VW/Audi 07K (2.5L 20V I5) Swap Thread
12-16-2021, 05:22 PM
#2446
Rennlist Member
I'd imagine your numbers are reasonably close although I'd be surprised if you could get a mechanic to do the swap for $2k. I know that labour is cheap in the US but that seems a little too optimistic. Do those numbers include the new ECU, harnesses and tuning? Assuming you're still running the 968 gearbox? What driveshafts are you thinking of? I'd consider upgrading if you're running stock. Referring to the other option of a 2.5lt Porsche motor...you could achieve 400hp comfortably enough with one of those.
12-17-2021, 04:03 PM
#2447
Burning Brakes
You're probably right about $2K being a little light for a mechanic to do the swap. The $9K estimate for the kit parts includes a standalone ECU, per Boost Brothers Garage's site. I am running a freshly rebuilt 968 gearbox, and I have a brand new torque tube with Black Sea's Super Bearings, so I'm definitely good to go in that department.
I suppose a 2.5K turbo would be a cheaper option, but I wouldn't imagine those engines being very easy to come by, especially since 951's are increasing in value, although I haven't ckecked availability.
Here's my motivation for this project: I just completed my first seasom competing in an arrive-and-drive series driving rented Radical SR1's at Atlanta Motorsports Park. The capability of these cars, understandably, vastly outpaces that of my 968 track car (and 99% of anything I've ever seen at any track, let alone driven), so, to better approximate the experience of the SR1, at least in the power-to-weight department, I'd need about 435 hp in my 968. I realize there's nothng I could do to the 968 to match the Radical's prodigous, neck-straining 1.9g cornering capability, but it would be nice to at least match the Radical's acceleration in my "practice car." So, would the 07K be expected to be more reliable, and have greater longevity, at this power level in a track application, or is it pretty much a toss-up between the 07K and a 435 hp 2.5l?
I suppose a 2.5K turbo would be a cheaper option, but I wouldn't imagine those engines being very easy to come by, especially since 951's are increasing in value, although I haven't ckecked availability.
Here's my motivation for this project: I just completed my first seasom competing in an arrive-and-drive series driving rented Radical SR1's at Atlanta Motorsports Park. The capability of these cars, understandably, vastly outpaces that of my 968 track car (and 99% of anything I've ever seen at any track, let alone driven), so, to better approximate the experience of the SR1, at least in the power-to-weight department, I'd need about 435 hp in my 968. I realize there's nothng I could do to the 968 to match the Radical's prodigous, neck-straining 1.9g cornering capability, but it would be nice to at least match the Radical's acceleration in my "practice car." So, would the 07K be expected to be more reliable, and have greater longevity, at this power level in a track application, or is it pretty much a toss-up between the 07K and a 435 hp 2.5l?
Last edited by Cloud9...68; 12-17-2021 at 04:05 PM.
12-20-2021, 02:16 PM
#2448
You're probably right about $2K being a little light for a mechanic to do the swap. The $9K estimate for the kit parts includes a standalone ECU, per Boost Brothers Garage's site. I am running a freshly rebuilt 968 gearbox, and I have a brand new torque tube with Black Sea's Super Bearings, so I'm definitely good to go in that department.
I suppose a 2.5K turbo would be a cheaper option, but I wouldn't imagine those engines being very easy to come by, especially since 951's are increasing in value, although I haven't ckecked availability.
Here's my motivation for this project: I just completed my first seasom competing in an arrive-and-drive series driving rented Radical SR1's at Atlanta Motorsports Park. The capability of these cars, understandably, vastly outpaces that of my 968 track car (and 99% of anything I've ever seen at any track, let alone driven), so, to better approximate the experience of the SR1, at least in the power-to-weight department, I'd need about 435 hp in my 968. I realize there's nothng I could do to the 968 to match the Radical's prodigous, neck-straining 1.9g cornering capability, but it would be nice to at least match the Radical's acceleration in my "practice car." So, would the 07K be expected to be more reliable, and have greater longevity, at this power level in a track application, or is it pretty much a toss-up between the 07K and a 435 hp 2.5l?
I suppose a 2.5K turbo would be a cheaper option, but I wouldn't imagine those engines being very easy to come by, especially since 951's are increasing in value, although I haven't ckecked availability.
