quote Originally posted by White 84 SE: Hey can anyone help with figuring the displacement and compression rate? I dont know how to do that at all. Each chamber is 1" at TDC and 1/4 of a 4"crescent shaped chamber.... It must be possible. Perhaps I will just have to build it and then shoot so many cc's of water to find the displacement? Would that even work? After that the compression will go from 1" to very nearly nothing, say .005....

I wouldn't recomend it... water is non-compressable, might damage something in your process there... If I were any good at math I'd offer to help with that... but, I graduated from high-school, I don't have to do math anymore :P

Thanks bro,

yea maybe the no math approach is good enough. I will just float some water in there after. It will be aluminum...no water damage....or oil I guess doesnt matter

quote Originally posted by White 84 SE: Hey can anyone help with figuring the displacement and compression rate? I dont know how to do that at all. Each chamber is 1" at TDC and 1/4 of a 4"crescent shaped chamber.... It must be possible. Perhaps I will just have to build it and then shoot so many cc's of water to find the displacement? Would that even work? After that the compression will go from 1" to very nearly nothing, say .005....

send me a well dimensioned picture and I can work that out for you....

I think I figured it out.....4"x5" cylinder with a 3"x5" one inside will have 62.84 ci - 35.35 ci to equal 27.5 ci x .01638706 = .45L phew....

so each rotation will dispace .45L actually less since there are the vanes....

now to figure the dukes requirements for air....dont know but there is 2 filled pistons per revolution if there there is 2 revs per power cycle per piston, since there is 4 pistons.

4" pistons with a 3" stroke? Ill have to look it up.. if so than the Duke needs .6179L per stroke

So a pulley on the supercharger will have to turn the SC at 1.37 times engine rev to function and up from there to acheive positive induction?

Sounds right but I cant know for sure since I am just having a go at this for the first time.

Maybe one of you dragsters have a line in on this?

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84 2.5L Holley TBI Manual Trans White

Displacement will depend on port size and location, as well as the size and offset of the vanes from the central axis. I wouldn't be afraid to use water to CC it, nothing will be hurt if you just use your hands. There won't be any force keeping the vanes against the wall, you could use very light springs for this.

Using your drawing to scale, I calculated a 2D area for a just-closed port (as is the case in your drawing) to be 1.59in^2. If all of this is scavenged, then you will be displacing ~32ci per charger rev. If you relocated the intake port, however, you could obtain a just-closed port area well past 2in^2. You should probably also relocate the exhaust port. I would say that your vanes are pretty grossly oversized. 1/4" thickness would be more than enough, which also gives you the option of a larger vane count, and again, would increase displacement and effeciency.

[This message has been edited by FastIndyFiero (edited 02-15-2009).]

Of course!!! We gotta measure the closed port areas!!!! I was actually close though huh? Thanks dude!!
Yea I am thinking to lower the intake port for more efficiency. yea those vanes are huge.... The idea behind that is for the rollers to have a larger area and lower the likeliness of scoring the chamber walls. I think it may be just as well to have 1/4" vanes and easier to manufacture. And I am figuring if the intake were lowered the pressure would go up. If I can make a SC that can work right at engine RPM I think it may be about as responsive as is possible seeing as there are 4 vanes to match the cylinders of the Duke. I had a crazy idea about the spring thing. How about using air pressure perhaps from within the SC? huh huh...woah to me thats like way cool as it could be adjusted via dial....! eh forget that!! Light springs would be fine if a channel were made for them in the vanes. Less stuff to go bad.

had a go at melting the aluminum last night. My foundry formed a little crack and I invisioned hot metal falling out and exploding on the cold garage floor so I shut her down. Will try again with another container tomorrow with luck.

[This message has been edited by White 84 SE (edited 02-16-2009).]

quote Originally posted by Four_hundred_86: Just for you when I finish my engine swap I'll rip apart my duke and give you pictures of my head just for you sir

Thanks for the offer but it won't be necessary. I have several dukes in the shop in various states of rebuilding and I have one complete SD4 I am rebuilding after windowing the block.

