Boost or Motor swap? (Miata content)

Keith wrote:

ReverendDexter wrote: The only advantage to the supercharger is if you have to pass california emissions. CARB no likey aftermarket tarboboostas.

Not necessarily true. FM doesn't sell any turbo systems with CARB approval at the moment, but there are a couple of options. "Big Gulp" had some pretty aggressive claims about the power output of that car. Moving 350 rwhp worth of air through an MP62 is beyond what most people would consider possible. But a wound-up supercharger does sound pretty cool.

That was at 26psi, though... Sounds about right. 26psi through a properly sized turbo would be FAR more power.

It certainly proves the efficiency difference between turbo vs. supercharger, does it?

Keith wrote:

ReverendDexter wrote: The only advantage to the supercharger is if you have to pass california emissions. CARB no likey aftermarket tarboboostas.

Not necessarily true. FM doesn't sell any turbo systems with CARB approval at the moment, but there are a couple of options.

Do you have more info? I've never seen a CARB-approved turbo kit.

I'm gonna let you do your own research instead of pointing you to our competitors The GReddy kit is no longer available new, but they do pop up from time to time. Just keep in mind that you cannot get a replacement manifold if it's cracked.

ETD made a Greddy mani. I have one. With the attached Greddy turbo. It's honestly a pretty weak kit. I'll sell you the whole thing for $400. Wrung off bolts and all.

That includes the weak sauce Greddy down pipe. Behold the glory of 5 lbs of boost. yeah.

Here is another option.

http://norfolk.craigslist.org/pts/2447518471.html

The GReddy kits have been used as a base for some decent power levels - I think they came with either a small or a large turbo. But you do end up replacing basically everything but the turbo and the manifold to do it, and usually the manifold too if you don't cut the stress relief cuts in the flange. Technically, to be CARB legal you can't change anything from the original kit. Technically.

That was at 26psi, though... Sounds about right. 26psi through a properly sized turbo would be FAR more power. It certainly proves the efficiency difference between turbo vs. supercharger, does it?

Well, to be apples-to-apples, you should compare it to a properly-sized supercharger running at 26 psi. A big twin-screw blower (like the old FM Ubercharger) would make a ton of power too. The problem with the M45 and MP62 kits isn't that they're roots blowers, it's that they're undersized for big power applications.

If you want to look up CARB EOs, they're searchable online. http://www.arb.ca.gov/msprog/aftermkt/devices/aftermktdevice.php

As for the original question, I'd go with the 1.8 over the JR, for the reasons Keith stated. (Actually I'd go for the 1.8 and a turbo later. :-) )

Keith wrote: I'm gonna let you do your own research instead of pointing you to our competitors The GReddy kit is no longer available new, but they do pop up from time to time. Just keep in mind that you cannot get a replacement manifold if it's cracked.

Haha, my apologies, I wasn't trying to extract a Miata kit from you, I just had never seen ANY California-legal aftermartket turbo kit so I was curious to see the CARB E.O. number with my own eyes.

Don't worry, man, when I finally get around to getting a Miata (and I will... someday), you guys are gonna be who I come to for parts. I already suggest FM to all the Miata guys I know

There are at least two EOs in the system for Miata turbo kits for a 1.6, but they're not necessarily available as new kits. Same with the 1999 model - there's an EO, but the company who "owns" it doesn't actually make the kits anymore.

You can't directly compare boost to power. Not the same thing. A small turbo pushing 12 psi might get stomped by a big turbo pushing 6 - it's really about airflow.

An MP62 spinning at 26 psi on a 1.8 is both way out of its efficiency range and quite probably putting the bearings at severe risk due to the blower RPM. That was a problem with the old Ubercharger - the twin-screws really like to move air to get into their efficiency happy place, but by the time you get there with a Miata engine you're running close to the speed limit of the blower unless you drop your redline.

There's been some skepticism around those "Big Gulp" claims in the past. I once saw a claim of improved 0-60 times by changing the cam on the throttle body. Really nicely made hardware though.

If you're autocrossing it in SCCA-world, the 1.8 would make for a heckuva CSP contender, especially if it's one of the later 1.8s with variable valve timing. The turbo would boot you off into no-man's land.

Keith wrote: An MP62 spinning at 26 psi on a 1.8 is both way out of its efficiency range and quite probably putting the bearings at severe risk due to the blower RPM. That was a problem with the old Ubercharger - the twin-screws really like to move air to get into their efficiency happy place, but by the time you get there with a Miata engine you're running close to the speed limit of the blower unless you drop your redline.

Yeah, the Uber in my car is set up to only push 10 psi or so, and the PO told me to shift at 6,000 to avoid getting close to the blower's redline.

I know i'm not helping the off-topic stuff, but the M62 on that car isn't exactly "ordinary."

I'm not saying everyone should go out and do it, on a smaller motor like this, i'll take turbo any day of the week.

Ok, so the supercharger is out of the question (sold...) and I will be doing a '99-00 motor swap. Isd it worth my while to get a MSD window to control the VICS in the intake manifold of the 1.8 motor?

Yes.

http://www.flyinmiata.com/tech/dyno_runs/99_050400.pdf

Run 29 is with hose disconnected and plugged for the VICS actuator. Run 30 is with VICS hooked up normally. Run 31 is with VICS locked in the low rpm position.

may have a lead for a complete '03 motor, time to start researching how to control the VVT, megasquirt maybe?

DIY Autotune sells a standalone VVT controller

The Hydra Nemesis can do it too. If you decide to run the stock VVT ECU and rewire the car, make sure you get the immobilizer and keys from the donor car. They're mated to the ECU.