Here's my motivation for this project: I just completed my first seasom competing in an arrive-and-drive series driving rented Radical SR1's at Atlanta Motorsports Park. The capability of these cars, understandably, vastly outpaces that of my 968 track car (and 99% of anything I've ever seen at any track, let alone driven), so, to better approximate the experience of the SR1, at least in the power-to-weight department, I'd need about 435 hp in my 968. I realize there's nothng I could do to the 968 to match the Radical's prodigous, neck-straining 1.9g cornering capability, but it would be nice to at least match the Radical's acceleration in my "practice car." So, would the 07K be expected to be more reliable, and have greater longevity, at this power level in a track application, or is it pretty much a toss-up between the 07K and a 435 hp 2.5l?
Last edited by Pdh; 12-20-2021 at 02:20 PM.
12-20-2021, 06:12 PM
#2449
On a side note if anyone needs a lamborghini header for their swap I have one for sale as I decided to go turbo instead of n/a. You can contact me here on rennlist or email me at pdh2409@gmail.com
12-20-2021, 10:54 PM
#2450
You're probably right about $2K being a little light for a mechanic to do the swap. The $9K estimate for the kit parts includes a standalone ECU, per Boost Brothers Garage's site. I am running a freshly rebuilt 968 gearbox, and I have a brand new torque tube with Black Sea's Super Bearings, so I'm definitely good to go in that department.
I suppose a 2.5K turbo would be a cheaper option, but I wouldn't imagine those engines being very easy to come by, especially since 951's are increasing in value, although I haven't ckecked availability.
Here's my motivation for this project: I just completed my first seasom competing in an arrive-and-drive series driving rented Radical SR1's at Atlanta Motorsports Park. The capability of these cars, understandably, vastly outpaces that of my 968 track car (and 99% of anything I've ever seen at any track, let alone driven), so, to better approximate the experience of the SR1, at least in the power-to-weight department, I'd need about 435 hp in my 968. I realize there's nothng I could do to the 968 to match the Radical's prodigous, neck-straining 1.9g cornering capability, but it would be nice to at least match the Radical's acceleration in my "practice car." So, would the 07K be expected to be more reliable, and have greater longevity, at this power level in a track application, or is it pretty much a toss-up between the 07K and a 435 hp 2.5l?
I suppose a 2.5K turbo would be a cheaper option, but I wouldn't imagine those engines being very easy to come by, especially since 951's are increasing in value, although I haven't ckecked availability.
Here's my motivation for this project: I just completed my first seasom competing in an arrive-and-drive series driving rented Radical SR1's at Atlanta Motorsports Park. The capability of these cars, understandably, vastly outpaces that of my 968 track car (and 99% of anything I've ever seen at any track, let alone driven), so, to better approximate the experience of the SR1, at least in the power-to-weight department, I'd need about 435 hp in my 968. I realize there's nothng I could do to the 968 to match the Radical's prodigous, neck-straining 1.9g cornering capability, but it would be nice to at least match the Radical's acceleration in my "practice car." So, would the 07K be expected to be more reliable, and have greater longevity, at this power level in a track application, or is it pretty much a toss-up between the 07K and a 435 hp 2.5l?
IMO there is no comparison between the stock engine and an 07K. If you blow a stock internal 07K you can throw another one in for $300. You can do a budget build (rods and pistons, stock bore) and make 600 whp which will require lots of tire and aero to properly use. A decently built 2.5, 2.85, 3L etc is in the thousands. The initial cost is tough for some to swallow but it really future proofs your build.
12-21-2021, 01:31 PM
#2451
Burning Brakes
Great inputs - thanks. I don't want or need more than 450 hp at the crank, but I'm struggling with the very low cost estimates for getting to this power level reliably in any engine, including an 07K. The turbo kit, machine work, head rebuild, new pistons, rods, and a forged crank (although there seems to be debate as to whether this is necessary, but I think I would get one for the peace of mind), tuning work, etc. would seem to easily push the cost to at least $15K, but I hope I'm wrong. I can see getting this level of power out of an 07K being cheaper than from a 2.5l stock engine because of the much higher initial cost of the latter, but then you have the cost of the swap kit with the 07K.
There's no denying the coolness factor, and the unique sound of the 5-cylinder swap, but is there anything in the 07K's design that makes it inherently more robust/reliable than a 2.5l 951 engine at the same 400-450 hp power level, given that the two engines have the same displacement? It was probably stated somewhere in this loooooong thread, but does the Porsche engine require higher levels of boost to achieve the same power compared to the 07K? I agree that 18 psi sounds like a very reasonable target to strike a good balance between power and longevity.
