Which supercharger to get new owner
10-14-2015, 01:19 PM
#76
Although people do it, running with higher fuel pressure is just not for me. I migrated to 30lb design 2 fuel injectors with the "more modern" 4 spray head units and metal body.
I did this for various reasons including the ability to run to full rpm without changing over the duty cycle and to prove to myself that I could tune the system using sharktuner without doing any damage to the motor. Before doing anything I did quite a lot of shark tuning runs with the stock injectors and programme so that I could at least understand and see what Porsche intended to happen and set a benchmark for comparison. Once I had a grip on this I started to try and improve on the stock programming and then played around with things like the exhaust mods etc. When i had this reasonably well sorted I then went to bigger injectors and found it reasonably easy to replicate what I had previously tuned.Thus if I wanted to add on a supercharger I feel confident i can do so safe in the knowledge that I now have a certain degree of competency to do so and that my injectors will definitely support a modest amount of boost.
if 19lb injectors can handle 345 crank bhp on a GTS then logic suggests 30 lb injectors should be able to handle around 500 crank bhp all things being equal.
Rgds
Fred
I did this for various reasons including the ability to run to full rpm without changing over the duty cycle and to prove to myself that I could tune the system using sharktuner without doing any damage to the motor. Before doing anything I did quite a lot of shark tuning runs with the stock injectors and programme so that I could at least understand and see what Porsche intended to happen and set a benchmark for comparison. Once I had a grip on this I started to try and improve on the stock programming and then played around with things like the exhaust mods etc. When i had this reasonably well sorted I then went to bigger injectors and found it reasonably easy to replicate what I had previously tuned.Thus if I wanted to add on a supercharger I feel confident i can do so safe in the knowledge that I now have a certain degree of competency to do so and that my injectors will definitely support a modest amount of boost.
if 19lb injectors can handle 345 crank bhp on a GTS then logic suggests 30 lb injectors should be able to handle around 500 crank bhp all things being equal.
Rgds
Fred
Thank's for sharing your experience. Where did you get the 30lb injectors?
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10-14-2015, 01:24 PM
#77
So you think I could tune the car with 30-36 lbs without increasing boost& retune-it once I decide to boost it?
Why did you choose turbo instead of SC? Every turbo systems I found for the 928 are near the 20K range...
Why did you choose turbo instead of SC? Every turbo systems I found for the 928 are near the 20K range...
10-14-2015, 04:26 PM
#78
Rennlist Member
I think your answer is one of the wisest one I've read so far & you're right on the bull's eye regarding tuning rule #1: LEARNING & KNOWING what's going on before attempting to putt on anything that could produce damage to this beautiful engineering piece of art. Actualy, what's scares me the most, is to put on a performance chip (found in a craker-jack box ), with out really knowing what's going on & voilà, you gain 50 more hp!
Thank's for sharing your experience. Where did you get the 30lb injectors?
__________________
Thank's for sharing your experience. Where did you get the 30lb injectors?
__________________
One of the many features ST2 permits is to disengage the Wide Open throttle map and use the cruise map to tune for full throttle- eliminates the need for the wide open throttle switch that is prone to failure [as mine was at the time].
ST2 is not something you are going to use every day but it is a marvelous asset for all later model 928 owners. Based on my experience tuning for the naturally aspirated motor I would not run a boosted application without the ability to pull some timing. I started a thread on this subject a week or two ago as to whether it is prudent to rely on the knock sensors ability to pull timing in the event of onset of knock. I actually think it is suited to doing this for a few degrees but not sure I would want to rely on it if the settings are too advanced for the running conditions, especially in a hot climate like ours where it is more critical.
Rgds
Fred
10-14-2015, 04:32 PM
#79
Rennlist Member
I think your answer is one of the wisest one I've read so far & you're right on the bull's eye regarding tuning rule #1: LEARNING & KNOWING what's going on before attempting to putt on anything that could produce damage to this beautiful engineering piece of art. Actualy, what's scares me the most, is to put on a performance chip (found in a craker-jack box ), with out really knowing what's going on & voilà, you gain 50 more hp!
Thank's for sharing your experience. Where did you get the 30lb injectors?
__________________
Thank's for sharing your experience. Where did you get the 30lb injectors?
__________________
One of the many features ST2 permits is to disengage the Wide Open throttle map and use the cruise map to tune for full throttle- eliminates the need for the wide open throttle switch that is prone to failure [as mine was at the time].
