So I made an impulse purchase at the junkyard today.
Its an M90 from a series 2 3800SC out of a 96 Riviera. The goal is to get this thing on my stock 2.8 for as little money as possible.
My plan so far: -Underdrive pulley for 7-8lbs boost -decap factory injectors -fuel pump upgrade -colder plugs -bigger exhaust, probably just a side dump -my own custom intake manifold adaptor -Custom tune, Ill be buying a chip burner and doing it myself. Going for longevity over raw performance.
I figure I should say the reason Im not just doing a 3800 seap is because I just cant stand the noise a 90* v6 makes... Plus no one has ever done this near as I can tell. Being different is cool.
Edit: I figure I should also say this is being done more for fun than to be a seriously powerful build. Plus supercharger whine mixed with 60* howl
[This message has been edited by Boot (edited 09-06-2016).]
You must have great fun at flea markets and garage sales.
Last time I went to one I walked away with a 1946 Evinrude zephyr 5hp 4 cylinder, for $30... cant help it when to comes to weird old motors. Its a problem lmao
You look like a senior member. Whats your opinion on this whole endeavour
You look like a senior member. Whats your opinion on this whole endeavour
I edited my previous post and added a link to a thread that might be helpful.
I suspect there's a good reason why this mod hasn't been attempted and/or succeeded with previously. I don't know anything about superchargers, but that thing looks massive sitting on top of a 2.8 engine. Any HP gains you make may be used up simply transporting that extra weight.
From what I gather, the 2.8 isn't super durable. I believe there were some improvements made with the '88 2.8, but if you have an earlier year you might end up greatly shortening its life span.
I'd like to see you succeed and pass on your knowledge, as I have a Formula that could use a few more HP at autocross. Just don't take any constructive criticism from the members here personally. Most of them are decent enough people who may only be trying to save you some grief.
[This message has been edited by Patrick (edited 09-07-2016).]
From what I gather, the 2.8 isn't super durable. I believe there were some improvements made with the '88 2.8, but if you have an earlier year you might end up greatly shortening it's life span.
Mines an '87, I think Ive heard of the improvements youre talking about. It was 87-88 iirc. Plus only got 76k on it, so its not toooo worn out.
And as for the supercharger lookin massive on top of it, well, that might be partly why Im doing it its so ridiculous looking. I love it
Thanks for the input, though. Ill have to go through that link when I get home from night school.
The 2.8L has been boosted many times before but mostly by turbo kits made by Miller Woods, Design One, John Ferris and others. It can take 7 psi without problems provided that the engine is in sound condition and tuned properly for boost. Sound condition means less than 50k miles on a well maintained engine. The 2.8L uses cast pistons that are not durable for boost so the amount of boost and the tune is critical. My first Fiero venture in mods was a 2.8L turbo with an auto and it ran well but it was not super fast. Faster than stock but nowhere near a 3800SC or V8. The disadvantage in the M62 supercharger is that it takes about 10 hp at WOT to drive it but if that is the way you want to boost then go for it. Also bear in mind that the stock Fiero #15 injectors can only support about 190HP, maybe 200 but that's pushing it. Good luck on the project.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, 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 "
The disadvantage in the M62 supercharger is that it takes about 10 hp at WOT to drive it but if that is the way you want to boost then go for it. Also bear in mind that the stock Fiero #15 injectors can only support about 190HP, maybe 200 but that's pushing it. Good luck on the project.
Its an m90, I believe. Series 2. There was a difference in the size of the rotors, it takes a little more power to turn but its way more efficient.
And as for the injectors, thats what decapping them is for. You grind off the pintle cap on each one, which increases the flow by about 100% but makes them not as precise because the only thing metering flow is the factory machining tolerances. Its an old import trick that a lot of the honda and nissan guys do. Its also free, which is why Im choosing to go that route
Are you expecting this to fit under the decklid, ore are you planning on compromising the structural integrity of the decklid and chopping a big hole to make it all fit?
Are you expecting this to fit under the decklid, ore are you planning on compromising the structural integrity of the decklid and chopping a big hole to make it all fit?
Theres no way in hell itll fit unless I can reroute the coolant hose coming out of the thermostat housing. So big gaping hole it'll be lol. But a big supercharger sticking out of your hood is cool in its own right imo
------------------ I have no idea what Im doing, but Im doing it.
