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3.4 to 3.6 X51

aracerx
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aracerx Member

aracerx

Posted
Posted

are there very many documented swaps to make this easier to understand. Is it workable to use the 3.4 wiring to ease the wiring issue and use the 3.4 intake for the throttle?

Dharn55 Member

Dharn55

Posted
Posted

Some major challenges with this conversion. Different DME's, and the VarioCam vs. VarioCamPlus issue. It has been done. PhilipJ tried it with

Roock and ended up with horror stories, sold the car and bought a 997. Doo some searches here and on 6 speed and Rennlist and you will find lots of discussions.

It is definitely not just a bolt in project!

aracerx Member

aracerx

Posted
  • Author
Posted
Some major challenges with this conversion. Different DME's, and the VarioCam vs. VarioCamPlus issue. It has been done. PhilipJ tried it with

Roock and ended up with horror stories, sold the car and bought a 997. Doo some searches here and on 6 speed and Rennlist and you will find lots of discussions.

It is definitely not just a bolt in project!

aracerx Member

aracerx

Posted
  • Author
Posted
Some major challenges with this conversion. Different DME's, and the VarioCam vs. VarioCamPlus issue. It has been done. PhilipJ tried it with

Roock and ended up with horror stories, sold the car and bought a 997. Doo some searches here and on 6 speed and Rennlist and you will find lots of discussions.

It is definitely not just a bolt in project!

My "obvious" direction in this "project" lie within have lower end rebuilt/poss. increase in diplacement..or swapping everything over to a later engine with lower mileage or poss. new factory rebuilt. I am learning on how much of a performance issue the vario cam/lift if left without hydraulic operation? rest of job is simple swap to me? This should be an interesting job.-M

phillipj Member

phillipj

Posted
Posted

Here is the deal... If you want a drivaeble car you have to do it right. You will have to upgrade to the 7.8 DME, replace the instrument cluster and rewire the harness. If you try to do it the cheap way you will have piece of crap on your hands. Trust me..... :angry:

Search her for engine conversions. Todd has done many and does all his own work and figured out schematics for re wiring the harness.

If you tackle this yourself your better have some skills.

You can buy a reman engine from Porsche but you will probably get no core refund for your 3.4. And unless you have a dealer do the install you will get no warranty ( and the rub is dealerships don't do conversions.) Call Suncoast for prices on engines...

Good luck but I would advise against it (unles you have a lot of experience and time on your hands.. Oh yeah and very deep pockets..

:cheers:

txhokie4life Member

txhokie4life

Posted
Posted
You can buy a reman engine from Porsche but you will probably get no core refund for your 3.4. And unless you have a dealer do the install you will get no warranty ( and the rub is dealerships don't do conversions.) Call Suncoast for prices on engines...

I've been told that some independents that perform the install can pass through the 2 yr warranty on reman engines.

YMMV,

Mike

phillipj Member

phillipj

Posted
Posted

I've been told that some independents that perform the install can pass through the 2 yr warranty on reman engines.

YMMV,

Mike

Mike,

On a conventional replacement yes.. conversion no way... Although I have heard that Suncoast in Fla does conversions. So maybe they would honor the warranty if they did the work.......

Dharn55 Member

Dharn55

Posted
Posted (edited)

First of all a disclaimer, I do not know these guys or their reputation. Now, I found this ad on ebay for a shop in Georgia that claims to do upgrades to 3.6's and 3.8's.

http://cgi.ebay.com/ebaymotors/Porsche-eng...sQ5fAccessories

I talked to them and the owner claims that they have perfected the upgrades. Says that Roock sometimes sends their work to him as Roock does not do the work himself.

And the price to do the upgrade is about $7,500 in addition to the cost of the engine. At this price hopefully it really is perfected.

Just thought I would pass along the info.

Edited by Dharn55
phillipj Member

phillipj

Posted
Posted

Booo..scary.... Be careful..If they don't upgrade the DME be very skeptical. And anyone that Roock deals with is to be dismissed....

aracerx Member

aracerx

Posted
  • Author
Posted
Booo..scary.... Be careful..If they don't upgrade the DME be very skeptical. And anyone that Roock deals with is to be dismissed....

the upgrade to 7.8 has been my primary choice....it sucks though.....I will likely spend a tremendous amount of time and effort on the wiring conversion. After so many years of this issue, I thought this one time I could get even a small break by someone posting their "proper" conversion. I sure would pay for the experience too, since time is (afterall) money.

It may just be a pipedream though, as all my life I had to do these "conversion" thingys and it DOES SUCK.

I will not perform this job without doing it the proper way.......not sure though how much of a perfomance issue the dynamic cam timing would effect........If all.........I guess I'm up the creek and have to do it, sadly, I may only do this a few times more and the effort sort of doesn't equal the initial time involved in getting wiring acclimated. thanks for your insite, thanks to Porsche for their f++k up.

phillipj Member

phillipj

Posted
Posted

There a quite a few reputable shops that will do your conversion the "right way" But be prepared for $10k plus for the conversion plus costs for engine, new clutch etc...

