S4 Twin Turbo will be a reality!
07-05-2005, 06:19 PM
#16
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Yes...I have considered adding just like 5-7 on the stock internals...time will tell.
Best news is...They ARE bidding on the GOLDMEMBER! 6 days to go and I'm about to take a bath in the tub with the dirty rings around the side! It has to go, I need the room for the S4. My new place has a nice area up front for doing all the work!
Hey, does my new car have a GTS rear bumper or what? I'm told this guy way a really cool guy...glad to hear the feedback Jim. It is a shame what happened, but hearing his collection I'm sure he woudl approve of what I am doing to his car!. Dennis, the guy who is selling his collection is really, really nice and is taking extra good care of the car for me. It even comes with a nice cover and GTS mirrors (I suspect he wanted a GTS someday) I was considering Mark Anderson's 90...then this car popped up. Not crazy about the chrome wheels, but at least it has some meats on it. I think the price I paid was also very reasonable. I'm excited to take possession of this one...big brakes, nice suspension...add manifold pressure and viola...instant supercar! You know, the S4s are quite a bit more refined than the older cars.
So...who would want a 5-7 psig bolt on to the S4...twin turbos and 5-7 psig, don't touch the insides...? I'd prefer not to grenade the ring lands on this car finding out how much it will handle.
Best news is...They ARE bidding on the GOLDMEMBER! 6 days to go and I'm about to take a bath in the tub with the dirty rings around the side! It has to go, I need the room for the S4. My new place has a nice area up front for doing all the work!
Hey, does my new car have a GTS rear bumper or what? I'm told this guy way a really cool guy...glad to hear the feedback Jim. It is a shame what happened, but hearing his collection I'm sure he woudl approve of what I am doing to his car!. Dennis, the guy who is selling his collection is really, really nice and is taking extra good care of the car for me. It even comes with a nice cover and GTS mirrors (I suspect he wanted a GTS someday) I was considering Mark Anderson's 90...then this car popped up. Not crazy about the chrome wheels, but at least it has some meats on it. I think the price I paid was also very reasonable. I'm excited to take possession of this one...big brakes, nice suspension...add manifold pressure and viola...instant supercar! You know, the S4s are quite a bit more refined than the older cars.
So...who would want a 5-7 psig bolt on to the S4...twin turbos and 5-7 psig, don't touch the insides...? I'd prefer not to grenade the ring lands on this car finding out how much it will handle.
07-05-2005, 08:38 PM
#18
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5-7 psi on a stock internal engine should be fine? That is what the supercharger guys are running with good results and so far good reliability! But if you want to build a 20+psi monster motor than you will definitely need serious engine work (pistons-rods-closed deck-etc)....
1000hp is possible with a properly built engine (5.0L)and race gas!
Brian
1000hp is possible with a properly built engine (5.0L)and race gas!
Brian
07-06-2005, 06:39 PM
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5-7 with a turbo is a whole different ball game compared to 5-7 with a Vortech...though the twin screw guys are doing it as well and that is the one that makes the hardest grunt down low.
I know the motor could handle the 5-7 psig....but what is it worth? I don't know.
I know the motor could handle the 5-7 psig....but what is it worth? I don't know.
11-14-2005, 01:04 PM
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Bypass valves are integrated into the turbine housings and turbocharger pressure is adjusted through a joint cycle valve controlled by the engine management system. Maximum turbocharger pressure is approximately 8.7 pounds per square inch (.6 bar) and is reached at an engine speed of 2250 rpm. Boost pressure then reduces slightly, to 7.3 psi (.5 bar), where it remains until the engine reaches its maximum horsepower at 6000 rpm
looks like they run at 8.7psi at 2250 rpm!!
No lag there
11-16-2005, 04:23 PM
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Herr Kuhn: Have you considered a combination of a supercharger and a turbo? VW just introduced a version of their VW Golf with a 1.4 liter engine that has both. It makes 170hp (121hp/liter).
It uses the supercharger until a clutch disengages it at 3500 rpm. The turbo is added gradually, I believe.
That little car goes from 0-60 in 7.8 seconds and tops out at 138mph. At the same time it gets an incredible gas mileage.
Just a thought - it might be too complex for your situation, but from what I read it works very well in the VW.