I'm just here offering my expertise and experience. Perhaps it would help if I posted some pics. I'll get some this weekend when I have a little free time.

Wow, I forgot about this thread... I see you found the backyard metal casting site as interesting as I did... He makes you feel like you can build anything, and I love that feeling!
Just wanted to drop by and provide a little inspiration for you... This is certainly no supercharger, but it is a vision I built from scratch, it came out exactly as I saw it in my head, and works flawlessly (I just tested it tonight):



Yes... It's a floor jack powered engine hoist. The jack is removable to use as a regular jack as well.
Moral of the story: Your ability is only limited by what you are unwilling to learn.

Now, give us some more updates!

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Journal of a concept: http://southeastfieros.com >>> Build Thread >>> Parts thread (for project funding)

bump...
nice floor/engine hoist ya got there...
this thread seems to be great for some guys wanting an actual supercharger for their iron duke.
granted there might be some engine flyaparts due to re-engineered home brew dukes.
i hope it works out good for you.
im planning on using your supercharger ideas in creating my own v6 supercharger....giving you the credit
for the unit of course

That's cool Black. I really think the Vane type supercharger with roller pins will prove to work out well. I am having much trouble with the "pattern". I have a friend who makes patterns for machines and will call him up asap. Mostly, having trouble getting true bores. Also, Ive realized that a blow in SC needs to be down wind of the heated air tubing. Routing issues that can be solved. Also found that the performance camshaft I am putting in may produce what is called overlap. A supercharger should have a no overlap cam.
By the way, for all you Dukers out there. have you checked the rear brakes for sticking. They ought to be as free wheeling as the fronts. If not that'll slow you down! I just replaced mine because of a flood my SE was in and now she really is nimble. Dont worry, I know it's been forever but I will get that prototype going some time in May I think. And I wont be testing it till I get my current project done. Right now I am preparing for an overhaul which I want to get done before June. Sorry, but I gotta do that first.

[This message has been edited by White 84 SE (edited 04-19-2009).]

Hey hey, how's it going, any updates to be had in this tale of adventure?

Errr... I will post a pick of my latest design. I went and overhauled my duke and it has alot more power. Not sure I want to bother with this project anymore....

There is alot of free metal to take off to let the Duke breath better. Still, a SC will stuff the air in.... I recommend porting the head and putting in a new fuel pump and youll get it roaring good man. Check out "Starting a Duke Overhaul with..."
I figure for $100 for the above projects....

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84 2.5L Holley TBI Manual Trans White

[This message has been edited by White 84 SE (edited 07-29-2009).]

quote Originally posted by KurtAKX: It'd be much better to cast a manifold that will accomodate an Eaton M62 (either the Bonneville style or the new Cobalt SS style). You could actually sell something like that in quantity. From a casting standpoint, it should be at the same level of difficulty you're going to face with this project. Machining for that is going to be quite the undertaking and without any real engineering work behind it, you don't know much about durability/longevity or efficiency.

Exactly. I'd love to see one of those.

Facinating and interesting project and I'm following this thread with great interest. How much horsepower do you plan on making with this engine? The rods, block and pistons of the Duke have strength limitations so how do you plan to work around this issue?

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Hey there Dennis,

Welp, I'll tell you, I've rebuilt my Duke with a performance cam, porting from head to toe, new fuel pump good for 15 psi and my Duke already rocks. It's gotta be getting 120-130 HP. It feels like it does anyway. I had a 119 hp Toyota which weighed 1999 which is very near the same as my SE and the Duke/4.10 has way better pick up now than that one did. I have to be careful to set the rings in the next 100 or so miles and not go around lugging like I have.

Any way, not sure I need more HP anymore. I was thinking of dropping the project. Or atleast changing to a Turbo concept to boost the highway speeds only for passing. I have to check out my Fiero a little more. If I get a chirp in all 4 on a dry hot road with the way things are I dont want any bit more HP maybe change my focus to MPG instead.

