Supercharging a 944 - Why so hard?
#181
When I looked at using a Eaton m62 or m90 I found I was going to have to cut the snout almost to the bearings just to have enough room to bring the inlet elbow around. Plus the throttle would need to be on the elbow and near the front. Creating a super long path which may hurt response. Now mounting the "to the side" and not directly to the intake would make plumbing a bit more complicated but allows an intercooler and the throttle response should be like factory.
this was how the thunderbirds were set up.
this was how the thunderbirds were set up.
#182
Yes I have seen it argued both ways on the endless "hot rodding" forums. I was hoping that I can use a bypass valve arrangement to get this to work with the TB after the SC. Could that work?
I do not plan to use the clutch. I will remove it and replace with a quick-change like pulley thingy.
Edit: After more research I will try and mount the TB before the SC.
I do not plan to use the clutch. I will remove it and replace with a quick-change like pulley thingy.
Edit: After more research I will try and mount the TB before the SC.
#183
i have VEMS ECU so i can use whatever injector i want.
i have a set of 55lb/hr and a set of 72lb/hr on the shelf. i'm sure there's a 3 or 3.5 bar FPR that will fit the NA rail, haven't looked too much at it since these injectors are more than big enough to work at stock 2.5 bar.
i have a set of 55lb/hr and a set of 72lb/hr on the shelf. i'm sure there's a 3 or 3.5 bar FPR that will fit the NA rail, haven't looked too much at it since these injectors are more than big enough to work at stock 2.5 bar.
#184
Second that, I'm using 2 Bosch style diverter valves for a vw/audi. Metal housing ones can come with different spring rates.
#185
RL Community Team
Rennlist Member
Rennlist Member
#186
Seems very competitive with centrifugals. I have seen Whipple W100AX (97 ci/rev) discounted to ~$2100. Par with Rotrex, cheaper than ProCharger. Smaller than a M90 (maybe a little longer 14.6" with shortest stock snout) . Seems like the ideal unit for a 2.5L. What's the downside other than cost?
#187
https://www.ebay.com/itm/BOSCH-02801...72.m2749.l2649
#189
Racer
Thread Starter
A basic question on SC ratings. Roots blowers are volumetric devices. An M62 gives about 62 CI of air per revolution. But is this rating based on the input air temperature or the outlet air temperature for the purpose of calculating the mass flow?
#190
Rainman
Rennlist Member
Rennlist Member
John, it moves 62 ci (volume) per revolution, period.
Mass flow will vary based on inlet temperature and outlet restriction.
62ci at 0*C is still 62ci at 100*C...
But those 62ci weigh less at 100*C.
I really don't think you need to waste time calculating that stuff - the SC will be pulling in ambient air from the air filter just like an NA car, so inlet temp should be the same.
The blower is going to move the air, no matter what - you need to focus on cooling the air down AFTER the SC.
Mass flow will vary based on inlet temperature and outlet restriction.
62ci at 0*C is still 62ci at 100*C...
But those 62ci weigh less at 100*C.
I really don't think you need to waste time calculating that stuff - the SC will be pulling in ambient air from the air filter just like an NA car, so inlet temp should be the same.
The blower is going to move the air, no matter what - you need to focus on cooling the air down AFTER the SC.
#191
Racer
Thread Starter
Ok, to make sure I understand... Assuming no inlet restriction I get 62CI of air at inlet density per revolution. Assuming no leaks we then will get that equivalent 62CI inlet conditions forced into the cylinders.
Then all intercooler does (on a positive displacement blower) is to reduce air intake temps to prevent detonation? In other words, hypothetically, if I am not detonating without an IC, then adding the IC has no other effect?
Then all intercooler does (on a positive displacement blower) is to reduce air intake temps to prevent detonation? In other words, hypothetically, if I am not detonating without an IC, then adding the IC has no other effect?
#192
Initial cut before figuring out how to better shape and cap the end.
The oem bracket for the alt and ac was completely removed and I reused the mounts replacing it with a steel tube frame to lower the alt and let the SC sit as low as possible.
Fitting with TB in front of SC. Eventually moved it back between the plenum and IC for other reasons.....i think both can work if the bypass flow is big enough.
About to cut out the NA nose to fit IC
The framing was way to narrow to fit the piping I wanted, so the radiator had to move down a bit.
Lowered radiator mount extension with aluminum bolted to welded extensions. Top angle bar to protect the radiator and stiffen the sub frame.
How it is now.
Another angle. double diverters...not recirculated.
Top view to see the orientation.
#193
Ok, to make sure I understand... Assuming no inlet restriction I get 62CI of air at inlet density per revolution. Assuming no leaks we then will get that equivalent 62CI inlet conditions forced into the cylinders.
Then all intercooler does (on a positive displacement blower) is to reduce air intake temps to prevent detonation? In other words, hypothetically, if I am not detonating without an IC, then adding the IC has no other effect?
Then all intercooler does (on a positive displacement blower) is to reduce air intake temps to prevent detonation? In other words, hypothetically, if I am not detonating without an IC, then adding the IC has no other effect?
#195