Murf928 Superchargers
10-29-2015, 01:16 PM
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Murf928 Superchargers
Hello fellow Shark owners!
There is a lot of good discussion in this forum lately with respect to supercharging so I would like to chime in with some of my thoughts and comments.
I know whenever I make a large purchase I research and read anything I can get my hands on so hopefully my posting will help direct more people here and read everyone’s opinions on the topic and become more informed. Adding a major performance modification to your car, such as supercharging, one needs to dive in with both eyes wide open and poised with as much information as they can get their hands on.
Our enthusiasm for these cars and the potential performance is Gods little gift to us for appreciating what the capabilities of the 928 is all about. It is amazing how fortunate we are to have such dedicated people that support the 928 community and give so much of themselves for all our benefit. What I do would mean nothing if it wasn’t for all the others that contribute to keeping these cars affordable and on the road. Of course not only am I talking about the major vendors but I also want to acknowledge all the other innovative players and contributors to this forum that keep these cars running and interesting.
There is a large contingency that think the 928 should be kept original as Porsche designed it. Then there are others who appreciate what Porsche did and also the opportunity Porsche gave us interested in a platform to totally make a HOT ROD out of these wonderful cars. I am of course on the HOT ROD side of life. I like fast cars, make that REALLY FAST cars. I drove a Hell Cat recently and although the car was extremely fast I would not shy away from him with my Stage 3 Murf928 supercharged car. It is too late this year but next summer I will have a chance to run against this car and I hope to add it to the many Murf928 kill stories.
Some suggest that if anyone adds boost to the 928 it is only a matter of time before you blow up your engine. I respectfully disagree with that if it is done right. I just looked at my numbers and I have sold 83 kits over the last 10 years which means about 100 cars have been supercharged with the Murf928 kit because kits get flipped and run on other cars. If it were common to blow up the engine by adding boost I think it would be a prevalent discussion on many car forums, especially here on Rennlist.
With respect to some other comments made in recent threads that are relevant to Murf928:
With a Murf 928 kit you will not need to tune that car after installing it, I would prefer that you do not do that. I also prefer that customers install the kit as designed and if you want to change something later it is up to you because you will have a much better understanding of your car and the design of the supercharger kit. Also, for this same reason I recommend that owners install your own kit when possible, it's a great sense of accomplishment. The Murf928 crew will be there to help you with every step along the way.
With a Murf 928 kit you get new fuel and ignition chips and they are programmed with a relatively conservative tune to run on just about any car. The Sharktuner is a fantastic tool but before you go messing with the tune of a car, especially a supercharged one, you need to completely understand what you are doing.
I have been extremely fortunate with so many kits being installed and very few problems. I’m not saying there have never been any issues because there have been. I recently had a problem with my fuel injector vendor who changed his supplier which resulted in a poor running customer car. Unfortunately this happened half way around the world but fortunately the customer had a very good mechanic who installed the kit and recognized where the problem was. He got the correct fuel injectors (factory Bosch not China knock offs) and the car runs as advertised. There are others but this was most recent and was very frustrating.
I have been kind of hanging low for the past couple years primarily because life just got in the way. Three teen age daughters tend to keep you pretty occupied.
I am in the process of fabricating a new batch of parts with some little changes that most would not even recognize. One change that is a little more major is new fan shrouds for the four fans that get mounted behind the radiator. I did some testing and they definitely improved the cooling capacity. The prototypes are on a Rennlisters car, I think he is in South Carolina. I will post some pictures when I get them back from the fabricator. I had a bunch of pictures of the prototypes on my phone but I lost them when I went for a swim with it.
I hope this post finds you all well and I look forward to your comments or questions.
Best regards,
Tim
There is a lot of good discussion in this forum lately with respect to supercharging so I would like to chime in with some of my thoughts and comments.
I know whenever I make a large purchase I research and read anything I can get my hands on so hopefully my posting will help direct more people here and read everyone’s opinions on the topic and become more informed. Adding a major performance modification to your car, such as supercharging, one needs to dive in with both eyes wide open and poised with as much information as they can get their hands on.
Our enthusiasm for these cars and the potential performance is Gods little gift to us for appreciating what the capabilities of the 928 is all about. It is amazing how fortunate we are to have such dedicated people that support the 928 community and give so much of themselves for all our benefit. What I do would mean nothing if it wasn’t for all the others that contribute to keeping these cars affordable and on the road. Of course not only am I talking about the major vendors but I also want to acknowledge all the other innovative players and contributors to this forum that keep these cars running and interesting.
There is a large contingency that think the 928 should be kept original as Porsche designed it. Then there are others who appreciate what Porsche did and also the opportunity Porsche gave us interested in a platform to totally make a HOT ROD out of these wonderful cars. I am of course on the HOT ROD side of life. I like fast cars, make that REALLY FAST cars. I drove a Hell Cat recently and although the car was extremely fast I would not shy away from him with my Stage 3 Murf928 supercharged car. It is too late this year but next summer I will have a chance to run against this car and I hope to add it to the many Murf928 kill stories.
