Which supercharger to get new owner
10-09-2015, 08:14 AM
#16
Rennlist Member
Erin
I have a VCB stage one s/c on my car. It's been on there as a daily driver for over two years and around 20,000 miles or so. I haven't had a s/c problem (or super charger induced problem) since installation. I had everything (turns out forgot coils and amps) refreshed replaced in /on the engine, gaskets, sensors, hoses
Car is supremely reliable, daily drivable and now has "more modern" amount of power. That being said, would I want a Greg Brown stroker over this setup? Hell yes. Do I currently want to choose his $30-$80k engine (a work of art btw) over a down payment on an airplane? No.
The s/c naysayers (Same for the tt naysayers) are armchair quarterbacks. I don't see them running them in any of their cars thus their opinions don't carry the same validity as one of us who has bolt on power and uses it regularly. Murph and victor have the kits sorted. Same goes for the tt setup. Get your engine in top form. Refresh all the rubber bits, electrical goodies under hood and head gaskets and you can take your pick of s/c or tt. Both will add reliable power and make your smile wider and wallet a little lighter.
If you want to know about a s/c setup or drive one, stop by here in Iowa or come to third coast and drive mine.
I have a VCB stage one s/c on my car. It's been on there as a daily driver for over two years and around 20,000 miles or so. I haven't had a s/c problem (or super charger induced problem) since installation. I had everything (turns out forgot coils and amps) refreshed replaced in /on the engine, gaskets, sensors, hoses
Car is supremely reliable, daily drivable and now has "more modern" amount of power. That being said, would I want a Greg Brown stroker over this setup? Hell yes. Do I currently want to choose his $30-$80k engine (a work of art btw) over a down payment on an airplane? No.
The s/c naysayers (Same for the tt naysayers) are armchair quarterbacks. I don't see them running them in any of their cars thus their opinions don't carry the same validity as one of us who has bolt on power and uses it regularly. Murph and victor have the kits sorted. Same goes for the tt setup. Get your engine in top form. Refresh all the rubber bits, electrical goodies under hood and head gaskets and you can take your pick of s/c or tt. Both will add reliable power and make your smile wider and wallet a little lighter.
If you want to know about a s/c setup or drive one, stop by here in Iowa or come to third coast and drive mine.
10-09-2015, 11:04 AM
#17
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FI naysayers formed their opinions before The Shark Tuner was available.
Get the engine in your 928 fully caught up on maintenance. 90+% chance it isn't caught up now and you are missing power and not ready for FI.
While you are doing that you can finish your research.
Get the engine in your 928 fully caught up on maintenance. 90+% chance it isn't caught up now and you are missing power and not ready for FI.
While you are doing that you can finish your research.
10-09-2015, 11:04 AM
#18
Nordschleife Master
That is correct. You writing that as a joke is comical, but probably for different reasons than you intend.
After JDS unlocked the stock computers, the whole game changed with the Sharktuners. Now it is the case that at every given level of reliability, forced induction provides the most hp per dollar. That's not even up for a debate, the science is settled as they say.
Correctly tuned 928 motor has two features. First, it is overbuilt to the point that it can handle absurdly high cylinder pressures and heat loads without any problem whatsoever. The pistons are heavy, rings are thick, ring lands are thick, the valve seats are wide, bearings are long and large diameter, etc. The 928 engine can be boosted cheaply and reliably.
Now, the alternative for making the power with forced induction is making it normally aspirated and that means with higher rpms. All the same factors that make the S4 engine ideal for forced induction make it unreliable at very high rpms. Consequently, to make a lot of N/A power with the 928 engine means that it can't be done cheaply and reliably. That's the fundamental reality that you're obviously not grasping.
After JDS unlocked the stock computers, the whole game changed with the Sharktuners. Now it is the case that at every given level of reliability, forced induction provides the most hp per dollar. That's not even up for a debate, the science is settled as they say.
Correctly tuned 928 motor has two features. First, it is overbuilt to the point that it can handle absurdly high cylinder pressures and heat loads without any problem whatsoever. The pistons are heavy, rings are thick, ring lands are thick, the valve seats are wide, bearings are long and large diameter, etc. The 928 engine can be boosted cheaply and reliably.
Now, the alternative for making the power with forced induction is making it normally aspirated and that means with higher rpms. All the same factors that make the S4 engine ideal for forced induction make it unreliable at very high rpms. Consequently, to make a lot of N/A power with the 928 engine means that it can't be done cheaply and reliably. That's the fundamental reality that you're obviously not grasping.
10-09-2015, 11:23 AM
#19
Developer
We have several low-boost (6 psi) solutions that have shown themselves to be very safe for extended periods of time. Adds another 150 or more HP to the S4, wakes it up nicely. Simple, all external, bolt-on installation.
My email address is below my signature - please let me know if you have any questions.
