2.5tip to 3.4 conversion

[goldnogard]

:renntech: I posted this on Aug 2oth 07

Hello, I am in the process of upgrading from a tiptronic 1998 boxster 2.5l Motor to a 996 3.4L. My questions are:

1) Will the 986 tiptronic fit the 996 motors or do I need to modify flywheel, pressure plate or clutch so it will bolt to the 996 motors?

2) When bolting back hoses, pipes and other component to the motor, how do I figure out the number of torque pounds needed to bolt the bolts back "I don't want to break seals by over tightening the bolts"?

3) Do I need an early "1999-2001" 996 tiptronic instrument cluster + cluster cover and if I do, do I need to modify it?

4) After the upgrade should I worry about covering fuel lines or placing them in specific locations other than original in fear or fire hazard?

Thanks

Ali

Updates:

Ok so I finally got the time to do my upgrade. I started on Wednesday 9/12/07and got the engine running on 9/21/07 “yesterday”. The project was actually straightforward lol. It was almost like removing a boxster engine then re-installing it back. Here are issues I had to deal with:

1) I used the boxster fuel railing, and modified it to fit on the 996 engine “easy mod”

2) I had to figure out a way to lower the engine down. So

A)I used a caliper and figured ½ inch is the way to go.

B)The front of the engine was easy to drop “front Engine mount” went to hardware store got ½inch solid bar and drilled 2 holes in it to make my two adapters to lower engine mount. “ p.s at first I only lowered the front engine mounts by ½ inch which allowed the engine cover to go on, problem is engine wont start!!! The torque converter was touching the engine at an angle. Lesson learned: make sure you drop both front engine mount and rear transmission mounts D'oh! lol”

C)The back of the engine “transmission mount” was the tricky part. Some used C2 engine mounts to lower the car. I even thought of using solid aluminum C2 mounts “the sport kind, which will add more torque to the car, but also make it noisy lol” them C2 mounts cost over $200 each !! I found some used C2 mounts for $75 each on ebay.I figured out a new solution. I basically used a hand saw and cut ½” out of the mount holder, then put a ½ inch washer behind” from hardware store” and it did the trick . I know it sounds confusing, but I shall post pics later.

I bought a 996 cluster off of Ebay it was for an early 996. All the plugs in the back “3 plugs” matched my boxster plugs. It seems to work the same way as my boxster so far. I will update if there are any future problems. I got 3.2 headers off of ebay, and the fabspeed cat + exhaust for a 3.2 s boxster. I noticed the passenger side cat pipe was shorter than the driver side and it made the pipe leak some air. I used a sleeve to fix that and every thing seems dandy now. I like the sound of the fabspeed kit “not too loud”. I had a GHL exhaust for my 2.5 engine, the GHL was LOUD MANG!!!

I installed an Evo cold air intake and used silicon pipes “3 inch” to rout it. Also installed cross-drilled brake rotors and colored the brake caliper red. As of now I am using the boxster 2.5 ECU and it seems to be running fine. I know FVD has a sport ECU for 2.5 to 3.4 conversion at $1500 !!! if any one knows of a more Economical way could you guys let me know? Anyhow I am still not 100% done with the car, I have to finish the ECU upgrade, then my sound system. I shall give more updates later and post pics. Thanks to all the members in this site for the tips that helped me finish my project

Thanks again B)

Ali

[tholyoak]

Congratulations on your conversion. Testing has shown that if you aren't running the 996 program and activating the second plenum of the intake, you are probably producing less horsepower than the 2.5 you took out, so get the correct software. You don't need to pay $1500 for performance software just have your DME flashed with the 996 program with a PST2 or PIWIS tester. If you can't find anyone to do it for you I can do it for $150.

Todd

[goldnogard]

Thanks a lot Todd. Your thread about 2.5 to 3.4 conversions gave me the confidence to jump in to my project.

Ali :notworthy:

[Bristol]

You don't need to pay $1500 for performance software just have your DME flashed with the 996 program with a PST2 or PIWIS tester. If you can't find anyone to do it for you I can do it for $150.

Hey Todd, instead of flashing the 986 DME can you just swap in the DME from a 996? I assume that would work fine, but I'm not 100% sure. I'm just curious since I've seen 996 motors sold with the wiring harnesses and DME. I'm wondering if there is any extra value or simplicity in getting the 996 DME with the engine.

Kirk

[tholyoak]

You don't need to pay $1500 for performance software just have your DME flashed with the 996 program with a PST2 or PIWIS tester. If you can't find anyone to do it for you I can do it for $150.

