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Discussion Starter #121
Things have been a little slow, but I finally got to see something today I wanted to see for a while.

The pieces for the left engine mount bracket are all cut out and fit together. They're ready to weld up and to have some 1/4-inch plate welded to the top for the mount to sit on. It looks like it will be pretty solid, although I will have to cut a slot in the back plate to access the lower mount retaining nut.

HMG_0907 - Small.JPG HMG_0906 - Small.JPG

Once the bracket is welded together, I'm putting crush tubes horizontally through the cradle for the bracket to bolt up to. Once I do the other side, the cradle will hold the engine up, and I can pull out that piece of angle iron supporting it!
 

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Discussion Starter #123
This weekend I was able to finish the left hand side engine mount bracket. After welding the bracket up, I positioned it with the engine mount attached. I then ran some temporary sheet metal screws to locate it on the rail. I took the rail and bracket out of the car, then reassembled them with the sheet metal screws to recover the right position. At that point the holes for the 12-mm through-bolts were drilled, and the crush tubes were run through the rail and welded in place.

The first picture shows the bracket bolted in, from an inside view. The funny-looking extension off the top of the bracket is for mounting a cross-member later. Since I don't know exactly where it will end up, the extension is bigger than necessary. Once the cross-member is designed, the excess will be trimmed off the extension.

The second picture is taken from the wheel well, from where you can see the slot cut in for access to the bottom mount bolt.

HMG_0914 - Small.JPG HMG_0908 - Small.JPG

This took too long, but now that I know what I'm doing, the right side should go quicker.
 

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looks good. what engine mounts are you using? I used corvette engine mounts and stock cayman transmission mounts and the engine is moving way to much. I have performance semi-solid engine and trans mounts on order. hopefully that will help tame the beast a little.
 

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Discussion Starter #125
looks good. what engine mounts are you using? I used corvette engine mounts and stock cayman transmission mounts and the engine is moving way to much. I have performance semi-solid engine and trans mounts on order. hopefully that will help tame the beast a little.
I'm using 2013 ZR1 Corvette mounts, along with stock Cayman transmission mounts. I am concerned about excessive engine motion also, because the engine mounts are so much further back on the Audi engine compared to the Porsche (on the nose of the engine). On the other hand, I only have about 2/3 the torque of your LS engine!

My plan for now is to leave it like it is, but to leave room to put a vertical torque strut from the front of the engine to the cradle. The Audi engine has that snubber bracket up there, and while I didn't trust it to carry the weight of the front of the engine, it might be just the thing to handle extra torque. Plus, I could try different stiffnesses without too much effort.
 

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When you get her running drive it with the engine cover behind the seats off and you can see how much the engine moves. It turns out the corvette engine mounts are not nearly as stiff as you'd expect them to be and the Cayman trans mounts are not much better. One thing may help you in your planning is the engine does not torque to the side the way would expect it to. Because the drive shaft's come out of the side of the trans instead of the back the engine is going to torque longitudinally meaning the front of the engine is going to go straight up during hard acceleration and straight down during deceleration. It seems obvious in hindsight but I never thought about it until I saw the engine moving and it wasn't moving the way I expected it to.
 

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Discussion Starter #127
When you get her running drive it with the engine cover behind the seats off and you can see how much the engine moves. It turns out the corvette engine mounts are not nearly as stiff as you'd expect them to be and the Cayman trans mounts are not much better. One thing may help you in your planning is the engine does not torque to the side the way would expect it to. Because the drive shaft's come out of the side of the trans instead of the back the engine is going to torque longitudinally meaning the front of the engine is going to go straight up during hard acceleration and straight down during deceleration. It seems obvious in hindsight but I never thought about it until I saw the engine moving and it wasn't moving the way I expected it to.
You're right, I expect that the front of the engine will want to lift. Where Porsche has the front mount is really where you'd like it, because the engine doesn't experience much roll torque side-to-side, but mainly pitch torque (which is best controlled by mounts spread far apart fore-aft). I think watching its motion with the cover off is a very good idea, and it's looking more and more likely I'll put a front vertical torque strut in.
 

