968 Supercharger Kit Development
10-20-2009, 07:02 PM
#346
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
superchargers dont have the lag because they are directly coupled...
i here what your saying that they design is the same... but there's a guy on here with a home made eaton kit for his 944 which is very inefficient and he says its way faster than his 944 turbo from 0-60.
the dyno supports my claim too with a really flat curve way down to 2,000RPMS.
10-20-2009, 11:06 PM
#347
Addict
Rennlist Member
Rennlist Member
We owe Carl many thanks, perhaps in more ways than one. For example, once a few supercharged 968s are "out there" and getting serious attention (forum talk, article in Excellence, etc.), there should be a renewed interest in the 968 and, hopefully, a run to buy this relatively scarce car..(raising the 968 overall value and desirability). Thanks, Carl. Hang in there. Money's are tight right now and there's a lot of uncertainty about stocks, job stability, and so on. Also, in this kind of budget crisis, spouses also can influence how moneys are spent. Now...when things start to rebound...hang on.
The price of the kit doesn't concern me as much as whether or not I have the skills to install one properly without really messing something up. And paying someone to do it (other than Carl or Raj) wouldn't give me any better confidence in the work...plus that would drive the cost up a bunch. I'm about to retire and I'm thinking this may be a great upgrade when I have more time to carefully do an install.
H2
The price of the kit doesn't concern me as much as whether or not I have the skills to install one properly without really messing something up. And paying someone to do it (other than Carl or Raj) wouldn't give me any better confidence in the work...plus that would drive the cost up a bunch. I'm about to retire and I'm thinking this may be a great upgrade when I have more time to carefully do an install.
H2
10-21-2009, 01:18 AM
#348
It's just out, new products are rarely instant sales successes, especially in todays troubled times. People aren't all losing their jobs, but until things settle down, this kind of spending is on hold for most of us. Timing is everything.
There will be Stage II and III kits coming, it's a matter of time.
Regards,
Chris
10-21-2009, 03:14 AM
#349
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
There is undoubtedly a market for a simple kit that works. We know of many, many 968 owners who spent huge bucks building turbo engines, not all of which are working as well as Raj's factory 968TS replica I may add. Furthermore, other companies managed to sell supercharger kits for the 968 despite having serious disadvantages (A/C loss, tuning and installation difficulties, etc.), if they did it a well sorted out kit will no doubt be a success.
It's just out, new products are rarely instant sales successes, especially in todays troubled times. People aren't all losing their jobs, but until things settle down, this kind of spending is on hold for most of us. Timing is everything.
There will be Stage II and III kits coming, it's a matter of time.
Regards,
Chris
It's just out, new products are rarely instant sales successes, especially in todays troubled times. People aren't all losing their jobs, but until things settle down, this kind of spending is on hold for most of us. Timing is everything.
There will be Stage II and III kits coming, it's a matter of time.
Regards,
Chris
10-21-2009, 09:13 AM
#350
Rennlist Member
exhaust takes time to build up, hence lag
superchargers dont have the lag because they are directly coupled...
i here what your saying that they design is the same... but there's a guy on here with a home made eaton kit for his 944 which is very inefficient and he says its way faster than his 944 turbo from 0-60.
the dyno supports my claim too with a really flat curve way down to 2,000RPMS.
superchargers dont have the lag because they are directly coupled...
i here what your saying that they design is the same... but there's a guy on here with a home made eaton kit for his 944 which is very inefficient and he says its way faster than his 944 turbo from 0-60.
the dyno supports my claim too with a really flat curve way down to 2,000RPMS.
Regards.
Raj
10-21-2009, 11:36 AM
#351
Instructor
the real beauty of this kit is multifaceted:
- SIMPLE installation (a timing belt install is far more technical and harder)
- NO permanent modifications to the car (no chopping or cutting up a rare car)
- SMOOTH linear torque curve (center-fugal charger) not "beating-up" on the drive-line
- RELIABILITY
- LOW COST (near 100hp) for $4k on a Porsche or about $40/hp
- OPTIONS (if Carl wants he can design higher boost kits for those who want more power).
