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Metalcorpse
06-05-2015, 10:08 PM
So I was nerding around and found an old post about the three different types of supercharger. From what I understand the m90 is a roots. Is there a twin screw blower available for the supercoupes? Also if I changed my #30 injectors to #80 (or smaller) would I need a tune or is it just adding the "potential" for more power? I don't fully understand how the injectors work. I plan on pushing max 325 hp no more. Have to keep it ca legal sadly. Thanks!

dthompson
06-05-2015, 10:23 PM
Generally speaking... you need more fuel and air to make more power. So in order to increase your hp, you need to get more air into the motor. That's why people upgrade heads cam blower etc. To keep up with the extra air, you need more fuel, that's why you need bigger injectors to match how much air is coming into the motor. Hope that makes sense.

As for twin screw sc's... Dave dalke makes them as custom fab jobs.

XR7 Dave
06-06-2015, 08:36 AM
To get to that power level and still pass emissions properly in CA you will have to be somewhat careful. I recommend doing things that don't attract attention from the people doing the testing because they can fail you on visual if they want to. Here is a plan that will get you to 325rwhp:

Head work - you will need to do headgaskets on an SC anyway, so you might as well do the heads while they are off. It won't affect emissions measurably and it's completely invisible. I recommend a cam to go with this but it has to be specifically designed for CA.

Keep the stock exhaust manifolds and EGR system (if your year had it). The rest of the exhaust should be changed to 2.25" duals but run 4 of the metallic core cats. Yes, I said 4. Be sure to get new 02 sensors.

Get a ported late model blower and MP plenum, or if you find a good deal on an MPX that will work too. Make sure you connect the EGR if your car came with it. You may not need it functional to pass, but if you do you'll want it in there. OD needs to be 15%.

You'll need at least 42lb injectors, but 60's work good too. 80's are too big. You'll need a cold air intake, 85mm TB, and 3.5" or bigger MAF to match. Of course a chip will also be needed to tell the EEC what size the MAF and injectors are. You'll need tuning as well so consider getting a QH and software for datalogging, etc.

A FMIC is going to really help overall performance and consistency, but you'll have to decide if you want to take the hit in the stock look department. A double IC from Ken will also help if you don't want the look of the FMIC.

If you do the work yourself and make good deals on used parts you might be able to do this for $4500-5000. If you buy all new parts you'll probably have $6000 or so in parts and do the work yourself. If you have a shop do it, count on $8-10K by the time you are done.

It does sound like maybe you aren't ready to dive into heads/cam though, so you should probably set your sights more at 270-280rwhp. That can be achieved for a lot less money and no internal engine mods.

Good luck!

Mercutio
06-06-2015, 09:26 AM
David, remember the CAI and throttle body aren't CA legal. You might get away with it, but you might not. Though it occurs to me K&N does make a very basic FIPK (just a cone filter) for these cars that comes with a CARB number. Might try adding an appropriate intake tube and just say it's part of the K&N kit. Might work.

Do all the MP plenums have the "Magnum Powers" script on them, or just the MPX plenum? You might have to grind that down, but I'm confident a smog tech out there wouldn't be able to tell the MPX from the regular M90 case. I also think a raised top could get through unnoticed.

OP, think of this as a sleeper build. Do what you can to disguise aftermarket parts. Paint/anodize overdrive pulleys black, etc.

Metalcorpse
06-06-2015, 12:04 PM
To get to that power level and still pass emissions properly in CA you will have to be somewhat careful. I recommend doing things that don't attract attention from the people doing the testing because they can fail you on visual if they want to. Here is a plan that will get you to 325rwhp:

Head work - you will need to do headgaskets on an SC anyway, so you might as well do the heads while they are off. It won't affect emissions measurably and it's completely invisible. I recommend a cam to go with this but it has to be specifically designed for CA.

Keep the stock exhaust manifolds and EGR system (if your year had it). The rest of the exhaust should be changed to 2.25" duals but run 4 of the metallic core cats. Yes, I said 4. Be sure to get new 02 sensors.

Get a ported late model blower and MP plenum, or if you find a good deal on an MPX that will work too. Make sure you connect the EGR if your car came with it. You may not need it functional to pass, but if you do you'll want it in there. OD needs to be 15%.

You'll need at least 42lb injectors, but 60's work good too. 80's are too big. You'll need a cold air intake, 85mm TB, and 3.5" or bigger MAF to match. Of course a chip will also be needed to tell the EEC what size the MAF and injectors are. You'll need tuning as well so consider getting a QH and software for datalogging, etc.

A FMIC is going to really help overall performance and consistency, but you'll have to decide if you want to take the hit in the stock look department. A double IC from Ken will also help if you don't want the look of the FMIC.

If you do the work yourself and make good deals on used parts you might be able to do this for $4500-5000. If you buy all new parts you'll probably have $6000 or so in parts and do the work yourself. If you have a shop do it, count on $8-10K by the time you are done.

It does sound like maybe you aren't ready to dive into heads/cam though, so you should probably set your sights more at 270-280rwhp. That can be achieved for a lot less money and no internal engine mods.

Good luck!

