Engine upgrade- did you do one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Porsche9 · 03-10-2014, 10:04 PM

I've seen and number of you have dropped in 3.4 and 3.6 motors (yes there is the LS option but want to keep this thread pure Porsche power) into your Boxster. In retrospect was it worth the time and expense? Did some of you do it just to make things as it should have been from the factory? Tell us your story.

landrovered · 03-11-2014, 06:32 AM

My 3.6 transplant was performed by Autometrics of Charleston SC. they are a race shop that specializes in preparing Cup cars, Grand Am and ALMS (Now TUDOR). It was done by the previous owner but I did see the final invoice. To put it plainly the shop owner still refers to the job as "the car from hell".

That being said the finished product is pretty amazing. It is faster than almost any non turbo standard 986, 996, 987, 997 out there. It sounds fantastic in the top end of the rev range and DE instructors riding shotgun all comment on how much torque it has and how strong it is. I have a zeintop on my car as well so it is like the 986 Cayman prototype that would have preceded the 987 but was never seen by the public. To this end I now refer to my car as a 986 RS in a half joking-half serious manner. It really is the RS that Porsche should have built but didn't.

The conversion is not without its issues but they are very minor. One... the radio will come on when the car is not running but when you start it the radio will not come on for the first five minutes or so of it running. There was some serious wiring loom voodoo that went on and I am not inclined to dig into it just to listen to the radio, the engine plays too nice a song anyway.

The car was set up to be a track day car with a single mass flywheel, when I got the car the front motor mount was failing and so I put a Wevo SS motor mount in its place. The car ran like a banshee but the NVH was considerable. It was exciting to drive but not enjoyable for more than 30 minutes. Long trips were taxing.

When I replaced my IMSB recently I replaced the single mass flywheel with a dual mass flywheel and the front motor mount with stock. The car is far smoother and much more of a pleasure to drive now. It feels almost exactly like a 3.8 4S 997 I drove recently, but more nimble and better balanced. I call it the velvet hammer now because it is smooth and powerful, much closer to what Porsche would have built if they did not protect the 911 at the top of the food chain.

In terms of cost, the conversion was exorbitant in price and the PO lost out as I paid less for the car than he paid to get the conversion done. I bought it early in my Porsche experience and I have realized that while I love the concept of a track missle, I do not want to drive one on the street so in reality I should have bought a 3.4 Cayman S instead of what I did but I have been able to turn my car into what it is and I will continue to enjoy it every time I drive it.

jb92563 · 03-11-2014, 07:20 AM

I noticed you qualified the power as compared to non-turbo 986's etc.

Does that mean that you feel that a Turbo converted base or S model engine might produce more power than a normally aspirated 3.6?

BTW, thats a real pretty 986 you have and with your power it sure fits the unrealized 986 RS version, except it needs some kind of fancy RS spoiler

landrovered · 03-11-2014, 12:21 PM

Yes a turbo S would be the choice for ultimate speed and cheaper in the long run IMO. You could embarrass a lot of other car owners with a 986 or 987 turbo 3.4.

I rode in a friends 3.6 996 Turbo and nothing that is naturally aspirated can do that, nothing. I also drove a slant nose a while back and that thing made the lights turn into lines like warp speed on star trek and it was a 3.3L. Unfortunately I found both of them nauseating as a passenger, driving is a different story but you better know where you are going when you hit the skinny pedal because you are going to get there really really soon.

I love the linearity of larger displacement but in my car the Variocam plus takes a small amount of linearity out of the equation... with a single mass flywheel you can feel the cam change modes at 3100 rpms. The dual mass has made that notch in the curves smooth out a lot but the engine does not rev as quickly now either.

Thanks for the compliments and I have thought about a big wing but the car has some of that old school Porsche sleekness about it and I like that.

thstone · 03-11-2014, 12:43 PM

Quote:

Originally Posted by landrovered

To this end I now refer to my car as a 986 RS in a half joking-half serious manner. It really is the RS that Porsche should have built but didn't.

986 RS. Perfect name!

BYprodriver · 03-11-2014, 03:49 PM

Quote:

Originally Posted by Porsche9

I've seen and number of you have dropped in 3.4 and 3.6 motors (yes there is the LS option but want to keep this thread pure Porsche power) into your Boxster. In retrospect was it worth the time and expense? Did some of you do it just to make things as it should have been from the factory? Tell us your story.

I wanted more power from my 2000 Box "S" using the original engine, so I wouldn't have to write a supplementary service manual to go with it. Boxster engines are identical to same year 996 engines except for the cylinder size. Once LN released the parts needed to enlarge the cylinders & pistons I began planning to install them in my engine. When Jake Raby announced his M96 engine rebuild class in 2009 I was the 4th person to signup. I believe this method leads to the best end result.

Porsche9 · 03-11-2014, 07:50 PM

Nice car Landrovered. Love the top.

Porsche9 · 03-11-2014, 07:52 PM

BYprodriver, what sort of power is your setup producing? What supporting mods did it need?

Jake Raby · 03-11-2014, 09:34 PM

I routinely receive complaint calls concerning engine swaps. The best way to get more power and do so seamlessly is to build the original engine into a more robust performer with failure points addressed.

I see guys swap more problematic engines (3.6 and 3.8) into their earlier cars and it doesn't make any sense to me. All those headaches for something thats more problematic.

landrovered · 03-12-2014, 03:52 AM

I'd like to hear from someone that did an electric conversion on their boxster!

Jake Raby · 03-12-2014, 06:10 AM

Quote:

Originally Posted by landrovered

I'd like to hear from someone that did an electric conversion on their boxster!

There's a really nice one in Atlanta.. I bought the M96 that came out of the car that he used as his foundation.

dghii · 03-12-2014, 08:22 AM

Jake,
Are you referring to this one by any chance?

1998 Porsche Boxster Electric Car!

BYprodriver · 03-12-2014, 01:16 PM

Quote:

Originally Posted by Porsche9

BYprodriver, what sort of power is your setup producing? What supporting mods did it need?

Doesn't "need" any mods, & cut all emissions in half compared to 75K stock test.

Here's a chassis dyno test with NHP sportcat manifolds & midpipes:

Waiting for the summer blend 91 octane gas to retest with the added Cayman airbox,75mm T/B & 997 plenum. expecting about 20hp.

Porsche9 · 03-12-2014, 06:46 PM

Byprodriver,

Nice jump in power over a stock 3.2. Looks like about the same power level as a stock 2002 3.6 without the hassles of a transplant plus you addressed known M96 weaknesses. Is that a fair assessment?

BYprodriver · 03-13-2014, 09:37 AM

Quote:

Originally Posted by Porsche9

Byprodriver,

Nice jump in power over a stock 3.2. Looks like about the same power level as a stock 2002 3.6 without the hassles of a transplant plus you addressed known M96 weaknesses. Is that a fair assessment?

This configuration gives more low RPM torque which really quickens acceleration in the real world & makes it so much easier to drive. I usually drive mine like a 3-speed now. 1st to 3rd to 5th. While the engine is apart you can send the IMS to LN for their triple row IMSB upgrade too.
Also balancing the engine reciprocating parts really makes it much smoother.