My Supercharged mx5 experience

[NitroDann]

Like this?

Dann

[thehillsarecalling]

Hey all,

Not to resurrect an old thread or anything, but as someone who is new to FI, I have found this thread fascinating.

It does leave me with one question though.... If the consensus among the technically literate is to turbocharge, why are the street and casual racer type FI packages for the NC all supercharger based?

I'm not talking about a 500hp track weapon, I'm talking about your usual MX-5-as-a-2nd-car owner who spends most of his life under 4000 RPM, and just wants a little bit of extra sauce for the winding hills drive or the odd track day.

Why are the FM kits supercharger based? Is it a space issue in the NC engine bay? Does the MZR in the NC have a stock supercharged option which parts are interchanged from that I'm not aware of?

[Sailor]

Trouble with the NC is that the exhaust is on the drivers side and the steering shaft takes up a lot of room where a turbo would fit.
It's been done thanks to Jay from TDR in the US and Chris Gough here in Oz.
Chris sent a RHD steering setup to Jay, and Jay built a manifold to suit.
Don't know if one has been installed here yet.
Superchargers were first done by Cosworth using a vane type SC and recently new inovations have seen the centrifugal type superchargers installed
by guys like Danny Irvine in Qld. Big advantage of the centifugal type is the ability to have as large an air to air intercooler as you want.
The Cosworth/FM type is limited to an internal air to water intercooler with it's associated pumps, wiring and radiator.
Drive wise..I don;t think there are any turbo NCs in Oz but those in the US seem to be producing humungous torque and HP and are being described as having
good driveability.
My Cosworth car is my wifes daily drive to work in traffic. She rarely revs the car above 3000rpm but has commented on how much extra torque is there now.
Other than the beautiful whine and a bit more exhaust noise the car drives exactly like an NA car
There is absolutely no lag with the SC, boost is always there as long as the engine is running with much of it just recirculated in various degrees according to throttle opening.
All the boost is there with large throttle application and builds with rpm.
There is no factory supercharged NC other than a few specials built by Mazda USA and FM (iirc) using the FM/Cosworth SC. It's exactly the same as the off the shelf FM kit.
I know people will say that you can build a turbo car with no lag...but I've never dríven one.
Daily drive as you describe with extra for fun days..IMHO you can't beat the instant response of the supercharger.

[thehillsarecalling]

Ah ha, I didn't realise that the exhaust was on the opposite side in the NC.

There's a guy in SA who drives around a piano black NC with a FM kit, and I must say that it's absolutely stock looking / sounding. To the point where it looks like a random extra pulley under the hood.

I haven't ridden in it, but I've been told it's very decent.

In terms of instant power, what about a non-intercooled 2556? From what I understand they would make boost at very low RPM on a 1.6 / 1.8. How would that compare to a supercharger type setup?

[Mr nanotech]

I've been doing some reading and I'm left with a few questions.

The supercharger I was using through this was a 5th generation Eaton M45 supercharger. They used this same charger on the John Cooper Works Mini and it ran stock at 11.6psi from factory. A lot of owners commonly bump this up to 14psi which is apparently the peak drive the charger is capable of spinning safely.

I ran mine at 9psi and it absolutely screamed yet high boost JCW Mini's are still pretty quiet. Mine screamed from as low as 2000rpm. For arguments sake lets assume mine didn't run so well because of the huge crossover pipe between inlet manifold and the charger thanks to the intercooler, and the performance/response came down to tune.
Why was mine so ridiculously loud?

What would be the ideal way to run a blower like this on an mx5?

Realistically I'll be going turbo, but I'm interested in finding this out. I guess, for future reference for the next owner, what would be the best way to set this up.

[timk]

Why was mine so ridiculously loud?

Was the supercharger inlet correctly throttled? I've had a supercharged NA and NB MX-5 and both sounded fairly stock until you sunk the boot in.

[johnnyreble]

Mine sounds stock up to about 5ooo rpm and i'm running a MP62 at 22psi , I think the MP45 is too small hence all the whining ...

[Mr nanotech]

Why was mine so ridiculously loud?

Was the supercharger inlet correctly throttled? I've had a supercharged NA and NB MX-5 and both sounded fairly stock until you sunk the boot in.

How do you mean? I don't have any photos of mine, but the supercharger was mounted above the exhaust and had an nb throttle body and a recirc valve fitted to it. I had dual throttles with mine too.

I'm wondering if the best way to run this would be to crank the boost up to 12-14psi, and use a V-mount intercooler setup. Basically tilt the radiator back and have the intercooler sit on top, creating an almost direct pipe from the supercharger to the engine. No longer than a normal cross over pipe.
The eaton m45's used on the mini's were designed to be used with an intercooler btw.

Instead of using two throttlebodies, will there be much difference deleting the stock one and running a single throttle body at the supercharger instead? Trying to think of the simplest way to set this up.

[Mr nanotech]

Just letting everyone know that I created a more focused thread relating to my last post. Looking for solid critiques and advice there.

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