Thanks for the detailed info. I planned on saving up and getting everything all at once. I could always buy a newer sc engine and build on it over time, eventually just have my old engine swapped. Im going to have my transmission rebuilt next friday since the top gears went out in it. As far as smog, I could always put my stock stuff on for the smog, then just swap it when i get home.

If i added a newer blower with more psi, am i risking any internals breaking since its mostly stock? I understand fuel to air ratio should be on point but other than that would adding more boost put too much pressure on other parts of the engine?

MadMikeyL
06-06-2015, 12:52 PM
If i added a newer blower with more psi, am i risking any internals breaking since its mostly stock? I understand fuel to air ratio should be on point but other than that would adding more boost put too much pressure on other parts of the engine?

Possibly. It really depends on the tune being right, and the condition of your current engine. Some stock bottom ends have held up to 400rwhp while others have blown up in stock form. My advice would be if you aren't prepared to rebuild whatever may break, then you should probably leave it alone. If the stock bottom end holds up for years, then you are ahead of the game, but if it blows up 2 months after you get everything done, you don't want to end up having to part it out and losing a bunch of money because you don't have the time or money to fix it.

XR7 Dave
06-07-2015, 10:27 AM
You could swap the CAI and associated parts for smog testing, but you'll need a different tune for that.

As for the engine itself, the condition of the internal parts is really the key here. Stock internal parts in good condition (bearings, pistons, rings) with a decent tune will handle 400rwhp more or less indefinitely but a bad tune will kill those same parts at 250rwhp.

ThunderRoad
06-07-2015, 11:15 AM
david, remember the cai and throttle body aren't ca legal. You might get away with it, but you might not. Though it occurs to me k&n does make a very basic fipk (just a cone filter) for these cars that comes with a carb number. Might try adding an appropriate intake tube and just say it's part of the k&n kit. Might work.

Do all the mp plenums have the "magnum powers" script on them, or just the mpx plenum? You might have to grind that down, but i'm confident a smog tech out there wouldn't be able to tell the mpx from the regular m90 case. I also think a raised top could get through unnoticed.

Op, think of this as a sleeper build. Do what you can to disguise aftermarket parts. Paint/anodize overdrive pulleys black, etc.

no more inspections :d

KMT
06-07-2015, 11:27 AM
Just get classic tags or ones 4 older cars

Good idea, but AFAIK, that would require at least a 1975 'Bird in this case :)

ThunderRoad
06-07-2015, 11:34 AM
Good idea, but AFAIK, that would require at least a 1975 'Bird in this case :)

IM IN PA :cool:

KMT
06-07-2015, 11:37 AM
See comment #12 in this thread about an extreme modded SC & Ca smog testing...

http://www.sccoa.com/forums/showthread.php?130838-Twin-Turbo-Supercoupe-on-Ebay&p=1041290#post1041290

ThunderRoad
06-07-2015, 12:26 PM
Go over the laws again we also have under 5000 miles a year no smog test:)

KMT
06-07-2015, 01:22 PM
He had a hard time selling it in Calif. just on smog alone as I recall...

820
06-07-2015, 05:25 PM
So did ironworker sell his car then?

KMT
06-07-2015, 06:11 PM
That thread ended in mid 2013 without an update I know of: http://www.sccoa.com/forums/showthread.php?130838-Twin-Turbo-Supercoupe-on-Ebay&p=1041375#post1041375

Last ebay listing here?

http://www.ebay.com/itm/1995-THUNDERBIRD-SC-TWIN-TURBO-UNIQUE-/171073332824?forcerrptr=true&hash=item27d4c3e658&item=171073332824&pt=US_Cars_Trucks

820
06-07-2015, 06:58 PM
Well I for one hope he is getting to enjoy his work of art. I mean after all the man endured with the divorce and all.

KMT
06-07-2015, 07:39 PM
It's Calif. She got one of the turbos, 3 spark plugs and 1/2 tank of methanol.

820
06-07-2015, 07:58 PM
Ya. That would suck.

1FSTBRD
06-16-2015, 02:22 PM
If i added a newer blower with more psi, am i risking any internals breaking since its mostly stock? I understand fuel to air ratio should be on point but other than that would adding more boost put too much pressure on other parts of the engine?

In my '91 with an '89 engine, I can tell you that I've beat on the car in 0-60 to 70 ish form with a very heavily ported late model blower and ported intake plenum and 10 percent overdrive, on stock injectors. The car runs great, and seems like it's not strained....I have a double intercooler and fan, as well as a better breathing exhaust with Dynomax Ultra Flo's.

Now, I can't vouch for the cruel sands of time in what running this may eventually hold (wanted to get a Quarterhorse and a Dave tune....but no money left), but I can tell you that I'm at 15 psi, and the car lays down a strip of rubber that's my profile picture right now. Before the blower/ pulley upgrade, I was at about 9.75-10 ish psi, so the ported/ polished blower and pulley added 5 psi with no adverse effects (so far).

Truthfully, I'm going to wait for Dave to tune the car, along with 36 lb injectors (which I already have), before I go any higher than a WOT run to 60-70 mph. Edit: in a timed 0-60, I get anywhere from 5.8-6.3 ish seconds, depending on throttle modulation off the line.