Smedric

First of all Thanks to PurdueGuy for the advice in my n00b thread. Definitely going to go CAI, but had have questions about:

Throttle body bore - various performance web sites sell these, but aren't they just stock bored out? Can I have a shop do this cheaper and without the waiting on shipping time?

Exhaust - I basically want to do the header down (insert question about Throttle body but header instead), but I really don't want that buzzing, fart, rice sound (have gotten 100 dollar ticket for that before. Loud = bad) something relatively similar to stock sound but lower would be nice. Any companies I should look into, or just hit up Midas?

Tires/Wheels - I don't want to lose gas mileage, but want to get rid of the tires look small in the wheel well look. Its like they stick in to far. I at least want them to be level with the body. I am thinking 17" but know nothing about tires. What is to big and will mess up the great gas mileage...

Any way to avoid the distortion of the speedometer after changing tire sizes?

PurdueGuy

You can have a shop do it, or you can dremel it out - just put a taper up to the butterfly. Don't shave out around the butterfly, or it'll mess with how it works and you'll need a new TB. There are some aftermarket TBs (and a few individuals) that have replaced the butterfly with a larger one as well as boring out. Not that advantagious unless you're going turbo or something, though.

Thermal, HKS, or a shop-made mandrel-bent 2 1/4". Don't bother replacing the cat - it's high flow from the factory. Might replace the resonator with a long glasspack.

I guess the question is whether you plan to just get bigger tires to go on the current rims, or if you're getting new rims. If you get new rims, you can keep the speedo accurate by buying tires that are a profile that maintains the overall size (like 1" bigger rims + 1" skinnier tire = same overall diameter) I'm not terribly knowledgable about tires yet, though.

Smedric

Thanks for the response. Dremel it out huh, sounds like a good way for me to break my car (but I love doing that)

So, taper before and after the butterfly plate or just before?

With the tires, would like bigger rims with a normal tire I guess. I would like to close some of that gap between the edge of the tire and the inside of the well (along with wider, to bring them flush with the body) But really don't want to drop the car, I already bottom out on my driveway and half the streets here in Colorado... Stupid road construction here, seems they can't make intersections or business entrances level.

PurdueGuy

If you keep the speedo accurate, you're always going to have the same overall sized wheel, so the only way to get rid of the gap is to drop the car. Larger rims & smaller sidewall tires might help it look like there's a little less gap, but it will still be noticable.

TB boring - taper both sides.

Coldsolderjoint

if you go with bigger rims, the car will be higher and youll have to drop it unless you want it to look like a 4x4.

if you go with bigger rims, you have to go with a smaller tire, which will lessen the ability to fight off pot holes.

although I had 205/40/17's on my car, and never screwed up a rim on a pot hole, those rims were screwed up by my own bad driving and also that one curb i drove over.

theres some pics on my cardomain available with the link "website", under this post.

I liked them, but they were just alittle unpractical. They ended up costing around $650 mouted and balanced shipped from wheelmax.com

thats pretty cheap as far as rims/tires go. I calculated the speedo error with those rims and it was like 1 mph.. so it wasnt increadbly noticable

heres a link to the website you can use.

http://www.miata.net/garage/tirecalc.html

gas mileage will probably be affected some because the 17's are wider and you have more rubber/friction on the ground.

I wouldnt recomend dropping the car on stock rims, i did on my 14" steels, and I would bottom out on a speed bump. I think goldie had marginal success on his 15" alloys

as far as the throttle body goes, you could take it slow and find a cheapie junkyard throttle body to mod out as practice this way you dont mess up your car's driveabilty.

*warning*- downer alert here: as for the exhaust, I would recomend just chopping off the stock muffler and welding on a magnaflow street series muffler. It will sound pretty good. I honestley dont think that youll notice much gain for the money youll spend on a custom exhaust.. that is.. if your just gunna be a tuner instead of hardcore engine mods.

but, for that muffler, I chopped it off and put my stock muffler back on because i needed to drive 1000 miles to school each way. It will get on your nerves and you will find new vibrations and buzzes that you never thought your car had. So... if you want a comfortable daily driver.. keep it stock

same thing goes for motor mounts if you ever think about getting those.. be forewarned.. they will make your car shake like a mother.

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Eddie
SPOC-NJ