ali123

Hi guys, i tried Googling this but came up with different price answers. I'm looking to build a budget 1.8 300hp Miata. (used parts, diy, etc). How much would it cost me to get there? Really sorry if this has been answered before.

Thanks

Reverant

iTrader: (10)

About $10k minus the depreciated value of the used parts.

Leafy

iTrader: (1)

Can you weld? If you pull everything out of my build except the things required to make it to 300hp, I'm around 10k but I did it in baller fashion.

If you can weld and assemble an engine I think you could do it for around 5-6k, but you can hit 250hp for 2-3k without knowing how to weld or assemble an engine.

Erat

iTrader: (5)

How long do you want it to make 300hp for?

I could probably do it for a few hundered bucks and some zip ties. You guys need to step up your game, 10k... pssh.

ali123

Hmm it seems like 250 is the better option then. Is that WHP? My budget is about 3k and my friend is a mechanic so I can get him to help me weld.

Thanks

Leafy

iTrader: (1)

Yeah the difference is, 250ish is the limit of stock internals, over that you have to open it up, and the price jumps.

Chiburbian

iTrader: (1)

Am I correct in stating that the external engine parts are pretty much the same for a 250 and 300hp build, but it is the internal engine upgrades that bump the price up to near $10k?

Aside from the internal upgrades I can think of the following upgrades that are necessary:

Upgraded radiator and fans. (Don't remove undertray and ensure air is ducted into radiator and then out if engine bay)

Coolant re-route

Next "level" of clutch. I recommend 949 Supermiata ceramic sprung... I'd say upgrade this once and be done with it.

Anything else? 3" exhaust?

Leafy

iTrader: (1)

More or less. You might run a different turbo between 250hp and 300hp, but in the Garrett range they're more or less the same cost.

fooger03

iTrader: (2)

transmission, clutch...
https://www.miataturbo.net/diy-turbo...k-links-56507/

Efini~FC3S

iTrader: (4)

Cheapest way to 300(w)hp:

ebay t3/t4
Log manifold that you weld yourself
ebay intercooler and pipes
Homemade MegaSquirt
Cheapest 600cc+ injectors you can find
Cheapest clutch upgrade you can find
E85

Then you'll need to build an engine with at least ebay forged rods, stock pistons are probably ok (especially if you're running e85).

It's been done before on the cheap, there are a couple builds thread here where people are making 270+ at the wheels with a ebay t3/t4. Megasquirt or equivalent engine management is required. If you're able to do this all for as cheap as possible, then you get to hope and pray your transmission lasts longer than 10 minutes...

Erat

iTrader: (5)

Your mechanic friend can help you weld?

Hmm

I wonder if my lawn care friend can help me do some electrical work.

pdexta

iTrader: (17)

That's a pretty good list, of course there are a lot of little things that you don't think about; oil lines and fittings, BOV, couplers/t-bolts, wideband, reroute, etc.

Also add at least a downpipe that's dumped with no exhaust. For practical purposes you really need a 6 speed. If it's a 1.6 you definitely need to swap out the rearend/axles/driveshaft and a 1.8 motor would be a wise move.

Then you get to things like wider wheels, softer/wider tires, suspension, brakes, etc. Things you don't "need" to hit 300whp, but you're going to want them so the car isn't miserable to drive.

Tekel

iTrader: (2)

I doubt it, but since he is working outside all the time and is near the outside of your house he can do your siding, brick work, and roofing.

ali123

What would that setup get me using 94 gas? (best here in Vancouver) and is this pretty much the same path to 250whp for under 3k?

Thank you

FAHREN

read

Erat

iTrader: (5)

So you'll let the guy who cuts your grass, roof your house.

Noted.

Efini~FC3S

iTrader: (4)

For 250whp you don't need such a big turbo. Any t28 size-ish turbo should do.

Also, for 250whp you don't need to build the engine with forged rods. A stock engine can make 250whp and if the tuning is good, it can be reliable.

And yes, you could probably make 300 without E85 but it's going to take more boost, and the engine won't be as happy about it.

And yes, my list certainly wasn't complete, you need a downpipe and as big of an exhaust (preferably 3"), a blow-off valve, oil feed and oil drain, etc. etc. The little details can add up to a lot of money.


250whp is certainly do-able for $3k, but you need to have some pretty good DIY capability. Building the manifold, downpipe, and exhaust will save a lot of money. If you can solder and understand electronics, building a MegaSquirt yourself will save you a lot of money. If you can cut and fit the intake and intercooler piping (and weld?), again that's going to save money.

Cheap hand-made, DIY turbo set-ups have been discussed here many, many times. I know the search function on this site isn't the best, but the info is here.

Staffah

How did you come up with 300hp? Have you driven in a 200whp Miata? What is the intended purpose of the car? What are the emission requirements of BC? Depending on whether you can run standalone factors into the quality of the tuning. Wait for the right used kit to show up on the classifieds here.

18psi

iTrader: (76)

He pulled it from his butt.

This is why I try not to waste time on threads like this anymore.

Efini~FC3S

iTrader: (4)

Here:

Cheapest way to ~300whp

https://www.miataturbo.net/diy-turbo...results-11402/