Could it be in the tune?
 

I recently picked up a Dprepared Miata for autocross. It's a 93 with a 94 1.8l. The motor has been built and has a stand alone megasquirt ecu.

Details
combustion chambers have been polish.
Ports polished and gasket matched.
s/s Supertech valves with stiffer springs, not oversized
stock cams.
Block was decked .015
crank balanced
Eagle h-beam rods with ACL race bearings.
Mazda 2001 pistons.
Stock lifters
3 angle valve job

It has a upgraded fuel pump, ss lines, a custom fuel rail and NB rebuilt injectors.

The dyno plot I saw showed 140whp and 123 tq. But doesn't that seem a bit low for the modifications? I still have a few questions for the previous owner that he hasn't got back to me on.

I'd appreciate any help or answers you'd have.

That sounds really healthy. Especially considering it still has an NA8 head that doesn't flow worth a darn. Fundamentally, it's a '94 1.8 with a compression bump. Everything else seems directed at durability or high-RPM safety.

What did you expect? Most your "modifications" are for track longevity and reliability, not power. That's actually pretty good all things considered.

Healthy motor, higher compression.

Just more strength in the parts & least likely to break.

Add flat top intake manifold and racing beat header? :dunno:

Flat top manifold won't fit his head. If he went to an NB head (BP4W or BP6D), he would definitely get some gains.

It does have a BP05 head. Reading back, that is misleading, sorry.

True. But I wouldn't mind more lol

I'm unsure if the intake has had any work at all, but I know the factory 1.8 header has had the welds ground out of the inside and re welded. Would I still benefit from a RB header?

And a few pics for reference.. This is during the motor swap
https://www.miataturbo.net/attachmen...ine=1462486980



https://www.miataturbo.net/attachmen...ine=1462486980

https://www.miataturbo.net/attachmen...ine=1462486980

BP05 is the OEM 1994-97 head. Bad choice (BP05 top, BP4W bottom):

https://www.miataturbo.net/attachmen...1&d=1462487561

Miata Engine History and Interchangability Guide

RB header is quite a bit better than the stock piece.

Interesting! Then I'll plan on another head build with cams, flat top intake and RB header.

Thanks, there goes the shock money. lol :bigtu:

Realistically you want a 01-05 vvt head. They top out the same as the 99/00 head but have a bit more area under the curve due to vvt. You will also need a ms3 of some type to control the vvt, or the diy autotune vvt tuner.

That's exact head I was starting to like. I have a megasquirt already in the car.

^+1.

Also, suspension/tires/seat time trump the little bit of power we're talking about here if you are after laptimes. I'd get the Xidas if I were you.

Never heard of Xida until now. I had Ohlins on the S2k that I ran in STR, I may see if MCS has anything for a Miata. But if the Xida work for the price, that would be awesome.

There are tons of different megasquirts out there. Only the ones of the Megasquirt 3 variety can control VVT. Post a picture of what yours looks like and we may be able to tell you what type it is.

Xida's are hands down the shocks to buy if you are tracking the car. Emilio@949Racing has put more R&D into miata shock development then any other company and has the wins in national races to back it up.

https://www.miataturbo.net/attachmen...ine=1462492487

https://www.miataturbo.net/attachmen...ine=1462492487

https://www.miataturbo.net/attachmen...ine=1462492487

Looks like a MS3 to me and seems like a really nicely set up car you picked up.

Thanks! A friend built it and raced in our region, he is a very talented machinist and welder. If he wasn't buying a house, I bet he wouldn't have sold it.

I haven't had the chance to run it yet, but I've been upgrading a few things that I see are inevitable, like the rear brakes to sport and 15x10's with 275's.

Those welds do look nice!

ms3x to be exact.

Rear Sport brakes offer a poor pad selection.