Porsche Boxster 986 - engine swap project

[Escy]

Thanks B'stard Child.

Rene, do you have a build thread for your project? I'd love to check it out. The transaxle i'm using is a 987 3.2 Boxster S, it's the same as the later 3.4 Cayman/Boxster S with the only difference being the shorter ratios in the 3.2. I think it's the G87.21. I also used the 987 driveshafts, mounts and the complete linkage/cables/shifter. Like you say, they are quite expensive.

The Audi 01x is an option but you'll need to sort out the gear linkage.

[Jens1968]

Hi Escy,

thnx for the reply. First time posting on this forum. Haven't got a building thread yet. working on that. still figuringout how this forum works

i could use the 2.7 trans, but its a 5speed and i think i won't last long against the 300bp ABZ. also read the threat from Beaker77 witch you reply'd on. unfortunly he didn't finished his project or doesn't post here anymore. he was planning to cut up the 986S trans for the starter and drill a hole fore the crank sensor. i wonder iff he did something to it.
also saw the thread from Hilly and his lotus. i believe he used de 01X trans but dit a huge mount off work on the gear linkage.

in my opinion the G87.21 is also a Audi unit. so iff i can find the cast numbers, maybe i could find one with an audi name on it. (iff i google Porsche Boxster 2.7 gearbox, i find prices from €700- and higher. if i google audi WWO 012 301 211R (witch are the numbers on my2.7 gearbox) i find tons of gearboxes for a audi A4 for €100- or a little more and they are exactly the same. so i'm hoping for the 6speed the same.

i saw you used a flywheel from TTV racing. that would be great for my project. how is your clutch handeling? is it a bit Smooth?

[Escy]

There might be an Audi version. I'm pretty sure I once came across an Audi part number for 2nd gear synchro as Porsche don't sell rebuild parts. I can't remember what model number it was, i've tried googling but nothing has come up.

If it's just the power that you think is the problem, the 2.7 box should be ok, a few people use them behind the bigger 911 flat 6's that are the same sort of power.

I've using the TTV flywheel and a B7 RS4 clutch. It's really nice, just like the factory clutch. I'm interested to see if it'll be ok once the boost is wound up.

[Barchettaman]

Slightly off-topic, but Jens - no need to apologize for your English, it's better than most of the native speakers who post on here. Best of luck with your project!

[Jens1968]

Barchettaman said:

Slightly off-topic, but Jens - no need to apologize for your English, it's better than most of the native speakers who post on here. Best of luck with your project!

thnx. trying the best i can

@ Escy... i saw you modified the gearbox carrier and the strut that goes under the gearbox. Did you move the engine and gearbox forward and lower?

i hope you don't mind asking question, but your project is a realy good help for me, even i'm using the 4.2 V8

[Escy]

Yes, moved it forwards and dropped it a little lower to aid clearance for the engine and it also improves the driveshaft angle which was pretty poor from Porsche originally. There should be a picture somewhere in the thread of the transaxle brackets what shows how I modified them.

[Jens1968]

Yes i saw them at the bottom off page 5. I Can't move forward with mine, but i want to lower the gearbox a little and want to make a custom strut also. I saw you made in the end another one from tube.

I realy enjoy seeing how you frabicated things. Its a good help.

[B'stard Child]

Escy said:

I've using the TTV flywheel and a B7 RS4 clutch. It's really nice, just like the factory clutch. I'm interested to see if it'll be ok once the boost is wound up.

On my new engine for the track car I've got my second TTV flywheel - Lotus Carlton Crank fitment, Monza GSE Friction plate and Audi S3 Pressure plate

Already been proved reliable when fitted to another car

this car



84 Opel Monza GSE

Engine is hybrid - C30SE Block, Lotus Carlton Crank and Rods - Custom JE Pistons - Lotus Carlton inlet manifold and throttle bodies

305 bhp





Sorry for the threadjack but I worked closely with TTV to get this flywheel made and I've not found many companies as willing to help create something bespoke

[Escy]

That's really nice. The TTV flywheel is a good bit of kit.

This is how the old wastegate was fitted. It was originally mounted lower but I needed to modify the exhaust and that's where it ended up sitting. Not ideal, would rather it mounted lower as there will be more airflow and it should help keep it cool.



Since the Forge wastegate flange was slightly different I re-made the rear part of that section of the exhaust and improved the wastegate angle and the position of the gate.



Wastegate fitted. I'm not going to connect the water cooling. You can see i'm halfway through connecting the screamer pipe.



I wasn't happy with how the tail pipe for the main exhaust was sitting, after all the adjustments in other areas it's ended up sitting too far central so i'm in the process of sorting that out before I connect up the screamer pipe. I'm using a load of wood blocks to try and get it in position, I can see it being a pain in the arse.

[gofasterrosssco]

Escy said:

wc98 said:

drewbagz said:

Can't wait to see this mapped and running at it's full potential.

