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Does enyone know if it's possible to do a turbo conversion on a none turbo C4??? I have done couple of conversions in the past with great success. I have never done one a Porsche. I'm thinking about doing a low boost (6-7 psi) to keep reliabilty, and using oem turbos, exhaust, etc... Any ideas will be appreciated.

I could use a 996 turbo parts diagram if anyone knows where to find it.....

post-40321-1242921172_thumb.jpg

Edited by badasbike
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I have heard that it's a nightmare. Very expensive and labor intensive. I'm sure other will chime in this.

BTW... Where did you get that front bumper cover on the white 996 in the picture? I like it!

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I have heard that it's a nightmare. Very expensive and labor intensive. I'm sure other will chime in this.

BTW... Where did you get that front bumper cover on the white 996 in the picture? I like it!

Got it on ebay brand new durafles with the lower lip under 900.00

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Is it Fiberglass or polyurethane? Is the fitment good?

Use the search tool here and search "turbo conversion". Quite a few folks have asked this question before. You may find some good information.

Thanks ! :)

Edited by phillipj
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Is it Fiberglass or polyurethane? Is the fitment good?

Use the search tool here and search "turbo conversion". Quite a few folks have asked this question before. You may find some good information.

Thanks ! :)

Thanks for the info. the bumper is polyurethane. I have to say it's like OEM fitment. only thing I had to do is buy a new set of side marker for 2005 and up since the older original ones dont work with this bumper...

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At todays prices, I would imagine a cost benefit analysis taking into account labor, parts, reliability, repair, warranty, resale and headaches would come out in favor of just going out and buying a TT and putting the current ride up for sale.

Another idea is to install a supercharger kit. It''s pretty much plug and play, no need to mess with compression or reprogramming the ECU. When it's time to sell, just unbolt it and you're back to stock.

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Turbo coupes are getting so cheap now that it would make more sense to just buy one. However, Turbo Cabs, which weren't made until 2004 are still pretty expensive.

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The turbo engines are completely different that your 996. Almost every internal part of the engine needs to be changed out to accomadate the boost power (ie the difference in compression is lower in turbos). The cost would be prohibitive, not to mention problems with longetivity. Even the transmisions are different, at least I know that the Tiptronic S are. The only solution would be to get a supercharger which would add the HP that you need or buy a turbo, getting cheaper by the minute.

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The turbo engines are completely different that your 996. Almost every internal part of the engine needs to be changed out to accomadate the boost power (ie the difference in compression is lower in turbos). The cost would be prohibitive, not to mention problems with longetivity. Even the transmisions are different, at least I know that the Tiptronic S are. The only solution would be to get a supercharger which would add the HP that you need or buy a turbo, getting cheaper by the minute.

You're right, however keeping boost levels to 5-6 psi max, will keep compression ratio under control. I'm not looking to build a monster engine, just add about 80 hp to my engine.

I looked at the supercharger option, but 10 K is a little too much. All available supercharger kits use a max of 6 psi at the intake and manufactures claim it will produce 400 hp or better. Also all internal stock engine parts are used.

Forking out 10 k it's not really logical, as you said TT are getting cheaper by the minute.

Thanks for the tips.....

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First, I cannot imagine that the Porsche engineers left any "room" for additional compression ratio, DYNAMIC compression ratio, via SuperCharging or TurboCharging, even "cooled" additional air "charge".

You could probably detuned/derate the base engine by reducing the static CR via using a spacer, or maybe even double up on the head gaskets.

The knock/ping detection might be able to compensate for low octane fueling via EFI mixture control but I doubt the EFI "range" will be sufficient enough to accomodate an SC or TC.

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First, I cannot imagine that the Porsche engineers left any "room" for additional compression ratio, DYNAMIC compression ratio, via SuperCharging or TurboCharging, even "cooled" additional air "charge".

You could probably detuned/derate the base engine by reducing the static CR via using a spacer, or maybe even double up on the head gaskets.

The knock/ping detection might be able to compensate for low octane fueling via EFI mixture control but I doubt the EFI "range" will be sufficient enough to accomodate an SC or TC.

Very intelligent view!!! I asked my self the same question when I first saw the supercharged kits out there, even when the manufacturers claim reliability. What's the stock compression ratio of the 996 vs 996tt???

Thanks for the info..

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Yes, it has ALWAYS bothered me that SuperCharged or TurboCharged engines, moreso the latter, run in detuned/derated, low FE mode, when simply cruising along on the highway at a relatively constant speed.

So I have often suggested, advised, that a new engine control technique be used, the Atkinson/Miller/West cycle. Make use of a variable intake valve closing delay to dynamically change the "effective" compression ratio for different driving "modes". For simply cruising along the compression ratio would be 12:1 (DFI assumed) with the power/combustion stroke expansion ratio being 15-16:1, ATKINSON CYCLE mode.

Put your foot into it, and the "RAW" compression CR goes quickly to 9.5:1 as the SC spools up to provide the additional cylinder charge required for POWER, MILLER CYCLE mode.

Use an HSD type e/CVT to drive a positive displacement SC via the combined engine and A/C synchronous motor inputs. Infinitely control the SC speed/boost level and thereby eliminate the throttle plate.

Edited by wwest
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Yes, it has ALWAYS bothered me that SuperCharged or TurboCharged engines, moreso the latter, run in detuned/derated, low FE mode, when simply cruising along on the highway at a relatively constant speed.

So I have often suggested, advised, that a new engine control technique be used, the Atkinson/Miller/West cycle. Make use of a variable intake valve closing delay to dynamically change the "effective" compression ratio for different driving "modes". For simply cruising along the compression ratio would be 12:1 (DFI assumed) with the power/combustion stroke expansion ratio being 15-16:1, ATKINSON CYCLE mode.

Put your foot into it, and the "RAW" compression CR goes quickly to 9.5:1 as the SC spools up to provide the additional cylinder charge required for POWER, MILLER CYCLE mode.

Use an HSD type e/CVT to drive a positive displacement SC via the combined engine and A/C synchronous motor inputs. Infinitely control the SC speed/boost level and thereby eliminate the throttle plate.

WOW!!! I must admit: I had to read your post 3 times in order to 'absorb' all of it!!! but I got it... It sounds like that will be the answer to compensate for the higher CR on NA engines.

Where can I find out more about this ATKINSON CYCLE mode?????

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A "simulated" (delayed intake valve closing) Atkinson cycle mode is used on the Prius, hybrid Camry, Ford Escape and Mariner hybrids. Miller cycle was most currently used on the Mazda Milennia "S". Miller cycle is simply a "superset, add-on" to the Atkinson cycle.

Insofar as I know no one has before suggested using the two "separately" and transitioning from one to the other.

Atkinson cycle is HIGHLY fuel efficient but poor at producing high torque per liter displacement, POWER. Hybrids make up for the shortcoming via electric drive suppliments.

Edited by wwest
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