There's no denying the coolness factor, and the unique sound of the 5-cylinder swap, but is there anything in the 07K's design that makes it inherently more robust/reliable than a 2.5l 951 engine at the same 400-450 hp power level, given that the two engines have the same displacement? It was probably stated somewhere in this loooooong thread, but does the Porsche engine require higher levels of boost to achieve the same power compared to the 07K? I agree that 18 psi sounds like a very reasonable target to strike a good balance between power and longevity.
12-21-2021, 07:18 PM
#2452
Great inputs - thanks. I don't want or need more than 450 hp at the crank, but I'm struggling with the very low cost estimates for getting to this power level reliably in any engine, including an 07K. The turbo kit, machine work, head rebuild, new pistons, rods, and a forged crank (although there seems to be debate as to whether this is necessary, but I think I would get one for the peace of mind), tuning work, etc. would seem to easily push the cost to at least $15K, but I hope I'm wrong. I can see getting this level of power out of an 07K being cheaper than from a 2.5l stock engine because of the much higher initial cost of the latter, but then you have the cost of the swap kit with the 07K.
There's no denying the coolness factor, and the unique sound of the 5-cylinder swap, but is there anything in the 07K's design that makes it inherently more robust/reliable than a 2.5l 951 engine at the same 400-450 hp power level, given that the two engines have the same displacement? It was probably stated somewhere in this loooooong thread, but does the Porsche engine require higher levels of boost to achieve the same power compared to the 07K? I agree that 18 psi sounds like a very reasonable target to strike a good balance between power and longevity.
There's no denying the coolness factor, and the unique sound of the 5-cylinder swap, but is there anything in the 07K's design that makes it inherently more robust/reliable than a 2.5l 951 engine at the same 400-450 hp power level, given that the two engines have the same displacement? It was probably stated somewhere in this loooooong thread, but does the Porsche engine require higher levels of boost to achieve the same power compared to the 07K? I agree that 18 psi sounds like a very reasonable target to strike a good balance between power and longevity.
The 07K needs nothing in order to meet your goals. The ECU also comes with the tune required to make that power.
I’m obviously a bit biased but I 100% believe everything I’m writing. I’ll let others chime in as well.
12-22-2021, 11:51 AM
#2453
Burning Brakes
Thanks again - you make a strong case for the 07K swap over a 2.5l. Are you of the opinion that a forged crank isn't needed at the 450 hp (~18 lb boost) level? And does anybody know about the expected power output at 18 lb of boost for the 2.5l vs. the 07K, all else being equal? Does the 07K's greater head flow rate and greater tuning capability give it the edge over the 2.5l at the same boost level?
12-22-2021, 12:56 PM
#2454
Thanks again - you make a strong case for the 07K swap over a 2.5l. Are you of the opinion that a forged crank isn't needed at the 450 hp (~18 lb boost) level? And does anybody know about the expected power output at 18 lb of boost for the 2.5l vs. the 07K, all else being equal? Does the 07K's greater head flow rate and greater tuning capability give it the edge over the 2.5l at the same boost level?
The 07K will definitely make more power than the 2.5 at the same boost levels. This is due to higher flowing heads and the ability to spin more RPM.
12-22-2021, 04:18 PM
#2455
Burning Brakes
The factory cast crank is good to 600 tq so 450 hp is a piece of cake for it. The pistons are the real weak spot due to thin ring lands and small pistons pins. The aftermarket versions solve both problems.
The 07K will definitely make more power than the 2.5 at the same boost levels. This is due to higher flowing heads and the ability to spin more RPM.
The 07K will definitely make more power than the 2.5 at the same boost levels. This is due to higher flowing heads and the ability to spin more RPM.
12-23-2021, 01:57 PM
#2456
also a question for hinton, does the swap kit use factory length belts? I looked up the part number on the parts sheet but its no longer posted.
12-23-2021, 02:04 PM
#2457
Front Belt = 5x985
Rear Belt = 5x1090
12-23-2021, 05:03 PM
#2458
Burning Brakes
Thanks
Mike G.
12-23-2021, 05:06 PM
#2459
I don’t have any experience with the built engine yet but if you stay under 800hp (where the block begins to move around) you should have a very reliable setup. My engine is being built with the TTRS crank so it can really give it the beans but a stock crank with forged rods and pistons should be pretty bulletproof at 500 wheel.