Supercharged 1986 944 NA
07-19-2006, 01:07 AM
#16
Racer
Thread Starter
Originally Posted by Camaro_Muncher
AWESOME! I have been thinking of this for the past few months. How much more room could a centrifugal save? You should make a plan for the brackets. I have almost no knowledge on engine management systems, is there a good site where i could learn more? BTW dont listen to people who try
to stop you from this, I know the feeling of loving your car but wanting it to go faster.
to stop you from this, I know the feeling of loving your car but wanting it to go faster.
Thanks for your support, these projects are always a learning experiences and you fix things and make them better on the way.
I am using a Paxton centrifugal blower, they are the simplest units to adapt to your car but don’t provide boost till you are above 2000 rpm. The Paxton is not the best unit to use, Speedforceracing uses an ATI Procharger but these are expensive units. To reduce the load on my motor, I have shimmed the Paxton so it takes very little force to turn it, Paxton superchargers are normally setup to run on V8s.
As for engine management you can use a Mafterburner or Split-Seconds ARC 2, these are piggy bank units that connect between the MAF and DME, these units allow you to create a custom fuel map, I use a Ford MAF in place of my Porsche unit (same voltage as Porsche).
With regards to learning more about engine management you can go to non Porsche sites, almost all web sites that talk about supercharging refer to the following subjects;
- Fuel enrichment with boost
- Fuel map management (Mafterburner, Split –Second, custom chips)
- Supercharger impeller speed
- BOV installation and use
- Intercooling for high boost applications (can waste allot of boost on low
boost applications)
Also look at this site, it has allot of good information;
http://frwilk.com/944dme/hfm.htm
As for brackets I made mine from 1/4 inch aluminum plate, I made a second bracket that holds the alternator, it’s a pretty sturdy setup. Brackets can be made for any supercharger, you just need lots of time and patients.
07-23-2006, 10:20 PM
#17
Racer
Thread Starter
Originally Posted by BMWM3PORSCHE944
OK if I am looking at this correctly, I am seeing that the intake is located at the rear of the SC. Rather hot intake charge wouldnt you think? Of course it IS on the "cold" side of the engine, but man, that's gotta be a hot charge of air your getting. I imagine your not seeing that much of a gain in over all power as you are loosing an average of 30% engine power to the SC pulley, not to mention you are pulling in HOT air.
Not to mention the large crease in the piping going into the intake manifold. Unless you are inflating that thing, believe it or not that's gonna cost you a few HP.
Please don't get me wrong, I think you did an OUTstandign job on the whole thing. Im just trying to point out some weak areas that could cost you alot of power. There is more but Im kind of drunk and dont feel like typing anymore.
OH YEAH, if those are magnecore wires, ditch them and go with OEM. Much better.
Not to mention the large crease in the piping going into the intake manifold. Unless you are inflating that thing, believe it or not that's gonna cost you a few HP.
Please don't get me wrong, I think you did an OUTstandign job on the whole thing. Im just trying to point out some weak areas that could cost you alot of power. There is more but Im kind of drunk and dont feel like typing anymore.
OH YEAH, if those are magnecore wires, ditch them and go with OEM. Much better.
I have been working on the piping for a while and I would really like to get a custom intake rather the use couplers and hose clamps, but for now the setup will have to do.
With regards to intake temperature, I don't think that's causing a major problem but I'm thinking of a way to get some cooler air to the SC intake, by the way I'm running a 944 turbo intercooler.
Now, the comment about not seeing much gain. The Paxton is shimmed so that it won't load the motor too much, Paxton SN series SCs are ball drive and are initially setup for V8s, when you install them on 4 cylinder motors you adjust them accordingly. Paxton SN 89 can produce between 5 and 8 PSI on 8 cylinder motors, when you put them on 4 cylinder motors they can produce 10+ PSI.
For the last six months the SC hasn’t been performing the way it did when I initially installed it, so your comments really got me thinking. While browsing the NET I found a WEB site of a guy who installed a Paxton SN 2000 in a 1988 N/A RX7, this installation produced 212 RWHP and proved that ball drive SCs can produce significant gains on 4 cylinder motors. I sent an message to the guy explaining how I’m not getting much power from my SC and he replied with a few recommendations, one was the drive belt has to be real tight for the Paxton to produce more than 5 PSI, so off to the garage I went. Last night I tightened the drive belt and adjusted my fuel map to be a little less rich. This afternoon I went for a drive and “WOW”!! first and second didn’t seem much different but I didn’t go beyond 3k RPM, when I hit third and went from 3k to 5k the car moved like I have never seen it before, the car moved so fast that I wasn’t used to breaking in that car at that speed, I didn’t even get out of third gear !!
So my installation does produce big gains over a NA but it takes allot of diligence to get things figured out. I still don’t think the car is performing to its maximum potential, I’m running a large 4” SC pulley to keep the SC speed in check, the MSD 6AL has a 5900 RPM chip that limits the engine speed and also protects the SC. I plan to use a slightly smaller pulley so the boost will come in earlier but ill have to watch my RPMs, one other thing is that the 944 Turbo intercooler drops some of PSI but I’m not sure how much, I would like to keep it because I believe my SC can produce more PSI.
07-28-2006, 01:07 PM
#18
This is very cool. You shoud either do a write up on how to do this. I am interested in getting more power out of my motor. I am either going the LT1 route or maybe this route if it is easier and cheaper to do.
08-02-2006, 01:59 PM
#21
Racer
Thread Starter
Originally Posted by TheArab944
Roughly how much did it run you?
The whole setup cost me around $2000 CAD using a Paxton SN 89, I could have done it much cheaper but I bought a bad supercharger on Ebay.
The SC it the most expensive item the Pxton SN series is not the best choice because of their mechanical make up, you really have to know what you are doing with them, you can destroy a unit in 10 seconds if its not setup right. There are other more suitable SCs on the market but they cost significantly more then the Paxton, I would recommend waiting for a good used ATI Procharger, once in a while you see low cost head units on Ebay. I also could have saved money if I had someone make my intake, I have bought many silicon couplers and aluminum hoses that I’m sure have cost more than someone making the intake. I also want to state that this is my first time supercharging a car and have made many mistakes, if I were to document the installation it would easy for someone else to do the job.