Hey Todd, instead of flashing the 986 DME can you just swap in the DME from a 996? I assume that would work fine, but I'm not 100% sure. I'm just curious since I've seen 996 motors sold with the wiring harnesses and DME. I'm wondering if there is any extra value or simplicity in getting the 996 DME with the engine.

Kirk

Doesn't make it any easier, they are the same part. If you obtained the DME with the motor, you would have to obtain the DME and immobilizer codes for that DME so you could match the immobilizer code in the DME to the one produced by the immobilizer in your car. Most dealers won't give you the codes without proof of ownership so it may be difficult to get the codes on a used DME

Todd

[Bristol]

Doesn't make it any easier, they are the same part. If you obtained the DME with the motor, you would have to obtain the DME and immobilizer codes for that DME so you could match the immobilizer code in the DME to the one produced by the immobilizer in your car. Most dealers won't give you the codes without proof of ownership so it may be difficult to get the codes on a used DME

Todd

I see, thanks for the clarification Todd. I imagine that a guy with a PST2 (not necessarily a dealer) could match up the immobilizer code of a 996 DME, but I understand that if you're going to go through that trouble you might as well just flash the DME with the 996 setup instead. That does seem a simpler.

Obviously staying with the same DME makes the engine change a lot simpler and cheaper... I've been trying to find out the best option for myself. I've got a 2000 Boxster S. I know switching to a 3.4 with Motronic 7.2 would be relatively simple, but little bang for the buck (50 hp). Were all of the 3.6L engines Motronic 7.8 and were there any power-up options for the 3.4L (like the X51 package) that would make it more appealing? I've searched a bunch on these two questions and haven't found any good answers. Hope you can help.

Kirk

[tholyoak]

The PST2 allows you to reprogram the computer, it doesn't allow you to extract the code information, the code information is needed to allow reprogramming. Porsche has a database with this information based upon the VIN of your car. You could use the PST2 to extract the VIN from the used DME but you would still need porsche to tell you the codes based upon that vin.

A 3.6 swap on your car is pretty easy, I wouldn't waste my time on a 3.4 swap on a 3.2 unless the engine was blown up. As a performance upgrade the difference just wouldn't be that great.

I believe the X51 option on the 3.4 was a ROW only option.

Todd

Doesn't make it any easier, they are the same part. If you obtained the DME with the motor, you would have to obtain the DME and immobilizer codes for that DME so you could match the immobilizer code in the DME to the one produced by the immobilizer in your car. Most dealers won't give you the codes without proof of ownership so it may be difficult to get the codes on a used DME

Todd

I see, thanks for the clarification Todd. I imagine that a guy with a PST2 (not necessarily a dealer) could match up the immobilizer code of a 996 DME, but I understand that if you're going to go through that trouble you might as well just flash the DME with the 996 setup instead. That does seem a simpler.

Obviously staying with the same DME makes the engine change a lot simpler and cheaper... I've been trying to find out the best option for myself. I've got a 2000 Boxster S. I know switching to a 3.4 with Motronic 7.2 would be relatively simple, but little bang for the buck (50 hp). Were all of the 3.6L engines Motronic 7.8 and were there any power-up options for the 3.4L (like the X51 package) that would make it more appealing? I've searched a bunch on these two questions and haven't found any good answers. Hope you can help.

Kirk

[Bristol]

The PST2 allows you to reprogram the computer, it doesn't allow you to extract the code information, the code information is needed to allow reprogramming. Porsche has a database with this information based upon the VIN of your car. You could use the PST2 to extract the VIN from the used DME but you would still need porsche to tell you the codes based upon that vin.

A 3.6 swap on your car is pretty easy, I wouldn't waste my time on a 3.4 swap on a 3.2 unless the engine was blown up. As a performance upgrade the difference just wouldn't be that great.

I believe the X51 option on the 3.4 was a ROW only option.

Todd

Right, okay I've got it now on the immobilizer code deal. Thanks again for making things clear. Definitely reflashing the DME to the 996 setup is the best way to go.

Yeah, you're right about the 3.4L X51 option, it was a ROW only thing. I was at Loren's work on cars day yesterday and we looked up the documentation on this mod. Loren said he thought it was somewhere around $10K for the X51 kit and it could only be purchased from Europe. After looking at the specs we saw that because of the valve and cam changes new pistons with additional valve clearances were a part of the kit. Wow, that's quite a job then to install this and with the cost it doesn't really seem worth it. It's supposed to raise the 3.4L from 300 HP to 320 HP. The 3.6L would be a simpler and cheaper route to go, for the same power.

