MX-3.com

I spent a few hours with the search function on here, Probe Talk and MX6.com, didn't get too many clear answers to my questions. I have been thinking about putting a M62 Mercedes clutched supercharger on my KLZE in my aaaah MX-3 I want to put the supercharger where the A/C compressor was.

Just like this set-up.


Knowledge I have gained.
I need:
-97-00 SLK-230 / C-320 Supercharger Mercedes Benz M62 supercharger
-Millenia S injectors
-A rising rate FMU
-A 255LPH fuel pump
-Colder spark plugs

What I still need to figure out.
1) Is the Mercedes pulley big enough? Do I need a custom crank pulley in order to make a decent amount of boost? (Thinking 5PSI)
2) What calibration of FMU do I need to use?

Well this is the exact same thing I have had going for a couple of years now.....before Dan even started his set up. It all depends on if you want to keep the clutched part of the supercharger. If so you are stuck at about 3.5??? pounds of boost for it stock, I can't remember but it is around that amount. If not you can buy different size wheels but then the supercharger will be on all the time and of course you can change the size for different amounts of boost. I was planning on running the clutched wheel since this in on my winter beater 323, since I was going to leave that I bought everything you have plus a megasquirt with switchable tables so I could turn on/off the charger. I got bigger wires, various aluminum 2-3.75" piping pieces to run the whole setup and a bov as well. Since my car has been sitting for a year and a half waiting for paint I am still unsure if I want to keep the clutch ot not? Was hoping for paint this month but it looks like it will wait until next summer again, the house has taken priority on the cars for now Good luck and if you need to know anything let me know.

IMACHU2 wrote: What I still need to figure out.
1) Is the Mercedes pulley big enough? Do I need a custom crank pulley in order to make a decent amount of boost? (Thinking 5PSI)
2) What calibration of FMU do I need to use?

I would go with the Mercedes pulley to start and go from there. The nice thing about the clutch is you can turn it on and off and save fuel especially at HWY speeds. If you change the pulley to a none clutch type with more boost then your millage will drop like crazy, but of course that's only if you care about fuel economy

with the FMU - you could get a piggy back, or because its such low boost you could go with something nice like an aeomotive Fuel Pressure Regulator with set spring rates, or get a boost sensitive adjustable fuel pressure regulator and a wide ban O2 and make the proper adjustments until you hit the desired A/F mixture.

Honestly I dream of this set up, it is reliable, just the right amount of power and it sounds cool.

Yes, the main reason was the sound for me, the extra 30hp does not hurt either. I hope to have mine running by next summer sometime.

Thanks for your answers guys.

I am from the old school, I was thinking about one of these units for fuel enrichment.

http://www.vortechsuperchargers.com/product.php?p=31

Vortec does have this baby now, which looks super cool. Fuel management with a screw driver (old guy friendly)
http://www.vortechsuperchargers.com/product.php?p=30

I want to leave the M62 clutched. You can increase the boost by changing the size of the crank pulley though.

My MSD FMU only cost 50 bucks and worked great, its just not aluminum or has fancy fittings

http://www.youtube.com/watch?v=wMxqIHBBJnk

Here are some visual answers

Josh the MSD 2222 Boost/Vacuum Rise Ratio is 1:1 most fuel pressure regulators do the same. FMU's have 4:1, 6:1, 8:1, 10:1, 12:1, ect rise ratios

The FMU works under the same principle as the stock fuel pressure regulator. The stock regulator has a spring that presses a plate against a hole that fuel flows through. It won’t let the fuel flow through the hole until pressure builds up to a predetermined pressure. One the pressure in the fuel rail reaches this pressure it pushes the plate to open the hole and let excess fuel flow back to the tank. A vacuum line attaches to the regulator to assist moving the plate to open the valve (hole) during vacuum and to push the plate closed during boost.

The FMU works on the same principle, except the size of the plate is bigger so that it is more sensitive to boost pressure. The FMU can be tuned by changing the size of the plate (disc) to best match the fuel pressure needed for your boost level and injector size.

My Xterra uses an M62. With the 2.72" pulley I'm making 6psi. Apparently you can get the Mercedez clutch pulley machined, but it's not cheap.

But also a note for fuel economy. On the X, attached to the supercharger, there's a bypass that's vacuum actuated. Basically, the harder you press the throttle, the more vacuum it's sucking, the more boost you'll pass into the motor. So basically if you cruising along and don't need boost, the pulley will be spinning the compressor but not compressing any air, so it saves on fuel, but of course, with the clutch you're not spinning the impellars, so you'll save that load on the motor, but with my X, since it replaces my IM, it helps to move air through instead of acting as a restriction.

Another point of the bypass is that when you're off the throttle, it's still not trying to compress air, which could cause "cavitation", but shouldn't be something to be concerned about unless your SC replaced your IM.

I've actually been waiting to turn up the boost on the X for a few years, but things are too tight to be playing with that, but I've wanted to put in an aftermarket rising-rate FPR to see if it fixes the reports of pinging using the 2.3" pulley.

In my experience the clutched pulley is a bit big to make decent boost, especically with a FMIC.

I had a custom crank pulley machined that increased the boost from about 2-3 to 5psi. That was a bit more impressive but it still wanted to spin faster IMO to really do it's job. After that, it looked like it would be time to loose the clutch for a smaller solid m62 pulley. At that point I think I had enough of pulleys and started aquiring parts for turbo. Turbo blew it away tbh. The two part harmony is sensational though and the immediate onset of boost. Turns many heads too, then switch off with the clutch. I still got 34mpg too with the SC ZE. So it depends on your goals I'd always recommend megasquirt though over RRFPRs.

Hey Marcdh do you have any quarter mile times with the supercharger on it? I actually put a KLZE into my 323 hatchback. The plan from the start was to have a dependable daily driver and perhaps tickle it with some laughing gas. The M62 looks like a really easy swap, without the costs of bottle refills, and like nitrous it would be there at the flip of a switch. I was thinking 5PSI max as this was supposed to not be a race car build. From what I have been reading the old MX-3 5 speed will become an issue. Thinkin' "daily driver" and "MR2 trans with aluminum transmission adapter and custom axles" don't go well together LOL

'Fraid not. It cost £50 entry and £30 in petrol to go drag racing when I had it installed!

Ah yes I know your car. That'd be sweet. I don't think the trans will hate you for it really, unless you're really nasty to it! lol well I think the e153 trans will actually make it more of a DD, then you know it will be reliable The m62 is fairly easy, so why not. The cost isn't that bad, and you know someone will buy it up if you sell on.

Any specs or info on the custom crank pulley?

Just on a related note to my post in relation to the bypass valve. My uncle had a old fox body 5.0L with a centrifugal supercharger and on his setup he has a bypass on it as well.