2.7L into a '99

[Yippee38]

My '99 Boxster engine recently died. I'm going to be swapping the motor myself as soon as I source a used replacement motor. This car is my daily driver, and money is really tight right now, so I have to get this swap done as quickly as possible, and as cheaply as possible. I will likely put in a 2.5L engine, but right now I haven't been able to find one in the mileage range I'm looking for; they're either really high mileage engines, or really low mileage engines, both of which make me nervous.

To give myself more options, I've started to consider putting a 2.7L from a 2000-2002. I won't do a 2003+ engine because of the DME issues and the added costs associated with that. Cost, and time, are the reasons I'm not going with a 3.4L.

I've seen some info on putting an e-gas engine in a non-e-gas car, but no specifics. From what I can tell after hours of searching here and on other Boxster sites, I have two options: 1) I can keep the pedal from my car and put the intake and throttle body on the 2.7L engine to make the engine non-e-gas. 2) I can get a gas pedal from a newer car and wire it to the DME somehow. I would also need to wire the Variable Resonance Flap. The pros of going e-gas would be possibly a slightly larger intake, and therefore I wouldn't be losing power as I might (if the 2.5L intake is smaller). The downsides would be the additional cost of having to buy the pedal (which shouldn't be that significant), and losing the ability to apply throttle while braking on the track. Am I missing anything else?

So my questions are:

1) If I choose to stick with the non-e-gas setup,

a) is the 2.5L intake significantly smaller than the 2.7L intake, or are they the same size? Is there a difference between the intakes on the 2.7L Boxster vs. the 2.7L Boxster S engines?

b ) is there anything else that I need to wire up on the 2.7L engine in the non-e-gas car?

c) the 2000-2002 engines are on the 7.2 version of the DME, where my car has the 5.2 version. I assume that means the 5.2 DME will need reprogramming. What specifically needs to be done?

2) If I choose to change over my car to the e-gas setup,

a) I need to run a wire from my pedal to the DME. Where are those connections (what pin)?

b ) The Variable Resonance Flap valve needs to be controlled by the DME. This requires (from the Pelican Parts article), "You wire this solenoid by running one wire to a 12V source and the other wire to pin 59 on the DME (the DME controls the valve with a switchable ground)." Is that accurate?

c) Is there any other wiring that needs to be done, and if so, specifically (what pins) must be wired?

d) Would the DME reprogramming issues be exactly the same as in case 1) above, or are there any differences?

I've found lots of information on swapping 3.4s and 3.6s into the older Boxsters, but very little on putting a 2.7L into them. Anything I have found has been vague (other than the wiring on the variable resonance flap, which, for a change, is specific). I'm looking for the specifics. I don't want to find issues when the new engine is in the car. I'd like to be able to address them up front so the swap can go smoothly.

Edited November 26, 2010 by Yippee38

[mikefocke]

You might talk to Pedro of www.pedrosgarage.com who just replaced his 200k+ miles 2.5 with a 2.7 by using the 2.5 heads. He said it went very easily with no odd-ball ECU mods or flashes necessary. He runs www.pedrosboard.com..the successor to PPBB.

[Yippee38]

You might talk to Pedro of www.pedrosgarage.com who just replaced his 200k+ miles 2.5 with a 2.7 by using the 2.5 heads. He said it went very easily with no odd-ball ECU mods or flashes necessary. He runs www.pedrosboard.com..the successor to PPBB.

Pedro kinda bypassed the DME issues by changing the heads. Since people can swap in the 3.4s and 3.6s without using the 2.5 heads, there has to be another way to do it. That's what I'm asking about. I don't want to rebuild the head (resurface and valve job), so I don't want to pull them or swap them. The gaskets will add cost, and the swap of the heads will add time and complexity.

I'm hoping there's another way to do it, and somebody can tell me what that is.

[infocusf8]

Yippee38 most of the questions you are asking are pretty technical, have you developed a relationship with a dealer or indy shop that you can talk to about the swap? My '99 is running very well but if anything happened to it I would probably put a 2.7L in. At one time I briefly discussed this with Tillman's in Santa Rosa, CA and with Alden at Flintworks in Campbell, CA. My recollection of the discussion was that it was a pretty straight up swap versus the 3.2L that requires a lot of extra parts and labor to do as well as a complete remapping of the EMC module. If it were me doing it I would definitely talk to a shop or dealer who has done this and can advise you. You might also post your questions on the PCA Boxster Board as I believe a couple of the members there have done this kind of thing.

[Yippee38]

Yippee38 most of the questions you are asking are pretty technical, have you developed a relationship with a dealer or indy shop that you can talk to about the swap? My '99 is running very well but if anything happened to it I would probably put a 2.7L in. At one time I briefly discussed this with Tillman's in Santa Rosa, CA and with Alden at Flintworks in Campbell, CA. My recollection of the discussion was that it was a pretty straight up swap versus the 3.2L that requires a lot of extra parts and labor to do as well as a complete remapping of the EMC module. If it were me doing it I would definitely talk to a shop or dealer who has done this and can advise you. You might also post your questions on the PCA Boxster Board as I believe a couple of the members there have done this kind of thing.

I will give that a try. I didn't ask the shop because I'm not having him do the work. I figured he might not want to waste his time helping me when he's getting no work/income out of it.

[infocusf8]

Yippee38 most of the questions you are asking are pretty technical, have you developed a relationship with a dealer or indy shop that you can talk to about the swap? My '99 is running very well but if anything happened to it I would probably put a 2.7L in. At one time I briefly discussed this with Tillman's in Santa Rosa, CA and with Alden at Flintworks in Campbell, CA. My recollection of the discussion was that it was a pretty straight up swap versus the 3.2L that requires a lot of extra parts and labor to do as well as a complete remapping of the EMC module. If it were me doing it I would definitely talk to a shop or dealer who has done this and can advise you. You might also post your questions on the PCA Boxster Board as I believe a couple of the members there have done this kind of thing.

I will give that a try. I didn't ask the shop because I'm not having him do the work. I figured he might not want to waste his time helping me when he's getting no work/income out of it.

That's why I prefaced it with "relationship." If you use a specific shop or shops and have spent money there most time they are very helpful. If you haven't another approach would be to stop in and explain to them you are thinking about an upgrade, suggest you had heard about them and ask a general question like what is involved. You might be surprised at the amount of information you get.

[Yippee38]

That's why I prefaced it with "relationship." If you use a specific shop or shops and have spent money there most time they are very helpful. If you haven't another approach would be to stop in and explain to them you are thinking about an upgrade, suggest you had heard about them and ask a general question like what is involved. You might be surprised at the amount of information you get.

Yeah. I guess that's what I'll have to do. I thought maybe some people here had done that kind of swap, but apparently not. Either they all have had a shop do it, or nobody does that swap.

[GTA_G20]

I too was considering this swap and thought it would be as simple as swapping the egas and non egas throttle bodies but apparently not.

[Yippee38]

I too was considering this swap and thought it would be as simple as swapping the egas and non egas throttle bodies but apparently not.

I'm a bit mystified by it.

[infocusf8]

Yipee38 you might join the PCA Boxster site and post your question there. Here is the link http://boxsterregister.org/index.php.

[Yippee38]

Yipee38 you might join the PCA Boxster site and post your question there. Here is the link http://boxsterregister.org/index.php.

Good idea. I've looked at that before, but I didn't see much recent activity. Thanks.