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84 2.5L Holley TBI Manual Trans White

quote Originally posted by White 84 SE: So you think a Eaton 62 would be the best choice. That would give a lot of room for Duke enhancements.

Bump from the dead.

There's a supercharger kit for 2.5L Duke powered Jeeps. Not priced for Fiero owners http://www.avengersuperchargers.com/

quote Originally posted by fierosound: There's a supercharger kit for 2.5L Duke powered Jeeps. Not priced for Fiero owners http://www.avengersuperchargers.com/

It's probably for the AMC 153 2.5 and not the GM 151 2.5.

I wouldnt pay $200 to make a duke into a 181crank hp motor.... People would honestly pay $4k to do that?

i mean dang, you could swap in any other motor and make that sort of power, and it would probably be easier.

If I were you, I'd definitely start with a junkyard M62, which you can probably get for really cheap and save all the crazy machining and fabrication for the intake manifold modifications and belt routing to make it work.

At one point, I was working on pumping up the Iron Duke as well: https://www.fiero.nl/forum/Forum2/HTML/093668.html

I found that the rumors of thick cast 2.5 blocks in the S-10 and S-15 to be false, as far as I can tell. The couple I dug through and the one I brought home looked exactly like my 86' Fiero block. I had a 91' DIS 2.5 that appeared to have a halfway acceptable block (nothing remotely like the brawny SD4 block), head with D exhaust ports, and better intake manifold (separated coolant passage from the last intake runner).

They want 300 at my local junkyard. Besides I think they are too big for a Duke no? Besides I want some sort of excuse to set up my sand casting foundry thingy.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

[This message has been edited by White 84 SE (edited 09-21-2009).]

Here's an idea:

Make a casting to replace the intake manifold with your supercharger.

Design it to accept M62 guts.

The air outlet bolts directly to the head.

The air inlet has a flange to bolt on a draw-thru TBI or carb.

quote Originally posted by White 84 SE: They want 300 at my local junkyard. Besides I think they are too big for a Duke no? Besides I want some sort of excuse to set up my sand casting foundry thingy.

The M62 as found in 91-95 L67 cars such as Park Ave Ultra and Olds LSS is not too big; its actually an ideal size. Eaton recommends it for 2.5-4.0 liter engines.

If the are trying to get $300, they're insane. They're on CL and ebay cheaper.

You can still sand-cast a sweet new manifold to mount the M62.

quote Originally posted by pmbrunelle: Here's an idea: Make a casting to replace the intake manifold with your supercharger. Design it to accept M62 guts. The air outlet bolts directly to the head. The air inlet has a flange to bolt on a draw-thru TBI or carb.

Cool, I've thought of that earlier in the thread but thanks for the reminder. That would certainly be good for size and would be right there with the pulley. One would loose the fuel warming function of the manifold.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by White 84 SE: Hey there. For those still interested in this project what would be wrong with this simple design I came up with? It would fit fine in place of the TBI. I dont know how to figure out how deep to make it yet though....... Anyone know how to calculate air volume required and depth of the bores? I figure 5" would be about right but....it would essentially be a wild guess although beefier than ones I've seen for old VWs and smaller than for those for 3 litre engines. Perhaps just right for the Duke.

To calculate the displacement of the blower, measure the area between the lobe and the casing. Then, multiply by the depth.

You're probably better off going oversize, and rotating the lobes slowly.

The flow rate of the blower, which is dependent on the pulley ratio, and the displacement, will more or less determine the amount of boost...

For example, if the blower displaces 5.0L / 2 crank revolutions, then you'll have the equivalent of 2 atm absolute manifold pressure.

quote Originally posted by KurtAKX: The M62 as found in 91-95 L67 cars such as Park Ave Ultra and Olds LSS is not too big; its actually an ideal size. Eaton recommends it for 2.5-4.0 liter engines. If the are trying to get $300, they're insane. They're on CL and ebay cheaper. You can still sand-cast a sweet new manifold to mount the M62.

cool thanks for the info.

I have a whole Eaton M62 somewhere around here (I think up north). Next time I go up there (likely Saturday), I'll grab it.

