What air intake/exhaust/radiator for NB Miata?

My sons car. It needs a radiator and exhaust, and he just wants an air intake. This is a daily driver, 365 days a year in northern Ohio, so durability is my primary concern. His is sound. The car currently has the Flowmaster muffler on a stock system that was on their when I bought it, and he doesn't like the sound. He also wants the air intake more for sound than anything. I know how that sounds - flaky. But his brother has a 300hp mustang and I just want to do some relatively inexpensive stuff to make him happy. So I'm thinking a stainless steel exhaust would be smart, and every air intake I can find just sucks in hot engine air. Are there any that don't? I saw the tube on the Flyin Miata website that takes in air from the cowl, but I'm not sure I want to cut the cowl to install it. And what's the deal with Miata exhaust system pricing? I bought a full stainless magnaflow dual exhaust with x-pipe for my mustang (on sale) for $375. Why do Miata systems cost so much? I don't get it. Anyway, and suggestions would be appreciated.

I like the K&N intake. Dunno if it makes power, but it sure looks nice and makes fun noises, no cutting required.

Exhaust... thems the breaks. There's been a lot of noise recently about the Roadstersport 3 exhaust. My previous red NB had that setup on it, it sounded nice. Can't speak to the power aspect of it, the car felt like a slug. Every car i've ever heard with an FM exhaust sounded great. Enthuza makes nice stuff, light, stainless, and usually loud. My own recent exhaust purchase was a Hytech setup off of one of the Blackbox Exocets that people are currently complaining about in the classifieds. Light, beautiful, and will probably be nearly unbearably loud.

Radiators, lots of nice choices. FM crossflow is awesome, Koyo Hyper V, CSF 42mm, etc etc etc.

Well to answer the pricing question there's about 10,000:1 Mustang to Miata ratio. And in the rust belt I would definitely go stainless.

I'd recommend an AEM Dryflow filter with prefilter bag, connected to the engine with Spectre modular chromed ABS pipe, and being fed the coldest air possible from the front of the car - how you achieve that depends on how much room you have.

For exhaust, stainless is always better if you can afford it even if only because it lasts longer - but it helps keep the exhaust heat where it should be (in the exhaust gases) too.

For a radiator, the best design you can get when sticking to stock size & layout is an all aluminum 3-row 3-pass, if you can't find/afford one of those get an all-aluminum 2-row 1-pass.

The Borla cat-back is under $500 and sounds pretty nice, in my opinion.

Summit racing link

In reply to jstein77:

I do too, but that's for an na, not an nb. They only show the muffler for the nb.

Racing beat exhaust, ddm intake, and ebay aluminum radiator

Any radiator will do; generally the end caps blow out before the radiator coils themselves fail. You are limited on air intakes since many of the early systems caused CEL's. A K&N with simple heat shield does as well as anything else. A cat-back system is all that you will find for NB's and as stated above, the market knows what people are willing to pay for a good exhaust system.

Full exhaust header-back is available for NBs from quite a few vendors.

bravenrace wrote: In reply to jstein77: I do too, but that's for an na, not an nb. They only show the muffler for the nb.

That's because of how Mazda built the NB exhaust system. There's a flange at the end of the downpipe and one at the rear axle. Basically, it's as if the cat pipe is 6' long. If you want to replace that as well, you're looking for a midpipe.

As for pricing, well, we don't carry any parts that are cheap and nasty. All our exhausts are built in the US out of stainless steel (including the flanges) and carry a lifetime warranty. We couldn't even build the equivalent Mustang exhaust for the cost of that Magnaflow setup.

I believe the answer to the answer in this case is a spinning turbine in the exhaust.

The exhaust and intake is just noise and very little gain compared to the price, IMO.

Save the money and buy a FM Turbo kit and enjoy actually having more power.

Keith Tanner wrote:

bravenrace wrote: In reply to jstein77: I do too, but that's for an na, not an nb. They only show the muffler for the nb.

That's because of how Mazda built the NB exhaust system. There's a flange at the end of the downpipe and one at the rear axle. Basically, it's as if the cat pipe is 6' long. If you want to replace that as well, you're looking for a midpipe.

^This. And, if you are replacing it, I might be interested in that old 6' long cat pipe.

I think I need to add/clarify a couple things.
1 - The current exhaust came with the car and is cobbled together and leaking. I was thinking that if I was going to replace it, why not do it with something sporty. My Magnaflow exhaust is the highest quality pre-bent system I've ever used, and I've used a lot of them. I don't need anything better. I just thought I'd get people's opinions on the sound, fit and quality of different systems out there. I'm well aware of the stock design of the mid-pipe/cat. Currently the pipe is a slip fit over the cat outlet. In any case, it needs replaced. I'm not sure how that design precludes the sale of a mid-pipe. If I can't get one that slips on or welds on, then I'll buy one with a cat connected to it, but I still need to get one.
2 - The air intake is because his old car, a CRX si had one on it when I bought it and he likes the throaty sound. I don't see a problem with that, as I like it too. But I'd also like to pull in something other than hot engine compartment air. So what brand does that best without cutting up the car?
3- The radiator is leaking. The car is stock. I need a stock replacement radiator. I was hoping to get suggestions on what brand might be better than another.

