Turbine Inlet Pressure
#31
Machinists, engineers, and mechanics all have very different fields of expertise. You won't find me trying to tell a machinist about feed rates, cutting speeds, etc. And when you've had 3/4ths of the engines you develop professionally make the Ward's 10 Best, you can let me know. Until then, leave the engineering to the engineers.
You talking about the Borg EFR turbos? Very niece pieces. Have a friend who is an engineer working in them. Gets to use his car as a test mule for them sometimes.
#32
Burning Brakes
That reminds me of an old saying,
In theory, reality and theory are the same. In reality they're not.
No I wasn't talking about EFR turbos, although they seem to be on the leading edge of efficiency and performance. Funny you should mention them since I saw an 8374 with a twin scroll T4 housing on a 2.4 liter EVO time attack car that had higher boost for a given backpressure up to 20 psi. At 20psi it was 1:1, as boost went up the ratio became less favorable. That was an eye-opener.
I'd love to see someone install an EFR on a 951 but the amount of custom fab work would be extensive and the turbos are not cheap. Precision is also doing nice work with their new CEA Gen2 wheels. I don't have back pressure readings on them but it seems like every time we put a PTE CEA turbo on a car we have to go back and install a larger wastegate and open up the wastegate passages so we can lower the boost. We're getting to the point on certain cars where the wastegate passage is the primary exhaust path while the turbo gets a lesser percentage of exhaust flow.
Teaser pic;
http://www.hindawi.com/journals/ijrm/2012/589720/fig2/
Here's some light reading
http://www.hindawi.com/journals/ijrm/2012/589720/
In theory, reality and theory are the same. In reality they're not.
No I wasn't talking about EFR turbos, although they seem to be on the leading edge of efficiency and performance. Funny you should mention them since I saw an 8374 with a twin scroll T4 housing on a 2.4 liter EVO time attack car that had higher boost for a given backpressure up to 20 psi. At 20psi it was 1:1, as boost went up the ratio became less favorable. That was an eye-opener.
I'd love to see someone install an EFR on a 951 but the amount of custom fab work would be extensive and the turbos are not cheap. Precision is also doing nice work with their new CEA Gen2 wheels. I don't have back pressure readings on them but it seems like every time we put a PTE CEA turbo on a car we have to go back and install a larger wastegate and open up the wastegate passages so we can lower the boost. We're getting to the point on certain cars where the wastegate passage is the primary exhaust path while the turbo gets a lesser percentage of exhaust flow.
Teaser pic;
http://www.hindawi.com/journals/ijrm/2012/589720/fig2/
Here's some light reading
http://www.hindawi.com/journals/ijrm/2012/589720/
Last edited by Dave W.; 09-13-2014 at 02:39 PM. Reason: added links
#33
Three Wheelin'
My friend has an E34 M5 with fully built 3.6 engine and Borg Warner S480 turbo running at 1.6 bars of boost and having maximum of 1.3bars of TIP Full boost is at 4700 rpm all the way to 8400 rpm.
Standing mile speed is 331 kph and that is with full weight (1820 kg with driver).
I installed and tuned ECU on that car so I have 1st hand information.
Standing mile speed is 331 kph and that is with full weight (1820 kg with driver).
I installed and tuned ECU on that car so I have 1st hand information.
#34
Rennlist Member
At what RPM was the 1.3 bar TIP measurement taken?
We have to think about that for second and not just assume it was at max RPM.
#35
An English guy has done just that, all with twin scroll and twin wastegates, on what seems to be an otherwise stock '89. He hasn't posted much since the car has been running, probably been busy with the tune.
#36
Three Wheelin'
#37
Leak now fixed on TIP gauge line. TIP at 17 psi boost is now quick spike to 22 psi then drop to 20 psi. Duel port wastegate so 2 psi drop should be related to delay in opening I am sure. Close to 1:1 so pretty happy going by data on RL.
#39
Solid Lifter Cam
Web - 457/274 grind:
Intake lift - .495"
Intake duration - 246 degrees
Exhaust lift - .480"
Exhaust Duration - 234 degrees
Lobe center - 112 degree lobe center - 16 degrees overlap
super 75 with T4 hot housing and 3 inch down pipe either .58 or .68 A/R don't remember which one I went with. 2000FCeramic coated headers
Web - 457/274 grind:
Intake lift - .495"
Intake duration - 246 degrees
Exhaust lift - .480"
Exhaust Duration - 234 degrees
Lobe center - 112 degree lobe center - 16 degrees overlap
super 75 with T4 hot housing and 3 inch down pipe either .58 or .68 A/R don't remember which one I went with. 2000FCeramic coated headers
#40
Race Car
That makes much more sense, and is pretty impressive.
#41