MAINEly MX-5's

[MLambert19]

Following the welding and seam sealing, everything got coated in LizardSkin Heat and Sound spray-on-liner. Everything, pretty much literally.

Lizard Skin 1.jpg

[MLambert19]

Hopefully the added weight and mess are worth it. I've yet to drive the car, so the jury is still out, although I've heard good things. I had installed DynaPad from DynaMat in the turbo car, and it helped with road noise immensely.

Lizard Skin Firewall.jpgLizard Skin Interior.jpgLizard Skin Tunnel.jpg
The firewall, transmission tunnel, and interior all received applications of LizardSkin. The door jams and some trim received some unfortunate over-spray where things weren't masked... I'm told a plastic scraper can remove the flecks without damaging the paint.

[MLambert19]

Once dry, it looks more like this:
Lizard Skin Interior Dry.jpg

Then, add a layer of paint:
Firewall Paint.jpg

I'm a bit worried about how well the paint will adhere to the LizardSkin over the long-term, and I'm equally concerned about the paint not being a great match for the original Crystal White. Combined with the fact that the entire engine bay wasn't painted (and should have been) this is one of the things I should have been more vocal about when the car was being worked on. One of the downsides to not having the time and tools to accomplish the work yourself, compounded by the fact that I was nearly 2000 miles away and often behind the curve on photos.

[oldgrayleather]

Excited to hear about all the updates Matt! Unfortunately the picture links in the last bunch of posts aren't coming through on the browser or in the Tapatalk app. Nevertheless, excited about all the progress!!

[MLambert19]

Excited to hear about all the updates Matt! Unfortunately the picture links in the last bunch of posts aren't coming through on the browser or in the Tapatalk app. Nevertheless, excited about all the progress!!

Fixed, maybe? Sorry for the delay, I've been trying to get my lower garage painted so that I can move my tractor and put the XTerra and Miata inside upstairs. You can guess which one is occupying the space now... (hint, hint, I'm playing catch-up with this thread).

[—Martin—]

Thanks, I see pictures now

Hurry with the updates, please!

[MLambert19]

Okay Martin, I'll try!

Powdercoat & IL Bushings.jpg

I had hoped, given that the car only had 11,000 miles, that the suspension components would be okay (aside from replacing shocks and swaybars). In truth, a good cleaning and it probably would have been passable. It wasn't in the original budget to have everything powder coated... but here we are. I went with the IL Motorsport bushing kit in the hopes of keeping decent ride quality and suspension noise to a minimum.

[MLambert19]

FM Fox.jpg

Combine the refreshed arms with some FM Fox (550/375 rates, I think), along with 949 endlinks and a new FM front sway bar designed for the V8, and I think that covers most of the suspension pieces. Al also installed some new tie rods, and probably other things I'm forgetting.

[MLambert19]

So, with the body modifications completed, Al continued by setting up the front and rear sub assemblies. I posted a picture of the modified rear cradle earlier, and it was shortly fitted with a new Getrag 3.42 limited slip differential. I had a tough time deciding between 3.42 and 3.23 ratios, and would love to hear from anyone running a 3.23 (or anyone who feels the need for 3.73 or 4.10 in a V8 Miata). Since buying the Getrag, I've been reading a lot about the "clunk" that many seem to be experiencing with it and hope that I don't find it to be a problem. Apparently there is some gear-lash in certain situations that people notice only with the Getrag.

Getrag Installed.jpg

I wanted a solid parking brake, and have read that the Wilwood setup isn't as stout as OEM. I also wanted my calipers to match front-to-rear. With those criteria in mind, I sourced new Mazdaspeed/Sport Brake rear calipers, rotors, and pads to match my front setup. Add in the rear axles, and things came together like this.

Rear in Progress.jpg

The finished result, less shocks.

Complete Rear.jpg

[MLambert19]

Okay, where were we? I guess I can ramble on about the really fun bits...

The engine is a new GM LS376/495. I would have loved to buy a new 5.3L L33-type aluminum truck engine, but from what I gather, GM doesn't offer one. You can buy a remanufactured one, but bang-for-the-buck (unless you're doing the rebuild yourself), the 6.2L makes more sense. They offer 3 variants of the 376: 430, 495, and 525 horsepower. It was only a few bucks to go from 430 to 495 (essentially the cost of the "Hot Cam"), while the 525 engine was nearly $1600 more. I hope I don't regret my choice, as it seems lots of people opt for the ASA-cam 525 engine. The oil pan gets swapped out, and CTS-V accessory drives are added. My 1991 didn't have factory A/C, but we also added that on.

