VW/Audi 07K (2.5L 20V I5) Swap Thread
#2431
I picked up a Turbo S and accompanying engine last week. After the second sheared bolt on my way to rebuilding the block i decided to hell with it and reached out to Mike to get in on their kit and then ordered a motor off ebay. Super excited to go down this path! I know my way around the 944 but have never taken on a swap of any kind. I'm also without certain luxuries such as a welding setup. Quick questions for the group:
- Is the spreadsheet on boost brothers comprehensive at this point, or are there other things that need to be picked up?
- For a naturally aspirated build, how are people running the exhaust? I have a custom welded 3'' exhaust from the previous turbo motor that I'd like to reuse. But, as mentioned above I don't weld. In a year or two, i'd like to go down the turbo path.
- Has anyone megasquirted? I know it's an option, and I have one, but it's not something I have messed with before.
- I have both a PS rack and a true manual rack/intermediate shaft. My preference is to run the manual rack. I know at least one or two people have done this in here - but as a first timer swapping, would you recommend sticking with the power rack?
- This isn't a day 1 requirement, but I live in TX and really want to have AC. Is a standalone electric unit the preferred option?
#2432
Rennlist Member
I picked up a Turbo S and accompanying engine last week. After the second sheared bolt on my way to rebuilding the block i decided to hell with it and reached out to Mike to get in on their kit and then ordered a motor off ebay. Super excited to go down this path! I know my way around the 944 but have never taken on a swap of any kind. I'm also without certain luxuries such as a welding setup. Quick questions for the group:
- Is the spreadsheet on boost brothers comprehensive at this point, or are there other things that need to be picked up?
- For a naturally aspirated build, how are people running the exhaust? I have a custom welded 3'' exhaust from the previous turbo motor that I'd like to reuse. But, as mentioned above I don't weld. In a year or two, i'd like to go down the turbo path.
- Has anyone megasquirted? I know it's an option, and I have one, but it's not something I have messed with before.
- I have both a PS rack and a true manual rack/intermediate shaft. My preference is to run the manual rack. I know at least one or two people have done this in here - but as a first timer swapping, would you recommend sticking with the power rack?
- This isn't a day 1 requirement, but I live in TX and really want to have AC. Is a standalone electric unit the preferred option?
2. You can run the stock 07K header but the outlet will have to be modified. The SPA turbo manifold can be used NA with the wastegate port blocked. Either way will require welding a custom exhaust/down pipe.
3. Not sure if anyone has done it yet but could be used. If it doesn't support the 4 tooth(2 big 2 small) cam trigger then you will have to run strictly off the crank trigger(60-2) or modify the cam trigger wheel if you want sequential injection and ignition.
4. Nothing wrong with the manual rack but there is a caveat. In factory form the 07K has a dual belt setup with the alternator/water pump belt driven off the A/C compressor pulley. For this swap the A/C compressor is replaced with a VW/Audi 1.8T power steering pump with a custom pulley and bracket for two reasons, 1. most 07K cars had electric power steering and 2. the A/C compressor doesn't fit. If you don't run power steering then you will have to come up with your own pulley solution. I think someone on here took an A/C compressor and removed the back part to retain just the pulley, not sure how it worked out.
5. Running a belt driven compressor would require a custom bracket and belt setup on the exhaust side of the engine. If you eventually go turbo you would have to get real creative with the turbo location and exhaust. Easiest solution is an electric A/C compressor. I will be moving the battery to the rear and mounting one in the battery tray. See my thread here: https://rennlist.com/forums/924-931-...l#post17101465
@hinton Hey Mike, any update on the documentation you guys were working on? I was thinking about starting a wiki or knowledge base website to consolidate all the swap information. Nothing wrong with Rennlist, Facebook, or other forums for communication but they aren't really ideal for go-to information. I am thinking like an 07K Clark's Garage.
Last edited by Sixline; 09-23-2021 at 10:58 PM.
#2434
1. It is not, it hasn't been updated in a while. It is a good base but I think most people are just figuring stuff out as they go since there is different ways to tackle things.
2. You can run the stock 07K header but the outlet will have to be modified. The SPA turbo manifold can be used NA with the wastegate port blocked. Either way will require welding a custom exhaust/down pipe.
3. Not sure if anyone has done it yet but could be used. If it doesn't support the 4 tooth(2 big 2 small) cam trigger then you will have to run strictly off the crank trigger(60-2) or modify the cam trigger wheel if you want sequential injection and ignition.
