If rebuilding supercharger, 94/95 blower still better?

Inigma

Registered User
Hi all. I'm thinking about sourcing another blower to have rebuilt while I continue to drive on mine. If rebuilding a 89/93 blower can I have the rotors coated for better efficiency or are the clearances different in the 89/93 blower vs the 94/95? Is the only main differences the rotor coating and the rectangular inlet or are there other important differences?

1990 Automatic
K&N panel filter
Cats replaced with the magma flow cats with the aggressive turn before the cat removed and resonator deleted. Probably gonna go back in to have the remaining exhaust reworked.

Thanks in advance for any help.
 
well the 94/95 is wayy more efficient, it spins slower and made the same boost and is better at keeping heat down.
id forshur look for a 94/95 blower tahts ready to install rather than rebuilding the old style, you can make some decent bucks on ebay off that old blower though. people use them for projects all the time.
 
Definitely scoop up a late model blower if you can, much better if you're looking to make more power. However it's not just that simple. You'll need the upgrades to go with it. Plenum, injectors, maf, tune, etc. Difference between the early and late is coated rotors and larger inlet. Worth 20 hp if I remember correctly.

Like a dummy I upgraded the blower and plenum on my 90 with no other upgrades, drove it hard, and ended up hurting the bottom end.

Not a problem if you baby it, but be careful of detonation if you drive it hard.

Just my experience, best luck,

JJ
 
If I understand it correctly though, doesn't it spin slower and keep the heat down mostly due to the coated rotors with the coating creating a tighter fit or tolerance and also working to prevent heat making it more efficient?

Does it really make more boost? I thought they put a larger pulley on it to have it make less boost because it wasnt heating the air as much as the previous model so it was moving denser air.

Buying a later model supercharger that bolts right on sounds awesome, but at 20+years old and who knows how many miles, it probably needs rebuilt or it could need to come back off again soon. Does the coating tend to wear off like an old Teflon coated pot that has been cooked in one too many times?
 
Thanks for the tip. I was planning on picking up the following

Matching plenum
Throttle body
Injectors
Higher flow fuel pump
Maybe newer style tank if I find one locally

Is the computer not able to adjust enough for the newer blower thus needing a dyno tune? And the maf was different? Dang. This sure snowballs fast. I need to compile an accurate list of what really needs or what really should be done to do it right. I don't wanna run it too lean by not planning it out properly.
 
I think you're pretty close, please just continue to check the forums for info. There's more to my story, I have some other bolt ons that likely contributed, but the blower itself was the biggest change I did.

The late model blower is more efficient, at lower blower rpm it moves more air at a lower temp, which means more fuel needs to added (again, it would only be an issue closer to full throttle because this is when the demand for air is the greatest.) The stock computer and injectors are only capable of adding xxx amount of fuel, which is designed to be mixed with xxx amount of air. Increase only the amount of air in the cylinders and the fuel ratio will become lean, which is very bad.

This is part of why the late models make more power, 30lb injectors from 89-93. 36lb injectors, more efficient blower, and bigger maf on 94/95.

There's a lot of other people on the forum that have much more knowledge than me, they'll chime in soon, this is a fun topic.

Tons of good info on this can be found in the search function.
JJ
 
The 94/5 blower is more efficient as stated. There is a lot more to the case design than just square vs. oval. I would not waste any time on an early model blower. The bigger pulley was there for a variety of possible reasons, but most people run the early model pulley on the late model blower for an extra pound of boost. It's like free power.

You can't just swap maf/injectors from a late model SC and think they will work on yours. The EEC is programmed differently to accommodate for those items, your early model EEC won't know what to do with them. You need a chip to tell the EEC what you have done.

If you put the 94/5 blower on the car with the stock 94/5 pulley then you can run the car as is with no changes. However, it should be pointed out that NO performance modifications whatsoever should be completed without first installing a HP fuel pump. I recommend the 255lph versions.
 
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