Moss has some interesting intakes that aren't totally hot air intakes. No idea if they net any power but look interesting and are what I'd get if I had a street driven NB. http://www.mossmiata.com/Browse/PlateMenuProducts.aspx?WebCatalogID=39&PlateTypeID=1&SubcomponentID=234&ComponentID=31

As for radiator, I like the Koyo. Fits well and long lasting. Most of the cheaper ones wind up needing replacement from what I've seen with my local Spec Miata guys. However, if you aren't tracking the car, I'd just get a stock replacement for under $100 and spend the savings on power or tuition or... There are a few of my Spec Miata buds in my region running with a stock radiator.

Nothing's stopping you from buying a full exhaust system. But you'll find that they're usually listed as two separate pieces.

The slip joint in your car currently is not a factory joint. Thus you will not find any aftermarket units that share that slip joint other than possibly the company that built the aftermarket part in the first place. If it's a cobbled together muffler shop job, don't even bother to look.

If you buy the FM exhaust, you'll no longer be able to say the Magnaflow unit is the highest quality system you've ever used

bravenrace wrote: 2 - The air intake is because his old car, a CRX si had one on it when I bought it and he likes the throaty sound. I don't see a problem with that, as I like it too. But I'd also like to pull in something other than hot engine compartment air. So what brand does that best without cutting up the car?

You shouldn't have to cut up the car, basically there are 3 approaches to getting cold air into the filter:

1. Put the filter at the very front end of the car with a long intake
2. Create a partition near the front of the engine bay that will receive cool air and put the filter in it
3. Run cool air from the front of the car to the filter through ducts or hoses (ideally with a box or partition)

You can use the pricey brake vent hose or any kind of hose that's handy - look into "barber shop hose" meant to carry hot air.

bravenrace wrote: 3- The radiator is leaking. The car is stock. I need a stock replacement radiator. I was hoping to get suggestions on what brand might be better than another.

Honestly, once you go all-aluminum, the quality difference between the eBay specials and the pricey name-brand stuff is nowhere near what the price difference would suggest - I'd have no problem running a cheap all-aluminum radiator. Usually it's the plastic end tanks that get you. The cost premium of the pricey stuff will get you welding porn, maybe a good warranty and better efficiency - but that cheap aluminum rad will still be leagues better than OEM-grade stuff.

GameboyRMH wrote:

bravenrace wrote: 2 - The air intake is because his old car, a CRX si had one on it when I bought it and he likes the throaty sound. I don't see a problem with that, as I like it too. But I'd also like to pull in something other than hot engine compartment air. So what brand does that best without cutting up the car?

You shouldn't have to cut up the car, basically there are 3 approaches to getting cold air into the filter: 1. Put the filter at the very front end of the car with a long intake 2. Create a partition near the front of the engine bay that will receive cool air and put the filter in it 3. Run cool air from the front of the car to the filter through ducts or hoses (ideally with a box or partition) You can use the pricey brake vent hose or any kind of hose that's handy - look into "barber shop hose" meant to carry hot air.

bravenrace wrote: 3- The radiator is leaking. The car is stock. I need a stock replacement radiator. I was hoping to get suggestions on what brand might be better than another.

Honestly, once you go all-aluminum, the quality difference between the eBay specials and the pricey name-brand stuff is nowhere near what the price difference would suggest - I'd have no problem running a cheap all-aluminum radiator. Usually it's the plastic end tanks that get you. The cost premium of the pricey stuff will get you welding porn, maybe a good warranty and better efficiency - but that cheap aluminum rad will still be leagues better than OEM-grade stuff.

Intake: Miatas are special. Cowl is the best area.

Radiator: FPI is a real thing with the ebay stuff.

We have tested non-eBay aluminum "race" radiators that did not perform as well as OE. Factory engineers know what they're doing.

Keith Tanner wrote: We have tested non-eBay aluminum "race" radiators that did not perform as well as OE. Factory engineers know what they're doing.

Was that a 1-row? If so I wouldn't be surprised, but most of them are 2-row, and it would take some real dunce work to make a 2-row rad worse than a 1-row of the same size.

GameboyRMH wrote:

Keith Tanner wrote: We have tested non-eBay aluminum "race" radiators that did not perform as well as OE. Factory engineers know what they're doing.

Was that a 1-row? If so I wouldn't be surprised, but most of them are 2-row, and it would take some real dunce work to make a 2-row rad worse than a 1-row of the same size.

Real dunces design and manufacture $99 52mm radiators.

Keith Tanner wrote: We have tested non-eBay aluminum "race" radiators that did not perform as well as OE. Factory engineers know what they're doing.

What method did you use to test them?

I have this on my 99

http://www.racingbeat.com/Miata-1990-2005/Intake-Kits-Air-Filters/56502.html

And have thought about adding this

http://www.racingbeat.com/Miata-1990-2005/Intake-Kits-Air-Filters/56499.html

But I think I can make an aluminum box that works just as well for less cost. Regardless, with the OBX header (Racing Beat tri-Y knockoff) and the open element, the heat noticeably affects power. I'll need to come up with something effective soon.

In reply to mapper:

Get the header ceramic coated inside and out, keep the heat in the exhaust and out of the engine bay. I did this on my 924 and it made a huge difference in underhood heat.

bravenrace wrote:

Keith Tanner wrote: We have tested non-eBay aluminum "race" radiators that did not perform as well as OE. Factory engineers know what they're doing.

What method did you use to test them?

Not all the numbers are published, but here's a description of the testing: https://www.flyinmiata.com/tech/rads.php

The ineffective rad was a dual core. People don't like hearing this, but it's true. Just because it's shiny doesn't mean it's good.