Carl,

There should have been around a 40 RWHP jump from the 6 to 9 psi run. Like you said the limiting factor must be the CIS. Can you adapt the Mercedes CIS to the 928? The last dyno run on my Mercedes 560 SEC produced 346 RWHP and 404 RWTQ on 7 psi of boost with methanol/water mix to cool the intake charge. I'm using an ATI procharger P1SC and the FI is CIS-E. A stock US SEC typically dynos at 200 RWHP but I did add custom headers. Fuel is regulated by cranking up the differential pressure. I'll soon be running around 13 to 14 psi with the addition of a cog belt and air to air intercooler. We'll soon see how much the Mercedes CIS can produce.

http://www.superchargersonline.com/h...r.asp?submit=1 I have found this hp calculator to be very accurate.

 

.... ... excellent work on that old buggar Carl .... Man I'll have to start looking out for ob's when I'm out there in my 32V cars. Not to mention the little 911 dangit.

 

I really find all of this shark huffing fascinating. Carl, looks like you have a very nice setup for the CIS cars. I'd like to see the other offerings that I've so far only heard rumors about... but that's a damn nice dyno sheet & set of photos....

Well, I can't really do anything like this for a year at least, unless something changes. But and happy huffing to all of you who are ready now!

 

I guess that once the CIS flapper is all the way down, the fuel distributor is maxed out & that's it for HP. If airflow is increased, fuel flow needs to be matched by some means... how about increasing the fuel pressure via RRFPR? It sounds like the flapper is at the physical limit at ~7 psi (?), so that is where the RRFPR should begin to kick in.

 

The numbers are fine... if you remember that this kit does NOT include any fuel system mods. Yes, 3 more psi should produce more HP than that in an ideal world - but this kit advertises to use the stock Porsche 928 CIS system as-is. No fuel system mods. At 6000 RPM, the air/fuel had dropped to 14.5 - that will not damage the motor - that is just an "economy burn" not a "power burn" like a 13.2 or 12.8 would be.

But, this is a early 8.5:1 CIS motor - that same kit on a 9.3:1 L-Jet will yield completly different numbers and not be as lean, either.

We do have, however, a CIS guel enrichment system that we put into our Stage 3 kit that I may be able to include on the Stage 2 kits if I raise the price. It is available for those that want it. Then this Stage 2 kit would perform better, but it raises the price and complicates the installation - two things we are trying to avoid.

Please recognise how different Tim's (and I think Andy's but am not sure) applications are from mine.

They are able to develop just 1 kit. We offer 3. Their kits are designed for 87 to 95 - they are all pretty much the same compression ratio, (10.0:1 or 10.4:1) and all one induction system (LH Jetronic) God, how nice that would be!

We have to have adaptive capability to span 8.5:1, 9:1, 9.3:1, 10:1 and 10.4:1 CR; and both CIS Euro and CIS US and L-Jet Euro and L-Jet US.

These numbers are from an early 8.5:1 CIS motor - that same kit on a 9.3:1 L-Jet will yield completly different numbers and not be as lean, either.

Jim - look at your own note! Methanol/water mix? headers? etc? Do not compare a cost-is-no-object, whatevcer-it-takes installation like yours to a kit designed for no fuels system mods and a simple 12 hour install. They are not comparable. I love what your doing - but my customers are pretrty conservative. I'll compare my Stage 3 numbers to yours, not never these dialed-back Stage 1 and 2 systems. They are scaled back for a reason.

Old & New - the air meter is not maxed out, and raising the fuel pressure is not the answer. Wish it were that simple.

What Jim Nowak is discussing is "what are the outer limits for CIS with mods?" -and that is a project I have going on right now. I am building a 5.0 liter motor bored out to 100.4 mm with steel sleeves and JE pistons, 15 to 18 psi of boost, intercooled, and a highly modified fuel system (I will not say how - competitors are listening). Yes -it will be CIS, and it will be ready to dyno sometime around Spring '05.

 

The methanol/water injection was $300 from www.snowperformance.net The headers were a bit more expensive since they are custom and cost $1,500. However, the rest of the system, at that time, was $1,500 for the plumbing, brackets, spacers, pulley, tensionser, and idler. Of course, a Procharger P1SC is fairly expensive at $1,800. I wouldn't say that was a cost-is-no-object kit. Without the headers or any exhaust work, I had around 300+ RWHP and the headers added another 40 or so RWHP. My CIS is stock with no mods other than increasing the differential pressure with a turn of a screw.

Keep up the good work on the 928. I ditched my CIS in favor of an Electromotive engine management system on the 928. Had you been supercharging the CIS motor 4 years ago and had a kit I'd have bought one and stayed with CIS. However, there were no 2-valve kits available at that time. I really feel forced induction is the way to go for maximum power rather inexpensively. It can get very very expensive with all the internal mods that are needed to make the early models fast.

 

Hi Carl,
How about the rest of us with L-Injection? Have you done any testing at 9 PSI of boost? How about max HP from the L set up.
BTW next year, Gonna call you for the hair dryer.........
Tony

 

TooFast - I should have Dyno results on a Stage 1 kit at 6 psi on an L-Jet to post in October.

Here is a recent emissions test:

 

Dang! what kind of tools do you have in your garage anyway!!

 

Those that have made the trek up to visit our shop can tell you it is corwded with tools on all sides. Drives me nuts sometimes. I am building a bigger shop on the vacant lot next to me - that'll be nice.

We use a true, calibrated Infra-red Spectrophotometer to emission check our kits. It is easier (and a LOT less expensive) to just use a wide-band )2 sensor - you get air/fuel measurement very nicely that way... but you have little idea how you are messing up emissions.

We try to design our kit so that an owner will pass emissions easilly after the supercharger is installed, so we have to check it with the same equipment that the DOT uses. At this time we can check HC and CO using the same 2-idle test that most states use. Now all I need is a "rolling road" for the rear tires. I am building one... (too expensive to buy)

 

good God that is so much torque for a 79!!!! That beast is wicked!!!!

Andy

 

Carl,

On blowing the L-Jet, is there any concern of overwhelming the available fuel towards a lean condition @ 6 PSI? I don't see any provisions in the kit for a rising rate regulater or any other fuel system mods. Can the L-jet deal with 6 PSI... or even more?

I'm also very curious to see the dyno sheets on this beast.

 

Would the brackets and nothing else cost Carl? JUST so that a supercharger COULD be bolted to the car. NO piping, no gauges, no bov, nothing else?

Thanks,
Brendan

 

We do not feel there is any problem on a L-Jet at 6 psi and 850 CFM, but in October I am going to verify that on a Powerdyne dyno with air/fuel meterin realtime. If it does prove to be a concern, a simple rising rate FMU will do the job. But first, we are going to do it with out the FMU to see what the stock L-Jet fuel system will do without mods at 850 CFM.

 

I gott spellcheck this stuff before I hit the button....
we are going to run it on a Dynojet dynometer and check the air/fuel mixture in realtime.
I will post the results.