Twin Turbo 928 fixed and back out there terrorizing the streets!
#1261
Nordschleife Master
Thread Starter
Test fitted intercoolers
The largest-that-will-ever-fit intercoolers are being test fitted:
This is a dual-pass cooler per side. Think of it as approximately the same volume and areas as the 944 and 968 Turbo intercooler, but on each side. Like with the 944 and 968 coolers, the core flows really well and the primary flow losses are in expectation coming from the end tanks.
The boost pipe will be run inside the wheelwell. You can see the red plug and where the boost pipe will have to connect.
The tire diameter expands a surprising amount at very high speeds. This clearance is important for that reason, and there's enough of it:
This is a dual-pass cooler per side. Think of it as approximately the same volume and areas as the 944 and 968 Turbo intercooler, but on each side. Like with the 944 and 968 coolers, the core flows really well and the primary flow losses are in expectation coming from the end tanks.
The boost pipe will be run inside the wheelwell. You can see the red plug and where the boost pipe will have to connect.
The tire diameter expands a surprising amount at very high speeds. This clearance is important for that reason, and there's enough of it:
Last edited by ptuomov; 07-09-2016 at 05:06 PM.
#1263
Nordschleife Master
Thread Starter
It's designed to have nothing between the intercooler core and the tire on the exit side. The inlet side to the core is sealed all the way to the bumper cover vent.
Last edited by ptuomov; 07-07-2016 at 12:35 PM.
#1264
Archive Gatekeeper
Rennlist Member
Rennlist Member
Chris, here are the front tires Tuomo's going to use, they provide a scavenging effect behind the intercoolers, improving flow and dropping intake temps.
#1265
Nordschleife Master
Thread Starter
Considered those tires for a while, but my calculations indicate that the front wheels will not touch the ground, ever, under boost. Short of an external motor powering the front wheels there will not be any spinning action and resulting low pressure field.
#1266
Addict
Rennlist Member
Rennlist Member
Join Date: Feb 2004
Location: Monterey Peninsula, CA
Posts: 2,374
Likes: 0
Received 16 Likes
on
12 Posts
Originally Posted by ptuomov
The largest-that-will-ever-fit intercoolers are being test fitted:
The boost pipe will be run inside the wheelwell. You can see the red plug and where the boost pipe will have to connect.
The tire diameter expands a surprising amount at very high speeds. This clearance is important for that reason, and there's enough of it:
The boost pipe will be run inside the wheelwell. You can see the red plug and where the boost pipe will have to connect.
The tire diameter expands a surprising amount at very high speeds. This clearance is important for that reason, and there's enough of it:
Will you be mounting a stone/pebble/debris mesh shield on the IC?
It looks awfully naked in that spot. My SC Range Rover has a similar mounting place for its AWIC radiator and it has a debris shield.
Then again you may have very clean roads compared to the ones I use.
#1267
Nordschleife Master
Thread Starter
Congratulations on the progress!
Will you be mounting a stone/pebble/debris mesh shield on the IC?
It looks awfully naked in that spot. My SC Range Rover has a similar mounting place for its AWIC radiator and it has a debris shield.
Then again you may have very clean roads compared to the ones I use.
Will you be mounting a stone/pebble/debris mesh shield on the IC?
It looks awfully naked in that spot. My SC Range Rover has a similar mounting place for its AWIC radiator and it has a debris shield.
Then again you may have very clean roads compared to the ones I use.
I was skeptical myself initially, but I drove the previous version with a similarly exposed core for a year and the passages stayed open. I think it's because the ducting to the bumper cover is sealed, it blows everything out of the core that might have the wrong idea of getting in there. There were insects on the front faces, but nothing in the air passages.
If you don't seal the inlet duct to the bumper cover, it might be a whole different thing.
Last edited by ptuomov; 07-06-2016 at 08:13 PM.
#1268
Rennlist Member
#1269
Rennlist Member
Will you be powder coating (or painting) the intercooler black? I'm sure you want as much heat exchange efficiency as possible (and the powder coat might act as an insulator), but that shiny aluminum just looks wrong!
#1270
Nordschleife Master
Thread Starter
The thin-wall stainless steel pipe that feeds the intercooler will be coated black. The boost pipes out of the intercooler will be painted silver, same as intake manifold.
#1271
Addict
Rennlist Member
Rennlist Member
Join Date: Feb 2004
Location: Monterey Peninsula, CA
Posts: 2,374
Likes: 0
Received 16 Likes
on
12 Posts
Originally Posted by ptuomov
It won't need one. It's a very sturdy unit and it gets enough air flow that it stays fully open.
I was skeptical myself initially, but I drove the previous version with a similarly exposed core for a year and the passages stayed open. I think it's because the ducting to the bumper cover is sealed, it blows everything out of the core that might have the wrong idea of getting in there. There were insects on the front faces, but nothing in the air passages.
If you don't seal the inlet duct to the bumper cover, it might be a whole different thing.
I was skeptical myself initially, but I drove the previous version with a similarly exposed core for a year and the passages stayed open. I think it's because the ducting to the bumper cover is sealed, it blows everything out of the core that might have the wrong idea of getting in there. There were insects on the front faces, but nothing in the air passages.
If you don't seal the inlet duct to the bumper cover, it might be a whole different thing.
#1273
Nordschleife Master
Thread Starter
And this is how the dots connect
Trading off the sharp turns, duct shape changes, cross sectional area changes, duct length, etc. lead John to pick this shape and path from the compressor to intercooler. The pressure loss will be very low and the small matter of being able run over bumps while turning the wheels is also covered.
That pipe may look small in the pictures, but it's a true 2.5" pipe the whole way. Two 2.5" diameter thin wall pipes can flow a stupid amounts of compressed air with minimal pressure loss.
Here's a comparison of the old 2.0" boost pipe with the new 2.5" boost pipe. Factoring in the wall thickness, it's almost 60% increase in flow area:
This shot shows the intercooler outlet pipe as well:
Clearance demonstration:
That pipe may look small in the pictures, but it's a true 2.5" pipe the whole way. Two 2.5" diameter thin wall pipes can flow a stupid amounts of compressed air with minimal pressure loss.
Here's a comparison of the old 2.0" boost pipe with the new 2.5" boost pipe. Factoring in the wall thickness, it's almost 60% increase in flow area:
This shot shows the intercooler outlet pipe as well:
Clearance demonstration:
Last edited by ptuomov; 07-09-2016 at 05:51 PM.
#1274
Nordschleife Master
Thread Starter
Intercooler pressure loss
This version will have pressure bungs in the 2.5" pipes that will allow us to measure the static pressure and then to compute the total pressure before and after the intercooler.
The other side, near perfect symmetry downstream of the compressor outlet turns:
Passenger side with the wheel on:
The other side, near perfect symmetry downstream of the compressor outlet turns:
Passenger side with the wheel on:
Last edited by ptuomov; 07-19-2016 at 09:04 AM.
#1275
Nordschleife Master
If you went with 2.5" ID racing springs on the front end you could run the pipe in behind the shock instead.....
I think there is enough room.
I will be doing this very thing but on the passenger side shortly. So it is interesting to see for sure.
I think there is enough room.
I will be doing this very thing but on the passenger side shortly. So it is interesting to see for sure.