ST2 is not something you are going to use every day but it is a marvelous asset for all later model 928 owners. Based on my experience tuning for the naturally aspirated motor I would not run a boosted application without the ability to pull some timing. I started a thread on this subject a week or two ago as to whether it is prudent to rely on the knock sensors ability to pull timing in the event of onset of knock. I actually think it is suited to doing this for a few degrees but not sure I would want to rely on it if the settings are too advanced for the running conditions, especially in a hot climate like ours where it is more critical.
Rgds
Fred
10-14-2015, 05:06 PM
#80
Nordschleife Master
Once you drive a turbocharged car, it is very hard to go back.....
I build my own using a mid mount or rear mount setup (manual vs auto).
I won't supply a kit because I prefer to ensure everything is as it should be. So I build the system to the car.
If you tune to 36# injectors without boost, then add boost, and retune, you will see no ill effects from this.
I build my own using a mid mount or rear mount setup (manual vs auto).
I won't supply a kit because I prefer to ensure everything is as it should be. So I build the system to the car.
If you tune to 36# injectors without boost, then add boost, and retune, you will see no ill effects from this.
10-14-2015, 05:35 PM
#81
Nordschleife Master
Once you drive a turbocharged car, it is very hard to go back.....
I build my own using a mid mount or rear mount setup (manual vs auto).
I won't supply a kit because I prefer to ensure everything is as it should be. So I build the system to the car.
If you tune to 36# injectors without boost, then add boost, and retune, you will see no ill effects from this.
I build my own using a mid mount or rear mount setup (manual vs auto).
I won't supply a kit because I prefer to ensure everything is as it should be. So I build the system to the car.
If you tune to 36# injectors without boost, then add boost, and retune, you will see no ill effects from this.
10-15-2015, 12:46 AM
#82
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George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
10-15-2015, 01:10 AM
#84
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Here is my write up from a few years ago:
http://928.jorj7.com/fuel/
The Sharktuner can tune the car from stock to your target HP, so you need to select the fuel injector size accordingly. By the way, after all the playing around with different fuel pressure regulators, I have since switched back to the stock S4 regulator. This was suggested by Tim. He had been using the Sharktuner longer then I have, and had figured out that with the Sharktuner and get the right fuel injectors, this combination would work quite well.
__________________
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
10-15-2015, 01:17 AM
#85
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George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
10-15-2015, 07:59 AM
#86
Supercharged
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Blah, blah, blah, blah! Get a Murf.
I have two supercharged car both twin-screw. I've installed several Murf kits too. I've ridden in these, plus a 928 Motorsports car, and twin turbo. I think I have more experience in a variety of boosted 928s than just about anyone.
Not to mention that I have no dog in this hunt.
Murf has a solid kit. The Stage 3 will make 500RWHP and is fast! It is by far the easiest kit to install and it just works.
If price were no object, then i would say turbo (if it is available), but your budget dictates that price is a limitation. And many of the people that are saying to spend your money on other maintenance first have a valid point, but many of them do not have a boosted car, but they have seen where some just slapped a blower on an worn car only to have it blow up later. The key is if the car is not in tip-top shape, any kit will highlight its failings.
It sounds like you have a solid car. So call Murf, buy a kit, go fast, smile, be done.
I have two supercharged car both twin-screw. I've installed several Murf kits too. I've ridden in these, plus a 928 Motorsports car, and twin turbo. I think I have more experience in a variety of boosted 928s than just about anyone.
Not to mention that I have no dog in this hunt.
Murf has a solid kit. The Stage 3 will make 500RWHP and is fast! It is by far the easiest kit to install and it just works.
If price were no object, then i would say turbo (if it is available), but your budget dictates that price is a limitation. And many of the people that are saying to spend your money on other maintenance first have a valid point, but many of them do not have a boosted car, but they have seen where some just slapped a blower on an worn car only to have it blow up later. The key is if the car is not in tip-top shape, any kit will highlight its failings.
It sounds like you have a solid car. So call Murf, buy a kit, go fast, smile, be done.
10-15-2015, 08:18 AM
#87
Nordschleife Master
10-15-2015, 09:06 AM
#88
I've been reading this thread and finally some one made a direct commend and good advice to the original question. +928 what he said
Blah, blah, blah, blah! Get a Murf.
I have two supercharged car both twin-screw. I've installed several Murf kits too. I've ridden in these, plus a 928 Motorsports car, and twin turbo. I think I have more experience in a variety of boosted 928s than just about anyone.
Not to mention that I have no dog in this hunt.
