GRM Exclusive Reveal: Exocet Spec-A

Keith Tanner wrote: My opinion on brake lines - they should be hard lines as much as possible. Stainless lines do flex, ever so slightly, and you don't want a spring rate in your brake system. It's a lot easier to simply plug together a bunch of flex lines, but it's also not hard to buy pre-flared lengths from your local auto parts store, bend them with a cheap HF bending tool and end up with a rock hard pedal and an OE-quality brake system. It's not difficult to route them in a safe manner in the tunnel.

I used to believe that, and still would, until I had to track down a mysterious soft pedal. I changed from flex line to hard line, and found no difference in pedal feel(with the lines plugged at the calipers). Flex lines do expand, but it such a tiny amount that other factors overwhelm it. In my case, the issue was eventually traced to flexing calipers!

Also, I have nothing but bad things to say about the HF flaring tool (though the bender can't be too terrible). Plus, if stainless hard line is used, between the line and the connectors, the system can end up costing more than a flex line solution. I won't use hard line again unless I'm forced to.

Sorry for the delay, but trust me, you guys don't want me on this forum right now. I'm not the PR guy, I'm the guy that's building stuff. That said, I need a 20 minute break:

Bodywork

We just got in the wooden bodywork leaves Monday night, and I've been a madman in the newly-built composites shop. All the skeletons are done, the hood buck is 70% built, the trunk has been mocked up and is being built now. I'll bring in my SLR tomorrow, my cell phone camera won't focus. I don't want to put up blurry shots and make the internet think we're hiding something! I can't wait to let the bonding agents cure and throw a coat of primer on it. It looks frikkin' great!

ARBs

I would suggest trying the stock ARBs before buying an upgrade. It is very, very easy to swap out an ARB on an Exocet (I've done front and rear in ~10 minutes). Even for track cars, I wouldn't go very stiff (in Miata terms). The only reason we had an FM front bar on XP-3 was because it was going to be handed to a few inexperienced drivers (people that helped the project) and we wanted a bunch of cushy, cushy understeer.

Target wheel offset Offset depends on the wheel width, but I personally like a zero offset 8" wheel. You will not need spacers in the front, but you'll need a total -4mm offset in the rear. The Brits use a 1" spacer built like a hub adapter (two sets of lugnuts) for stock Miata wheel sizes and offsets. If you use one of those, be sure to check your inner lugnut torque after a heat cycle. Get long studs and a 1" blank spacer if you want to run stock Miata wheels. If you seat the studs straight, you don't even really need hubcentric spacers.

The increased scrub radius means more steering feedback and weight, as even a depowered rack feels a little light in an Exocet. I don't worry about accelerated wheel bearing wear, as the straight-line loads should be a wash or reduced when you consider the reduced weight. The kinematics of cornering loads mean the bearings should see slightly less stress on the outside wheel and a little more on the inside, which has less weight on it.

Here's a spreadsheet I made a while back on spacers

Glad you asked about offset. It's not on our store yet, but we're going to sell an "official" Exocet wheel that makes things a lot better than using spacers. It's a 15"x8" zero offset, lightweight, flow-formed wheel perfect for the Exocet. The model is the Traklite Holeshot, but we're selling them with Exomotive center caps and Miata-sized hubcentric rings for $150 apiece and $550 for a set of 4 (when shipped with a car). I love these things, they're perfect for the application and affordable.

Kevin just had a set of 205 Rivals mounted up on a set:

We weighed them at 33lbs 11oz with a fresh Rival, which BFG claims is 20 lbs. Not bad, not bad at all. If you can't tell, I hate wheel spacers.

Brake Lines

If you want a painless install, buy the braided line set from us. I was a hardline Nazi (seriously, I shamed Kevin for an earlier build) until I drove one of our cars with full soft lines. The pedal feel is still very stiff, because our firewall is rock solid and the reduced weight of the car means more g of deceleration with the same pedal pressure. Is there a noticeable difference? Not that I can feel with Miata calipers. The soft lines are really easy to install, although they won't give you the sense of satisfaction that a well-bent hardline will instill. Either way, the kit comes with plenty of Cunifer alloy hardline. That stuff is pretty easy to flare and bend.

The bending tool works fine. Cheap flare tools are a curse. There's no real reason to use stainless hard line, mild steel works. After all, this is unlikely to become a Michigan salt car and of course you won't let water get into the inside of the system. So standard mild steel lines will work for the next couple of decades.

If you have crap flexy calipers, you're right. They'll flex a lot more than the line will. But if you're actually trying to build a good car with good calipers, it's enough to be a factor. I don't think you'd ever see a professionally built racer using braided lines for long runs in the brake system.