I can go on, but you see the benefits are many, with little or no downsides. I have had a SC installation on one of my VW's for nearly 7 years now, and reliability has never been an issue. Also, with the car being older and me wanting to move on, I am planning removing the kit and going back to stock to sell the car, it's literally plug and play, with any minor mods not being noticeable or costing $ to replace parts modified.
Carl has done an excellent job at designing this kit, and I am appreciative, and will be buying one in the near future.
To Carl and 928 Motor-sports
- SIMPLE installation (a timing belt install is far more technical and harder)
- NO permanent modifications to the car (no chopping or cutting up a rare car)
- SMOOTH linear torque curve (center-fugal charger) not "beating-up" on the drive-line
- RELIABILITY
- LOW COST (near 100hp) for $4k on a Porsche or about $40/hp
- OPTIONS (if Carl wants he can design higher boost kits for those who want more power).
I can go on, but you see the benefits are many, with little or no downsides. I have had a SC installation on one of my VW's for nearly 7 years now, and reliability has never been an issue. Also, with the car being older and me wanting to move on, I am planning removing the kit and going back to stock to sell the car, it's literally plug and play, with any minor mods not being noticeable or costing $ to replace parts modified.
Carl has done an excellent job at designing this kit, and I am appreciative, and will be buying one in the near future.
To Carl and 928 Motor-sports
10-21-2009, 12:02 PM
#352
Developer
Thread Starter
Thanks guys. These are good posts to hear.
I'm not new to this... I know how it goes.
The 968 kit needs to get in the field a few times, then the owners post their findings on forums, and the thing goes viral.
Our Ferrari Mondial kit was later adpative to the 308 and then tto the 328 the same way.
As to the kit making 300 CHP... I think it can and it just might right now. My dyno results show this car produced a little less than correct HP when I did the baseline dyno. Many of you have commented on this. Still I could not compare before-and-after by what this car shoulda produced, I had to ethically post what it DID produce.
We have now suspected a bad MAF sensor and replaced it. The car runs better even still. If I find the time, I will run it down there and get new numbers. The dyno I use is 1 hour away - just lacking the time right now to run it down there.
I'm not new to this... I know how it goes.
The 968 kit needs to get in the field a few times, then the owners post their findings on forums, and the thing goes viral.
Our Ferrari Mondial kit was later adpative to the 308 and then tto the 328 the same way.
As to the kit making 300 CHP... I think it can and it just might right now. My dyno results show this car produced a little less than correct HP when I did the baseline dyno. Many of you have commented on this. Still I could not compare before-and-after by what this car shoulda produced, I had to ethically post what it DID produce.
We have now suspected a bad MAF sensor and replaced it. The car runs better even still. If I find the time, I will run it down there and get new numbers. The dyno I use is 1 hour away - just lacking the time right now to run it down there.
10-21-2009, 03:32 PM
#353
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
I think you are comparing apples to ranges. Eaton superchargers are not the same as the ones being used here. Those superchargers make power right off the bat, unlike the ones here. Look at the power curve, no different than a low boost application. What makes it a viable option is that it requires minimal changes to the current setup to make it work. Even a low boost turbo application would be much more involved.
Regards.
Raj
Regards.
Raj
10-21-2009, 03:34 PM
#354
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
the real beauty of this kit is multifaceted:
- SIMPLE installation (a timing belt install is far more technical and harder)
- NO permanent modifications to the car (no chopping or cutting up a rare car)
- SMOOTH linear torque curve (center-fugal charger) not "beating-up" on the drive-line
- RELIABILITY
- LOW COST (near 100hp) for $4k on a Porsche or about $40/hp
- OPTIONS (if Carl wants he can design higher boost kits for those who want more power).
I can go on, but you see the benefits are many, with little or no downsides. I have had a SC installation on one of my VW's for nearly 7 years now, and reliability has never been an issue. Also, with the car being older and me wanting to move on, I am planning removing the kit and going back to stock to sell the car, it's literally plug and play, with any minor mods not being noticeable or costing $ to replace parts modified.
Carl has done an excellent job at designing this kit, and I am appreciative, and will be buying one in the near future.
To Carl and 928 Motor-sports
- SIMPLE installation (a timing belt install is far more technical and harder)
- NO permanent modifications to the car (no chopping or cutting up a rare car)
- SMOOTH linear torque curve (center-fugal charger) not "beating-up" on the drive-line
- RELIABILITY
- LOW COST (near 100hp) for $4k on a Porsche or about $40/hp
- OPTIONS (if Carl wants he can design higher boost kits for those who want more power).