4. Nothing wrong with the manual rack but there is a caveat. In factory form the 07K has a dual belt setup with the alternator/water pump belt driven off the A/C compressor pulley. For this swap the A/C compressor is replaced with a VW/Audi 1.8T power steering pump with a custom pulley and bracket for two reasons, 1. most 07K cars had electric power steering and 2. the A/C compressor doesn't fit. If you don't run power steering then you will have to come up with your own pulley solution. I think someone on here took an A/C compressor and removed the back part to retain just the pulley, not sure how it worked out.
5. Running a belt driven compressor would require a custom bracket and belt setup on the exhaust side of the engine. If you eventually go turbo you would have to get real creative with the turbo location and exhaust. Easiest solution is an electric A/C compressor. I will be moving the battery to the rear and mounting one in the battery tray. See my thread here: https://rennlist.com/forums/924-931-...l#post17101465
@hinton Hey Mike, any update on the documentation you guys were working on? I was thinking about starting a wiki or knowledge base website to consolidate all the swap information. Nothing wrong with Rennlist, Facebook, or other forums for communication but they aren't really ideal for go-to information. I am thinking like an 07K Clark's Garage.
2. You can run the stock 07K header but the outlet will have to be modified. The SPA turbo manifold can be used NA with the wastegate port blocked. Either way will require welding a custom exhaust/down pipe.
3. Not sure if anyone has done it yet but could be used. If it doesn't support the 4 tooth(2 big 2 small) cam trigger then you will have to run strictly off the crank trigger(60-2) or modify the cam trigger wheel if you want sequential injection and ignition.
4. Nothing wrong with the manual rack but there is a caveat. In factory form the 07K has a dual belt setup with the alternator/water pump belt driven off the A/C compressor pulley. For this swap the A/C compressor is replaced with a VW/Audi 1.8T power steering pump with a custom pulley and bracket for two reasons, 1. most 07K cars had electric power steering and 2. the A/C compressor doesn't fit. If you don't run power steering then you will have to come up with your own pulley solution. I think someone on here took an A/C compressor and removed the back part to retain just the pulley, not sure how it worked out.
5. Running a belt driven compressor would require a custom bracket and belt setup on the exhaust side of the engine. If you eventually go turbo you would have to get real creative with the turbo location and exhaust. Easiest solution is an electric A/C compressor. I will be moving the battery to the rear and mounting one in the battery tray. See my thread here: https://rennlist.com/forums/924-931-...l#post17101465
@hinton Hey Mike, any update on the documentation you guys were working on? I was thinking about starting a wiki or knowledge base website to consolidate all the swap information. Nothing wrong with Rennlist, Facebook, or other forums for communication but they aren't really ideal for go-to information. I am thinking like an 07K Clark's Garage.
#2435
@hinton Hey Mike, any update on the documentation you guys were working on? I was thinking about starting a wiki or knowledge base website to consolidate all the swap information. Nothing wrong with Rennlist, Facebook, or other forums for communication but they aren't really ideal for go-to information. I am thinking like an 07K Clark's Garage.
#2436
Rennlist Member
I'll reach out to you privately and maybe we can get something going.
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HelloGoodLuck (10-20-2021)
#2437
Let me know if you'd like to collaborate on documentation! I'm finally making progress on the kit installation so I'm going through all the pages. I've started to document the swap on GitHub using markdown format. This is nice for a few reasons:
- It's in the cloud, available to all & free
- Anyone can suggest edits via GitHub
- Anyone can "clone" this repository which will copy everything over to their account so they can modify it as needed
- Markdown format supports version control and has a lot of support.
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HelloGoodLuck (10-27-2021)
#2438
Let me know if you'd like to collaborate on documentation! I'm finally making progress on the kit installation so I'm going through all the pages. I've started to document the swap on GitHub using markdown format. This is nice for a few reasons:
- It's in the cloud, available to all & free
- Anyone can suggest edits via GitHub
- Anyone can "clone" this repository which will copy everything over to their account so they can modify it as needed
- Markdown format supports version control and has a lot of support.
#2439
Sounds good! I'll break out the 07K swap content to it's own file so people won't need to dig through my race car build stuff. I will work on that this weekend.
#2440
Here is the new github 07K swap link. I stripped out non-swap material to keep is clearer for folks. The table of contents at the top has a drop down for all the anchors of the file.
If the group really wanted I could look into making a website but I think a markdown file is the simplest.
Just for reference we plan on getting the engine in the car near thanksgiving so I'll update the .md file when I have more content.