Murf has a solid kit. The Stage 3 will make 500RWHP and is fast! It is by far the easiest kit to install and it just works.
If price were no object, then i would say turbo (if it is available), but your budget dictates that price is a limitation. And many of the people that are saying to spend your money on other maintenance first have a valid point, but many of them do not have a boosted car, but they have seen where some just slapped a blower on an worn car only to have it blow up later. The key is if the car is not in tip-top shape, any kit will highlight its failings.
It sounds like you have a solid car. So call Murf, buy a kit, go fast, smile, be done.
I have two supercharged car both twin-screw. I've installed several Murf kits too. I've ridden in these, plus a 928 Motorsports car, and twin turbo. I think I have more experience in a variety of boosted 928s than just about anyone.
Not to mention that I have no dog in this hunt.
Murf has a solid kit. The Stage 3 will make 500RWHP and is fast! It is by far the easiest kit to install and it just works.
If price were no object, then i would say turbo (if it is available), but your budget dictates that price is a limitation. And many of the people that are saying to spend your money on other maintenance first have a valid point, but many of them do not have a boosted car, but they have seen where some just slapped a blower on an worn car only to have it blow up later. The key is if the car is not in tip-top shape, any kit will highlight its failings.
It sounds like you have a solid car. So call Murf, buy a kit, go fast, smile, be done.
10-21-2015, 06:16 PM
#89
Blah, blah, blah, blah! Get a Murf.
I have two supercharged car both twin-screw. I've installed several Murf kits too. I've ridden in these, plus a 928 Motorsports car, and twin turbo. I think I have more experience in a variety of boosted 928s than just about anyone.
Not to mention that I have no dog in this hunt.
Murf has a solid kit. The Stage 3 will make 500RWHP and is fast! It is by far the easiest kit to install and it just works.
If price were no object, then i would say turbo (if it is available), but your budget dictates that price is a limitation. And many of the people that are saying to spend your money on other maintenance first have a valid point, but many of them do not have a boosted car, but they have seen where some just slapped a blower on an worn car only to have it blow up later. The key is if the car is not in tip-top shape, any kit will highlight its failings.
It sounds like you have a solid car. So call Murf, buy a kit, go fast, smile, be done.
I have two supercharged car both twin-screw. I've installed several Murf kits too. I've ridden in these, plus a 928 Motorsports car, and twin turbo. I think I have more experience in a variety of boosted 928s than just about anyone.
Not to mention that I have no dog in this hunt.
Murf has a solid kit. The Stage 3 will make 500RWHP and is fast! It is by far the easiest kit to install and it just works.
If price were no object, then i would say turbo (if it is available), but your budget dictates that price is a limitation. And many of the people that are saying to spend your money on other maintenance first have a valid point, but many of them do not have a boosted car, but they have seen where some just slapped a blower on an worn car only to have it blow up later. The key is if the car is not in tip-top shape, any kit will highlight its failings.
It sounds like you have a solid car. So call Murf, buy a kit, go fast, smile, be done.
What's wrong with the other kits, beside ease of installation?
Any SC or turbos can bring a boost to 10psi & up...a real kicker for sure, but for how long & how many TBO's???!!! (a F1 tbo is ONE race...)
10-22-2015, 06:47 AM
#90
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Nevermind the fact that the OP seems to have dropped the forum like a hot potato.
There are simple reasons for all of the views put forward.
Twin screw over Centrifugal for instant constant boost. Remember that a centrifugal is a non positive displacement supercharger, boost increases as revs increase, so, for instant boost response a positive displacement blower is required - Twin Screw.
Turbo over Centrifugal for improved response and full boost earlier in the rev range = massive mid range power
There is probably an argument for Turbo over Twin Screw in which turbo will ultimately produce more power but nobody NEEDS that much power anyway !
And at the end of the day, there are no Twin Screw kits, John's TT is more expensive, so Murf's kit is the best within the budget anyway.....
There are simple reasons for all of the views put forward.
Twin screw over Centrifugal for instant constant boost. Remember that a centrifugal is a non positive displacement supercharger, boost increases as revs increase, so, for instant boost response a positive displacement blower is required - Twin Screw.
Turbo over Centrifugal for improved response and full boost earlier in the rev range = massive mid range power
There is probably an argument for Turbo over Twin Screw in which turbo will ultimately produce more power but nobody NEEDS that much power anyway !
And at the end of the day, there are no Twin Screw kits, John's TT is more expensive, so Murf's kit is the best within the budget anyway.....