2.5 to 3.4 conversion

[yfz/700R]

Originally Posted by blinkwatt

Low mileage would be anything under 60k,those engines can last a long time if properly carred for. I saw a 3.4L on a 996 that had 140k on the original engine.

You should also consider changing your clutch to a Sachs Performance/Sport Clutch Kit to make up for the increase in power.

thanks for the reply, so i guess i'm looking for a 1999 996 3.4 motor

[racer_troy]

...this is most likely the ideal upgrade in my mind...smooth reliable power increase with relatively little stress on the engine...the clutch upgrade is a good idea...but i've been told it's not an absolute must unless you are some sort of hot shoe and are notoriously hard on clutches...at the minimum...you will have a 3.4 interface to contend with and a converted 3.4 std clutch would likely be all that is required...I also know patrickmotosports.com is making a bolt in clutch for the specific conversion you are looking for...they also have a good and solid reputation for track prep cars and porsches...

if you are comfortable with a used motor...this guy at instant-g may be able to help you out...he generally can locate a motor for you and will go through it to make sure it's ready for the transplant...again, i think he echoes the comments of blink in regards to under 60k....it's all about what you are looking for....

http://www.instant-g.com/Projects/Boxster34/

the 3.4 conversion page is just pictures…you’ll want to surf around to get a real feel for what the guy is doing…the page is a little down home, but for me, I think that's the appeal, some guy with a phd just loves to build and race porsches...built a racecar for his wife (btw racecar spelled backwards is racecar)...and seems to be a straight shooter, which i always appreciate...I asked him to quote me a conversion and it was in the $8-9K range and he ships me the motor, wiring harness, mounts, brackets, exhaust, et. al....if you want him to do the install, it's going to run around $12-13K and 2 months, one for install and one for shake down...

also, if you want to source your own motor, you may want to give http://www.oklahomaforeign.com/ a shout...his been lisking a 6o somthing K motor on ebay off an on for the last 6 months...I believe the motor is still available and the price jumps around from $5000 - $5500 depending on his mood...

Anyway, you should be OK with the 5spd tranny with just the 3.4 conversion...other shops may tell you otherwise (RUF, Gemballa), however, Instant-G and FVD.us believe the 5spd is fine for up to 300bhp...

....good luck and have fun with this conversion...it is the way this car should have been delivered from the factory...

cheers,

--troy

[pecivil]

I am supposed to get my 00 box back from the shop tomorrow from its 3.4 conversion. :dance:

I can speak for Steve Timmons at Instant G. I bought the entire instant g header/cats/muffler set up for the conversion. The quality of his product is outstanding. It takes a awhile to get it, as he makes them when he gets an order. It is not cheap, but the stock boxster header/cat/muffler strangles the 3.4. Of course you can't use the 3.4 stock exhaust stuff cause it dont fit.

You can probably sell your 2.5 for something. I bought a used 2001 3.4 with 31k miles taken from a front end wreck. Subtracting out the price I got for my 2.7l (with 56k miles) the 3.4 cost $4500. My mechanic was able to throughly go over it before I paid.

On the clutch, you cannot use 996 components with the boxster 5 speed tranny. The splines dont match. Plan on buying completely new clutch stuff. My clutch was shot at 56k, and I also needed a new flywheel, as it was too messed up to resurface. I went with the AASCO lt wt flywheel. At least, you pay no extra for labor, since the tranny is already out.

The 996 carrera came with the center radiator, like the Boxster S. You need to think about wheather or not to add it. There are a couple of places that sell a add on kit for it, or your mech can just buy the stock porsche parts. I decided to add it to be safe, but my mech told me that you are probably ok without it for the street. Of course, if you do add it, you will need a boxster S or 996 or GT-3 front bumper cover with the opening for it.

Have you mech replace the RMS on the 3.4 as a precaution. Use the new, revised seal.

You will need a 3.4 throttle body. The boxster one does not work. You will also need some "revised" intake tubing, as again the stock boxster one does not make it distance wise to the filter.

Another easy thing to add is a oil temp & pressure gauges. You use the 3.4 oil pressure sender already on the engine. Add a temp sender on the opposite port (to the oil pressure sender) on the block, and run the wires in to the cabin. I am going to mount then in one of the cubbies below the radio.

You can also do a ECU remap for the 3.4 from GIAC or FVD. They take into account the exhaust mods if you get them. I am going with GIAC.

FVD also has "sport cats" for this engine, which they add to their conversions, I believe. I will see how it feels without the cams. I may add them later. Supposedly they make a big "feel" difference in the motor.

Hope this helps

Monte

[yfz/700R]

Originally Posted by pecivil

I am supposed to get my 00 box back from the shop tomorrow from its 3.4 conversion. :dance:

I can speak for Steve Timmons at Instant G. I bought the entire instant g header/cats/muffler set up for the conversion. The quality of his product is outstanding. It takes a awhile to get it, as he makes them when he gets an order. It is not cheap, but the stock boxster header/cat/muffler strangles the 3.4. Of course you can't use the 3.4 stock exhaust stuff cause it dont fit.

You can probably sell your 2.5 for something. I bought a used 2001 3.4 with 31k miles taken from a front end wreck. Subtracting out the price I got for my 2.7l (with 56k miles) the 3.4 cost $4500. My mechanic was able to throughly go over it before I paid.

