mdnt08

When I cut the m62 from the GM Cobalt to fit a 90 cast elbow on it, it was about 1 inch from the needle bearings. Given this is one of the longer SC, I'd say any other should fit unless we are trying to fit a m112 with a long pulley nose.

mdnt08

My TB is still in between the plenum and IC, the only draw back I found was the larger diverter valve needed when you are off-throttle and in gear at a high rpm. People said it would create more heat due to the SC....have not noticed it. I may move it to see, but it's doable without moving it for low boost set ups. The bypass is a must tho.....

mdnt08

I used a Bosch 3bar FPR for a turbo Saab, inexpensive and it bolts right on....looks identical...other than the part # and pressure.

mdnt08

Second that, I'm using 2 Bosch style diverter valves for a vw/audi. Metal housing ones can come with different spring rates.

Ish_944

Could you post a link to it?

Which fuel rail do you have? One of the 2 early styles?

mdnt08

That's why the GM LSJ m62 or 5th gen is not a bad one to use. It's a more efficient roots, kind of under the twin screw...but much less costly.

mdnt08

Uh...the one that the fuel line runs my the brake booster?

https://www.ebay.com/itm/BOSCH-02801...72.m2749.l2649

jderimig

Do you have a pic that shows the fit of the Cobalt M62 in your engine bay?

jderimig

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?

V2Rocket

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.

jderimig

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?

mdnt08

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.

mdnt08

Well in the end you should be able to produce more power by being able to run a higher ratio pulley set up (that will increase the air temp) and add back timing that will produce much more power......kind of a big difference.

V2Rocket

looks awesome!

mdnt08

Thanks, hoping this will help others to get motivated that when certain aspects are carefully understood..it can be a stable set-up.....take advantage of that VEMs so we can figure out how to best tune and mod the config.