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Discussion Starter #128
Hallelujah! The powertrain is finally mounted!

The first two pictures show the right hand side engine mount bracket, bolted to the cradle and engine. And no temporary beam support. There is about 1/2 inch of clearance right now between the cradle and the alternator. But I intentionally mounted the engine a bit low, so that I can adjust it upward with spacers.

View attachment 100721 View attachment 100729

The third picture shows the installed powertrain, but without the suspension support diagonal braces that go to the rockers or the bottom aluminum tray. It was nice to see how much room there is down there, because of the engine placement (the upside of having the engine higher than I'd like, to keep it level). I won't have any problem finding places for coolant pipes, I just have to choose the best route.

View attachment 100745

The fourth picture shows the whole package from a front view. You can see that the bottom of the cradle is even with the bottom of the floor pan. The bottom of the oil pan is roughly one inch higher than that. If you look close, the bottom of the transmission and the inner CV joints are visible from this angle. I think with the right ducting and panels I can direct more air up there than with the original Porsche engine, whose lower oil pan blocked that air path.

HMG_0922 - Small.JPG
 

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As a guy who also blew a 3.4, I'm in awe at this attempt. I wish I had engineering talent and training - this is much cooler than my boring 3.8! Can't wait to see the finished product.

Sent from my VS990 using Tapatalk
 

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Discussion Starter #131 (Edited)
As a guy who also blew a 3.4, I'm in awe at this attempt. I wish I had engineering talent and training - this is much cooler than my boring 3.8! Can't wait to see the finished product.

Sent from my VS990 using Tapatalk
Well, I won't call a 3.8 Cayman boring! For me, necessity is the mother of invention, so it's the (cheaper) Audi for me. But it is fun.
 

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Discussion Starter #132
I've been working on the exhaust system for a while now, and one problem I've run into is finding flanges to mate to the Audi exhaust manifolds. The production pipes that mate to the manifolds are flared, and the 3-bolt flanges hold them against a ball-shaped ridge on the manifold.

Manifold Flanges.jpg

I haven't been able to find any flanges or "flange and flared pipe" that will necessarily fit. It seems like the inside of the flange would want to be tapered to follow the pipe, but I can't make it out from the photos I've found.

Does anyone out there know a source for these flanges? The distance between adjacent bolts is 3.125 inches (about 80 mm), making a bolt circle of 3.61 inches (about 92 mm). I need to get stainless steel ones to match the rest of the system. I'm using 2.50-inch pipe.
 

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Discussion Starter #133
The rest of the exhaust system has been a little simpler. I found some BBK Varitune mufflers that will let me adjust the exhaust noise (with an adjustable bypass). Otherwise it's a standard three-pass muffler with a good size, nicely built from stainless steel.

varitune_muffler.jpg

I built a bracket on the back of the transmission to hang the mufflers from a piece of exhaust pipe going cross-car. It was cut and welded to angle forward by 6 degrees on each side, to roughly follow the bumper. I'm trying to leave room in the middle for airflow past the transmission and out the back. We'll see.

HMG_0954 - Small.JPG

The exhaust is going to run alongside the transmission, angle outward through the cat's, and then into the mufflers. To avoid having the converter housing flanges running into things, I got some MagnaFlow cat's that are made from spun stainless.

mpe-59926_xl.jpg

These will fit nicely. They don't have heat shields, but I can put them where necessary. I've ordered some tight mandrel bends to put most everything together.

Now if I could just find the right manifold outlet flanges...
 

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Discussion Starter #134
I've been waiting on some exhaust pipes, so I worked on the coolant pipes today. I hadn't decided whether to keep the "quick disconnect" couplers on the ends of the coolant pipes or not. But last night, I tried to shove the old hoses into them, they didn't go easy, and I decided they were too much of a pain.

