Rear Mount Turbo Progress??????
12-25-2005, 03:41 AM
#106
Burning Brakes
PS.
Merry Christmas, fellow pork-lovers!
Update on the turbo setup... I tinkered with the setup the other night, and since I've ignore that car for so long, and have other projects that need to take priority, I've had to shelf it in hopes that Lance J would pick up where I left off and make some improvements to my setup...
Basically, the turbo wasn't spinning at idle, nor even moving up to 2000rpms, and the overly high oil pressure going through it was choking it to death... Should have known better though, but thats why its called a 'prototype', right?
I popped off the oil return line from the turbo, and a nice piece of metal fell out with the ~1000mi. old oil that looked like it 10000 mile oil... So, gotta rip apart the turbo and check stuff out there, change the oil in the car with a new filter (which is now mounted up in the rear bumper and takes a standard Chevy filter [I can buy something at Schmucks for a 928 now!!!]), and do a couple things to the car...
I had forgotten that I welded everything as mainly one piece, so the turbo met the sawzall, and I never got around to making the charge pipe removable at the front of the engine, so I guess I'll have to bust out the saw again if I want to tighten that new timing belt
But, since this is all coming off, I now know what works, what doesn't and can only make improvements from here
So, thats the update for now! Now I gotta pull the engine out of my 951 and hopefully bore to 104mm and start on that 400+rwhp beast
Lance, take 'er away...
Merry Christmas, fellow pork-lovers!
Update on the turbo setup... I tinkered with the setup the other night, and since I've ignore that car for so long, and have other projects that need to take priority, I've had to shelf it in hopes that Lance J would pick up where I left off and make some improvements to my setup...
Basically, the turbo wasn't spinning at idle, nor even moving up to 2000rpms, and the overly high oil pressure going through it was choking it to death... Should have known better though, but thats why its called a 'prototype', right?
I popped off the oil return line from the turbo, and a nice piece of metal fell out with the ~1000mi. old oil that looked like it 10000 mile oil... So, gotta rip apart the turbo and check stuff out there, change the oil in the car with a new filter (which is now mounted up in the rear bumper and takes a standard Chevy filter [I can buy something at Schmucks for a 928 now!!!]), and do a couple things to the car...
I had forgotten that I welded everything as mainly one piece, so the turbo met the sawzall, and I never got around to making the charge pipe removable at the front of the engine, so I guess I'll have to bust out the saw again if I want to tighten that new timing belt
But, since this is all coming off, I now know what works, what doesn't and can only make improvements from here
So, thats the update for now! Now I gotta pull the engine out of my 951 and hopefully bore to 104mm and start on that 400+rwhp beast
Lance, take 'er away...
12-25-2005, 12:48 PM
#108
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Robbing chankshaft HP to overdrive a CS, then venting off makes absolutely no sense. Temperatures skyrocket and you just burned a bunch of fuel to pump compressed air to the atmosphere. Please explain the logic in that to me because I just don't see the point. The CS will never approach the efficiency or have the manners of the turbo setup.
Hey, I never said they didn't work. There are many people on here bashing the turbo 928 having never seen or ridden in one. I've ridden in a few large V8 CS cars and truth be told they were fast in the low gears, but none impressed me all that much from an overall package. Noisy and lacking mid range compared to the turbo. Not sure about how you guys drive, but I prefer not to peg my tach all day just to get boost. Remember, if you have torque and RPM you automatically have HP. So, more torque at a given RPM always means more power there.
Last I recall I said the twin screw was the way to go if you boost a 928 with a belt. That gives the instant boost that people believe comes with all superchargers. Unfortunately, I believe many people are sold a bill of goods on "instant boost" with the CS as it just ins't so. People hear supercharger and they think it has off idle boost and that isn't true.
Check out the hotrod magazine article a few years back on "Battle of the Boost"...it gives some interesting insight into what works best where. For your 0-60 and mid range the clear winner of the superchargers would be the twin screw and I agree.
Don't worry Dave, I'm not upset with you. For Pete's sake it is Christmas we should all be happy, right?
