Magnusson S-Ported Supercharger for 95SC - please reply asap!

cc95sc

Registered User
Hello, I'm the second owner of a 95 5-speed SC with approximately 130,000 kms (approx 81,000 miles). I am replacing my supercharger with a Magnuson Products remanufactured Eaton supercharger, S-Ported 3.16" Pulley, and the installation is in two days.

I have been reading the forums and I need clarification on if I should also be doing modifications (e.g. exhaust) to my SC to prevent the head gaskets from blowing because there was talk in the forums that "...there is no place for the air to go as a result of the different oversize pulley"... etc. I am wondering if these comments relate ONLY to the situation where an SC owner replaces the pulley only and NOT the entire s-ported supercharger (i.e., my situation)..

My intention at this time is to keep the rest of my car stock, and I just ordered the s-ported for extra power, but if I now have to do other modifications (to prevent future problems) I just want to know that. If I do, then I don't want to drive my car yet after the installation.....

Am I safe simply having the remanufactured supercharger put in, and not having to worry about any other modifications??

Thanks in advance for your help and any quick replies would be appreciated..

Cory

PS - I'm really impressed with the website!
 
Well....

I suggest that if you have the stock pulley on there.....no problem.....an early style pulley (the 94-95 blowers used a LARGER pulley to spin the blower slower), is no problem. If you go with a 5% or 10% blower pulley, you need exhaust.

The size you are saying is a stock 89-93 pulley. Should be no problem. Although, I suggest to gain performance, go with a aftermarket exhaust (at least Cat-back), to alleviate the back-pressure in the system.

BTW...Nice car....I have a 95 5-speed and it's a rare car. Only 574 made....Makes it the second rariest T-bird around since 1955!!!!


Don
 
Thanks for your amazingly quick reply... and thanks for your comment about the car... I've had it for almost six years and am really proud of it!

I suggest that if you have the stock pulley on there.....no problem.....an early style pulley (the 94-95 blowers used a LARGER pulley to spin the blower slower), is no problem. If you go with a 5% or 10% blower pulley, you need exhaust.

I'm confused about the pulleys... for my 95 model car, the stock pulley would be on there, but would my remanufactured supercharger come with a replacement pulley say 5% or 10%? I'm not sure if when someone comments on a 5% or 10% pulley if that's something separate from the supercharger or not.

Also, at this time, I do not want to do any further modifications, I'm only concerned about if I'm going to screw up my car by adding the s-ported supercharger!

The size you are saying is a stock 89-93 pulley.

I do not understand this comment above because if my car is a 1995 why would it have an older style pulley, unless the SC had the same stock pulley from 1989 to 1995...

Anyway, thanks again for your help..

Cory
 
A couple more questions for clarification...

Regarding the 3.16" pulley that comes with my new remanufactured supercharger, are you saying that that's the size of the pulley in the 89 to 93 models?

OR, is the 3.16" pulley the same thing as a 5% or 10% blower pulley?

Cory
 
The 95 pulley is 3.25". The 89-93 pulley is 3.15". A 5% pulley is 2.95" and a 10% pulley is 2.85". By the math your 3.15" pulley is about 3% OD.

Your S-Port supercharger with the 3.15" pulley on it will provide plenty of boost for your car, more than likely it will peg the boost gauge.

The stories you hear about exhaust and headgaskets are a misconception. The headgaskets in all SC's are to varying degrees, defective and or likely to blow at some point. While higher boost levels will put additional stress on the headgaskets it will not cause headgasket failure. It may only bring on the inevitable a little sooner. If you are really concerned about boost and your headgaskets then your {edit} right foot is going to be the determining factor. ;)

Less lead foot, less boost. :D
 
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A 3.16" pulley will be just fine for your app. A 5% is something like 2.9?" or 3.0?" A 10% is about 2.85". Your head gaskets will survive (depending on the mileage of the car) and (depending on how heavy your foot is). Regardless of any of these factors an SC headgasket will eventually fail. It is a fact of life. If your car has somewhat low mileage and you do not abuse it (TOO MUCH) they should last over 100k. It is all pretty much a crap shoot after that.
 
Smaller pullies spin the SC faster.

Sizes are approximately:
94-95 3.275"
89-93 3.135"
5%OD 2.935"
10%OD 2.850"


A 89 pully on a 95 blower is about a 5% overdrive.

To be honest, I would have to recommend a dyno run with a wide band oxygen sensor after the bolt on of the new blower. The point being that in general, the blower change with the smaller pully shouldn't pose a problem. The adaptive system in the EEC-IV should be able to adjust without an issue to deal with the increased air flow. The stock exhaust is restrictive, but if the air fuel mixture stays within tollerance it simply shouldn't cause a head gasket failure.

Factory head gaskets on the 3.8 generally will fail regardless of what you do outside of replacing them. (you may want to see if yours was already replaced under warranty)

Post your dyno chart and let some people in the know evaluate it. If all is fine then you don't need to worry. But my guess is you may be running a touch lean, even before swapping the blower. Something that could be improved quite a bit with a custom chip. A custom chip could also add a level of protection into the system as well.
 
Thanks...

My head gaskets were replaced under warranty in 2000 before the five years were up... does this mean that I don't have to worry about the head gaskets anymore... i.e., any factory installed deficiency would have been rectified when the Ford dealership redid the heads..?

Cory
 
:p

Having the head gaskets replaced was a good thing, but the deficiency remains. Seriously though, you have it as good as anyone. I run mine at 21psi without failure so far so I think you'll be fine. :)
 
It's a good and bad thing.....

The head-gaskets being replaced by the dealer is a good thing. It at-least gets the older gaskets out of there. The main question is: where the heads milled or decked (meaning checked for smoothness and straightness)? This is one of the main reasons that the gaskets blow on these. As Dave is aware of, the Ford tolerances are horrible!!!! The blocks were never milled correctly and the heads sometimes have major warpage.

The main thing is what you're willing to do. If you're going to race.....down the line....things will go...maybe years from now...maybe never.


I suggest installing the blower, replacing the exhaust at least cat-back and enjoy the car. It's a great car to drive and have fun with.


Before modding more, post your ideas here. Many will chime in with advice on what to do next.

Good luck and enjoy the car!!!!!!!
 
Just bolt it down and roll....it will be fine.

To get the most out of that S port supercharger, a Magnum Powers inlet plenum would be a good investment.

David
 
The main question is: were the heads milled or decked (meaning checked for smoothness and straightness)? This is one of the main reasons that the gaskets blow on these.

Regarding the above, I will check back through my records and/or contact the dealership to find out what was done.

I will report back after awhile once my supercharger is installed and I will keep in mind specific comments/suggestions/tips including:
-adding an aftermarket exhaust (e.g. Cat-back) to gain performance
-adding a custom chip
-investing in a Magnum Powers inlet plenum
-posting on the forum if/when/before I start doing other modifications
-dyno run
-etc…

Thanks for all of the comments and suggestions and if anybody wants to add or suggest anything else please feel free… I certainly feel more knowledgeable now and better in particular about the supercharger… and I’d just like to say that it’s sure great to find others that have the same appreciation for the SC/XR7’s as I do. They are truly unique and fun cars and as an SC driver for almost six years I really don’t want to drive anything else…
 
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cc95sc said:
The main question is: were the heads milled or decked (meaning checked for smoothness and straightness)? This is one of the main reasons that the gaskets blow on these.

The main reason HG's blow is because of heat and, in your case, it would be backpressure from lack of exhaust flow.
 
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