It uses the supercharger until a clutch disengages it at 3500 rpm. The turbo is added gradually, I believe.
That little car goes from 0-60 in 7.8 seconds and tops out at 138mph. At the same time it gets an incredible gas mileage.
Just a thought - it might be too complex for your situation, but from what I read it works very well in the VW.
11-16-2005, 04:31 PM
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With John Speake's Sharktuner, that setup would be easier now. You can change the timing and function of the flappy actuation in the LH to do the SC->turbo changeover. I don't think Herr Kuhn would go for that system because he'd have to use liquid intercooling instead of air-air.
11-16-2005, 06:10 PM
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O/N...remember your Vortech has the ultimate lag...redline=full boost anything less than redline = less than full boost. Can't change that without bleeding off or a variable speed drive. I believe the turbo to be the best because 1st gear you don't pull full boost (don't need it), maybe not even in 2nd under moderate throttle...let's talk 3rd gear, where the loads are high...3,500 RPM-4000 RPM...you drop the hammer in the Vortech car and I drop it on the turbo car...who gets to redline faster?..of course we are talking about the same boost on the same engine, not a 4.5 liter vs. 5.0 liter as you always make comparisons to. If you really think the Vortech can pull that one off you should do a double take. Take a look at the torque curves of a turbo vs centrifugal on the same angine at the same boost pressures. On 8 psig the Callaway made 355 ft-lbs. On 12 psig it made 385 ft-lbs. Show me any CS boosted 4.5 liter that made even close to those torque numbers. Even the little Goldmember K-24 setup put down over 350 ft-lbs at a low 3,500 RPM. The HP may be the same on the centrifugal car at the same boost level, but the powerband width and area under the curve is what tells the real story.
People who say they have no need for power below 4,500-5000 RPM are not making sense. Your engine had to pass through 3,500, 4000, 4,500 before you got there. Nobody can tell me you can always keep the tach between 4,500 and 6,000 RPM, specifically on the street. Ever come out of a corner in say 3rd gear at 3,500-4000 RPM...that is where the turbos can really shine, the boost response there is virtually instantaneous, it follows your right foot. Still the centrifugal falls short of the turbos potential at anything but the highest top end point for boost production. it isn't even linear...check out htis link to see the differences: http://home.att.net/~jroal/blown.htm
The boost response of the centirfugal (i.e. boost vs time plot) gets worse and worse as you go up in the gears. The turbo is just the opposite, the response time drops as loads increase. It depends on loads, not RPM. Positive SC is different altogether and has a more favorable boost curve, though they do take HP to drive and I'm not sure a 5.0 liter needs 8 psig right off idle, but the arguement for all of your boost by 3,500 is a strong one.
The super/turbo is unique...but I'm having enough difficulty with fitting the big turbos let alone another device. It is a tight squeeze in that engine bay, but I know it can be done. I've gotten as far as the air filtration system design and some of the large intake pipes to each bank...but I had to stop to address the (ex) Callaway's needs for now.
I've strongly considered air to water, but I'm just not sold on it yet. I have the air to air figured out, it is just execution now. The twin setup allows for much larger flow paths on the 928, so I believe it to be the path to really strong and reliable power production.
Fuel management...man what a topic. So many options, some better than others, some chepear and easier than others. That is a big topic!
People who say they have no need for power below 4,500-5000 RPM are not making sense. Your engine had to pass through 3,500, 4000, 4,500 before you got there. Nobody can tell me you can always keep the tach between 4,500 and 6,000 RPM, specifically on the street. Ever come out of a corner in say 3rd gear at 3,500-4000 RPM...that is where the turbos can really shine, the boost response there is virtually instantaneous, it follows your right foot. Still the centrifugal falls short of the turbos potential at anything but the highest top end point for boost production. it isn't even linear...check out htis link to see the differences: http://home.att.net/~jroal/blown.htm
The boost response of the centirfugal (i.e. boost vs time plot) gets worse and worse as you go up in the gears. The turbo is just the opposite, the response time drops as loads increase. It depends on loads, not RPM. Positive SC is different altogether and has a more favorable boost curve, though they do take HP to drive and I'm not sure a 5.0 liter needs 8 psig right off idle, but the arguement for all of your boost by 3,500 is a strong one.