Hey, I never said they didn't work. There are many people on here bashing the turbo 928 having never seen or ridden in one. I've ridden in a few large V8 CS cars and truth be told they were fast in the low gears, but none impressed me all that much from an overall package. Noisy and lacking mid range compared to the turbo. Not sure about how you guys drive, but I prefer not to peg my tach all day just to get boost. Remember, if you have torque and RPM you automatically have HP. So, more torque at a given RPM always means more power there.
Last I recall I said the twin screw was the way to go if you boost a 928 with a belt. That gives the instant boost that people believe comes with all superchargers. Unfortunately, I believe many people are sold a bill of goods on "instant boost" with the CS as it just ins't so. People hear supercharger and they think it has off idle boost and that isn't true.
Check out the hotrod magazine article a few years back on "Battle of the Boost"...it gives some interesting insight into what works best where. For your 0-60 and mid range the clear winner of the superchargers would be the twin screw and I agree.
Don't worry Dave, I'm not upset with you. For Pete's sake it is Christmas we should all be happy, right?
12-25-2005, 03:31 PM
#109
Drifting
Hey John,
I just believe you can tout the benefits of a turbo setup without putting down the other styles of boost. We all know where your loyalty's live but it shouldn't be at the expense of other designers and engineers.
I do find it hard to believe that never having ridden in a supercharged 928 that you speak with such authority on the subject. I think you'll find the differences much less than you rant about.
Have you ever heard me bash the turbo design for a 928? I am looking forward to information on the rear mounted as well as your developments but I sure get tired of all the bashing of other systems. If your system is so superior, just prove it without all the yapping. I for one want to see it but your attitude toward other's ideas and designs really tarnishes anything good you may do for the 928 community. I'm worried about what you'll have to say if your system does work as well as you anticipate. How many potential customers will you run off with your superior "I told you so" attitude? Me for one.
What I'm saying is maybe you should join the community, not fight it. We can help Lance and Tom as well as John with the development of the rear turbo system or you can sit on your little hill and state how much better your system "will" be. Do some learning, ride in a couple of supercharged cars and see that the differences will not be as drastic as you try to dominate every conversation with. The CS system works and works well. So many people know that already but most of them will not bother to respond to your attacks. They have tired of it.
I don't think you are upset with me in fact I'm just trying to help the community as a whole. I don't want people to quit reading and helping with the rear turbo development just because they don't want to read your posts. I'd like to see your system come to fulfillment and hope you sell enough to at least break even but man, you have to quit putting down competitors efforts.
I hope your holidays are going well.
I just believe you can tout the benefits of a turbo setup without putting down the other styles of boost. We all know where your loyalty's live but it shouldn't be at the expense of other designers and engineers.
I do find it hard to believe that never having ridden in a supercharged 928 that you speak with such authority on the subject. I think you'll find the differences much less than you rant about.
Have you ever heard me bash the turbo design for a 928? I am looking forward to information on the rear mounted as well as your developments but I sure get tired of all the bashing of other systems. If your system is so superior, just prove it without all the yapping. I for one want to see it but your attitude toward other's ideas and designs really tarnishes anything good you may do for the 928 community. I'm worried about what you'll have to say if your system does work as well as you anticipate. How many potential customers will you run off with your superior "I told you so" attitude? Me for one.
What I'm saying is maybe you should join the community, not fight it. We can help Lance and Tom as well as John with the development of the rear turbo system or you can sit on your little hill and state how much better your system "will" be. Do some learning, ride in a couple of supercharged cars and see that the differences will not be as drastic as you try to dominate every conversation with. The CS system works and works well. So many people know that already but most of them will not bother to respond to your attacks. They have tired of it.
I don't think you are upset with me in fact I'm just trying to help the community as a whole. I don't want people to quit reading and helping with the rear turbo development just because they don't want to read your posts. I'd like to see your system come to fulfillment and hope you sell enough to at least break even but man, you have to quit putting down competitors efforts.
I hope your holidays are going well.