Anyhow, it's an opinion. Exomotive sells a kit made of braided lines. FM won't, and we don't use that sort of setup in cars we build even if it is easier. Customers can make their decision.

We actually found the provided Cunifer line difficult to work with - and of course, it arrives coiled so you'll never get it nice and straight. We used new line throughout on ours. It was quite easy.

In reply to kb58: I actually Lol'ed at your distaste for making hard lines. I own and have read your Kimini book and been so continually impressed by the amount of fab work you are willing to do that something as relatively simple as hard lines irritating you seems odd. Do you have a quality flaring tool?

Just a note: I finger-fudged the 4-wheel price. It's $550. I edited my previous post, too.

Thank you everyone for the feedback! I think I'll start with 300/200 springs and take it from there. I'll have to see if I still have the stock front bar, if not I'm sure I can pick one up pretty easily.

MrJoshua wrote: In reply to kb58: I actually Lol'ed at your distaste for making hard lines. I own and have read your Kimini book and been so continually impressed by the amount of fab work you are willing to do that something as relatively simple as hard lines irritating you seems odd. Do you have a quality flaring tool?

I do now... but it's never been used. Which reminds me, I need to put it up for sale.

Ya Snrub, Facility rates are not fun at all. I ran into a similar problem trying to insure a right hand drive van. You may have gone down this road already but, ask why you are being rejected. In Ontario all the insurance companies must provide a quote. The only exceptions to this are for vehicles that the insurance company has filed a rule against with the Government. It turns out a lot of companies have filed rules against right hand drive vehicles. So I would find out why they a rejected you and then flat out ask if the have filed a rule. Its a little 'in your face' but I can imagine your Facility quote...

I too dislike the idea of wheel spacers. When can I buy the wheels you pictured above? I then will sell my 6ULs.

A webcam of the shop with a large highly visible chassis number hung on each frame would be cool. Customers with Order numbers could then see how close or far away theirs may be.

Big brother fabrication?

I've been thinking stock sway bars instead of my big red ones. Also wondering about whether to go poly or FlyinMiatas upgraded rubber. Definitely hard lines as much as possible in my opinion. I got rid of my 10" 6ULs & kept my 9s, but that may be too much based on the charts...

Sounds like my kit should be in my hands before the month is up.

In reply to SteadFast:

Did the 6UL you buy require spacers? And are spacers so bad that it's worth switching from the 6UL to the (somewhat unknown) Traklites?

mrvwcastner wrote: Also wondering about whether to go poly or FlyinMiatas upgraded rubber.

You talking sway bar bushings specifically, or all the suspension bushings? I've been struggling with that decision. My initial thought was "upgrade to poly" but a couple friends who track Miatas and RX7 have recommended I stick with rubber, and upgrade to the IL Motorsports when the stock ones wear out.

linuxd00d wrote: In reply to SteadFast: Did the 6UL you buy require spacers? And are spacers so bad that it's worth switching from the 6UL to the (somewhat unknown) Traklites?

I bought 6UL 7". The problem is, if I follow Warren's comments to reach the optimum distance I will have to use roughly a 1 inch spacer. I personally don't like the idea of using spacers for safety concerns. If I look at the cost of 4, 1" spacers, it is roughly $300ish. I can sell my current 6UL's (brand new) hopefully for close to what I bought them for. I then can buy the correct wheels with the correct offset and not have to use spacers. I think the cost difference, which should be little, is well worth it.

SteadFast wrote:

linuxd00d wrote: In reply to SteadFast: Did the 6UL you buy require spacers? And are spacers so bad that it's worth switching from the 6UL to the (somewhat unknown) Traklites?

I bought 6UL 7". The problem is, if I follow Warren's comments to reach the optimum distance I will have to use roughly a 1 inch spacer. I personally don't like the idea of using spacers for safety concerns. If I look at the cost of 4, 1" spacers, it is roughly $300ish. I can sell my current 6UL's (brand new) hopefully for close to what I bought them for. I then can buy the correct wheels with the correct offset and not have to use spacers. I think the cost difference, which should be little, is well worth it.

6ULs plus one inch spacers may weigh more than Traklites without spacers. Not that a one pound (or so) delta should drive a decision on wheels it's at least worth noting.

Well, the number of Exocets registered in California has gone up by one. None of them had windshields that I know of.

You won't increment that number - legally - in Colorado without a windshield.

