VW/Audi 07K (2.5L 20V I5) Swap Thread
#1591
Rennlist Member
I would agree for NA the stock 944 rad with stock 07k water pump should do the trick. Thanks for the tip on the golf rad, good option for simpler plumbing.
With three times the stock power I’m not sure how the 944 rads will cope. Heavy duty fan will help up to about 40mph, after that it’s all down to coolant flow rate and surface area and ambient temp. Where is the typical threshold for big power 951 or LS swapped cars with the stock rad?
Craig
With three times the stock power I’m not sure how the 944 rads will cope. Heavy duty fan will help up to about 40mph, after that it’s all down to coolant flow rate and surface area and ambient temp. Where is the typical threshold for big power 951 or LS swapped cars with the stock rad?
Craig
I have a radiator spreadsheet at work that I could use if you want me to plug in a particular radiator. Need core dimensions, number of cores, fin size and spacing, tube size and spacing, and altitude. I can just plug in 1000 ft for altitude, guessing that would cover most tracks in US.
#1592
#1594
Rennlist Member
We actually found a pretty good setup for Mikes car using formed hoses from Autozone. I believe we still have all the stickers on the hoses so we can share the part numbers to save you some time. Now I just have to remember to get those numbers next time I’m at PE!
#1595
Rennlist Member
Sort of... Two ports on the h-valve get connected to the heater core ports in the firewall, one gets connected to the smaller of the two large barbs on the rear coolant flange, and one goes to the bypass pipe coming out of the thermostat housing. We will document all this when we put my car together.
#1596
I’ve seen LS swap guys run with a new stock 951 rad with 350 to 400 whp on street and track. I don’t know anyone who has tried it with higher hp than that. They are good radiators, but the problem is the lower hose connection is on the wrong side.
I have a radiator spreadsheet at work that I could use if you want me to plug in a particular radiator. Need core dimensions, number of cores, fin size and spacing, tube size and spacing, and altitude. I can just plug in 1000 ft for altitude, guessing that would cover most tracks in US.
I have a radiator spreadsheet at work that I could use if you want me to plug in a particular radiator. Need core dimensions, number of cores, fin size and spacing, tube size and spacing, and altitude. I can just plug in 1000 ft for altitude, guessing that would cover most tracks in US.
Any idea how the coolant flow rate of a 951 compares to a 07k? If the 07k is considerably higher then we have a head start there.
#1597
That would be great!! I was not looking forward to forming my own hoses 😅. Did they all mock up nicely with no adapters?
#1598
Sort of... Two ports on the h-valve get connected to the heater core ports in the firewall, one gets connected to the smaller of the two large barbs on the rear coolant flange, and one goes to the bypass pipe coming out of the thermostat housing. We will document all this when we put my car together.
#1599
I have been running a Davies Craig electric water pump and controller on my 944 engine for a few years now. If possible I would like to keep that setup on the new engine as I have had zero issues with it.
From what I can see I will need to create a block off plate for where the water pump bolts up, remove the thermostat, and cap some ports on the thermostat housing and port on the rear of the engine to cut off the engine-only loop so that it will always flow through the radiator.
Does anyone see any issues with that? Removing that and the heater loops from the equation looks like it should simplify things quite a bit for me in terms of coolant piping. Another benefit is that with no power steering, AC, and water pump it looks like the only thing left that's belt driven is the alternator so hopefully it has a tiny bit less parasitic loss.
From what I can see I will need to create a block off plate for where the water pump bolts up, remove the thermostat, and cap some ports on the thermostat housing and port on the rear of the engine to cut off the engine-only loop so that it will always flow through the radiator.
Does anyone see any issues with that? Removing that and the heater loops from the equation looks like it should simplify things quite a bit for me in terms of coolant piping. Another benefit is that with no power steering, AC, and water pump it looks like the only thing left that's belt driven is the alternator so hopefully it has a tiny bit less parasitic loss.
#1600
I have been running a Davies Craig electric water pump and controller on my 944 engine for a few years now. If possible I would like to keep that setup on the new engine as I have had zero issues with it.
