968 Supercharger Kit Development
#886
Three Wheelin'
i'm off to the dyno again tomorrow night. In addition to the larger injectors, I added a high flow pump (Welbro 392) to make sure the fuel is flowing. While I was back there I put in a new fuel filter, just in case. Welded a bung on the exhaust so that I don't have to remove the supertrapp discs to measure A/F. I'm certainly getting fuel as this point, let's hope that it is not too much
Cheers,
Mike
Edit: Obviously I've never removed a factory pump before. Have done some research and now I know that it must be the inline pump, replacing the factory inline pump.
Last edited by mikey_audiogeek; 10-17-2010 at 09:39 PM. Reason: ignorance
#887
VERY NICE SETUP,COMPACT SUPERCHARGER AND ALL IN THE SPACE OF THE STD AIRBOX
ABOVE THE RADIATOR AND FANS ,JUST AN ADD ON INSTALLATION
SEEMS ALSO LIKE AN ORIGINAL PORCHE FACTORY INSTALLATION.
310 BHP ,WITH FULL TORQUE AT 2600 RPM
PERFECT FOR THE STREET OR TRACK ,THE TWIN PULLEY DRIVING SYSTEM SEEMS TO ELLIMINATE ANY EXPERIMENTS TO SOLVE THE BELT SLIPAGE ISSUES.
ANYBODY MARKETS THIS KIT?
ABOVE THE RADIATOR AND FANS ,JUST AN ADD ON INSTALLATION
SEEMS ALSO LIKE AN ORIGINAL PORCHE FACTORY INSTALLATION.
310 BHP ,WITH FULL TORQUE AT 2600 RPM
PERFECT FOR THE STREET OR TRACK ,THE TWIN PULLEY DRIVING SYSTEM SEEMS TO ELLIMINATE ANY EXPERIMENTS TO SOLVE THE BELT SLIPAGE ISSUES.
ANYBODY MARKETS THIS KIT?
#889
Not in Fallbrook yet...
As for the 968 SC... the owner of the car is not from our area. Apparently, the guy who engineered the setup built 10 kits for people on another 968 list. I told the owner of the 968 SC that, if the developer were to offer the same kit on Rennlist, the 968 world would lead a path to his door.
Personal note... I've never seen a modification as clean as this.. I was stunned at the fit and finish of all the parts and the factory look of it all... made wish I'd sprung for a 968 when I bought my 944 S2.
Last edited by MacinTek; 10-17-2010 at 07:06 PM. Reason: Was asked to remove references to owner for privacy issues.
#890
Nordschleife Master
I would think it would be in good taste to start a new thread about a competing SC, afterall, this is Carl's thread about "HIS" SC.
Well, Franky II went to Barber this weekend to test and tune. Saturday morning started out in the mid 40's. By the time I got on track it was 55 and the SC loved that cool dense air. I was amazed at how well the car pulled and the pull was very linear. No surprises, no big kick of power, just smooth acceleration. I got in 3 good sessions with the SC. Just prior to the last run of the day I started the car and heard a strange noise. Looked under the hood and it appeared that the SC pulley was wobbling. We pulled the bolt, which was still tight and were then not able to get the pulley off while in the car. So, I pulled the SC and it appears that the pulley and key are screwed. Not sure why it happened, will need to talk with Carl.
I was determined not to miss my track time on Sunday, so I proceeded to pull the SC stuff from the car and set it back up as an NA. This took about 1hr, the biggest pain was that I had to remove my gutted AC compressor and reinstall the AC delete kit (move the alternator down low), since I had an AC delete belt on hand. This allowed me to run all day on Sunday in NA form and A/F was spot on all day (wide band and visual inspection of plugs). That's really cool as I wanted to have the option of jumping classes and setting up different wt/hp options for different race groups. I'm going to look for a belt that will allow me to take the SC out of the loop but not move remove the AC and relocate the alternator.
Well, Franky II went to Barber this weekend to test and tune. Saturday morning started out in the mid 40's. By the time I got on track it was 55 and the SC loved that cool dense air. I was amazed at how well the car pulled and the pull was very linear. No surprises, no big kick of power, just smooth acceleration. I got in 3 good sessions with the SC. Just prior to the last run of the day I started the car and heard a strange noise. Looked under the hood and it appeared that the SC pulley was wobbling. We pulled the bolt, which was still tight and were then not able to get the pulley off while in the car. So, I pulled the SC and it appears that the pulley and key are screwed. Not sure why it happened, will need to talk with Carl.
I was determined not to miss my track time on Sunday, so I proceeded to pull the SC stuff from the car and set it back up as an NA. This took about 1hr, the biggest pain was that I had to remove my gutted AC compressor and reinstall the AC delete kit (move the alternator down low), since I had an AC delete belt on hand. This allowed me to run all day on Sunday in NA form and A/F was spot on all day (wide band and visual inspection of plugs). That's really cool as I wanted to have the option of jumping classes and setting up different wt/hp options for different race groups. I'm going to look for a belt that will allow me to take the SC out of the loop but not move remove the AC and relocate the alternator.