LS376-495.jpg

Full specs and such here: https://www.gmperformancemotor.com/parts/19370411.html

[MLambert19]

Behind the engine is a Z06 clutch and flywheel rated for 505hp and mated to a new T56/6060 hybrid transmission. There was some confusion about this early on, and a regular 56-Magnum was ordered directly from GM. The new 56 Magnum will not fit, although I understand there may be another option available directly from GM that will. There are a few companies that sell 6060 gearsets with F-body tail housings, which is what you need for this swap. Flyin' Miata uses the Tranzilla from Rockland Standard Gear in New York. I went the same route as Project Thunderbolt of YouTube fame, and enlisted the help of Tick Performance in North Carolina. The gearbox is a new Tremec 6060 6-speed with a genuine F-body tail segment, with gear ratios of 2.66, 1.78, 1.30, 1.00, .80, .63 (1-6, respectively). I elected for their level 3.5, which is rated for 700ft/lb of torque... considerably more than I'll ever need. It's comical how large the box is next to the car, but also gives you a good idea of just how tight a fit it is.

Tremec Box.jpg

The folks at Tick were extremely helpful. They offer different ratios, powdercoating, and other options. I'm hoping that the 2.66 first gear will allow me to use first gear without turning my 225 Toyo R1R's into smoke and noise (unless I choose to!).

LS&T56.jpg

Put the two together, and they're pretty much ready for test-fitment!

[Slampen]

I can't see your attachments.
Otherwise, very nice.

[— John J —]

As an owner of a V8 Roadster for several years I will share my experiences. First I installed a LS2 engine out of a wrecked Corvette with an automatic transmission. It had just over 7,000 miles on the wrecked vechile which included all the necessary parts to install it in the Miata-complete engine assembly, wiring harness, PCM, and accelerator. All other parts used in the rest of the build were new. The clutch and flywheel assembly used were the LS7 parts, a new 3:42 CTS differential assembly and front pulley assembly with power steering and A/C. The transmission used was a new Transzilla T56, the racing version. From the time it was first driven the gear noise was greater than anticipated which I lived with and it never has had a problem-other than the noise. Another issue that occurred within the first year of driving the car was a power steering pump failure. I decided to by-pass the power steering pump and proceeded to depower the steering rack. The car was and always since being built has been profession tuned since by Jeremy @ Fasterproms with great results. After a couple of years and minor engine upgrades, I decided that I wanted to make some major upgrades in the engine valvetrain which included a Howard version 525 cam, rocker-arm trunnion bearing, and pushrods and a retune of the engine. The power upgrade was immediately and immensely noticeable.

While the 3:42 differential had provided a very enjoyable driving experience with the stock cam, now with the engine cam upgrade it did not. When accelerating from a light the powerband of the cam required either double-clutching to prevent engine lugging to letting the clutch out with higher RPM's which caused excessive starting acceleration- both were annoying and less than satisfactory. Add in the fact you were driving a car without power steering often in heavy traffic did not help the experience. At the other end of the experience that problems occurred on the RPM ranges for using 5th and 6th gears in different traffic situation do to the powerband of the cam.

My intention was to obtain a used 3:73 posi-traction differential then have the differential rebuilt. However, I learned the used 3:73 differentials are not readily available for purchase used-nor is 3:91 differential. I also learn that no manufacture makes 3:73 or 3:91 ring and pinions to replace the existing differentials already manufactured as replacements parts. Being lucky I found a 3:91 Pontiac differential with 67,000 miles. After a minor housing modification to work in the Miata, it has proved to be everything I could asked for in a differential. I learned also from the day the 3:42 was installed to when I pulled it out that the differential was the source or the original gear noise. My recommendation for anyone building a V8 conversion is to calculate the gearing RPM to speed; against and the power band of the cam installed. When I was in 6th gear @ 70MPH the car was at approximately just under 1800 RPM. The cam in my car just begins hitting the powerband at 1800 RPM. My 3:42 gear was great for a track car just not so great for driving on the street. My most recent upgrade added E-power steering to my car-it has also greatly improved the driving experience too. I hope your driving experience driving a V8 Roadster is as enjoyable and fun as mine has proven to be.

[MLambert19]

John J, thanks!

Hoping to finally put some miles on the car this coming weekend. It's interesting, and completely counter-intuitive, that more HP would lend itself to what seems (to me) to be "more aggressive" gearing... but as you've stated, I guess it wholly depends on your powerband and what you're doing with the car. I know some of the FM cars are geared 3.73, and perhaps it's because of the 525 cam's powerband.

Question about your T56 Tranzilla: is the shifter angled towards the driver? Are you using the Flyin' Miata adaptor for the shift knob? I always see pictures that show perfect placement and it seems to be mostly vertical, but mine is slanted toward the driver... I have a picture somewhere to show what I'm referring to.

[— John J —]

The transmission that I bought was the one V8 Roadster used to sell for racing applications; it has proven to be very strong and reliable. The placement of my shifter appears to be one that's very close to the original Miata location. The location of the shifter was already placed in that location by the builder of the transmission for the units application in a Miata.