So I got a large tubing cutter from Lowe's, cut off those connectors, and made a dimpling tool from an electrical connection crimper (as I saw on a YouTube video). You can see one of the old couplers in the first picture. As for the dimpling tool, it was a $12 crimper from Lowe's, from which I cut off the ends of the jaws. I just repeatedly pushed the bump into the pipes, all the way around. (FYI - I looked at five different tools before I found one that had the two sides aligned perfectly.)

HMG_0979 - Small.JPG HMG_0981 - Small.JPG HMG_0980 - Small.JPG

So now I can order the coolant pipes and hoses to go from the existing ones to the engine. Little steps.
 

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I've been waiting on some exhaust pipes, so I worked on the coolant pipes today. I hadn't decided whether to keep the "quick disconnect" couplers on the ends of the coolant pipes or not. But last night, I tried to shove the old hoses into them, they didn't go easy, and I decided they were too much of a pain.

So I got a large tubing cutter from Lowe's, cut off those connectors, and made a dimpling tool from an electrical connection crimper (as I saw on a YouTube video). You can see one of the old couplers in the first picture. As for the dimpling tool, it was a $12 crimper from Lowe's, from which I cut off the ends of the jaws. I just repeatedly pushed the bump into the pipes, all the way around. (FYI - I looked at five different tools before I found one that had the two sides aligned perfectly.)

View attachment 108657 View attachment 108665 View attachment 108673

So now I can order the coolant pipes and hoses to go from the existing ones to the engine. Little steps.
That is brilliant! I wish I would have seen that 6 mo ago
 

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I'm thinking about doing this swap as well since I picked up a salvage 08 2.7L Cayman. I also had another idea, anyone know if the Audi 3.0T engine will bolt up to the 987.1 6-speed? I know the engine management is made by Siemens instead of Bosch and it has direct injection, but considering it's wiring and programing I think I could figure it out because I am an Engineer.
 

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Discussion Starter #138
I'm thinking about doing this swap as well since I picked up a salvage 08 2.7L Cayman. I also had another idea, anyone know if the Audi 3.0T engine will bolt up to the 987.1 6-speed? I know the engine management is made by Siemens instead of Bosch and it has direct injection, but considering it's wiring and programing I think I could figure it out because I am an Engineer.
If you do the swap we'll need to compare notes on the electronics. I believe that will be the biggest challenge.

I can't say much about the bellhousing pattern for the Audi V6, but the 987.1 6-speed fits almost perfectly to the 2002 Audi V8. I know the V8 pattern changed at least once, but I don't know the history. Someone in the Audi community should know, like on Audizine.

I also found someone doing a 2.7T in a Boxster:

(Porsche Boxster S 986 - Audi 2.7 Bi-Turbo engine swap)

Not much help on the bellhousing issue, but I'll bet his swap would have a lot of commonality with yours on other issues.
 

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This is an incredible swap and thanks for documenting and sharing it. I'm about two years away from trying this, and will most likely follow in your footsteps. Not sure if you're aware of these guys and I'm not affiliated with them, but MRS-electronics may be a resource for CAN bus integrating when you get to that point. They are the ones who helped flying miata put an LS based motor into the new ND chassis. They are working on brz/frs LS integration but their facebook says they are not limited to these motors and platforms.
 

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Discussion Starter #140
This is an incredible swap and thanks for documenting and sharing it. I'm about two years away from trying this, and will most likely follow in your footsteps. Not sure if you're aware of these guys and I'm not affiliated with them, but MRS-electronics may be a resource for CAN bus integrating when you get to that point. They are the ones who helped flying miata put an LS based motor into the new ND chassis. They are working on brz/frs LS integration but their facebook says they are not limited to these motors and platforms.
Thanks. I'm really enjoying the project, although summer activities have crowded it out a bit. I'll keep MRS in mind as a resource. I have some research to do about electronics before choosing a direction.
 
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