The Breakup (Miata build)

[drummingpariah]

I'm sure Walter will confirm, but I am under the impression that non-stock induction does in fact mean any variation from stock. Cold air intake, non-stock manifold, non-stock TB, etc.

In short, if you're considering ITB's for logical reasons, stop now.

I love that way of thinking! Can't wait to hear it with these!

That means these will bump me up to SP5. I don't really want to stay in SP6, as my only competition has been one other car, but I'd like to be able to keep up with the pack when I do move to SP5.

Unless I do some headwork, compression-raising, and cams, it won't sound amazing. Luckily, parts are cheap and I could do all that reasonably easily. I don't think any of those affect class, oddly enough. It's like free power.

cool. I've seen some vws make good power with itbs in the past, so was curious. I'm sure port work and cams help much more...but every itb car I've heard is pure music, love the sound.

I was only curious of class because the other miatas are in SP5. I couldn't even remember if you ran in U or SP class last time I was at the hills

Nobody else is silly enough to run a 1.6 or stock suspension. I ran U6 at Ascutney, but these (plastic) stock radiators are prone to catastrophic failure after 100k miles, and I replaced it with an aluminum version, which bumped me to SP6. That's where I've been ever since.

Classification

• SP5 cageless ITB build - If I keep the ITB's, I'll also upgrade to coilovers, good anti-roll bars, and some r-compound tires (on another set of the stock 15x6 wheels that weigh about 8grams for a set of 4).
• SP5 cage ITB build - Adding a cage would allow me to upgrade to 15x9 wheels and a proper exhaust. I would still end up pretty power limited, and 15x9 might just be too much wheel/tire to push around with so little power (estimated 100-125whp after raising the compression and camming it).
• SP5 cage turbo build - At the polar opposite end, I could forego grip upgrades and make more power with the little saab t3 I have in the basement. This is certainly the most sensible path if I want to be competitive, and would make for the best daily driver (this is my daily, after all).
• SP5 cage turbo build (non-intercooled) - I don't think this is a good idea, but if I can make it reliable and durable, it is the most competitive SP5 build I can come up with. It gets the best of all worlds: respectable power output (estimated 150-200whp or so), anti-roll bars, 15x9 r-compounds (please don't flip over due to soft springs in hard corners). I would have to spend some time setting up e85/water injection to cool the intake/combustion charge, which puts even MORE tax on the MegaSquirt2 system. This is the plan for the Datsun (to keep it in SP4), but that engine is quite a bit more durable and is running MegaSquirt3, with quite a bit more capacity for 'advanced feature management'.

[walterclark]

In Unprepared, it is permitted to change the air filter and its housing, which could describe a cold air intake, so its reasonable to assume the same is true in SP without taking the modified intake penalty. Once you get to changing throttle bodies, carbs, and manifolds however this is clearly a modification. Whether it causes a class change depends on the vehicle and how it adds up on the worksheet. The early Miatas with the 1.6 probably have a bit of room to play with mods compared to the 1.8 versions.

[drummingpariah]

In Unprepared, it is permitted to change the air filter and its housing, which could describe a cold air intake, so its reasonable to assume the same is true in SP without taking the modified intake penalty. Once you get to changing throttle bodies, carbs, and manifolds however this is clearly a modification. Whether it causes a class change depends on the vehicle and how it adds up on the worksheet. The early Miatas with the 1.6 probably have a bit of room to play with mods compared to the 1.8 versions.

The 1.6 does have a little more wiggle room, but I'm knocking on SP5's doors pretty hard right now.

Walter, I have to thank you for the recommendation of Marc Swanson at efiexpress. Working with him this morning was superb, I'm very happy with my results. After spending a couple hours on the dyno, we greatly improved the driveability of the car and squeezed out a little more power. I am now officially at 9 hamsterpower, up from the previous 7. We found that my ignition cut was set to 6500rpm, which explained a lot of things and could improve my run times a bit. There are certainly still some dips to flatten out, but this is so much better than it was before, it's hard to even compare the two. I'm confident in saying that what little power I have is delivered very predictably now. I couldn't say that last week, at all.



I also started the process of installing the seat I picked up from Mike at Okemo II. The seat itself fits beautifully, but the brackets I made don't clear an extra hump from the transmission tunnel, so I need to make a new inboard-mount. I hope to make time for that today, but it might get pushed off to tomorrow.



I'm trying to drop my under-hood pressures. I worked together a plausible prototype for a splitter that would accomplish that, but haven't had time to put together a mounting solution for it. I want to have better control over where air goes in the car, and how it gets there. Again, hopefully this weekend. Filling the gap between the splitter and the bumper is going to be a bit of a challenge.


As for next weekend, I'm making a concerted effort to reduce my body roll. It's too easy to upset the car during transitions, and I don't really have a reason to stay with the OEM dampers I have (all of them are in sad condition). I just received my dampers, and am waiting on some bump stops and a front anti-roll bar, all of which should come together to get more predictable handling.

Once that's all done, I think I will have maxed out what I can get from the car in SP6. I'll try not to change too much else during this season, and just focus on keeping Ascutney clean and starting to learn Philo on my rookie event there.

[drummingpariah]

I spent yesterday wrestling suspension components in. Right around when I finished everything up, I realized I could've just disconnected my upper a-arms on the front and saved myself about 4 hours, overall. Next time!

You may see a Datsun poking its butt out in the background. It's eagerly awaiting some heavy work that starts tomorrow. I'm extremely excited to see that come together.

[drummingpariah]

I haven't been happy with the audio I've been getting from the past few events (action cams tend to get more wind than engine noise), so I dedicated some time to sorting that out today. I used one of my cheap tom mics and a small Tascam dr60 to get some decent audio. I'm fairly pleased with the results, but I'd like to wire up a second mic for exhaust sound. I might also record some pace notes for my own reference in the future.

[Chief Geek]

I haven't been happy with the audio I've been getting from the past few events (action cams tend to get more wind than engine noise), so I dedicated some time to sorting that out today. I used one of my cheap tom mics and a small Tascam dr60 to get some decent audio. I'm fairly pleased with the results, but I'd like to wire up a second mic for exhaust sound. I might also record some pace notes for my own reference in the future.

Sounds good. Nice and clean.

Paul

[drummingpariah]

Minor winter update: I did some minor maintenance and finally got my 2015 tires and wheels combined. Here they are next to last season's wheels.


If I end up driving the Miata in 2015 (if I break the Datsun, or it's uncooperative in general), I'll have more grip than I did last season ... even if I have one wheel off the ground entirely.

[drummingpariah]

Now that it's not as winter as it had been, I invested a little time into the NA. I just finished taking my measurements for the 'other car' that I plan to race this season, but I'm sure I'll end up in the Miata again at some point (or I'll loan it to someone else).

Winter mode treated me well, with some quality un-studded tires (studded tires are legal in NH, but not necessarily everywhere else).


I had a minor off at Philo that dented the passenger's fender in, and rather than spending the time to try to bend it back, I just picked up a new one for $65 (including shipping). Swapping that was a painful, nightmarish learning experience. I'm going to have to be more careful with my fenders, so I don't have to do that ever again.



There was still a little bit of daylight left, so I decided to pull the winter tires off and put the race wheels on to test fitment. The winter tires have been REALLY noisy lately, apparently 185 series winter tires don't provide much grip at higher temps). Here are the 14x4.5's next to the 15x8's.


They ended up fitting surprisingly well on stock springs, but there's a little bit of fender lip rubbing while going over bumps so I'm going to have to roll the fenders in so I don't have any problems at race events. I may end up going with slightly stiffer springs, since these wheels alone will bump me up a class.


(before the suspension settled)

[drummingpariah]

Building a car is hard ... the cage for the FC has not gone well. I thought I had access to a mandrel bender, but it turns out that it was just a very nice hydraulic pipe bender ... so now I have a lot of excess 1.62" DOM tubing that I can't use. I'll be in the Miata again for Ascutney, and just ordered prebent DOM for it (modified spec miata design). Hopefully I can get tube bent for the FC by Burke, but one way or another, this should be my last event in an X-car.

This is the story of my life. Minimalism in the middle of excess.

[walterclark]

Wait. 1.62" DOM? That would be 1.75" OD .065 wall?