I can go on, but you see the benefits are many, with little or no downsides. I have had a SC installation on one of my VW's for nearly 7 years now, and reliability has never been an issue. Also, with the car being older and me wanting to move on, I am planning removing the kit and going back to stock to sell the car, it's literally plug and play, with any minor mods not being noticeable or costing $ to replace parts modified.
Carl has done an excellent job at designing this kit, and I am appreciative, and will be buying one in the near future.
To Carl and 928 Motor-sports
10-21-2009, 04:30 PM
#355
Rennlist Member
You can run more boost without lowering compression, just add an intercooler. That itself will allow an additional 2-3 psi of boost. You have to remember, it's not a turbo where you can control boost so easily. To make more boost in this setup, it will require changing the pulley/pulleys.
Raj
Raj
10-21-2009, 04:32 PM
#356
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
You can run more boost without lowering compression, just add an intercooler. That itself will allow an additional 2-3 psi of boost. You have to remember, it's not a turbo where you can control boost so easily. To make more boost in this setup, it will require changing the pulley/pulleys.
Raj
Raj
10-21-2009, 04:32 PM
#357
Rennlist Member
10-21-2009, 05:28 PM
#358
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
on the other hand this article from http://www.superchargersonline.com/content.asp?ID=19 supports my claims
Lag
This is perhaps the biggest advantage that the supercharger enjoys over the tubo. Because a turbocharger is driven by exhaust gasses, the turbocharger's turbine must first spool up before it even begins to turn the compressor's impeller. This results in lag time which is the time needed for the turbine to reach its full throttle from an intermediate rotational speed state. During this lag time, the turbocharger is creating little to no boost, which means little to no power gains during this time. Smaller turbos spool up quicker, which eliminates some of this lag. Turbochargers thus utilize a wastegate, which allows the use of a smaller turbocharger to reduce lag while preventing it from spinning too quickly at high engine speeds. The wastegate is a valve that allows the exhaust to bypass the turbine blades. The wastegate senses boost pressure, and if it gets too high, it could be an indicator that the turbine is spinning too quickly, so the wastegate bypasses some of the exhaust around the turbine blades, allowing the blades to slow down..
A Supercharger, on the other hand, is connected directly to the crank, so there is no "lag". Superchargers are able to produce boost at a very low rpm, especially screw-type and roots type blowers.
This is perhaps the biggest advantage that the supercharger enjoys over the tubo. Because a turbocharger is driven by exhaust gasses, the turbocharger's turbine must first spool up before it even begins to turn the compressor's impeller. This results in lag time which is the time needed for the turbine to reach its full throttle from an intermediate rotational speed state. During this lag time, the turbocharger is creating little to no boost, which means little to no power gains during this time. Smaller turbos spool up quicker, which eliminates some of this lag. Turbochargers thus utilize a wastegate, which allows the use of a smaller turbocharger to reduce lag while preventing it from spinning too quickly at high engine speeds. The wastegate is a valve that allows the exhaust to bypass the turbine blades. The wastegate senses boost pressure, and if it gets too high, it could be an indicator that the turbine is spinning too quickly, so the wastegate bypasses some of the exhaust around the turbine blades, allowing the blades to slow down..
A Supercharger, on the other hand, is connected directly to the crank, so there is no "lag". Superchargers are able to produce boost at a very low rpm, especially screw-type and roots type blowers.
10-21-2009, 05:34 PM
#359
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
page 322 of the book "Supercharged" by Corky Bell says:
page 120 of the book "Supercharged" by Corky Bell says:
this book covers all types of Superchargers, including centrifugal superchargers.
"While lag is usually present in with turbochargers, it is not a significant factor with superchargers."
"and lag created by a supercharger is not large in any case"
10-21-2009, 05:37 PM
#360
Banned
Join Date: Dec 2002
Posts: 2,379
Likes: 0
Received 0 Likes
on
0 Posts
here is a cool horsepower calculator for Superchargers:
http://www.superchargersonline.com/hp_calculator.asp
http://www.superchargersonline.com/hp_calculator.asp