12-25-2005, 05:45 PM
#110
Originally Posted by jeff jackson
The real problem I see with turbocharging the 928... (other than installation logistics for both turbos, connected via adapters bolted to the factory exhaust manifold outlet flanges, and adapting to appropriately sized turbos of approx. 300 to 400 cfm per side)... and the intercoolers,... envision side mount intercoolers, mounted in the brake rotor cooling ducts, similar in concept to the Mitsubishi 3000GT VR4)...is the 10 to 1 or better compression ratio, of the 85 and later 928 engines. I don't care what sort of turbo, and intercooling, you provide for this configuration...even with the superior breathing of the 4V cylinder heads...add boost..., even <10 psi...and cylinder pressure, combined with the increased intake mixture temperature, is going to yield detonation. And remember...the 928 engine was originally designed as a high performance, "naturally aspirated" engine. So...these extreme cylinder pressures and temps, were NOT included in the OEM engineering concept for this engine. So...without radical reduction in the static compression ratio, prior to adding "turbocharged" boost...Detonation, and piston / valve problems, (due to "knock"), are certainly likely. Increased intake mixture temperature, under even moderate boost, will yield cylinder pressures and temperatures far in excess of OEM design criteria. Water/alcohol injection might help..but think about it...with th quality of fuel currently available, unless a "purpose Built" (read LOW COMPRESSION), short block is put together, the OEM engine ISN'T at all well suited for turbocharging. Without substantially changing the OEM designed "concept" for this car. That is...no AC...high octane fuel requirements...fabbed turbo and intercooler installation, supplemental fuel management. etc. Don't get me wrong, I feel turbocharging is a far superior means of HP production than supercharging. My point is ...with a car like this one, a "purpose built" motor / fuel management system is highly desireable for turbocharging, vs. a basiclly straightforward "bolt on" type install for the supercharger. So... go where your heart and your wallet leads, and happy holidays 
The same limitations are true for S/Cs of any kind. Really in a high compression engine Nitrous is the best of the three forced induction methods.
12-25-2005, 05:50 PM
#111
Originally Posted by heinrich
Again. turbo is NOT better than supercharger. Not for everyone, and not even for MOST. Why is that Sniper? Cause no-one has the time or money to turbocharge, but superchargers are cheap and easy now. That, a turbo can never be. You have to replace your intake and exhaust; you should mill your pistons; you have to pipe oil, and you have to intercool. So, where in all of that is the "better" of the turbo?
I like both systems, but both have advantadges and disadvantadges.
I like turbos for auto cars, and S/Cs for manuals.
Last edited by m21sniper; 12-25-2005 at 06:15 PM.
12-25-2005, 06:01 PM
#112
Burning Brakes
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The same limitations are true for S/Cs of any kind. Really in a high compression engine Nitrous is the best of the three forced induction methods.
Nitrous to me "really" doesn't qualify as a "Forced Induction" system...as you can only use it in brief bursts...and have to refill / switch a tank very frequently if the system is used.... A forced induction system, is operated by the engine is is powering...and not a "pressurized can of gas"...
Nitrous to me "really" doesn't qualify as a "Forced Induction" system...as you can only use it in brief bursts...and have to refill / switch a tank very frequently if the system is used.... A forced induction system, is operated by the engine is is powering...and not a "pressurized can of gas"...
12-25-2005, 06:05 PM
#113
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I think the cheapest FI for our cars right now is the rear mounted turbo being run by Tom M and made by the guys in Seattle. Mark Robinson has a system that I think is getting close to being available but he has been having some problems getting the final kinks worked out. I give the tc guys as much crap as anyone but only because they don't have a proven, affordable system on the market yet. When they do they can bark all they want but there ain't no bite to the bark at this point. i would love to see their theories be proven out i.e. that they can provide a superior system to the SC's . By superior I mean power, affordability, longevity and no motor issues like running hot.
Merry Christmas
Merry Christmas
12-25-2005, 06:16 PM
#114
Originally Posted by jeff jackson
The same limitations are true for S/Cs of any kind. Really in a high compression engine Nitrous is the best of the three forced induction methods.
Nitrous to me "really" doesn't qualify as a "Forced Induction" system...as you can only use it in brief bursts...and have to refill / switch a tank very frequently if the system is used.... A forced induction system, is operated by the engine is is powering...and not a "pressurized can of gas"...
Nitrous to me "really" doesn't qualify as a "Forced Induction" system...as you can only use it in brief bursts...and have to refill / switch a tank very frequently if the system is used.... A forced induction system, is operated by the engine is is powering...and not a "pressurized can of gas"...