I want to do full chassis bushings. 92k miles on my clean donor. Car is clean csp prepped with racing beat sways & Flyinmiata big brakes. I think all uprated rubber & stock sways. I depowered the rack & will eventually install my tubular subframe with tubular control arms. Im hoping someone makes non poly tubular control arm option soon. I have mixed thoughts because i like to drive ass out but dont want my bad habit to create a poorly built car. Eventually I will do a motorswap as well. I think a Honda K series motor & all the tubular parts could get car down to low 1300 lb range 50/50 distribution and over 250 HP (not that i have been obsessing). Now im thinking of selling my 8 black 9" 6ULs & buying 16 correctly fitted 8" wheels. Damn you budget busting options.

mrvwcastner wrote: I want to do full chassis bushings. 92k miles on my clean donor. Car is clean csp prepped with racing beat sways & Flyinmiata big brakes. I think all uprated rubber & stock sways. I depowered the rack & will eventually install my tubular subframe with tubular control arms. Im hoping someone makes non poly tubular control arm option soon. I have mixed thoughts because i like to drive ass out but dont want my bad habit to create a poorly built car. Eventually I will do a motorswap as well. I think a Honda K series motor & all the tubular parts could get car down to low 1300 lb range 50/50 distribution and over 250 HP (not that i have been obsessing). Now im thinking of selling my 8 black 9" 6ULs & buying 16 correctly fitted 8" wheels. Damn you budget busting options.

Where are you located? for some reason I was thinking Portland but I can't remember why.

Yes Portland OR. I will most likely sell off my 8 6ULs my racing beat sways & my too stiff Eibach springs. My email is mrvwcastner@yahoo.com I'm leaving for Calgary for a week. I'm also re-building an 05 Elise that met a tree. This & Exocet will co-habitate in a 25'10" inside length enclosed trailer. The Lotus will be naked with exo-style roll cage. Is anyone else local to Portland building an Exocet?

I'm in Portland. Not 100 percent sure on exocet just yet. I'm probably 3-4 months away from ordering if I go this route. I am thinking basic build at first. I will most likely do the k24 swap at some point. I love the idea of about 250 hp and NA. I am also all about saving weight wherever possible. I will shoot you an email. I would love to check out the kit when it arrives.

In reply to thestig: My kit due in Portland after 14th some time. I'm travelling until then and again on 24th so May 3rd will be welding weekend. I'm adding a hitch for tire trailer & some type of brace over stearing wheel. I use a friends shop out in Willsonville. I think body will be a month later than the chassis per speculation of FlyinMiata. In the mean time i'm trying to do chassis upgrades & maintenance in the evenings (if im not working on the Lotus project).

I'm NOT powdercoating, will paint myself. My chassis has welded floors & double diagonals. I still need to do full bushings & just finished de-power of rack still lots to do.

K20 is lighter & has better flowing head. I'm still researching & learning Honda.

I have a mild K20 in my Si and it is a very nice engine. Compared to the F20 in my 01 S2K I actually think they are very close. The Hondata reflash makes for a more drivable K series but with less revs/more tractable delivery. I like the idea of a K series swap for a Miata but looking at the kits for swaps it sure looks expensive. Does anyone know or have considered doing a NC 2.0 liter Duratec swap or similar? Maybe 2.3 Duratec from Ranger or Focus/Fusion etc.. These things make similar power (200-250NA)and there are still some Cosworth parts out there for them. I don't know how the trans or PPF would work between Na/NB and the NC but it seems like it may be an easier and cheaper swap.

http://www.k20a.org/forum/showthread.php?t=112309

I think kit is $4500 plus motor, Hondata etc..

Honda motor & tubular subframe should easily get Exocet to 50/50 & 250 HP naturally aspirated with Vtec might be awesome.

mrvwcastner wrote: http://www.k20a.org/forum/showthread.php?t=112309 I think kit is $4500 plus motor, Hondata etc.. Honda motor & tubular subframe should easily get Exocet to 50/50 & 250 HP naturally aspirated with Vtec might be awesome.

As someone who's been monitoring the development of and very much considering an exocet, I love the idea of a K20 swap. It seems better suited than the purely bonkers LS swap and the more 'mild' turbo'd miata motor. If you can truly get the weight down in the low 1300 range, a naturally aspirated 250+ horse motor, 50/50 distribution, and you can wring that motor out at near 9000rpm, you've got a freaking awesome setup. You're pretty close to having an il4 literbike+ powered car, but at a lower price point and greater reliability. As cool as a possible turbo powered busa /zx14 exocet with a paddleshifting sadev gearbox could be, it would have to be outrageously expensive and would take a ton of time to build and get properly sorted.
Speaking of cost, I'd be very interested in confirming the true parts cost of a K20 swap less the cost of the motor. $4500 is already a big chunk of coin and probably a good bit more expensive than an LS swap. I also bet that you are looking at more than $4500...question is how much more? That extra $$ might be worth it to have a light, high rev, and honda reliable motor mated to the exocet.