It may be easier for me to just send it to you, so you have the physical part to see where potential interference is.

Gimme a couple days to go digging.

quote Originally posted by KurtAKX: I have a whole Eaton M62 somewhere around here (I think up north). Next time I go up there (likely Saturday), I'll grab it. It may be easier for me to just send it to you, so you have the physical part to see where potential interference is. Gimme a couple days to go digging.

I thought of something...you can just photocopy it from the bottom and I can get to work on that then. Easy and cheap!

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by White 84 SE: I thought of something...you can just photocopy it from the bottom and I can get to work on that then. Easy and cheap!

I might just try that at the FedEx-Kinkos when they're not looking.

Also, this is what you should be able to find them for, price-wise.
http://southbend.craigslist.../pts/1343327255.html

quote Originally posted by KurtAKX: I might just try that at the FedEx-Kinkos when they're not looking. Also, this is what you should be able to find them for, price-wise. http://southbend.craigslist.../pts/1343327255.html

Woah on the price, on Ebay I just about purchased one for a Mitsubishi for $70 that needed recon. Anyway, sent you a PM with address info for you to send that copy. Or send the whole darn thing cause itll need an adapter for the TBI fit unless it will be jutting out the hood.


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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

[This message has been edited by White 84 SE (edited 09-23-2009).]

quote Originally posted by White 84 SE: Hey there. For those still interested in this project what would be wrong with this simple design I came up with? It would fit fine in place of the TBI. I dont know how to figure out how deep to make it yet though....... Anyone know how to calculate air volume required and depth of the bores? I figure 5" would be about right but....it would essentially be a wild guess although beefier than ones I've seen for old VWs and smaller than for those for 3 litre engines. Perhaps just right for the Duke.

The only problem per say is tolerances. If you want it to work, your tolerances are probably going to be tighter than you can manufacture too.

quote Originally posted by 86fierofun: The only problem per say is tolerances. If you want it to work, your tolerances are probably going to be tighter than you can manufacture too.

Hmph the mortal doubteth my skills....
Actually I have more faith in the inherent efficiency of a sliding vane setup. I will further develop the concept. Actually I have the design I just gotta figure scale and start the fabrication.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

quote Originally posted by White 84 SE: By the way I got the injector and tried it out.........It is different but it's subtle. But for what it's worth it works and it cheap.. Cant tell if performance was improved....although it wasnt hurt. It seems to have a lower tone..It seems quieter...maybe the 93 is a better design than the 84?...

Is it the same flow rate? Assuming it's a higher flow rate injector, the mixture will be enriched by a ratio depending on the old vs new injector flow rate. Except for closed-loop cruising where the computer may compensate.

The computer expects a certain injector flow rate, you can't just slap on an injector and expect it to run well without proper programming.

Don't be surprised if your car became a gas sponge.

As for the blower, aside from casting, you'll also have to learn how to use a mill, lathe, drill press...

quote Originally posted by White 84 SE: Hmph the mortal doubteth my skills.... Actually I have more faith in the inherent efficiency of a sliding vane setup. I will further develop the concept. Actually I have the design I just gotta figure scale and start the fabrication.

It's not so much your skills, just your wallet. What the machines cost to get that kind of accuracy is more than 10000 fieros

quote Originally posted by pmbrunelle: Is it the same flow rate? Assuming it's a higher flow rate injector, the mixture will be enriched by a ratio depending on the old vs new injector flow rate. Except for closed-loop cruising where the computer may compensate. The computer expects a certain injector flow rate, you can't just slap on an injector and expect it to run well without proper programming. Don't be surprised if your car became a gas sponge. As for the blower, aside from casting, you'll also have to learn how to use a mill, lathe, drill press...

Actually, it seems BETTER for gas mileage.....? Strange I know. I DID just slap on an injector and it DOES run well. Strange....I know! It's only been 2 days so I can not make claims but well, dang it, it works fine....might even be an improvement but I gotta wait for the #s. I dont know what changes they made from 84 to 92 but perhaps they tweaked the thing.