The m90 isn't a good fit for the 2.8. I'd take it back and get an m62 from a Mercedes. A much smaller easier package to remote mount and a better efficiency range for the 2.8. Unless you are going to port the hell out of the heads and up the valve size, the VE is just not there for that big of a charger. This is my opinion, there are a few 60*v6 with M90s on them.
If you keep the M90, don't put it on top. Mount it on the side and intercool it. It will leave you with more options (read cheaper than the intercoolers you get that are already available mid intake mount water to air) and can easily be adapted to meth injection spray post SC which might be a good idea seeing as how the bay doesn't get much air flow for an intercooler. And no custom intake manifold. While you have it out I would suggest swapping the pistons to a lower CR and forged if you can find them. Whats a few hundred bucks for the piece of mind?. If you keep it under 5500 rpm the rods should survive so you want to just fight detonation. Swap the injectors.
Change to a 7730 or 85 year with a knock sensor. Don't use an FMU and get a wideband o2. This is all I can think of for now.
Not to be a nay-sayer, but if you sit down and make a list of all the work you have to do I think you will find what many of us here already discovered -- It is easier to find and install a stock 3.8 Super Charged Engine!
You will start with 240 horsepower and can easily upgrade from there.
Like others here, I did the supercharged, and then the turbo 2.8, 3.1, and 3.4. They performed, but no where near the power level and drivability of the 3.8SC.
Originally posted by Boot: Theres no way in hell itll fit unless I can reroute the coolant hose coming out of the thermostat housing. So big gaping hole it'll be lol. But a big supercharger sticking out of your hood is cool in its own right imo
Well the thermostat housing would really be the least of your concerns there. The M90 is really too wide to fit between the heads of the 60 degree engines.
Would be better to mount it off to the side I think, if possible, and build an output flange to route over to the stock intake and throttle body, as Slammed suggested. It will be much better than cutting the decklid, or trying to make an adapter from the middle intake to the blower.
If you cut through that part of the decklid, it will not be fun, as you're cutting through the major support structure of the decklid at that point.
Thoughts on using the Edelbrock 2.8 carb intake with an adapter for the SC?
I really wouldn't put a blower on the (~stock) 2.8 at all, unless the bypass is opened 90% of the time and it's only for show. More than likely the stress of an active blower will slowly result in the crank breaking off at the first counterweight.
A turbo would be so much easier and won't put as much stress on the bottom end. And with a properly sized and tuned turbo, the boost will come on low enough that the typical argument for a blower versus a turbo will be moot.
I really wouldn't put a blower on the (~stock) 2.8 at all, unless the bypass is opened 90% of the time and it's only for show. More than likely the stress of an active blower will slowly result in the crank breaking off at the first counterweight.
A turbo would be so much easier and won't put as much stress on the bottom end. And with a properly sized and tuned turbo, the boost will come on low enough that the typical argument for a blower versus a turbo will be moot.
Originally posted by 2.5: Turbo would be fun too. Easier too?
Much easier. The 2.8 was practically built to have a turbo from GM, but the turbo engine option got scrapped.
To mount say, a 90s Subaru 2.5 turbocharger in a V6 Fiero, all you have to do is make a custom Y-pipe, with an appropriate flange, and such, as the turbo has an internal wastegate. You can mount it in pretty much the perfect spot above the trans, and at the ~8 PSI peak you should have, you don't really need an intercooler, so intake piping changes are minimal. Can even use the stock filter housing, run it to the turbo inlet, and out from the turbo straight to the throttle body. Then just burn a MEMCAL with fixed timing/fuel tables, and you're pretty much set. I don't think you'd even need to change fuel injectors. Maybe switch to 93 instead of 87, but that's about it. A turbo blanket to shield the heat might be good. Getting the manifolds and Y-pipe TiN coated would be optimal too, but not absolutely necessary.
Much easier. The 2.8 was practically built to have a turbo from GM, but the turbo engine option got scrapped.
To mount say, a 90s Subaru 2.5 turbocharger in a V6 Fiero, all you have to do is make a custom Y-pipe, with an appropriate flange, and such, as the turbo has an internal wastegate. You can mount it in pretty much the perfect spot above the trans, and at the ~8 PSI peak you should have, you don't really need an intercooler, so intake piping changes are minimal. Can even use the stock filter housing, run it to the turbo inlet, and out from the turbo straight to the throttle body. Then just burn a MEMCAL with fixed timing/fuel tables, and you're pretty much set. I don't think you'd even need to change fuel injectors. Maybe switch to 93 instead of 87, but that's about it. A turbo blanket to shield the heat might be good. Getting the manifolds and Y-pipe TiN coated would be optimal too, but not absolutely necessary.