The good ones will stand behind their work as well. Mr. Roock.......Not so much..... :angry:

tholyoak Member

tholyoak

Posted
Posted (edited)

It really isn't that hard that hard to integrate the 7.8 DME, just requires the knowledge. It makes sense for Boxsters because you can't buy a 3.6 or 3.8L Boxster. The costs involved really don't make any sense on a 996 as you can just buy a 3.6 or 3.8 996 especially if you are not doing the work yourself and have to pay labour charges on top of the parts cost.

-Todd

Edited by tholyoak
  • 2 weeks later...
jrgordonsenior Member

jrgordonsenior

Posted
Posted
It really isn't that hard that hard to integrate the 7.8 DME, just requires the knowledge. It makes sense for Boxsters because you can't buy a 3.6 or 3.8L Boxster. The costs involved really don't make any sense on a 996 as you can just buy a 3.6 or 3.8 996 especially if you are not doing the work yourself and have to pay labour charges on top of the parts cost.

-Todd

Todd I just blew my 99' 3.4. It's a full race car and I was considering gpoing with a 3.6 as I have access to a just built Koni motor. Since it's a race car and I don't need all the accessories, etc. I'm considering trying it without changing the harness using my cable TB and intake. I would use a programable window switch for the variocam+, and program my ECU on a dyno for fuel mapping, etc. Am I out of my mind?

JRG

geoff Member

geoff

Posted
Posted

1. Listen to Todd and Phillip

2. Talk to Jake Raby at flat 6 regarding options to increase power and displacement (and most likely reliability) of your existing 3.4 engine

3. Talk to Ruf in Texas about conversions like this. A friend had his 987 S set up with the 3.8 X51 engine, along with all the other goodies, and loves his car. It took Ruf a lot longer than they expected to get the conversion running right

4. Do the math on what it will be cost you to do the conversion vs. how much just getting a stock car with 3.6 or 3.8 X51 engine, then look seriously at what you car would be worth after you do the conversion to see if it makes any sense whatsoever. If you have to ever get your car smogged, probably add more to your estimate for conversion cost.

5. Listen to Todd and Phillip

tholyoak Member

tholyoak

Posted
Posted

For a track/race car you could use a simple rpm switch to control the valve lift since you will be at full throttle most of the time. However, the valve timing on the variocam plus is 40 degrees total vs 25 on the variocam motor, thus you will need custom DME program to account for this along with the minor changes to fuel mapping etc. So no, you are not crazy and this is a good approach for a race car.

-Todd

It really isn't that hard that hard to integrate the 7.8 DME, just requires the knowledge. It makes sense for Boxsters because you can't buy a 3.6 or 3.8L Boxster. The costs involved really don't make any sense on a 996 as you can just buy a 3.6 or 3.8 996 especially if you are not doing the work yourself and have to pay labour charges on top of the parts cost.

-Todd

Todd I just blew my 99' 3.4. It's a full race car and I was considering gpoing with a 3.6 as I have access to a just built Koni motor. Since it's a race car and I don't need all the accessories, etc. I'm considering trying it without changing the harness using my cable TB and intake. I would use a programable window switch for the variocam+, and program my ECU on a dyno for fuel mapping, etc. Am I out of my mind?

JRG

jrgordonsenior Member

jrgordonsenior

Posted
Posted

Thanks for the response Todd. It make sense to me too though especially because of this motor tht was offered to me.

I could use some advise on programming the DME. Do you know of any sources or have you done this before?

JRG

533x8000787.jpg

For a track/race car you could use a simple rpm switch to control the valve lift since you will be at full throttle most of the time. However, the valve timing on the variocam plus is 40 degrees total vs 25 on the variocam motor, thus you will need custom DME program to account for this along with the minor changes to fuel mapping etc. So no, you are not crazy and this is a good approach for a race car.

-Todd

It really isn't that hard that hard to integrate the 7.8 DME, just requires the knowledge. It makes sense for Boxsters because you can't buy a 3.6 or 3.8L Boxster. The costs involved really don't make any sense on a 996 as you can just buy a 3.6 or 3.8 996 especially if you are not doing the work yourself and have to pay labour charges on top of the parts cost.

-Todd

Todd I just blew my 99' 3.4. It's a full race car and I was considering gpoing with a 3.6 as I have access to a just built Koni motor. Since it's a race car and I don't need all the accessories, etc. I'm considering trying it without changing the harness using my cable TB and intake. I would use a programable window switch for the variocam+, and program my ECU on a dyno for fuel mapping, etc. Am I out of my mind?

JRG

phillipj Member

phillipj

Posted
Posted
1. Listen to Todd and Phillip

2. Talk to Jake Raby at flat 6 regarding options to increase power and displacement (and most likely reliability) of your existing 3.4 engine

3. Talk to Ruf in Texas about conversions like this. A friend had his 987 S set up with the 3.8 X51 engine, along with all the other goodies, and loves his car. It took Ruf a lot longer than they expected to get the conversion running right

4. Do the math on what it will be cost you to do the conversion vs. how much just getting a stock car with 3.6 or 3.8 X51 engine, then look seriously at what you car would be worth after you do the conversion to see if it makes any sense whatsoever. If you have to ever get your car smogged, probably add more to your estimate for conversion cost.

5. Listen to Todd and Phillip

:clapping: :clapping: :clapping:

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