1998 Boxster 2.5 To 2001 2.7 Engine Swap Upgrade

[Erlinrys]

I wish you good luck. It seems as we both may encounter some dilemmas. Good Luck you might need a new DME. Read this

Boxster 2000 (2.7L & 3.2 S)

"The Boxster 2000 chassis can accept any Carrera 996 3.4L engine, or can use any Boxster engine from 1997-2002. In 2003, Porsche switched to a vane-cell adjuster mechanism to control the variable camshaft timing, and this system requires the later DME running Motronic 7.8. Unless you upgrade the car to use the later DME (very difficult), you cannot use any 2002 or later 996 Carrera engine or any 2003 or later Boxster engine. You can swap in any replacement engine of the same displacement from 2000-02 without having to remap the DME. (I.E. a 2000 2.7L Boxster with a blown motor can accept a 2002 2.7L engine with no remapping needed). Installation of a 3.2 Boxster 'S' engine would be an easy installation, but would require an updated map for the DME.

These cars ran the Bosch Motronic 7.2 system, which uses an electronic throttle body, linked to an electronic gas pedal (also known as drive-by-wire). When installing an engine into one of these cars, you need to use an electronic throttle body and corresponding crossover tube that matches that engine. (I.E. use the electronic throttle body from a 2000 or later 996 Carrera when installing a 3.4 engine).

If for some reason, you want to back-date the engine to a smaller displacement 2.5L engine, then you will have to use the injection system and DME map from a 2.7L engine. The 2.5L engine injection doesn't have the extra cross-over tube on the intake, and also has the cable-driven throttle body, which is not compatible with the electronic throttle 7.2 DME.

Installing a 996/997 3.6 or 3.8 engine or 2003-08 Boxster/Cayman engine is very difficult on these cars, as you need to manually update many other systems in the car to get them to work properly. These later engines used Vario-Cam Plus, which is a system for controlling variable valve lift. You need to run Motronic 7.8 in order to control the variable valve lift properly. It is possible to run a piggyback computer that independently controls the variable valve lift, but this solution is not ideal and is complex to implement."

Originally Posted by Brian in Tucson

I've never done the swap you're contemplating. If it were my car, if the 2.5 is running well, I probably wouldn't mess with it.

Some problems I see, you will have to use the automatic trans wiring. It's different from the manual, I believe. Your engine wiring will have to be transferred over.

Your 98 is mechanical throttle cable, the 01 is drive by wire so you may need to adapt the intake to use the older throttle body.

Will the trans bolt up? Don't know & don't know if you can transfer your flexplate over, either.

I'm in the process of putting an 00 to 02 2.7 into my 01 Boxster base with a 2.7. I know I'm gonna have to transfer the wiring over, and maybe the fuel rails. I guess I could have tracked down a 3.4, but it's all so complicated and I'm not an expert.

It seems to me, you're asking the wrong people. I would take a list of your questions and go see what your mechanic says. Your questions are valid concerns.

[Brian in Tucson]

I suspect my biggest problem will be R&R the engine and trans in my carport. Thanks for the "Good Luck" and I think we are all wishing you well, I think you're going to need the good luck, too.


Mine is coming out because the previous owner neglected it and it's been pretty hot at least a couple of times. My replacement is a factory rebuilt (50,000 mi ago) with an upgraded IMS bearing. Leak down variance is less than 6% and no apparent oil leaks--tho I did replace the crank seal and the rear main seal just because. $2300 plus shipping.

Keep us in the loop & Merry Xmas!

[Erlinrys]

Hey Guys,

A month after all the triumphs my 986 is on the road running strong and ready for day-to-day drives!!!

It sounds Nasty, and I will book it into the shop for the minor skirt incident.

After a couple mods, I was able to utilize my tip tranny from the 98 986 and swapped in the 2.7. We did need to modify the throttle from egas to 98 throttle system. Modified the injectors, intake, and other minor modifications in which required to take a minor step back, in order to create a custom fit.

Engine sounds obnoxious with the headers, custom exhaust, electric cut out, and other minor mods.

Happy Porsche! And F all the Nayers!!! Because I am sayer!!! haha jk..


Since you have taken your time to share information with me, I would like to share my story in how you and I connected.

Here is my story…….

I started this crazy engine swap from my 2.5 engine to 2.7 engine because I overheated my 57k Boxster engine. I needed to swap it out, knowing how expensive it was going to be I started my search for engines. I found one in Chicago, with close to similar miles, 10k plus, from a 100 r5 star review, Ebay Porsche Seller, and he also included all the four clips of the suspension. Since I also experienced a minor curb bump to the wheels and suspension in the driver side as you will see in the image of my Boxster at Porsche Bethesda.

Thousand, and thousands and thousandths of dollars later, and after all the “NAY, Sayers” in which my setup was not going to work, was able to get her running and sounding like a beast!

I finally booked her into Porsche Bethesda (one of our local service centers) to top her fluids, she’s back home.

I am also booking her into the body shop this week in order to repair the minor skirt incident, and the “one" matching wheel shall arrive within the next couple days, along with other minor mods.

Attached see the images when an officer securely delivered her to me. See images of triumphs during the swap process, her sitting happily inside the new 4 level Porsche Bethesda Facility, in our local Rockville Service Area.

That is my 986 welcome story, for trying to save a buck, she became stuck! Now, I am pleasing her with all the services to keep her running better and faster and unique, she’s my “UNICORN!."

Sorry, i am unable to add images, But i will figure it out. If not I can email them to you upon your request. Or, if anyone needs help in the swap from 98 Boxster to 2.7 I think I can provide material information for your swap.

[Paul]

From one unicorn owner to another: CONGRATS!

Hopefully you will have a code free future.

[Erlinrys]

No lights and no codes!

[Brian in Tucson]

Originally Posted by Erlinrys

No lights and no codes!

Is the difference in power noticeable?

Mine is within a day or two of firing up. I'm retired (late middle age) and I can do all of the work, I just daydream more than I used to. Engine is in, trans is all hooked up. Working on getting the hatch behind the seats closed up--finally bolted the a/c pump down and tried to install the wrong surp. belt, too big.

Glad to hear that your project went without a hitch.

I'm planning on firing it up day after tomorrow.

[Boxstard]

Originally Posted by Brian in Tucson

Is the difference in power noticeable?

Mine is within a day or two of firing up. I'm retired (late middle age) and I can do all of the work, I just daydream more than I used to. Engine is in, trans is all hooked up. Working on getting the hatch behind the seats closed up--finally bolted the a/c pump down and tried to install the wrong surp. belt, too big.

Glad to hear that your project went without a hitch.

I'm planning on firing it up day after tomorrow.

I'm curious too, if one has gone through those troubles to fit 2.7 on pre-2000 cars it got to have some reward... Or I'd just stick with 2.5 if not stepping up to 3.4.