The super/turbo is unique...but I'm having enough difficulty with fitting the big turbos let alone another device. It is a tight squeeze in that engine bay, but I know it can be done. I've gotten as far as the air filtration system design and some of the large intake pipes to each bank...but I had to stop to address the (ex) Callaway's needs for now.
I've strongly considered air to water, but I'm just not sold on it yet. I have the air to air figured out, it is just execution now. The twin setup allows for much larger flow paths on the 928, so I believe it to be the path to really strong and reliable power production.
Fuel management...man what a topic. So many options, some better than others, some chepear and easier than others. That is a big topic!
11-16-2005, 09:07 PM
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Originally Posted by Herr-Kuhn
It would seem to me the TS super has a bit too much grunt right off idle. 9 mile burnouts anyone?
Zero lag.....
..non..nada...nunca...nyet....Whats in your engine.
(from the commercial...get it
)Let me dig up a GTECH run from a TT Cayenne
11-16-2005, 11:58 PM
#27
The boost response of the centirfugal (i.e. boost vs time plot) gets worse and worse as you go up in the gears. The turbo is just the opposite, the response time drops as loads increase. It depends on loads, not RPM. Positive SC is different altogether and has a more favorable boost curve, though they do take HP to drive and I'm not sure a 5.0 liter needs 8 psig right off idle, but the arguement for all of your boost by 3,500 is a strong one.
Koenigsegg
http://home.att.net/~jroal/blown.htm That's a great link to a guy who thinks positive displacement blowers are the way to go! I tend to agree but a centrifugal isin't bad either. Turbos are great but the additional cost and complexity over a supercharger system can be a real deal breaker for many.
11-17-2005, 12:14 AM
#29
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Originally Posted by Jim Nowak
Let me introduce you to the Rotrex supercharger Rotrex supercharger You may change your mind on centrifugal blowers. Many are running two of these on their higher hp engines. Have you ever heard of the Koenigsegg CCR? It runs to 60 mph in 3.2 seconds, 1/4 mile in 9 seconds at 146 mph, and a top speed of over 242 mph. Yep, those centrifugal blowers are really crappy. The worst of both worlds!
Koenigsegg
http://home.att.net/~jroal/blown.htm That's a great link to a guy who thinks positive displacement blowers are the way to go! I tend to agree but a centrifugal isin't bad either. Turbos are great but the additional cost and complexity over a supercharger system can be a real deal breaker for many.
Koenigsegg
http://home.att.net/~jroal/blown.htm That's a great link to a guy who thinks positive displacement blowers are the way to go! I tend to agree but a centrifugal isin't bad either. Turbos are great but the additional cost and complexity over a supercharger system can be a real deal breaker for many.
11-17-2005, 11:17 AM
#30
The old SN Paxton series uses a ball bearing drive and they can not be spun very fast. I've gone through an SN89 and an SN2000 and they are not very dependable if you over spin them. However, I really like the sound the old SN's produce. It's a much nicer sound than what my Procharger makes.
The Rotrex can be spun at 90,000 to 250,000 rpm depending on the model/step drive and has a greater adiabatic efficiency than the most efficient turbos. Step ratio varies from 7.5:1 to more than 12.5:1 so they produce power more in line with a positive displacement blower on the low end and a turbo in the top end.
This month's issue of Hot Rod magazine has a twin supercharged 6.0 Gen III small block producing 928 hp @ 5900 rpm and 825 lb-ft of tq at 5700 at 20 psi. They were using a pair of C38-71 Rotrex supoerchargers. Each one can support around 650 hp.
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350Z Rotrex kit
The Rotrex can be spun at 90,000 to 250,000 rpm depending on the model/step drive and has a greater adiabatic efficiency than the most efficient turbos. Step ratio varies from 7.5:1 to more than 12.5:1 so they produce power more in line with a positive displacement blower on the low end and a turbo in the top end.
This month's issue of Hot Rod magazine has a twin supercharged 6.0 Gen III small block producing 928 hp @ 5900 rpm and 825 lb-ft of tq at 5700 at 20 psi. They were using a pair of C38-71 Rotrex supoerchargers. Each one can support around 650 hp.
Active Autowerke
350Z Rotrex kit