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Relocating the Turbo on a 951?

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Old 11-08-2011 | 08:49 PM
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Originally Posted by Barnaby Jones
SO here everyone goes calling me a troll again... (nothing new from rennlist!)

Might I suggest to anyone wanting to undertake such a venture as relocating the turbo on a 951 (944 Turbo?) that they do so in secret off the board, pull it off, and then post up proof of the effort. Simply explaining that you did it because it could be done, not to make anyone happy except yourself!

OTHERWISE

You will receive all kinds of haters trying to kill your dream! because any armchair engineer can tell you why you SHOULDNT do it.. but only a truly motivated person can do it! (how many here ever had someone tell them they couldn't do something and then pressed on to prove the hater wrong?)

Stay tuned rennlistville... I am sure great things are waiting in the wings to be revealed to the world!
I didn't mean to offend you or anything, but everything you said made me mad/confused. Also I don't have any pictures to prove it but I'm pretty sure it's been done
Old 11-08-2011 | 08:55 PM
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Originally Posted by ihaza944t
I didn't mean to offend you or anything, but everything you said made me mad/confused. Also I don't have any pictures to prove it but I'm pretty sure it's been done
No worries...

Although I dont immagine the OP of this thread wants to do it on a 16V head..

9FF did..


And there is also a rear mount NA turbo job out there too.. although he poorly chose to use PVC piping in his build... not my first choice, but hey not my car either..
Old 11-08-2011 | 09:52 PM
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Originally Posted by robstah
That is the biggest BS I have ever heard. If that's the case, why not mount the turbo remotely in the muffler area?

It's not the heat that spools the turbo, it's the energy. You lose energy when you move the turbo farther away from the source. The 951 is terribly inefficient due to the turbo placement alone, and it's a nightmare to work on because of it.
How inefficient is it?

Could someone please define "terribly"?

Isn't heat energy, and therefore if the heat (energy) were kept in the exhaust stream what difference would it make to move it to the moon (other than the obvious complication of moving the exhaust the roughly 200,000 miles and back?)

I wonder why Porsche put that silly thermal stuffing inside the exhaust.. must have been to complicate the system and make it such a pain in the *** to work on... While on topic I wonder why they used that silly water cooling stuff in the factory turbo setup... I mean, who needs to cool off the center section of the turbo if so much efficiency is lost just getting the energy (heat) to the turbo in the first place?

I wonder if anyone has documented the actual thermal, pressure, or flow losses of the factory 944 turbo setup between the exhaust ports at the head and the turbo inlet / outlet?

Just musing out loud here... but then I am not staying at a holiday inn express tonight but I might have watched a movie about this stuff once upon a time!
Old 11-08-2011 | 11:17 PM
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Originally Posted by Barnaby Jones
How inefficient is it?

Could someone please define "terribly"?

Isn't heat energy, and therefore if the heat (energy) were kept in the exhaust stream what difference would it make to move it to the moon (other than the obvious complication of moving the exhaust the roughly 200,000 miles and back?)

I wonder why Porsche put that silly thermal stuffing inside the exhaust.. must have been to complicate the system and make it such a pain in the *** to work on... While on topic I wonder why they used that silly water cooling stuff in the factory turbo setup... I mean, who needs to cool off the center section of the turbo if so much efficiency is lost just getting the energy (heat) to the turbo in the first place?

I wonder if anyone has documented the actual thermal, pressure, or flow losses of the factory 944 turbo setup between the exhaust ports at the head and the turbo inlet / outlet?

Just musing out loud here... but then I am not staying at a holiday inn express tonight but I might have watched a movie about this stuff once upon a time!
Entropy. Heat is energy, but not always useable.
Old 11-09-2011 | 12:25 AM
  #20  
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Originally Posted by robstah
If that's the case, why not mount the turbo remotely in the muffler area?
What production turbo car has that arrangement?

