because it is taller, it needs to be smaller in diameter to let some air past it so it can mostly act like the stock plate during the first 80% of its travel.

[911st]

There is a formula in Bruce Anderson's book on modifying Porsche's for computing approximate effective compression ratio of a motor on boost. For a supper charged motor with little or modest inter-cooling they suggest keeping the effective CR under about 11.6/1. It is interesting to me the factory on there NA 993's went to 11.3/1.

It comes out at the about the following limits.

6.5/1 at 1.2 bar
7/1 at 1.1 bar
7.5/1 at 1 bar
8/1 at .8 bar
9.5/1 at .45 bar

It may be possible to go past this with extra fuel, pulled back timming, and an extra efficient inter-cooler but I do not understand the principles yet???

[RarlyL8]

I've done some fiddling in the past with the ideas in this thread.

Several stock 930 air boxes were hacked up before I tossed them all and stuck a simple paper filter on top the air meter assembly. I removed the cone from one of the air boxes and mounted it on the bottom side of the filter lid. Figured Porsche wouldn't have it there if not needed. I could not tell any difference with or without so I chucked that as well. My thought at the time was that this cone may have more function with the idle characteristics of a stock engine and not be necessary with my minimal CIS and non-stock tune.

Exactly what performance gain do you expect to see with the spun aluminum CIS version of the Tornado? I'd be glad to dyno one for you but I'm not sure what significant benefit this is for a sub-350whp 930. You would need to tell me exactly what parameters to measure. I assume AFR, HP and torque throughout the operating range.
Also, does installing this device on the metering plate require a re-calibration of the plate?

Someone mentioned fuel heads. The Mercedes V8 is the same casting as the 930. You can also use a 928 CIS fuel head. The problem with this is fuel distribution of the extra 2 injectors. The stock 930 pancake intake is not designed to distribute fuel evenly. Another problem is fuel mileage. You now have 8 injectors running all of the time.

[911nut]

Originally Posted by 911st

Found my old add from when I sold my old what I call at the time "electronic WUR"

930/CIS Fueler/tuning w a Lap top FS

Man it worked well:

Keith, had you just finished bathing it before snapping that picture?

[laughac]

That's a beer can... hmmm....

Originally Posted by mark houghton

Close, but no cigar. Just needs to be about 115mm in diameter to cover the entire metering plate. The one I've pictured is a bit smaller.
I'm interested in a being part of a group buy, if/when it all comes together.

[jeff91C2T]

Interesting points...makes sense that the plate gets out of sink with respect to the air flow requirements as soon as we starting making changes. As mentioned earlier in this thread, I saw a similar instance where a stock 91 turbo was dyno'd and it had a pefectly flat AFR result. Then we dyno'd mine which had the classic rising afr to 6k (running headers and no cat).

Not sure if this has been added yet...but the audi turbo crowd has chased this quite a bit as well. Below is an older link discussing measuring the throw on the fuel plate which seem to be discussed here quite a bit;

http://www.sjmautotechnik.com/trouble_shooting/outofuel.htm

Seems like a good idea to add an air handling device (either on the fuel plate or in the cone) to help flatten out that curve. Trial and error could lead to to a few versions for different mod's.