Another benefit is that with no power steering, AC, and water pump it looks like the only thing left that's belt driven is the alternator so hopefully it has a tiny bit less parasitic loss.
Another benefit is that with no power steering, AC, and water pump it looks like the only thing left that's belt driven is the alternator so hopefully it has a tiny bit less parasitic loss.
I've read some articles showing the load from the alternator compared to the power requirements for turning pulleys is negligible. Meaning, belt drive power loss is comparable to the power loss from the added load on the alternator. On that note, if an electric water pump works for you, by all means go for it. Sounds like you've got it figured out
#1601
I have been running a Davies Craig electric water pump and controller on my 944 engine for a few years now. If possible I would like to keep that setup on the new engine as I have had zero issues with it.
From what I can see I will need to create a block off plate for where the water pump bolts up, remove the thermostat, and cap some ports on the thermostat housing and port on the rear of the engine to cut off the engine-only loop so that it will always flow through the radiator.
Does anyone see any issues with that? Removing that and the heater loops from the equation looks like it should simplify things quite a bit for me in terms of coolant piping. Another benefit is that with no power steering, AC, and water pump it looks like the only thing left that's belt driven is the alternator so hopefully it has a tiny bit less parasitic loss.
From what I can see I will need to create a block off plate for where the water pump bolts up, remove the thermostat, and cap some ports on the thermostat housing and port on the rear of the engine to cut off the engine-only loop so that it will always flow through the radiator.
Does anyone see any issues with that? Removing that and the heater loops from the equation looks like it should simplify things quite a bit for me in terms of coolant piping. Another benefit is that with no power steering, AC, and water pump it looks like the only thing left that's belt driven is the alternator so hopefully it has a tiny bit less parasitic loss.
For no heater you probably can do away with the stat and just run the Davies Craig pump controller. If I went this route I was thinking the thermostat housing could be replaced with an adaptor and use an inline stat, like from a BMW 2002tii or Mustang. I want to keep some minimum level of flow so my heater works and keeps the turbo from becoming a hotspot.
#1602
Ya I originally did it for reliability on the 944 engine. I had my original pump seize up and luckily saw the car was overheating before the belt burned through on the pulley. I have driven it with the electric pump in weather ranging from 30*F at high altitude in Colorado, up to sitting in traffic in 115*F in Vegas and it has always handled it just fine. If I lived in a place that wasn't 70+ all the time I would probably get a size down from the pump I bought since it takes a while to get up to temp when it's cooler out.
I never expected to get much, if any, additional power from swapping to it but the simpler belt routing, coolant line routing, and low rpm flow make it nice to have. One of the best features is that the controller keeps the pump and fan running for a few minutes when you shut the car down to prevent heat soak which is nice after running it really hard.
I never expected to get much, if any, additional power from swapping to it but the simpler belt routing, coolant line routing, and low rpm flow make it nice to have. One of the best features is that the controller keeps the pump and fan running for a few minutes when you shut the car down to prevent heat soak which is nice after running it really hard.
#1604
I have the aluminum EWP115. It looks like on their site that it is the recommended size for a 2.5L so maybe I was wrong about going a size smaller if you live in a cooler climate.
I do have an old model of controller and I think the new ones have much better control over the pump. My controller is basically an on/off switch and pulses until the engine is warm and then runs continuously. It looks like the new models have variable speed control and better temperature management so the warm up times I'm seeing in cold weather are probably less of an issue.
I do have an old model of controller and I think the new ones have much better control over the pump. My controller is basically an on/off switch and pulses until the engine is warm and then runs continuously. It looks like the new models have variable speed control and better temperature management so the warm up times I'm seeing in cold weather are probably less of an issue.
#1605
Rainman
Rennlist Member
Rennlist Member
did you maintain the stock 944 water pump casting when fitting the EWP? do you have a thermostat? remember that the stock 944 pump has a built-in bypass circuit (from the head back to the impeller) that closes off as the thermostat opens. if that's running wide open it might be why your car takes so long to warm up.