Im pretty sure i saw someone posted in the thread using e85 / race gas with the kit and hit about 230 i believe?

edit.. found it.. 100oct. 235

So 100oct? So maybe with e85 and some anger we are real close to my 250whp goal.

Seriously eyeing the TSE EFR solution. I just don't know if I could make it happen anytime soon which sucks since I'd reakky enjoy the fruits of my current efforts.

This would be my first turbo miata, but have no intentions of moving on from this one..fuck, do it once and do it right?

Will be your personal fitness trainer for turbo, includes a diet and work regimen.

New question, 6258 or 6758 for my goals?

6258 for sure. You can safely stretch the 6258 into the low 300whp range without turning it into a hot air machine, owing to the high-boost efficiency of the compressor. The 6758 spools extremely well, but it doesn't have the ultra-crisp response of the 6258. The 6758 feels like a turbo that spools really well, but a well-done 6258 setup almost doesn't feel turbocharged at all.

5951 I really want to see that fucker when it comes out.

Hey you have my same set up in mind, can you give me some perspective of the 6258? Let's say, rolling in 3rd at around 3000rpm, and you lean into the throttle, what's the spool up like? I am building a street car above all else so that "experience" of boost is quite important to me. Not sure if that makes me crazy or not.

But I guess I don't want that crazy laggy turbo, but I can't imagine the 6758 being described as laggy on a street car, maybe on the track where that ~0.5 is crucial.

Rolling into 3rd at 3 grand you have full boost.1st and 2nd are pretty much worthless to me right now on 205s. 3rd is the first gear I can really get on it. I feel it is the best street turbo for a Miata. It spools the same as a 2554 or better with a 100 hp more on top. The 6758 is a 400hp type deal from what I read. I am sure a few street guys will give the 5951 a go whenever it finally gets released but I am super happy with my 6258. My only issue is a lack of built bottom end.

Damn sounds like I am yet another candidate for the 6258.

Any suggestion on an intercooler I can use for stock block all the way to 400hp? I've seen some precision stuff and such but nothing set in stone for me yet. Just easy to set up with a good as can be efficient as possible up to those levels.

And any suggestion for downpipe back exhaust? Thinking ArTech's price can't really be beat.

If 400 is your goal then I would go 6758. Precision or maybe the larger vibrant? I went cheap eBay. Working great so far and was super easy to mount. 275-300 is my goal someday. I don't want to pop trannies all the time.

I have yet to find an IC that tops the Precision 350hp. Something with a Garrett core might compare. I peeked at the Spearco cores at SEMA this year and they look pretty poor inside.

I've got a larger vibrant core sitting on my porch, used about a month. Lmk if you want it.