The biggest issue I see with going from a 3.2 to 3.6 is the change from Motronic 7.2 to 7.8 and the addition of VarioCam Plus. I know those are issues you're still working through, so I'll be following your work carefully.

Kirk

[goldnogard]

I should drive my car "running rough on the 2.5 ECU" to my local dealer some times this week to get the immobilize code for my car.

[goldnogard]

What is a good brake upgrade to the boxster 3.4L? What is your take on that? I am considering the 996TT caliper and rotors, or cayenne caliper and rotors. I am thinking about making brackets for the calipers, and maybe try and find a boxster rotor hub, and apply it to the donor rotor!! Hmm o r maybe the boxster brakes are good enough!! Not sure yet!!

[Stefan]

For street driving, I don't think a brake upgrade is necessary. The base boxster brakes are excellent.

[Jinster]

Congrats Ali! Well done.

Finally, someone with a tip has done the upgrade. I would be very eager to find out how the tip copes with the extra power and torque.

This is very encouraging.

I might embark on the same thing soon as I spot a spare 3.4L engine (which, in Australia, is very hard to come by).

Jin

:renntech: I posted this on Aug 2oth 07

Hello, I am in the process of upgrading from a tiptronic 1998 boxster 2.5l Motor to a 996 3.4L. My questions are:

1) Will the 986 tiptronic fit the 996 motors or do I need to modify flywheel, pressure plate or clutch so it will bolt to the 996 motors?

2) When bolting back hoses, pipes and other component to the motor, how do I figure out the number of torque pounds needed to bolt the bolts back "I don't want to break seals by over tightening the bolts"?

3) Do I need an early "1999-2001" 996 tiptronic instrument cluster + cluster cover and if I do, do I need to modify it?

4) After the upgrade should I worry about covering fuel lines or placing them in specific locations other than original in fear or fire hazard?

Thanks

Ali

Updates:

Ok so I finally got the time to do my upgrade. I started on Wednesday 9/12/07and got the engine running on 9/21/07 “yesterday”. The project was actually straightforward lol. It was almost like removing a boxster engine then re-installing it back. Here are issues I had to deal with:

1) I used the boxster fuel railing, and modified it to fit on the 996 engine “easy mod”

2) I had to figure out a way to lower the engine down. So

A)I used a caliper and figured ½ inch is the way to go.

B)The front of the engine was easy to drop “front Engine mount” went to hardware store got ½inch solid bar and drilled 2 holes in it to make my two adapters to lower engine mount. “ p.s at first I only lowered the front engine mounts by ½ inch which allowed the engine cover to go on, problem is engine wont start!!! The torque converter was touching the engine at an angle. Lesson learned: make sure you drop both front engine mount and rear transmission mounts D'oh! lol”

C)The back of the engine “transmission mount” was the tricky part. Some used C2 engine mounts to lower the car. I even thought of using solid aluminum C2 mounts “the sport kind, which will add more torque to the car, but also make it noisy lol” them C2 mounts cost over $200 each !! I found some used C2 mounts for $75 each on ebay.I figured out a new solution. I basically used a hand saw and cut ½” out of the mount holder, then put a ½ inch washer behind” from hardware store” and it did the trick . I know it sounds confusing, but I shall post pics later.

I bought a 996 cluster off of Ebay it was for an early 996. All the plugs in the back “3 plugs” matched my boxster plugs. It seems to work the same way as my boxster so far. I will update if there are any future problems. I got 3.2 headers off of ebay, and the fabspeed cat + exhaust for a 3.2 s boxster. I noticed the passenger side cat pipe was shorter than the driver side and it made the pipe leak some air. I used a sleeve to fix that and every thing seems dandy now. I like the sound of the fabspeed kit “not too loud”. I had a GHL exhaust for my 2.5 engine, the GHL was LOUD MANG!!!

I installed an Evo cold air intake and used silicon pipes “3 inch” to rout it. Also installed cross-drilled brake rotors and colored the brake caliper red. As of now I am using the boxster 2.5 ECU and it seems to be running fine. I know FVD has a sport ECU for 2.5 to 3.4 conversion at $1500 !!! if any one knows of a more Economical way could you guys let me know? Anyhow I am still not 100% done with the car, I have to finish the ECU upgrade, then my sound system. I shall give more updates later and post pics. Thanks to all the members in this site for the tips that helped me finish my project

Thanks again B)

Ali

[goldnogard]

Here are some pics from the first few days of the conversion:

this is my 98 boxster engine with 55k

this is the rebuilt 996 motor

parts to go on 996 motor

996 engine done

i realized i cut the solenoid wire by

mistake so i made a tool to hold

camshafts in place so i can swap

solenoid

the green circle shows new solenoid,

blue shows the bracket i made for

fuel railing to fit 996 motor, then in

red the ground cable."notice the 3.2

sports headers"

this is the 996 motor ready for

transmission

and finally the 996 motor with

the boxster tiptronic transmission

, good to go

i shall post some more pics later,

i hope these pics will help any one

interested in an upgrade

Ali

Edited October 5, 2007 by goldnogard

[goldnogard]

Congrats Ali! Well done.