Some suggest that if anyone adds boost to the 928 it is only a matter of time before you blow up your engine. I respectfully disagree with that if it is done right. I just looked at my numbers and I have sold 83 kits over the last 10 years which means about 100 cars have been supercharged with the Murf928 kit because kits get flipped and run on other cars. If it were common to blow up the engine by adding boost I think it would be a prevalent discussion on many car forums, especially here on Rennlist.
With respect to some other comments made in recent threads that are relevant to Murf928:
With a Murf 928 kit you will not need to tune that car after installing it, I would prefer that you do not do that. I also prefer that customers install the kit as designed and if you want to change something later it is up to you because you will have a much better understanding of your car and the design of the supercharger kit. Also, for this same reason I recommend that owners install your own kit when possible, it's a great sense of accomplishment. The Murf928 crew will be there to help you with every step along the way.
With a Murf 928 kit you get new fuel and ignition chips and they are programmed with a relatively conservative tune to run on just about any car. The Sharktuner is a fantastic tool but before you go messing with the tune of a car, especially a supercharged one, you need to completely understand what you are doing.
I have been extremely fortunate with so many kits being installed and very few problems. I’m not saying there have never been any issues because there have been. I recently had a problem with my fuel injector vendor who changed his supplier which resulted in a poor running customer car. Unfortunately this happened half way around the world but fortunately the customer had a very good mechanic who installed the kit and recognized where the problem was. He got the correct fuel injectors (factory Bosch not China knock offs) and the car runs as advertised. There are others but this was most recent and was very frustrating.
I have been kind of hanging low for the past couple years primarily because life just got in the way. Three teen age daughters tend to keep you pretty occupied.
I am in the process of fabricating a new batch of parts with some little changes that most would not even recognize. One change that is a little more major is new fan shrouds for the four fans that get mounted behind the radiator. I did some testing and they definitely improved the cooling capacity. The prototypes are on a Rennlisters car, I think he is in South Carolina. I will post some pictures when I get them back from the fabricator. I had a bunch of pictures of the prototypes on my phone but I lost them when I went for a swim with it.
I hope this post finds you all well and I look forward to your comments or questions.
Best regards,
Tim
10-29-2015, 02:55 PM
#2
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Tim -- Thanks for chiming in. For those of us considering improving the performance of our 928, it's nice to know what our options are. More information is almost always helpful. For example, it's good to know that you do not recommend sharktuning a 928 with your kit installed (at least not until the owner has gained a lot of experience driving the car with the kit installed). It's comforting to know that the car won't need a lot of fiddling to run well after the kit's been installed. It's also good to know that you recommend the owner install the kit rather than hire a mechanic to do the install. That implies that the kits are well thought out and fairly easy to install. Even if someone would rather have their mechanic install the kit, knowing that every item has been thought of is a big plus.
In the spirit of more knowledge being better, allow me to ask you a couple of questions. But first, let me offer several suggestions regarding your website: It's missing a lot of information. You say Murf equipped 928s have spent a lot of time on the dyno, but you only provide one example of an 85/86 car. What about S4s? It would also be nice for you to tell us the price of the kits and list everything that's included. You correctly say a prospective buyer needs to do a lot of research. Your website adds precious little to that process.
Now for the questions:
Again, thank you for chiming in. I wish you nothing be success.
In the spirit of more knowledge being better, allow me to ask you a couple of questions. But first, let me offer several suggestions regarding your website: It's missing a lot of information. You say Murf equipped 928s have spent a lot of time on the dyno, but you only provide one example of an 85/86 car. What about S4s? It would also be nice for you to tell us the price of the kits and list everything that's included. You correctly say a prospective buyer needs to do a lot of research. Your website adds precious little to that process.
Now for the questions:
- How does the kit affect emissions? I know you cannot be an expert in each state's laws, but you should be able to say whether a Murf equipped car can pass emissions in most jurisdictions, but not California, for example.
- How do you deal with the venting of crankcase gasses? A prominent member of the 928 community claims all boosted 928s violate federal law by venting crankcase gasses to the atmosphere.
- On average, how long does it take a weekend mechanic to install your kits? This would help us know if it's simply too much work for us to take on by ourselves. It would also help with estimating installation costs if we have it done professionally.
- Can the driver adjust the amount of boost or is the boost delivered simply a function of the pulley size and RPM?
Again, thank you for chiming in. I wish you nothing be success.
10-29-2015, 03:56 PM
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Very glad to see you posting Tim, welcome back.
10-29-2015, 06:17 PM
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Hi DKWalser,
You bring up some good questions and observations.
Yes, the website sucks. Really need to put some work into that.
As far as emissions go, I have had a number of customers run their supercharged car on the rollers and pass the tailpipe emissions, numerous times. The crankcase breather can be plumbed to the intake filter and the blow off valve plumbed back into the airbox. This makes it a Closed Crankcase Ventilation system. All crankcase fumes go back through the combustion chamber. By making this statement does not imply in any manner the legality of operating a Murf928 Supercharged car on public roads. The individual is responsible to comply with their local emission laws.
