PROJECT ND: Parts Development, Testing, Measurements, DYNO

[Brian]

Yes, you need a lift....and that's just getting started. Here is my instructions cheat sheet, courtesy of Mazda's own Dave Coleman.

Mark the steering shaft U-joint position and remove the clamp bolt.

Remove the two bolts holding the steering rack to the subframe.

Slide the rack forward out of its double-shear mounting brackets, then let it drop down.

Unbolt the sway bar and slide it out.

No need to remove either tie rod end.

Sway bar has already come out of our LE, it is not easy, bushings are bonded to the bar making it a fight to get out. We might be at the point that most folks pay a shop to do the sway swap.

[__vladster__]

Ouch. What took about 30-45 minutes on an NB, a bit more than that on the NC, is now a job that a home garage mechanic will probably not be able to do anymore. That's a bit of a bummer.

How about the rear bar? Any issues there?

Also, any idea why the bushings are bonded to the car? My guess is to create a tighter coupling with the chassis and reduce vibration.

[Brian]

Rear is mere minutes, but supports are suspect in the way NA front mounts were suspect, so we are looking at that.

Not sure why the bushings bonded to the bar, something seen on recent Ford products too.

[Ryan @ GWR]

Having the bushings bonded to the sway bar makes the whole bar resist pivoting within the mounting bracket. This helps prevent nose dive under braking, might offer some added fore-aft stability at freeway speeds too. My guess is this feature is made necessary by the very soft factory springs, and the need for it disappears with stiffer springs fitted.

-Ryan

[Brian]

Took our new Blue ND from dealer direct to Auto Armour for full front end protection film. Didn't even let the dealer pull the plastic wrap...just to make sure it got to filming without any nicks in the paint. Now we finally get to drive it and start wrenching!

First on our BLUE ND is RoadsterSport Race for ND Production Sample test fit. Sound clips soon...this one is seriously fun and at just 11 pounds about half the weight of the stock muffler!

Also shown our ND RoadsterSport Q with the nice rolled tip!

[Brian]

OEM Springs on ND LE (non Club)

156 front
80 rear

These are measurements made on our springs from our LE, not official from Mazda....but same machine measured stock NC fronts at just 110 many years ago and that was later confirmed by Mazda. Thus, appears despite massive body lean the ND actually has more rate? How can that be some will ask? The secret is ND also has lots more TRAVEL, the NC depended more on the stops for rate. These rates remind me of NB Sport, which if memory serves were about 164 front /97 rear lbs/in

[morrisg]

Wow that's soft! 156 is about 2.8 kg/mm! 80 is about 1.4 kg/mm!

And to think I bumped my NC Ohlins up from 7 / 4 kg/mm to 9 / 7 kg/mm for my STR setup. I think I understand better the amount of body roll I'm seeing on the ND.

[Brian]

Yes, still incredibly soft rates.. but normal in Miata history to have soft springs.

[Brian]

RE-Print of Mark Booth's review of our first production RoadsterSport Q for ND from Miata.net thread.

Brian made a very generous and awesome offer to let me try one of Good-Win Racing's production sample exhausts when they came in. So, I was down at the shop bright and early this morning to have it installed.



RoadsterSport Q in all of its shiny and sparkly glory:

The tip:

RoadsterSport-ND-Q-tips.jpg (53.57 KiB) Viewed 7632 times

So, how does it sound? Way better than stock! The difference is immediately noticeable and the sound should only improve with age/break-in. I drove it home with the baffle in place and that was much too quiet. Still louder than stock, but definitely not a big enough change (for my ears) with the baffle in place. After lunch, I removed the baffle and Cathy and I went for a drive to chase some canyons. I got a big grin on my face every time I put my foot into the pedal!

That said, this Q model is still a bit quieter than the RoadsterSport III that I had on my NB. Part of that might be the break-in period (I recall the III sounded better and better as it aged). But I still think my III was a bit louder from the get-go.

This Q is probably going to be perfect for a good percentage of ND owners. We tried it with the top up and it was perfect for us with the top up. Just the right amount of pleasing growl and deep throatiness. And no annoying drone whatsoever. If you keep your top up a fair amount of the time, this Q is possibly the exhaust you'll want from the Good-Win Racing line.

But, as with all Miata exhausts I've tried over the years, there's a difference in loudness between top up and top down. And, since we drive with the top down 99% of the time, I'd rather have an exhaust that's a little bit too loud with the top up and just right with the top down.

Brian has a couple more things that he's going to let me try. I might even end up trying a RoadsterSport Race. But, while I'm sure that one will be way fun, my gut is telling me it will be a bit too loud for the Mrs (particularly with the top up).

My thanks to Brian for letting me try the exhaust on for size! It's definitely a lot more fun than the too-quiet stock exhaust!

Mark

[Brian]

Mark's great video from multiple camera angles listening to ND RoadsterSport Q muffler...at THIS LINK