On the clutch, you cannot use 996 components with the boxster 5 speed tranny. The splines dont match. Plan on buying completely new clutch stuff. My clutch was shot at 56k, and I also needed a new flywheel, as it was too messed up to resurface. I went with the AASCO lt wt flywheel. At least, you pay no extra for labor, since the tranny is already out.

The 996 carrera came with the center radiator, like the Boxster S. You need to think about wheather or not to add it. There are a couple of places that sell a add on kit for it, or your mech can just buy the stock porsche parts. I decided to add it to be safe, but my mech told me that you are probably ok without it for the street. Of course, if you do add it, you will need a boxster S or 996 or GT-3 front bumper cover with the opening for it.

Have you mech replace the RMS on the 3.4 as a precaution. Use the new, revised seal.

You will need a 3.4 throttle body. The boxster one does not work. You will also need some "revised" intake tubing, as again the stock boxster one does not make it distance wise to the filter.

Another easy thing to add is a oil temp & pressure gauges. You use the 3.4 oil pressure sender already on the engine. Add a temp sender on the opposite port (to the oil pressure sender) on the block, and run the wires in to the cabin. I am going to mount then in one of the cubbies below the radio.

You can also do a ECU remap for the 3.4 from GIAC or FVD. They take into account the exhaust mods if you get them. I am going with GIAC.

FVD also has "sport cats" for this engine, which they add to their conversions, I believe. I will see how it feels without the cams. I may add them later. Supposedly they make a big "feel" difference in the motor.

Hope this helps

Monte

good info, thanks
i live in sandiego, did you buy your motor locally? it sounds like you got a good deal
thanks
willy

[pecivil]

I bought the motor from a wreck up in LA.

[yfz/700R]

Originally Posted by pecivil

I am supposed to get my 00 box back from the shop tomorrow from its 3.4 conversion. :dance:

I can speak for Steve Timmons at Instant G. I bought the entire instant g header/cats/muffler set up for the conversion. The quality of his product is outstanding. It takes a awhile to get it, as he makes them when he gets an order. It is not cheap, but the stock boxster header/cat/muffler strangles the 3.4. Of course you can't use the 3.4 stock exhaust stuff cause it dont fit.

You can probably sell your 2.5 for something. I bought a used 2001 3.4 with 31k miles taken from a front end wreck. Subtracting out the price I got for my 2.7l (with 56k miles) the 3.4 cost $4500. My mechanic was able to throughly go over it before I paid.

On the clutch, you cannot use 996 components with the boxster 5 speed tranny. The splines dont match. Plan on buying completely new clutch stuff. My clutch was shot at 56k, and I also needed a new flywheel, as it was too messed up to resurface. I went with the AASCO lt wt flywheel. At least, you pay no extra for labor, since the tranny is already out.

The 996 carrera came with the center radiator, like the Boxster S. You need to think about wheather or not to add it. There are a couple of places that sell a add on kit for it, or your mech can just buy the stock porsche parts. I decided to add it to be safe, but my mech told me that you are probably ok without it for the street. Of course, if you do add it, you will need a boxster S or 996 or GT-3 front bumper cover with the opening for it.

Have you mech replace the RMS on the 3.4 as a precaution. Use the new, revised seal.

You will need a 3.4 throttle body. The boxster one does not work. You will also need some "revised" intake tubing, as again the stock boxster one does not make it distance wise to the filter.

Another easy thing to add is a oil temp & pressure gauges. You use the 3.4 oil pressure sender already on the engine. Add a temp sender on the opposite port (to the oil pressure sender) on the block, and run the wires in to the cabin. I am going to mount then in one of the cubbies below the radio.

You can also do a ECU remap for the 3.4 from GIAC or FVD. They take into account the exhaust mods if you get them. I am going with GIAC.

FVD also has "sport cats" for this engine, which they add to their conversions, I believe. I will see how it feels without the cams. I may add them later. Supposedly they make a big "feel" difference in the motor.

Hope this helps

Monte

so how does it run? did they do a good job on the install?

[Rail26]

pecivil...thanks for the great write up. I am not interested in doing the conversion, but always wondered what was involved. I would love to know how the conversion stands up to the new '07 box.

[pecivil]

still waiting to get her back..... the shop doing it is a very good shop, but it is only a 2 man shop and they are taking forever!! They work on several racecars, so every Friday, they tend to only work on racecars going out that weekend, and on Monday, they tend to only work on broken race cars coming back from the weekend. So all the "street" cars they work on get squeezed into Tues, Wed, Thurs.

Friday was the 2nd "it'll be done" that didnt happen. But the bottom line is they are doing an excellent job, which is what really matters.

So....I should get it this week. As soon as I get it, I will do a write up on how it feels.

[WillieB]

I should have my 3.4L Conversion back as well by Wednesday. It has been approx. 3-4 weeks. But went to look at her on Sat. and she is looking great. Fired up on the first crack. Remaining parts to be added cats, exhaust, etc. I have a 99 Boxster pre-egas. Can't wait! Props to Todd Holyoak and Trent Carter for their assistance on this. The information they have provided on this has been awesome!!!