Installing a Stage one kit can be done in a day and a Stage 3 kit in a long weekend. Now that's with someone who knows the kit and has done it before. I would expect the average Joe to install a Stage 1 in 10-15 hours. The Stage 3 kit would take another 10 hours or so because the intercooler adds quite a few more pieces to the puzzle. Most guys that are doing this are not in a rush and take their time while tackling other maintenance items along the way.
Boost can be adjusted in a number of ways. The easiest is to adjust the angle of your foot on the gas pedal
Supercharger pulley size plays a role as does restriction to the supercharger inlet. I designed a "Valet Mode" to keep the car from going into boost and severely limit the HP but I have never sold or installed one.
You bring up some good questions and observations.
Yes, the website sucks. Really need to put some work into that.
As far as emissions go, I have had a number of customers run their supercharged car on the rollers and pass the tailpipe emissions, numerous times. The crankcase breather can be plumbed to the intake filter and the blow off valve plumbed back into the airbox. This makes it a Closed Crankcase Ventilation system. All crankcase fumes go back through the combustion chamber. By making this statement does not imply in any manner the legality of operating a Murf928 Supercharged car on public roads. The individual is responsible to comply with their local emission laws.
Installing a Stage one kit can be done in a day and a Stage 3 kit in a long weekend. Now that's with someone who knows the kit and has done it before. I would expect the average Joe to install a Stage 1 in 10-15 hours. The Stage 3 kit would take another 10 hours or so because the intercooler adds quite a few more pieces to the puzzle. Most guys that are doing this are not in a rush and take their time while tackling other maintenance items along the way.
Boost can be adjusted in a number of ways. The easiest is to adjust the angle of your foot on the gas pedal
Supercharger pulley size plays a role as does restriction to the supercharger inlet. I designed a "Valet Mode" to keep the car from going into boost and severely limit the HP but I have never sold or installed one.
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Speedtoys (10-27-2023)
10-30-2015, 04:31 AM
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Mr Murphy, I think you have done an excellent job with your systems. I just purchased an 87 S4 with your Stage 3 kit at 11psi. It runs very well and is obviously tuned conservatively. I fully intend to make some changes and upgrades that will allow me to tune for more power. I should point out I do know what I am doing, my daily is an 850 rwhp Silverado I built and tuned. I am certain I will be contacting you at some point lol. You have a great product sir.
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10-30-2015, 03:27 PM
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10-30-2015, 04:53 PM
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I've got to chime in here regarding Tim's impact on boosted 928's.
In my mind, all of the boosted 928's you see on the road today owe at least a tip of the hat to Murph.
There was a time that when the issue of boosting a 928 5L would come up, the naysayers would talk about there being "no way" to boost a car with a 10:1 C/R, or that that the free standing cylinder towers wouldn't take the pressure, or that you'd never get the head gaskets to seal, or you'd never be able to tune the engine to run properly, and on and on. While everyone was basically sitting around with their thumb up their bung hole talking about why it couldn't work, Murph just did it. And he didn't just find out what worked, he packaged it all together as a complete DIY kit. We now have a variety of boosted 928's on the road, turn key kits available, and more kits being developed for S/C'd and Turbo'd cars.
Murph is the OG of boosted 928's. All hail the boost king.
In my mind, all of the boosted 928's you see on the road today owe at least a tip of the hat to Murph.
There was a time that when the issue of boosting a 928 5L would come up, the naysayers would talk about there being "no way" to boost a car with a 10:1 C/R, or that that the free standing cylinder towers wouldn't take the pressure, or that you'd never get the head gaskets to seal, or you'd never be able to tune the engine to run properly, and on and on. While everyone was basically sitting around with their thumb up their bung hole talking about why it couldn't work, Murph just did it. And he didn't just find out what worked, he packaged it all together as a complete DIY kit. We now have a variety of boosted 928's on the road, turn key kits available, and more kits being developed for S/C'd and Turbo'd cars.
Murph is the OG of boosted 928's. All hail the boost king.
10-30-2015, 07:17 PM
#10
I'm a big fan. Had mine for a few years, never want to go back!!!! It is reliable and easy, no nonsense, no downside. I've got 151,000 miles and always drive like I stole it. I always try to exceed 100 mph for even a bit every time I drive her. Tim is the Man.
10-31-2015, 12:13 AM
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Tim! 
10-31-2015, 10:39 AM
#12
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Have you done a dyno run?
10-31-2015, 10:41 AM
#13
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Very interested in the fan shrouds ready to beta test in Florida with stop and go driving with air on. 😗
Resently finely tuned and modified it kicks butt 424 to the wheels with 10lbs of boost, runs like it should have been from the factory. Down side I need LSD so to not bump the car next to me! The best thing it drives like a normal 928 until you hit it.
Resently finely tuned and modified it kicks butt 424 to the wheels with 10lbs of boost, runs like it should have been from the factory. Down side I need LSD so to not bump the car next to me! The best thing it drives like a normal 928 until you hit it.