My email address is below my signature - please let me know if you have any questions.
10-09-2015, 11:34 AM
#20
I don't understand why everyone thinks the 928 must be in bad shape. The guy said it is pristine condition. To me that means it completely updated on every aspect. He simply asked for advice on which SC to get. The 928 S4 will feel much slower than the 335 even if it was in pristine shape. Specially if the 335 was tuned a little. A very close friend has a 335 very little $$$ the car became a beast. The 928 S4 needs the boost.
10-09-2015, 11:39 AM
#21
I don't understand why everyone thinks the 928 must be in bad shape. The guy said it is pristine condition. To me that means it completely updated on every aspect. He simply asked for advice on which SC to get. The 928 S4 will feel much slower than the 335 even if it was in pristine shape. Specially if the 335 was tuned a little. A very close friend has a 335 very little $$$ the car became a beast. The 928 S4 needs the boost.
10-09-2015, 11:41 AM
#22
Developer
No special preparation needs be made prior to installing our kit. However, we suggest a standard tune-up, and that the timing belt/water pump service be reasonably current. That's about it. If it's running well - then your good-to-go.
10-09-2015, 11:44 AM
#23
Developer
What Sean is talking about is the camshaft cover breather hoses that run under the 32v intake manifold. They are often cracked and split from oil degradation. Check 'em. I can send you pics - show you where they are.
10-09-2015, 01:11 PM
#24
Nordschleife Master
First choice is Murf's SC setup, it comes with proper injectors, and chips which have proper fueling and ignition timing pulled out to ensure reliability and safety.
Second option is VCB setup. His comes with injectors and PEMS and is only tuned as good as the person on the computer.
None of the other kits on the market currently are safe. The motorsports kit runs stock timing, doesn't increase the injector size, instead just ramps up stock fuel pressure to compensate. A very dangerous method. As well, they do not remove any timing and therefor rely on the stock knock sensors to pull ignition timing.
What everyone else has said is true though. You must do an intake refresh first, replacing both knock sensors, the hall sensor, and if you have more than 70k miles, a rebuilt JDS Porsche MAF sensor is highly recommended.
When you do remove the intake, have it powdercoated, and make 1000% sure that the inside of the intake is perfectly clean before bolting it back together and installing it on to the engine.
As always though, do your own research and learn as much as you can about everything before pulling the trigger!
Second option is VCB setup. His comes with injectors and PEMS and is only tuned as good as the person on the computer.
None of the other kits on the market currently are safe. The motorsports kit runs stock timing, doesn't increase the injector size, instead just ramps up stock fuel pressure to compensate. A very dangerous method. As well, they do not remove any timing and therefor rely on the stock knock sensors to pull ignition timing.
What everyone else has said is true though. You must do an intake refresh first, replacing both knock sensors, the hall sensor, and if you have more than 70k miles, a rebuilt JDS Porsche MAF sensor is highly recommended.
When you do remove the intake, have it powdercoated, and make 1000% sure that the inside of the intake is perfectly clean before bolting it back together and installing it on to the engine.
As always though, do your own research and learn as much as you can about everything before pulling the trigger!
10-09-2015, 01:12 PM
#25
Nordschleife Master
I don't understand why everyone thinks the 928 must be in bad shape. The guy said it is pristine condition. To me that means it completely updated on every aspect. He simply asked for advice on which SC to get. The 928 S4 will feel much slower than the 335 even if it was in pristine shape. Specially if the 335 was tuned a little. A very close friend has a 335 very little $$$ the car became a beast. The 928 S4 needs the boost.
They are just saying that it's important to be absolutely certain that the engine is operating the way it's supposed to be before doing any performance mods. Even John Speake says that about installing his chips. Make sure the car is running very well before hand.
"Pristine condition" at 97k miles. Has the intake been refreshed? When? Injectors cleaned and tested? When? Hall & Knock sensors working properly? MAF? O2 & Temp II? Wiring good? This stuff is all 20+ years old.
There have been plenty of stories about people wanting to do upgrades to their cars, being told to "do all this and then do the mods" then coming back and joyfully sharing how much better the car ran when it was all fresh.
10-09-2015, 01:31 PM
#26
Rennlist Member
If a 928 engine is running to spec (verified w/ Shark Tuner) and all 20 yr old parts refreshed (maybe Head Gaskets too).
NOS, Turbo, Stroked or SC if "tuned" correctly for the amount of added HP will NOT hurt the 928 Engine.
We have a few modded here in MI with 400 to over 500 HP and all have been running great for years and have been taken on many a long trip too.
NOS, Turbo, Stroked or SC if "tuned" correctly for the amount of added HP will NOT hurt the 928 Engine.
We have a few modded here in MI with 400 to over 500 HP and all have been running great for years and have been taken on many a long trip too.
