420a supercharger

[DrewmHolland]

Recently I picked up an old Eaton m90 supercharger off of a Grand Prix and I would like to slap this bad boy on my 420a… it’s been built and is ready for boost but I need help with the fab work for this so if anyone has done this before please let me know how and I don’t care if my hood doesn’t fit anymore.

 

[97egl]

Those superchargers max out around 14 psi. You can spin them faster to get maybe 17 or 18 but they are so inefficient at that point that the air is so hot all you do is hurt performance.

It would be a very unique and cool build so if you're going for the unique factor go for it but you will be looking at way more work and money for less horsepower than a turbo. Especially if you are having someone else handle the fab work as aluminum welding is not cheap

 

[DrewmHolland]

They flow enough to feed boost to a 3.8l v6 all day so it works for me, all I need is like 8-10psi

 

[BLACK'98DSM]

The M90 is not a small supercharger. The only way you'll be able to use a hood is if you cut a huge rectangle out of it. But the biggest issue is hooking that thing up to our tiny intake manifold. You'd have to cut the top off of the intake manifold and make a massively oversized flange to bolt it up. Having it equally distribute boost to all 4 cylinders will be impossible. To make a usable cut you'd be cutting into the throttle body plenum.

 

[BLACK'98DSM]

The only option I see is making an upper manifold/plenum from scratch. Modifying the stock manifold is not plausible. Also you need to measure how far the pulley sits from the center of the crossflow area. I bet it isn't even close to lining up with our crank pulley. Installing the belt is your next huge hurdle. That supercharger is meant to sit in a V engine valley. Not riding above an inline 4.

 

[DrewmHolland]

so far what I'm seeing just setting the blower on top of my motor is that yes, its huge. but if i were to mostly cut off the top of my intake and weld an adapter plate then I could make it work. the serpentine belt could be run off of the power steering pulley but ill probably need an extra idler pulley so that it doesn't scrape my motor mount. I know aluminum welding isn't cheap since I had to have a bellhousing welded but it may be worth it

 

[DrewmHolland]

if this doesn't look like it'll work then Im gonna try to put it on my lt1 vette
its been done before and made 480whp on 8psi, though the blower was at its max. Ill probably target like 5psi

 

[DrewmHolland]

Update: I recently found a guy who put an m90 on a 420a, the way he did it was by making a plate that was held on by the header bolts and extends over the headers so the blower pulley is right over the power steering pump pulley. its simple but genius!