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Super or Turbo?

Ok, so i am now on the market for another 944 series from now until i purchase one. What i was wondering, was what do you think would wield the most performance in terms of forced induction, super or turbo charged?

i'm thinking in terms of HP and 1/4 mile. I know, I know, our love is not a dragster, but still it's important... do you think i would be able to get more HP from higher boost lower compression, or lower boost higher compression (relatively higher to turbo charging, not an n/a)

i'm just curious, because that will decide how i go about purchasing my next 944/951. what i was thinking was i could either get a 951, or get a 944 put a supercharger on it and lower the compression with a 951 crank. would that work? i heard about a 968 with a 951 crank to lower compression, that's what got me onto speculating. also, the initial cost of 944 is much cheaper than a 951... and i wouldn't mind learning how to tear down an engine... my next 9 series will be a project, not a daily driver like my last.
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Old 02-16-2004, 11:46 AM
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Educate me... how would a 951 crank lower the compression? If the dispacement is the same for turbos and NA engines, I'd be surprised if the bore and stroke were different.

I think what you want to lower your compression is low compression (turbo) pistons or to hog out your combustion chamber to decrease your compression ratio. I'd opt for the first choice.
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Old 02-16-2004, 12:03 PM
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i don't remember where, i'll try and find the site, but the guy said on his site that he replaced the 968 crank 11:1 compression ratio to 7:1 with the 951 crank. i guess because it lowered the stroke length...

go here:
http://www.944968.com

then under 968CS click "turbo conversion"

then read the second paragraph.
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Last edited by ds475; 02-16-2004 at 12:17 PM..
Old 02-16-2004, 12:06 PM
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Don't take this the wrong way DS (I do like you now ya know) but..

Why not just buy a $1500 early (save it from destruction), sell/part out the engine and drop a Corvette LT1 in her.

I know, I know, what I speak of is sacralige...but I continue ..


I have heard tell (from forces on the dark side) that the conversion goes well although it does screw with your weight distribution. This would give you the speed you so desire and probably end up more economical...

Kind of a street "sleeper" of sorts .. Nobody that knows 944's expects it to be really fast off the line.
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Old 02-16-2004, 12:28 PM
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By the way

GET BACK TO WORK!


-I know your boss....

J/K !
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Old 02-16-2004, 12:28 PM
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but can the transmission handle that kind of power? that would be cool... although, i would rather keep a PORSCHE power plant, but whatever.

furthermore, i don't have to be the fastest on the road... just comepetitive.
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Old 02-16-2004, 01:25 PM
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If you want maximum power, the tranny doesn't know whether the power is being supplied from Chevy or Porsche. If you want 300+hp, the tranny won't care what name the horses are wearing, and getting power out of a SBC is very economical.

Second, a 968 does not run a 2.5 engine like the 944 and 951, I am not familiar with the differences between a NA and a turbo engine, but I would suspect the pistons would make the difference in compression, not the crank.

Third, you are just trying to control the detonation with the boost/compression comprimise. Many times the detonation is fuel delivery related. I would think that running proper octane fuel and adequate delivery rate system, and an ignition advance curve that is conservative enough that it doesn't promote detonation that you could combine boost with the NA's compression ratio to produce some respectable power numbers.

Forth, Porsche engineers did a great deal of research to come up with a very workable compression ratio and boost combination, with the proper fuel delivery system and safely designed ignition curve that can be tuned for tremendous power numbers. I would reccomend that you use their work as a model to follow, but it would be much cheaper to simply acquire an example of the fruits of their labors. You could probably duplicate it yourself with either a super or turbocharger, but it won't be cheap or simple.

I fully support endeavors to acchieve higher power numbers from the 944, but the book Maximum Boost discusses boosted power applications, (and I reccomend it as a resource for your project). One of the first pieces of advice the book gives is, if the manufacturer offers a turbo model start with that rather than trying to turbo a NA version.
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Old 02-16-2004, 02:13 PM
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Yup, what he said....

I personally LIKE that the N/a doesn't really leave room for improvement. Just something else to tap my $ and drive me nuts.

The engineering on the car is what has made me fall for the watercoolers. Most of the time they were way ahead of all of the "new" mods that are coming out today.
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Old 02-16-2004, 03:04 PM
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yea, but nothing is better than the original, turbo-charged!
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Old 02-16-2004, 04:06 PM
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I'd try to find a nice S2 or 968 if I had the $$$. I second the fact that I'm happy the n/a is pretty limited due to its engineering - there simply isn't much room for improvement. There's the $5K supercharger mod (which I've actually considered) or NOS, but why have either when you can have a turbo - they're so much more efficient and consistent with the "spirit and intent" of the Porsche design. Not to say I might not at some point, but I think the $$$ would be far better spent towards a turbo car. Then I'd have two - my 944 n/a to make a showpiece out of, fun, daily driving, etc. and the turbo to build up crazy and for balls-out going fast.

Don't let my wife see my evil plan.
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Old 02-16-2004, 05:16 PM
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Go here and read all about the LT1 conversion and it will answere everything you have heard, and most is lies.

http://www.renegadehybrids.com/
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Old 02-16-2004, 07:38 PM
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