Finally, someone with a tip has done the upgrade. I would be very eager to find out how the tip copes with the extra power and torque.

This is very encouraging.

I might embark on the same thing soon as I spot a spare 3.4L engine (which, in Australia, is very hard to come by).

Jin

thank you jin. i am not done yet. as of now the car runs a lil rough. i am sending todd my ECU to get it flashed to 996. i hope that will take care of the roughness issue. if not i will figuer it out. i always have a trick or two up my sleeve.I shall post updates soon ;)

[fitsintite]

HI,

Nice work keep us posted :clapping:

Thanks

[goldnogard]

I just ordered:

1) Ksport Kontrol Pro Fully Adjustable Coil over Kits for boxster, I guess it has the adjustable sports shocks, and adjustable cambers. I am thinking 1-1.5 front, 2-2.5 rears.

2) Eibach Anti Roll Kit.

3) Front and rear sway bars.

The parts shall be here next week or so. I shall post updates later

Ali

[goldnogard]

Sorry i didn't add more pics yet. i lost my USB cable to my digi cam, once i find it, or buy another i shall update the pics

thanks

Ali

[catmanluge]

Sorry i didn't add more pics yet. i lost my USB cable to my digi cam, once i find it, or buy another i shall update the pics

thanks

Ali

Ali

A while back you said you would show how you lowered the engine mounts. Do you have any photo's of the mods you made to achieve this?

Thanks

catman

[goldnogard]

Yes i do have the photos of lowered mounts, plus more, i just need to get the USB cable to my digicam. i should have it this coming week.

Ali

Sorry i didn't add more pics yet. i lost my USB cable to my digi cam, once i find it, or buy another i shall update the pics

thanks

Ali

Ali

A while back you said you would show how you lowered the engine mounts. Do you have any photo's of the mods you made to achieve this?

Thanks

catman

[catmanluge]

Yes i do have the photos of lowered mounts, plus more, i just need to get the USB cable to my digicam. i should have it this coming week.

Ali

Thanks

:)

Sorry i didn't add more pics yet. i lost my USB cable to my digi cam, once i find it, or buy another i shall update the pics

thanks

Ali

Ali

A while back you said you would show how you lowered the engine mounts. Do you have any photo's of the mods you made to achieve this?

Thanks

catman

[HJK]

Ali,

Any issues with the tiptronic? Please let me know, i'm in Bangkok, and considering the same trick you pulled.....

Thanks for the write up, good to know it all fits with a tip.

Henk

[goldnogard]

Ali,

Any issues with the tiptronic? Please let me know, i'm in Bangkok, and considering the same trick you pulled.....

Thanks for the write up, good to know it all fits with a tip.

Henk

Just make sure you flash your ECU from boxster to the 996 ECU, you can also get an after market Sport ECU for 996 "expensive". if you keep the boxster ECU , the car will run bad for tiptronic "EX: in tip tronic mood 1st gear changes around 2500rpm, but 2nd gear changes after 3500rpm!!! , then 3rd doesnt change untill about 5000rpm..etc" there is a guy here who can flash the ECU for a good price. if you want let me know and i will give you his info.

Ali

[goldnogard]

Yes i do have the photos of lowered mounts, plus more, i just need to get the USB cable to my digicam. i should have it this coming week.

Ali

Thanks

:)

Sorry i didn't add more pics yet. i lost my USB cable to my digi cam, once i find it, or buy another i shall update the pics

thanks

Ali

Ali

A while back you said you would show how you lowered the engine mounts. Do you have any photo's of the mods you made to achieve this?

Thanks

catman

ok got the trans mount lowering pics :)

Notice how i cut about 1/2" of the trans mount and used 1/2" spacer

the green arrow points to the spacer, the red points to where i made the cut

This is the engine mount

I shall post some more pics of work done on this car

Ali

Edited December 12, 2007 by goldnogard

[HJK]

Ali,

Flashing the 996 3.4 maps on the 2.5 ecu solved the shifting problems you had initially? So no need to do anything with the tiptronic ecu? How is it sofar, any hickups?

Henk

[Halfbreed83]

Any updates? :D