10-09-2015, 01:57 PM
#27
Developer
Erin,
here is a good thread that asked the very same question only a few weeks ago:
https://rennlist.com/forums/showthre...eferrerid=4282
here is a good thread that asked the very same question only a few weeks ago:
https://rennlist.com/forums/showthre...eferrerid=4282
10-09-2015, 02:29 PM
#28
Nordschleife Master
The stock MAF boot works for boosted motors pretty well provided that
(a) it doesn't overheat because of inadequate cooling air flow under the hood
(b) the stocks clamps are not overtightened, or an aftermarket constant torque clamp is used and tightened sensibly
(c) if stock clamps are used, the straps are not missing
(d) the MAF housing element is grooved
(e) the MAF housing element is supported properly and rigidly from the air box side
With a-e, my experience is that the stock MAF boot holds at least mid-20's of boost. Without those, it's hit and miss. Before I had a-e, I did pop it out a couple of times. The worst combination is overtightening and heat cycles with the stock clamps, because each cycle makes the clamp cut a little deeper into the boot.
I am not a fan of the currently available aftermarket silicone MAF boot because it creates steps in the air flow. That design could be revised to be adequate by staring at the MAF housing and throttle body elements for 30 seconds and putting 2+2 together.
If the motor has not overheated and if the same coolant hasn't been left in there for years of inactivity, I don't think changing the head gasket pre-emptively before boosting makes sense. And if the motor has overheated or if the car has sat in a barn with the same coolant fluid for years, you might want to do something about it even if you aren't planning to boost the motor.
We run hundreds of dyno runs on a bone stock '87 S4 motor with turbos, up to 700 rwhp. That engine is off the car (so a hot rodded engine can go in) and as far as I can tell the stock motor would have lasted forever. We'll document everything when we open it, it'll be interesting to see what the components look like after repeated workouts at 2.5x the factory stock power.
(a) it doesn't overheat because of inadequate cooling air flow under the hood
(b) the stocks clamps are not overtightened, or an aftermarket constant torque clamp is used and tightened sensibly
(c) if stock clamps are used, the straps are not missing
(d) the MAF housing element is grooved
(e) the MAF housing element is supported properly and rigidly from the air box side
With a-e, my experience is that the stock MAF boot holds at least mid-20's of boost. Without those, it's hit and miss. Before I had a-e, I did pop it out a couple of times. The worst combination is overtightening and heat cycles with the stock clamps, because each cycle makes the clamp cut a little deeper into the boot.
I am not a fan of the currently available aftermarket silicone MAF boot because it creates steps in the air flow. That design could be revised to be adequate by staring at the MAF housing and throttle body elements for 30 seconds and putting 2+2 together.
If the motor has not overheated and if the same coolant hasn't been left in there for years of inactivity, I don't think changing the head gasket pre-emptively before boosting makes sense. And if the motor has overheated or if the car has sat in a barn with the same coolant fluid for years, you might want to do something about it even if you aren't planning to boost the motor.
We run hundreds of dyno runs on a bone stock '87 S4 motor with turbos, up to 700 rwhp. That engine is off the car (so a hot rodded engine can go in) and as far as I can tell the stock motor would have lasted forever. We'll document everything when we open it, it'll be interesting to see what the components look like after repeated workouts at 2.5x the factory stock power.
10-09-2015, 03:52 PM
#30
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Gentleman,
Lots of good commends. Useful information but inconclusive. This is the same result from my research.
My car is in superman mode. All service up to date. I have talked to the Porsche dealer that has done the service recently, have the receipts and the previous owner is a good friend.
The intake been refreshed( 2 months ago), injectors cleaned and tested(2 months ago), Hall & Knock sensors working properly, MAF, O2 & Temp II, Wiring good.
Like I said previously the car is in pristine shape.
My friend had the car prepared for supercharger. He sold to car to me because of a divorce. At the end he was happy I bought the car which he loved dearly.
The car is ready for supercharger. It is strong. My 335 beat this 928 side by side of the line.
I have planned it and ready for a supercharger.
Can not decide which supercharger to get.
I need help deciding which supercharger is best.
Lots of good commends. Useful information but inconclusive. This is the same result from my research.
My car is in superman mode. All service up to date. I have talked to the Porsche dealer that has done the service recently, have the receipts and the previous owner is a good friend.
The intake been refreshed( 2 months ago), injectors cleaned and tested(2 months ago), Hall & Knock sensors working properly, MAF, O2 & Temp II, Wiring good.
Like I said previously the car is in pristine shape.
My friend had the car prepared for supercharger. He sold to car to me because of a divorce. At the end he was happy I bought the car which he loved dearly.
The car is ready for supercharger. It is strong. My 335 beat this 928 side by side of the line.
I have planned it and ready for a supercharger.
Can not decide which supercharger to get.
I need help deciding which supercharger is best.