A truly outstanding build and worthy or readers car of the year!

i will second this , great vision and determination coupled with a huge dose of ability. absolutely love it

Thanks, it's nice to read comments like these.

Prof, that's an interesting transaxle, not seen one before. In my opinion it won't work. I used the 987 transaxle which also has the differential further forward compared to the 986 transaxle, the limiting factor in how far forward I could mount my engine was the driveshafts fouling the suspension carriers. The problem with the V8 conversion isn't the transaxle positioning, it's the size of the inlet manifold. If you could fabricate a custom inlet manifold you might be able to limit the hacking required. I'm not entirely convinced they are worth the effort for the BHP gained. There is some recent V8 discussion on the US 986 forum http://986forum.com/forums/performance-technical-c...

This gearbox is the Audi OB1. Found in B8 chassis A4 / A5's (maybe some others).

My self and a few others mucked around with this a few years ago looking at installation into MR2's, and it will bolt to an Audi V8, but the starter motor support has to be trimmed off on the engine side to allow the differential to fit. I don't think anyone got any further on the clutch / flywheel combo or on the gear selector mechanism.

http://www.mr2oc.co.uk/forums/283/141885.html?star...

[Escy]

Finished up the exhaust alterations after changing the wastegate.



Went back to Kwikfit to get my front camber set-up.





The turbo oil return pump is on it's way out, it ran dry for a while when the turbo was starved of oil. Guess it's best to have it happen now and not on the dyno.

[DanielSan]

That looks brilliantly ridiculous from that angle.

[Jens1968]

+1. That looks great. You did a very nice job.

Little question. The "cradle" you made to suport the engine. How thick are those tube's? It looks about 30x30mm, but maybe im wrong. I'm not sure how thick i'm have to make them.

[Escy]

Thanks, I'm pleased with how it's turned out.

I made the cradle out of 25x25 box section. Have you seen this Cayman V8 build? It looks like the project has stalled but it might be useful for ideas. http://www.planet-9.com/987-cayman-and-boxster-mod...

[Escy]

It's been slow progress considering there isn't that much to do. I feel like another summer is slipping away from me.

I replaced the oil return pump for the turbo. The old one was drawing more amps and sounded really rough.



I've been pressure testing the boost pipes and have found a few leaks. There was one on the clamp for the compressor outlet housing, Holset use a strange size v-band and it wasn't sealing so I ended up cutting it off and using a silicone hose instead.



I had a leak on the compressor housing where the big circlip holds it onto the turbo. I needed a mate to come over to help me get it back on, it was a nightmare and that circlip under tension is dangerous.



An EGT sensor fell apart on me, I think perhaps I over tightened it. I've been having problems with the nuts coming loose so this time I've added some JB weld to the threads, that should do it.



I now have no boost leaks up to 15psi but the tester was popping off the turbo inlet at that point so I couldn't test further. Anything after that is likely to be a hose popping off so I took it for a test drive and started winding up the boost, I got to 25psi and the hose on the throttle body kept coming off. There is a bit of a problem, the throttle body is off an RS4 but they have a metal pipe bolted on rather than a hose. There is no lip on the throttle body to stop a hose coming off. I watched a Youtube video of someone using hairspray to help stop boost pipes coming off so thought i'd give that a go, when you spray it on it acts like a lubricant and when it sets it's like a glue. I haven't tested it yet, hopefully it does the trick.

[samoht]

So it really is a hairdresser's car, then? ;-)

[Escy]

I've taken it for a test drive and the hairspray is holding the pipe on at 25psi now. If I trust it at the dyno is another matter. 

I decided to add a pair of fire extinguishers. Wouldn't want it to go up in smoke because of something silly catching fire like the rear bumper. I wanted them inside the cabin and there isn't much space so I thought this was the best place. There is a recess in the floor so they fit in nicely. Held in with a velcro strap.

[Escy]

samoht said:

So it really is a hairdresser's car, then? ;-)

Ha ha, I don't want it to stray too far from it's roots.

[B'stard Child]

Escy said:

It's been slow progress considering there isn't that much to do. I feel like another summer is slipping away from me.

I replaced the oil return pump for the turbo. The old one was drawing more amps and sounded really rough.

Is this something you have added to resolve the drain issue of a low mounted turbo?

It's something I have considered to solve a smoke problem on this



It's has old style turbos without 360 deg seal and at idle a lack of crankcase vacuum leads to the turbo drains backing up and as a result lots of smoke!!

[Escy]

Awesome car

The pump is for the oil drain on the turbo. I remember from my days with 200SX's, a (temporary) cure for a turbo with leaking seals was a one way valve added to the PCV hose from the cam cover to the inlet pipe (post MAF sensor, pre turbo). This increased the vacuum in the crankcase. Perhaps something you could look into?