It's also by far the cheapest and easiest forced induction system to install of the three.
12-25-2005, 06:21 PM
#115
Originally Posted by Jim_H
I think the cheapest FI for our cars right now is the rear mounted turbo being run by Tom M and made by the guys in Seattle. Mark Robinson has a system that I think is getting close to being available but he has been having some problems getting the final kinks worked out. I give the tc guys as much crap as anyone but only because they don't have a proven, affordable system on the market yet. When they do they can bark all they want but there ain't no bite to the bark at this point. i would love to see their theories be proven out i.e. that they can provide a superior system to the SC's . By superior I mean power, affordability, longevity and no motor issues like running hot.
Merry Christmas
Merry Christmas
However, with both an S/C and a turbo the drivetrain is going to be a problem long before either type of system can approach full potential, so the 'who's better at putting out max power' argument is irrelevant. Really even the unsupported alusil cylinder sleeves of the 928 V-8 will need to be addressed before anyone can get into any really serious boost. Notched o-ringed heads with a filled block and steel sleeves will be needed before anyone can test the full potential of the 928 V-8 with either system.
12-25-2005, 06:34 PM
#116
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jim.....all the guys using the rear mount turbo system have found that its a cheaper way. POWER amd COST are proven. but motor issue haven't. and that will come over time. plus the biggest reason none of the rear mount turbo guys can brag yet is. 1) b4 you start promoting a system you must be a rennlist sponsor...2) then you will be mobbed to make it into a kit....providing tech support and backing your product. who wants to sit in there house making kits when you can be driving your boosted shark..i'm not doing it. what ever i do to my shark is my concern. i will help people with free advice like barry help me. i dont want to get paid off helping adbvance out cars into the same bracket as theses new cars. let us turbo guys finish out cars and get them tuned so we can put anything coming off the showroom in our rear view mirrors.
ps. looking to keep a spare engine so i can take those ricer risk to get big hp from my motor and always have a back up
ps. looking to keep a spare engine so i can take those ricer risk to get big hp from my motor and always have a back up
12-25-2005, 06:38 PM
#117
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m21sniper.. you have to baby the drivetrain. like "st" over on the 951 board. his car is putting out 532rwhp and his drivetrain is fine. thats cause he babies the tranny until he getting into higher speeds. then he puts the fear of god into m3's, vette's etc. and he's running an 944 s2 trans
12-25-2005, 06:40 PM
#118
Originally Posted by Lance J
m21sniper.. you have to baby the drivetrain. like "st" over on the 951 board. his car is putting out 532rwhp and his drivetrain is fine. thats cause he babies the tranny until he getting into higher speeds. then he puts the fear of god into m3's, vette's etc. and he's running an 944 s2 trans
I'm a hit it hard and early kinda guy, lol.
12-26-2005, 11:58 AM
#120
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Dave, since there are benefits of the turbo system there must be less desirable features in the other systems. Most people don't know all the differences and many are misled as a result. By pointing to the superiority of one, you are automatically pointing out the lesser of the other.
A few years back a few select individuals told me the turbo system was not an option on the 928 and that it could not make the power of the CS, it was inferior, etc. I've never put anybody's personal work down. Selection of hardware, maybe in this regard but never personal work.
As I said before, I like the TS setups and I think it is best option for belt driven boost on a 928, especially for a street driven car.
Why is is people think the same cylinder pressure and knock issues don't apply to supercharging? Pressure and heat in the charge is a function of the boost pressure and the efficinecy of the compressor and intercooler. It doesn't matter that the heat and pressure came from a turbo or super, the same limitations apply.
A few years back a few select individuals told me the turbo system was not an option on the 928 and that it could not make the power of the CS, it was inferior, etc. I've never put anybody's personal work down. Selection of hardware, maybe in this regard but never personal work.
As I said before, I like the TS setups and I think it is best option for belt driven boost on a 928, especially for a street driven car.
Why is is people think the same cylinder pressure and knock issues don't apply to supercharging? Pressure and heat in the charge is a function of the boost pressure and the efficinecy of the compressor and intercooler. It doesn't matter that the heat and pressure came from a turbo or super, the same limitations apply.