Category: HyperMiata Build

4+ months spent working out details for the custom flywheel/clutch for this project, and then at the eleventh hour – right before the flywheel gets CNC’d – SpeedSport double-checked a measurement I had sent over right in the beginning and they realize they won’t be able to build it. Facepalm.

For the record, all the measurements on my end were correct from the beginning. Turns out the person on their end who had been handling this project with me overlooked some of the details in those measurements that he should have caught much earlier. Someone else checked the numbers and threw up a flag. Bottom line, they can’t make a clutch for this engine.

Moving forward!

So… looks like SPEC is my huckleberry. Wasn’t my first choice but beats putting a 50+ lb stock combo in there. Spoke with them today about the options, because the car doesn’t use a pilot bearing they recommend a solid hub disc over sprung, and based on that they recommend a full face disc over pucked so that it’s not entirely an on/off switch.

Have some thinkin’ to do, leaning towards the Stage 2 with the billet cover (+130 lbs-ft of torque capacity). At least they can build the clutch in only a week…

Final package from V8R arrived!

LFX ECU complete with V8R’s tune as well as the interlock deactivated:

Shifter Kit which relocates the shifter to the Miata’s position:

Took a lot longer than expected but the clutch and flywheel specs/measurements are finally finalized finally. Protos are paid for and in the works now, 4-6 weeks out.

The factory clutch and flywheel total out to over 50 lbs. That’s not going in my car if you paid me.

There are very few clutch options in the aftermarket. Because the factory setup uses a flex plate, to switch to an aftermarket clutch you also need to change to a new flywheel made by the same company as the clutch. So if you find you don’t like the clutch from that brand, changing is going to be a bigger investment as you need to toss out the flywheel as well. This means I don’t want to take a gamble on the few options that already exist and none of them check all the boxes I’d like anyways.

So we’re working with SpeedSport on a carbon/carbon clutch and flywheel that does check all the boxes. Should be good for way more torque and heat than the factory clutch with much less rotational mass yet similar to stock pedal feel and easy to drive.

More parts in from V8R 

“Stage 2” 32 spline axles rated for 550 lbs-ft with billet hubs and ARP studs:

MV7 to Getrag Driveshaft:

The list of parts I’m waiting on is diminishing!

Still waiting on:
– Clutch/flywheel
– Radiator
– ECU with V8R’s tune – after speaking with Shandelle about options I’m going to run their tune rather than tune it ourselves here so that we can build experience on their off-the-shelf offering.

LFX Fuel Kit arrived, sans fuel pump as I already have a Walbro 255 from the turbo setup that will do the job. Kit uses a Corvette fuel filter, SS lines and AN fittings:

Clutch and flywheel are still in the works with some delays, but nothing unexpected as it’s all prototype stuff.

Because the car won’t be running at Laguna Seca, I’m picking up some of the remaining large items from V8R when we see them at that event (driveshaft and axles).

I’ve been so busy with ND MX5 development that I’ve decided that I don’t want to rush the LFX swap just to have it (hopefully) running in time for Miatas at Laguna Seca in October. Prototype clutch is still in the works and a few weeks away, driveshaft and axles are still a few weeks out.. and I wouldn’t take a car to Laguna Seca that I haven’t had time to shake down and work out the kinks.

I’ll be starting the project this month, but extending the deadline frees me up to keep some focus on the many ND projects we have going on, and I’ll be able to do things right on this LFX project as I go.

Someone asked me if the LFX had built-up a good track pedigree yet. As far as I know, it hasn’t. Most of the Camaros going to the track are the V8 variety.

However, GM has chosen to use the 3.6L V6 in the new ATSV-R (article here for those who haven’t seen it) and while the more direct production variant of that LF4.R motor is the LF3 in the new ATS-V, the LFX is also a direct relative – lacking just the forged internals and turbos. In other words, if there are weak points, I’m confident there will be solutions for them.

This circles back to my original post that there are questions that remain to be answered about this motor and swap. However everything looks promising enough for me to reject the more common swaps and take a leap down this path to find the answers to those questions.

Also to consider, the next variant of the engine includes twin turbos (3.0 vs. 3.6 liter) and 400hp. Same block architecture sounds like that would be a drop-in as long as one got all the necessary electronics worked out. That would be wild. That or the existing LF3 in the ATS-V, would just be nuts aaaand both have flappy-paddle gearboxes that *who knows* might be something that could be carried over 

For me though, I don’t see myself revisiting the turbos on this new drivetrain for quite some time if at all. BTDT in terms of heat management and decreased engine life. My hopes are to find in this a naturally aspirated, runs-all-day honest 300 horsepower that I can replace for 1.5k from the junkyard when it wears out.

I was going to put my current motor/turbo/cooling system up for sale in the next week or so, but a local customer jumped all over it. I’m rather satisfied that it’s staying local. Took me 4+ years, many many hours, and many revisions to get the turbo to run dead reliable at the track.

(old pic)

V8Roadsters just finished up dyno tuning on their car. 99* F ambient, 60%RH on a dynojet so these are conservative numbers. On a cooler day they would be in the 290’s.

Yes please:

In the next few weeks they plan to switch over to E85, which should easily break 300hp.

If you google 2012 Camaro dyno sheets, the few you’ll find are lower than this on average. More power in the Miata application is in part due to improved tuning and in part due to less rotational mass. V8R’s numbers above are with the stock flywheel and clutch (HEAVY). Expect to see a bit more at the wheels with a lighter combo. We have exciting things in the works on this front.

Debated over this for a while. The Camaro comes with an Aisin LY6 6-speed with the “MV5” designation. That box has some interesting ratios. From 1st to 6th gear: 4.48 / 2.58 / 1.63 / 1.19 / 1 / 0.75

1st and 2nd are super short, 3rd has a big drop and is very long, then 4th is very short again. I can think of arguments for and against this, depending on the specific scenario/track.

The base model Cadillac CTS uses the same engine, and has a manual gearbox option – that transmission is the MV7, and it has much more evenly-spaced ratios: 4.16 / 2.51 / 1.69 / 1.27 / 1 / 0.75

To visualize the differences between the two transmission, I graphed them:

I decided to go for the MV7. Turns out this trans is rather rare – likely because the base model CTS is rarely chosen with a manual – but I finally found one with low miles in Texas and had it shipped over. $1200 including freight: