SlowTeg

Hey guys, new around here. I recently picked up a 99 w/ 130k miles, NB1 miata. I'm not new to the track or track cars but been trying to gather all the info I can to try and do things right the first go around. The goal is a 220-250whp fun track car.

For cooling, is there a goto radiator option? I see Supermiata makes a crossflow radiator as does FM. The car came with a Megan Racing radiator which I'm guessing won't cut it with boost..?

For hubs I ordered a set of BroFab hubs. They seem like a solid option and should hold up better than new OEM hubs.

For brakes, the car has the non sport brakes. For the front the Afco 11.75x1.25" supermiata BBK seems like the way to go. For the rear, is it best to upgrade to the rear sport calipers and rotors, or will just the rear sport rotors (with some brackets for the non-sport calipers) be good? Is it also worth upgrading the stock MC? I see people have mentioned going to a full 1". Is there a preferred option? I like a nice stiff pedal and apparently the 99 has a smaller MC so it seems like a no brainer to replace the oem ones as I'm sure it's tired. Should I also consider upgrading the brake booster? Finally.. brake ducts.. with a turbo are brake ducts a pain to run? I'm personally opting towards getting the car running, seeing how pad life goes, and adding ducts later if need be but appreciate any input.

I'm sure I'm leaving out some other questions but for now that's enough. Obviously I will be getting a rollbar, seats, harnesses, but that stuff seems fairly straightforward. The Kraken kit with the 2560 with good vents seems like the way to go. I will remove the AC to allow better airflow to the radiator.

Any suggestions I'm all ears. I appreciate any help/input.

rjacobs

Supermiata radiator with a reroute here. No issues on track in the heat of the summer, but im just N/A, not boosted. Hottest day on track I think track temps were between 120-130, ambient was like 110... brutal... but the car ran great.

If you go with the big Afco setup you may or may not need cooling. I've got an 11.75x1.25 afco setup(not the supermiata one) and I put Foxhole Fab ducted backing plates on when I put the car together, but not running any hoses to them currently. You can add ducting later if you need it pretty easily.

As far as the M/C goes, I know there are a few pretty in depth threads on it, but MOST are talking about factory brakes at all 4 corners. With the big Afco's up front and their braking ability, you may or may not want/need to change the master. NOW a manual rear prop valve is a must to balance things out. Im on full sport rears, not brackets. My prop valve is only turned in about 1 or 1.5 turns so it doesnt take much, but maybe you like slightly more rear bias than front, you can adjust it.

Manual steering conversion... these cars are known to boil power steering fluid on track. Do a good one where the sector shaft is welded and the internal piston is removed, dont just pull and cap all the lines. Local guy here to Dallas does a really nice one with everything welded up and painted.

Put good coilovers on it... Xida, MCS, Penske's, etc... and good bushings. Im running A1GC delrin, or whatever they call it. Supermiata 863 bushings are another option that, since they were re-designed, seem to be a pretty solid choice also.

Theres other stuff down the rabbit hole like aero.

SlowTeg

Thanks, someone mentioned the wilwood prop valve and it's on the list for sure. With the larger Afco's the thinking is the larger pistons would require more pedal travel to move the larger pistons. A larger diameter MC would compensate by moving more fluid, reduce pedal travel, and result in a firmer pedal..? The MC has to be replaced, so I hate doing things twice, I figured I'd just get the correct one from the beginning. I get changing the MC and booster is a bit more subjective though.

Interesting that's not something I heard.. I was contemplating going to a depowered rack but with wider tires I figured the powered rack would be nice. Does anyone make an underdrive pulley for the ps pump to maybe reduce assist?

Plan is to replace all bushings with some stiffer rubber bushings and mounts. The car has some (likely crappy) BC coilovers on it but I might just run them for the time being..

Ya that's a rabbit hole I hope to delve into later on. Maybe I can just get by with hood vents, ducting and sealing airflow to the radiator, and a big wing..

rjacobs

IIRC the piston area on the AFCO's isnt really that crazy compared to stock, but their braking ability far surpasses what a stock setup can do so need to be able to balance it. As far as M/C size, im not help because I run Honed booster delete which recommends a 7/8 M/C so I went the opposite direction of most people.

Ive never heard of anybody messing the power steering pump except to delete it all.

There is a massive bushing thread here to get lost in.

And as far as aero if you do a big wing you need a front air dam and splitter to balance it out... Your front grip will suffer and the car will be difficult to drive. Buddy of mine found that out as he was buying his aero in stages and did a track weekend with just the 9 live big **** and said the car was actually slower because of the understeer he was constantly fighting due to front grip.

Z_WAAAAAZ

Only got a little time to mess around before my lunch break is over so I don't have time to put my two cents in for every question.

I ran the 11.75x1.1 Supermiata BBK all last season at 210whp. My setup included sport rear brackets, rotors, and calipers w/ steel braided lines, G-Loc R12 front and R10 rear pads, stock 7/8" master cylinder, an adjustable prop valve, and master cylinder brace. I didn't add the SuperMiata brake ducts until my last event. My car is dual duty so I run the R12/10 combo on track only and run G-Loc GS1 pads front and rear on the street. I got 7 and a half track days out of the R12 front pads and still have about 40-50% life left on my rear R10s. My brake pedal feels almost exactly like a fully stock setup with steel braided lines, maybe a touch firmer. I was honestly surprised I didn't notice a bigger difference as I installed the big brakes and MC brace at the same time.

Also running BC coilovers here. Xidas are on my upgrade list but I have no complaints about these right now.

SlowTeg

Gotcha.. I read some threads with people complaining about mushy pedals but it's definitely subjective.

Did your friend add any front aero at all? I am planning hood vents. Some people don't think of them as aero but I installed hood vents in my s2k and a big wing at the same time.. I was surprised how the car didn't understeer and was fairly neutral. It tamed the rear end down at speed with just a touch of understeer. I'm hoping the miata will be the same, we'll see.

SlowTeg

Appreciate the response. Thanks for your real world experience w/ the brakes. I am always left scratching my head because you have people say completely different things. Some people say the 11.75 kit will be way too big but clearly that's not the case for everyone. A lot of it comes down to driver. If you're slow, you're not going to be taxing the brakes, or you're just easy on the brakes. 7.5 days isn't a lot but it's also not horrible especially if the pads are affordable. That's good to hear on the brake feel. I prefer a stiff pedal with a shorter throw.

Ya I'm hoping the BC's will do alright. I haven't given them a fair shake. Old bushings I'm sure made my initial impressions worse.

rjacobs

He MAY have had hood vents at the time, but I dont know to be honest. He now has the full 9 lives front aero setup on his car so its all balanced.

SlowTeg

On the topic of bushings, can you comment on your delrin bushings? Are these Sadfab or some other mfr? I was originally planning on just doing a stiffer rubber bushing for ease of maintenance and disdain for poly bushings but maybe delrin or other kits are better than the old ES kits. Any issues with your bushing kit?

rjacobs

as I already posted they are A1 Ground Control sold through Miata Roadsters... As far as I know Sadfab is out of the bushing market.

I love them, but again, my car see's zero street miles. They have basically zero compliance. Once step below a spherical.

Supermiata bushing kit is "similar" except instead of using delrin they use poly, but both kits have a steel sleeve in the middle that the bolt rotates around. The delrin or poly is just basically to hold the steel sleeve in place and provide "some" cushion.

I would recommend the A1GC kit 1000%, but again, its not much of any compliance and for a car that might see the street it might be to harsh... im running 1200/650 springs on my car also so its kinda hard to judge, but no complaints from me on the A1GC bushing kit.

SlowTeg

My apologies, I punched in A1GC into google with delrin bushings and it didn't come back with anything. I didn't know what the acronym stood for. It looks like they are currently out of stock.

The car will primarily be a track car with occasional street miles. It looks like the A1GC bushings are out of stock. I will likely just get the stiffer than oem rubber bushings and call it a day. I know some very good drivers who run the same rubber bushings so if/when I get to a point where I'm pushing the limits of the car and notice some issues I'll cross that bridge then. Thanks appreciate your input.

Gee Emm

Not sure why anyone would build a delrin-based 'poly-bronze' bushing. Delrin is stiffer than (most?) poly, a plus for racers, but delrin lacks the 'stiction' effect that the bronze bushing is meant to overcome. This requires no lubricant, presumably a steel/steel bushing would wear without the lube. Having used rubber (factory), poly, poly-bronze, and delrin, and currently running sadfab poly-bronze in my road-biased dual duty car, I vote poly-bronze for all but the most hardened track weapons, for which delrin-no-bushes would be my choice.

rjacobs

There has to be a reason that nobody runs straight delrin with no sleeve. I am pretty sure even Sad-Fab's delrin kit had the steel sleeves.

Gee Emm

From memory (quite a few years ago), my delrin went into the outer bushing housing, there was what I called a hollow 'pin' (about which the delrin rotated), and the suspension bolt went through the pin and held the pin tight (ie not allowing the pin to rotate). That replicates the poly bushing arrangement, and doesn't need a sleeve as the delrin rotates freely (without 'stiction') about the pin. The poly-bronze arrangement inserts a bronze tube (sleeve) between the pin and the poly, it is held by the poly and rotates with the poly about the pin. Again from memory, all this is set out in the bushing megathread.

rjacobs

The delrin in the A1GC setup is pressed into the control arm and doesnt rotate.

The delrin then needs to be reemed so the steel sleeve can rotate freely with very little slop.

The steel sleeve is what contacts the sub frame when everything is torqued down. So the steel sleeve rotates inside of the delrin. The bolt just basically aligns everything at that point and holds everything in place.

Gee Emm

I think we are in agreement: The delrin moves with the suspension arm - that is, the arm/delrin rotates about the fixed pin(sleeve) which is held immobile by the suspension bolt. I look at it as the suspension arm moving relative to the car, you can look at it the other way around I guess.

IIRC in my instructions there was a suggestion that if the delrin was a looser fit in the arm and might/did rotate inside its housing, to pin it with a grub screw or similar. I never had to ream mine, but again that was mentioned as a possibility that may be required.

SlowTeg

Question for you guys.. so is the OEM NB TB ok as long as you put some epoxy over the shaft/screws? It seems like the skunk2 has its own set of problems..

rjacobs

as long as you leave the intake manifold to block brace on you shouldnt have any issues.

It seems to be when people remove that brace that they have issues.

Gee Emm

None of the S2 problems involve the ingesting of a screw.

None of the remedies to stop stock TB breakages are guaranteed, including epoxy, including the brace.

Don't be frightened, read the S2 threads, the fixes are kid's stuff and work, so you never again have to worry about whether the epoxy is going to work or the brace is working, maybe the screw won't do any damage on the way through ....

SlowTeg

Any links to specific threads? I've been doing so much reading/digging over the last few weeks and I'm sure I'm still forgetting stuff. I'm all for changing things to avoid failure points, especially in a 25yr old car. It's clear the OEM design is pretty weak and adding stiffer mounts, power, etc. only adds more harmonics/vibrations to the engine which contributes to different failures. I appreciate the input from everyone and ultimately I might just err on the side of caution and get the skunk2 TB. I haven't started tearing into the car but will soon.

One question for you guys. It seems like Megasquirt is the goto standalone for Miatas. Is there a multi gauge setup/output that reads the CAN bus from the MS? My thinking was to run the standard oil press/temp into the MS and have an output (maybe via the CAN bus) to a gauge setup. Either a simple 2" gauge like gaugeART or some kind of tablet? If someone could point me in the right direction it would be much appreciated. I've been digging through build threads to gather more info but I could probably spend a year or two just digging in my spare time before I go through most info on here.
Edit: Man, there is a lot to digest with regard to displaying data including digital dashes.. Very cool.