Don't want to hijack the thread, but are there pics of this done? Cool.
This Cobalt SS setup grafted to a modified upper fiero plenum appears to be the most practical approach although once upon a time there was a supercharger made to fit this motor if you can find one. http://www.ebay.com/itm/GM-...AOSwgZ1Xte9P&vxp=mtr
As has already been mentioned, the 2.8L pistons are definitely weak and not on par with those installed in the 3100-up series pistons, including those found in the 3.4L which where the same without a dish, they are much stronger. I've broken a ring land on a 2.8L piston but never on any of the later design pistons, chipped a few from a severe spark knock incident but no ring land damage.
Really the M62 they use on the SLK would be the easiest. Bracket, belt, charge pipe and throttle body adapter. No fussing with rusty exhaust pipes and cracked manifolds
M90 - M62 - M45
[This message has been edited by Slammed (edited 09-07-2016).]
I think I am going to mount it right on top of the motor. I like how it looks there, and itll be the least work. Trunklid be damned Maybe offset to one side if it'll help with the belt situation. The water pump pulley is in an awkward place. (I think it needs a new one, too. Electric water pump maybe?)
My original plan was to build right off of the lower intake manifold, but after checking it out that would be a royal pain if I want to keep my fuel injection. With the way the injectors stick out at an angle, between the intake ports, it would be a nightmare to weld and keep it all straight. So, I'll use the middle intake instead. My thought was that I can make two plates with the same dimensions, and match one to the ports on the middle manifold, and one to the bottom of the supercharger. Ill use thick plate so I can tap bolt holes in them. I have some 3/8 sitting around. Once Ive made these plates, Ill weld them together as the top and bottom of a box shape. The sides of the box will be the correct height to get the supercharger where I want it so it clears everything. Then, I can bolt this all together and voila, Ill have the meanest looking 2.8 in history
If anyone can think of a reason why this wont work right off the bat, please let me know before I do too much work
I don't think the box can be flat-bottomed; it need some relief in the center, otherwise it will hit the fuel-injection stuff. Might need some spacers.
You could go for a partial trunk; it could start from the rearmost edge of the deck lid vents. The trunk could be hinged from the rear edge of the decklid vents. The hinges could be welded to the real estate available on top of the shock towers.
Essentially, it would be like a Toyota MR2 missing its engine hood.
Vibration, warpage, sealing, heat, clearance, intercooling, and I'm sure there are more. On top will not be easier. I could side mount an m90 in a day. On top is a freaking project
As some one who has put a blower on a engine that dint come with one i say go for it you will have your challenges but it is fun over coming them and having something you figured out how to do you will have a great sense of pride when it is done and running i will be watching you and all your ideas on it
I don't think the box can be flat-bottomed; it need some relief in the center, otherwise it will hit the fuel-injection stuff. Might need some spacers.
You could go for a partial trunk; it could start from the rearmost edge of the deck lid vents. The trunk could be hinged from the rear edge of the decklid vents. The hinges could be welded to the real estate available on top of the shock towers.
Essentially, it would be like a Toyota MR2 missing its engine hood.
Youre right about that, I just went and peeked and it looks like itll need an inch or so of spacing to be safely out of the way of that stuff under there. Fuel injection? I have no idea lmao.
And that partial trunk is an awesome idea. I just may have to do that, because I use my trunk all the time.
As some one who has put a blower on a engine that dint come with one i say go for it you will have your challenges but it is fun over coming them and having something you figured out how to do you will have a great sense of pride when it is done and running i will be watching you and all your ideas on it
Right on! Doin stuff "right" the first time is no fun. I like to figure it out the hard way. Ill try to keep the thread updated so you have something to watch!
So, I just picked up a middle intake manifold off eBay for $15 When it gets here in a week I'll start mocking things up. I figure that between the spare manifold and my car, Ill be able to get all the measurements I need without dissassembling anything too much. Just gotta go to Oreilly's and get some gaskets too, so I can get the plates all laid out for drilling. Ive got access to a bridgeport, so Im going to use that to do all of my drilling & milling so that I know its straight and accurate. Then it'll all get tig welded together on the frame table so that it stays straight. Hopefully I can avoid the warpage.
Just don't take any constructive criticism from the members here personally. Most of them are decent enough people who may only be trying to save you some grief.