If the group really wanted I could look into making a website but I think a markdown file is the simplest.
Just for reference we plan on getting the engine in the car near thanksgiving so I'll update the .md file when I have more content.
#2441
Happy Thanksgiving y'all!
Question: Where are folks mounting the map sensor? I originally was planning on using one of the npt ports on the intake manifold and an adapter but I thought I'd ask around.
Question: Where are folks mounting the map sensor? I originally was planning on using one of the npt ports on the intake manifold and an adapter but I thought I'd ask around.
#2442
Burning Brakes
I know this sounds like an idiotic question after over seven years into this thread, but could someone sum up in a sentence or two the benefit of going this route over, say, turbocharging a 3.0 liter (I have a 968)? I love the uniqueness of this swap, the fact that the block is somehow shorter than the stock engine, pushing more of the weight rearward, and I've read through the nicely summarized differences between the 07K and the Porsche engine(s) at the beginning this thread, and most of the differences, other than maybe the availability of the standalone ECU, are fairly subtle, although taken in their entirety, I suppose they add up to some moderately significant advantages. The unique sound of a 5-cylinder certainly amps up the cool factor, and getting rid of the wretched balance shaft belt assembly is a major blessing. But as far as the big stuff, is there really a major advantage to the 07K swap? By "big stuff", I mean things like:
- Can the 07K deliver higher power than a turbo 3.0 liter, more reliably?
- Is the longevity of the 07K inherently superior to a 3.0 liter (mine's a track car)?
- Other than the lack of the need to do belt replacements (no small thing!), is there less maintenance on an 07K?
Thanks; as you can see, I'm on the fence about this, but I have contacted Boost Brothers Garage about their kit, and if I decide to go this route, I'm looking at doing it sometime in 2022. As technology marches on, I feel like I'm bringing a bread knife to a gun fight at the track when lining up alongside modern hardware, and having some more power to go along with the massively extensive suspension mods I've done to my car would go a long way toward levelling the playing field, and I'm intrigued with the 07K approach. Thanks.
- Can the 07K deliver higher power than a turbo 3.0 liter, more reliably?
- Is the longevity of the 07K inherently superior to a 3.0 liter (mine's a track car)?
- Other than the lack of the need to do belt replacements (no small thing!), is there less maintenance on an 07K?
Thanks; as you can see, I'm on the fence about this, but I have contacted Boost Brothers Garage about their kit, and if I decide to go this route, I'm looking at doing it sometime in 2022. As technology marches on, I feel like I'm bringing a bread knife to a gun fight at the track when lining up alongside modern hardware, and having some more power to go along with the massively extensive suspension mods I've done to my car would go a long way toward levelling the playing field, and I'm intrigued with the 07K approach. Thanks.
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Droops83 (12-15-2021)
#2443
Rennlist Member
To me it boils down to availability and accordingly the price of the engine your modifying. The difference is roughly a magnitude of 10 going from an 07K to the 3.0L 4cly. Porsche motor.
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Droops83 (12-15-2021)
#2445
Burning Brakes
The other huge advantage I can see for the 07K swap is that the swap would potentially require a tiny fraction of the down time of, say, turbocharging a 3.0. I could buy an engine and send it to a shop to get rebuilt and turbocharged, buy the conversion kit and the attendant "extra" parts, then send both, along with the car, to a mechanic to do the swap. According the Boost Brothers, it is now possible to do the swap as a "turn key" operation (not by me, but by someone who does this sort of thing for a living). Conversely, turbocharging a 3.0 is a custom operation, often taking years. Although I suppose buying a 2.5l 951 engine and rebuilding it would be another option, but the availability is probably very limited.
As far as cost, I don't see a huge difference between the two approaches. Rebuilding and turbocharging an 07K to hit my target 400+ hp I'm sure would cost in the neighborhood of $15K, the swap kit and other parts runs about $9K, and I would estimate about $2K to do the swap. I could recoup probably $3K from selling my 3.0l, bringing the net total to about $23K, which is probably in the same ballpark as turbocharging a 3.0l. Please check my numbers, as they're nothing but SWAGs.
As far as cost, I don't see a huge difference between the two approaches. Rebuilding and turbocharging an 07K to hit my target 400+ hp I'm sure would cost in the neighborhood of $15K, the swap kit and other parts runs about $9K, and I would estimate about $2K to do the swap. I could recoup probably $3K from selling my 3.0l, bringing the net total to about $23K, which is probably in the same ballpark as turbocharging a 3.0l. Please check my numbers, as they're nothing but SWAGs.