#891
#897
Developer
Thread Starter
I suppose I should respond... all I have to look at (like you) are those two photos.
Remember our kit fits without any modification to the car also. This thread has taken a turn into the racing application and away from the street install - but no modification to the car is required for a street install.
Remember that you are comparing a currently available kit with one that is either no longer produced or never was. There are a number of home-built elements in those photographs that make me beleive it was a hand-made and very low production kit.
As to "awaiting CARB certification" - probably not. If the $10,000 to $30,000 CARB certification fees dont get you (Divide $10k by 10 kits and see what that will do you your per-kit price). And thats the filing fee. More CARB fees come later. Generally speaking, unless you can sell 1000+ units, CARB certification just doesnt make sense. Look at the Edelbrock manifold website - CARB certification just doesnt make financial sense on any but the most common highest volume units.
The picture shown is using a very small Rotrex supercharger (look how small the volute is), which, when you compare to the size of our volute - will help you know which will make more HP.
Observe the oil lines and know that this install requires oil lines to and from the supercharger. It will run hotter as a result (the motor oil will pre-heat the supercharger case as it passes thru) and possibly should have an intercooler. The installation will also be more complex as a result.
I can also see from the photo that the induction tubing makes a large jump in size right at the inlet to the throttle body. Thats a bad idea, and will put flat-spots in the throttle response.
Just a few observations that I was frankly reluctant to make at all. It looks like a well-made, hand-made kit. But, if it is not commercially available, the comparison is rendered moot.
Remember our kit fits without any modification to the car also. This thread has taken a turn into the racing application and away from the street install - but no modification to the car is required for a street install.
Remember that you are comparing a currently available kit with one that is either no longer produced or never was. There are a number of home-built elements in those photographs that make me beleive it was a hand-made and very low production kit.
As to "awaiting CARB certification" - probably not. If the $10,000 to $30,000 CARB certification fees dont get you (Divide $10k by 10 kits and see what that will do you your per-kit price). And thats the filing fee. More CARB fees come later. Generally speaking, unless you can sell 1000+ units, CARB certification just doesnt make sense. Look at the Edelbrock manifold website - CARB certification just doesnt make financial sense on any but the most common highest volume units.
The picture shown is using a very small Rotrex supercharger (look how small the volute is), which, when you compare to the size of our volute - will help you know which will make more HP.
Observe the oil lines and know that this install requires oil lines to and from the supercharger. It will run hotter as a result (the motor oil will pre-heat the supercharger case as it passes thru) and possibly should have an intercooler. The installation will also be more complex as a result.
I can also see from the photo that the induction tubing makes a large jump in size right at the inlet to the throttle body. Thats a bad idea, and will put flat-spots in the throttle response.
Just a few observations that I was frankly reluctant to make at all. It looks like a well-made, hand-made kit. But, if it is not commercially available, the comparison is rendered moot.
Last edited by Carl Fausett; 10-19-2010 at 12:26 PM.
#898
Nordschleife Master
I spoke with Carl this morning. I had an issue early on with the pulley bolt that likely caused the malfunction on Saturday. A new pulley is on the way and I should be up and going in FI form soon, thanks Carl!
#899
Still no anwer from anyone,is it available ?even without CARB certification?
as someone mentioned earlier the rotrex is about torque, over the entire range .,and 310 bhp seems
enough without going for uprated brakes e.t.c.
it makes sence,given the wide ratios that the 968 has for the 3rd to 6th gear with the last 2 being overdrive,the torque is needed.
it is torque which pulls the car out of the corners,especially with fat slicks and wide 18 inch rims.
that should be the interest anyway for a supercharger kit for fast road/track ,although now seems that a close
ratio 3rd to 6th gear set, at half the cost of a current supercharger kit ,perhaps will achieve the same and possibly
better results on the track, with the improved 15% ingear acceleration and without the additional weight penalty
upfront.
as someone mentioned earlier the rotrex is about torque, over the entire range .,and 310 bhp seems
enough without going for uprated brakes e.t.c.
it makes sence,given the wide ratios that the 968 has for the 3rd to 6th gear with the last 2 being overdrive,the torque is needed.
it is torque which pulls the car out of the corners,especially with fat slicks and wide 18 inch rims.
that should be the interest anyway for a supercharger kit for fast road/track ,although now seems that a close
ratio 3rd to 6th gear set, at half the cost of a current supercharger kit ,perhaps will achieve the same and possibly
better results on the track, with the improved 15% ingear acceleration and without the additional weight penalty
upfront.
#900
Developer
Thread Starter
I didn't post for a comparison.
the design wasn't about the HP, it was about torque over the whole rpm range.