931's definitely suffered from their turbo placement. Porsche also learnt from endurance racing:

924 turbo


924 carrera gt


924 carrera gts




924 carrera gtr








note the turbo is mounted similar to a 931 but much more forward and higher.


porsche 924 Carrera gtp


porsche 924 carrera gtp (944LM)


Notice the direction the race cars went?

p.s the last big twin turbo 951 fiasco:
https://rennlist.com/forums/944-turb...rbo-951-a.html
Old 11-09-2011 | 12:38 AM
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http://usuarios.multimania.es/cporsc.../tag_turbo.gif

Here is another engine with some distance from the exhaust port to the turbo that made decent power, granted the similarities end there but some of the same engineers may have been involved.
Old 11-09-2011 | 01:22 AM
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Not a Porsche, but similar in displacement and size...

Here's is one of my old Turbo 2.3 Ford motors that i built.. and it was prior to installing a front mount intercooler (or in this case, an intercoller period..)




Old 11-09-2011 | 01:40 AM
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Everyone quit being pansies!
Old 11-09-2011 | 01:46 AM
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FYI the remote mount turbo kits are popular with the domestic crowd. Google STS turbo systems.
Old 11-09-2011 | 01:55 AM
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Originally Posted by ModdedEverything951S
FYI the remote mount turbo kits are popular with the domestic crowd.
So are Dixie flags, Bush Light, and marrying your cousin.

That doesn't mean it's good for everyone.
Old 11-09-2011 | 06:18 AM
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Originally Posted by Hacker-Pschorr
So are Dixie flags, Bush Light, and marrying your cousin.

That doesn't mean it's good for everyone.
Old 11-09-2011 | 08:46 AM
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Originally Posted by Hacker-Pschorr
So are Dixie flags, Bush Light, and marrying your cousin.

That doesn't mean it's good for everyone.
Doesn't make it bad, either.
Old 11-09-2011 | 09:05 AM
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I'm impressed people even CONSIDER stuff like this. Most of us have enough trouble keeping a mildly modded 951 running well and reliably.

When you guys figure out this whole turbo thing, please work on a transverse mounted engine.
Old 11-09-2011 | 09:29 AM
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Originally Posted by robstah
That is the biggest BS I have ever heard. If that's the case, why not mount the turbo remotely in the muffler area?

It's not the heat that spools the turbo, it's the energy. You lose energy when you move the turbo farther away from the source. The 951 is terribly inefficient due to the turbo placement alone, and it's a nightmare to work on because of it.
Yet is is totaly true, With 931 Porsche had turbo car, but the turbos were unreilable. Heat was the main problem. Remember this was in the early days of street car turbocharging and things were different then. Any for reliability reason Porsche chose to move the turbo to the cooler side of the engine. They also water and oil cooled the turbo. There is also a turbo water pump designed to cool the turbo on engine shut down. Due to heat issues on the 931 Porsche worked extra hard to make the 951 turbo last. As drive ability... That has proven to be adequate over the years. Back in the early 80's 220 hp was more than 911 of its day and darn near super car performance. All the while the car got 25 mph on the hwy and could run over 100 miles with cats in place. I remembe their was an early 944 turbo run on the street for something like 200k miles in a publicity stunt to show longevity of the system.

Now technology has moved on and it may very well be possible to put the turbo in a hoter enviroment and make it last. There are high power race motors that have right side turbos. These are few however and the ones that I know of often put the turbo in the passenger foot wheel after some major cutting.

The turbo placement in the 951 met the goals of porsche back in the early 80's. Remember the entire 944 family was designed to to price point and performance point. It was never designed to be the flag ship of Porsche. That design ethos left the 944 only adequate in a number of areas.

These days you can chose all the right side turbo placement you want, but packaging in the tight engine bay become and issue. Most fined it much easier and simpler to work off the basic left side placement of the turbo and just live with draw backs of the extra exhaust pumbing.
Old 11-09-2011 | 09:36 AM
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Originally Posted by ModdedEverything951S
Doesn't make it bad, either.
Sure it does, especially on a car that already has a factory turbo option. The #1 reason why the remote systems are popular on Camaro's and pick-up trucks is ease of installation and cost. Nobody is going that route because it's the preferred location for the turbo's.

Taking a car that's already turbocharged from the factory and moving the turbo 10 feet away from the engine is a horrible idea. Designing a turbo system from scratch on a car that never had a factory option, it's a case of "better than nothing". Eliminating custom exhaust manifolds greatly reduces the cost and fabricating involved with turbocharging a car. That doesn't apply to a 944 since there is already a factory turbo manifold.


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