bastarddsm
20+ Year Contributor
- 5,620
- 1,457
- Aug 26, 2003
-
Mendota,
Illinois
So, I have a second 4bar map on the way as well as a 7blade hx35 to replace my current 8 blade. I also have a twinscroll manifold, as well as a open manifold. I also have a 12cm and 20cm divided housing. When I come home for thanksgiving break, I'm planing on doing the mother of all spool, flow, drive pressure tests.
Any way today I was bored so I plumed a boost gauge into one half of the t/s setup, the results were exactly as I suspected. Right now, the car has a 8 blade 56mm Wh1c on it, along with a 12cm t/s housing and a true t/s manifold. The runner lengths are not equal, but I doubt that effects it a whole lot. The car is 8.5:1 compression, 2.0l, has delta 272's straight up, 2gmaf, and an old school tube plenum smim. Boost is set at 25psi. I started watching the gauge at 5000rpm, and made a 3rd gear pull to 8500. As it sits the car should run hi 11's at 122mph.
Time for results:
At 5000rpm and 25psi, I saw 30psi drive
At 8000rpm and 25psi, I saw 50+psi drive. It was off the scale of the gauge, and almost into the vacuum scale. Extrapolating it out, I figure it was right around 50.
So we start at a 1.2:1 drive to intake pressure ratio, and end up at a 2:1 ratio, that is far less than optimal. Also, the drive is higher than the boost throughout the pull.
I'm going to try and make a spacer plate, and effectively "open T3" my set up and take some measurements. I might also swap on the 20cm housing and check that out as well.
So, I sourced a open T3 flange, and put that in to open it up. Ends up with almost the same drive pressure at full boost. But up until full boost, the drive stays much lower than the boost. So maybe the open T3 setup actually flows more? Maybe its drive stays lower because its laggier? I think that if the open t3 flowed better it would show up at much higher boost, maybe not even until you were in an unwastegated situation.
Any way today I was bored so I plumed a boost gauge into one half of the t/s setup, the results were exactly as I suspected. Right now, the car has a 8 blade 56mm Wh1c on it, along with a 12cm t/s housing and a true t/s manifold. The runner lengths are not equal, but I doubt that effects it a whole lot. The car is 8.5:1 compression, 2.0l, has delta 272's straight up, 2gmaf, and an old school tube plenum smim. Boost is set at 25psi. I started watching the gauge at 5000rpm, and made a 3rd gear pull to 8500. As it sits the car should run hi 11's at 122mph.
Time for results:
At 5000rpm and 25psi, I saw 30psi drive
At 8000rpm and 25psi, I saw 50+psi drive. It was off the scale of the gauge, and almost into the vacuum scale. Extrapolating it out, I figure it was right around 50.
So we start at a 1.2:1 drive to intake pressure ratio, and end up at a 2:1 ratio, that is far less than optimal. Also, the drive is higher than the boost throughout the pull.
I'm going to try and make a spacer plate, and effectively "open T3" my set up and take some measurements. I might also swap on the 20cm housing and check that out as well.
So, I sourced a open T3 flange, and put that in to open it up. Ends up with almost the same drive pressure at full boost. But up until full boost, the drive stays much lower than the boost. So maybe the open T3 setup actually flows more? Maybe its drive stays lower because its laggier? I think that if the open t3 flowed better it would show up at much higher boost, maybe not even until you were in an unwastegated situation.
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