2.0L BP4W 182whp
 

https://www.miataturbo.net/attachmen...ine=1328923775
http://949racing.com/server/crusher/...o_021012_w.gif
This is the engine we built for the OGK last year. Finally found time to get it into a car and run it. Some details:

85.5mm, 11.0:1Supertech pistons shaved to get to 10.5:1 BP4W, ported and polished SuperMiata shim under bucket lifters, Supertech 1mm oversize valves, Supertech single valve springs, custom .425 lift, 272° cams, lightened crank, BE oil pump, M-Tuned forged rods, ACL race bearings, adjustable cam gears, MS3 DIY PnP with sequential fuel, Racing Beat header, square top intake manifold, OEM T/B, COPs Toyota.

We spent about an hour on the dyno today with it. Still needs another hour or so to get the rest out of it. Still has a fairly conservative timing map and can probably take another 2-3° above 5000rpm. Have not messed with cam gears yet and that will probably yield some gains.

Running CA91 here. Rev limiter set at 8200 but it was still pulling obviously. Guessing it'll nose over at 8400 or so. 272° isn't very long and I don't think the OEM square top will allow much more than that. In fact, I'm wondering if the flat power isn't an indication of intake restriction from the manifold. We'll see the next time we go back. We have a B18/BP4w hybrid manifold to throw on there. That and E85 will get it past 200whp I'm sure.

Then we add the C30-94, or Borg-Warner 6258

image attachments hate you :(

Good HP numbers, but how much torque is that red x laying down?;)

Mad skillz... they be mine! Linked from 949 and m.net.

https://www.miataturbo.net/attachmen...ine=1328924151
This is the engine we built for the OGK last year. Finally found time to get it into a car and run it.
Some details:

85.5mm, 11.0:1 Supertech pistons shaved to get to 10.5:1
BP4W, ported and polished
SuperMiata shim under bucket lifters
Supertech 1mm oversize valves
Supertech single valve springs
Custom .425 lift, 272° cams
Lightened crank
BE oil pump
M-Tuned forged rods
ACL race bearings
Adjustable cam gears
MS3 DIY PnP with sequential fuel
Racing Beat header
Square top intake manifold
OEM T/B
COPs, Toyota

We spent about an hour on the dyno today with it. Still needs another hour or so to get the rest out of it. Still has a fairly conservative timing map and can probably take another 2-3° above 5000rpm. Have not messed with cam gears yet and that will probably yield some gains.

Running CA91 here. Rev limiter set at 8200 but it was still pulling obviously. Guessing it'll nose over at 8400 or so. 272° isn't very long and I don't think the OEM square top will allow much more than that. In fact, I'm wondering if the flat power isn't an indication of intake restriction from the manifold. We'll see the next time we go back. We have a B18/BP4w hybrid manifold to throw on there. That and E85 will get it past 200whp I'm sure.

Then we add the C30-94, or Borg-Warner 6258 or 7064. Decisions..

I'd guess the header is more of a restriction than the intake. The collectors suck ding ding, and the primaries are pretty small on the RB header.

BTW, did you guys sonic check the cylinders on the block you used, or have you found Miata blocks to be plenty thick for the 85.5 bore size?

Aww, you took all the fun out of it. I wanted everyone to guess what the engine was. Image thing is a mt.net glitch.

As long as we're sharing..

M-Tuned fuel rail
Injector Dynamics 1000cc @ 60psi
Hondata manifold gasket
NGK BKR7EIX-11

We sonic test every engine we build.

Emilio, any way you'd post the current maps for that thing? I'm building a similar motor and could use a great starting point!

Thanks,
Greer

Nope. Use MS3. Pay for Tuner Studio. Let software tune your car for you. Win.

I do some manual here and there when the changes are big, or experimenting but we get some great looking datalogs letting the software tune itself.

I know what I'll be building now :)

There's a manifold for the chrysler 2.0 (neon) with huge runners / plenum that makes the power flatten like that:

https://www.miataturbo.net/attachmen...ine=1328929146

Have you found many that aren't suitable for use with the bore that large, or are most of them fine? 2.5mm over sounds REALLY big for pedestrian engines like this.

Well my tec-2 is driving the motor so tuner studio and ms3 just aint there right now. I was looking for timing & a/f values as a reference.

-Greer

12.8-13.0 AFR. 26~32° on top

Thanks, I'll work between the OE maps I can grab and some stuff here. I appreciate it. The tec-2 is outdated so support is limited but any bit of data helps.

-Greer

This is VERY relevant to my interests.

Fantastic numbers so far Emilio!

Where did you get the cams from?

Custom from Steve Gruenwald (Integral) before he sold his designs to Megacycle. Good luck getting cams from them.

Head gasket?

Stock 94-00, trimmed a few thou to clear pistons.

Why so little compression?
Shitty gas?

F/I in the works. In which case, it's a bunch of compression :)

The culprit

https://www.miataturbo.net/attachmen...ine=1328952758

I did notice some components missing; most notably the ATI damper and a crank scraper. Budget issues? Also why no VVT?

Anyway, great numbers. Really eager to see what this baby does with more tuning, a better manifold and E85.

Custom crank scraper and baffle. ATI damper not needed, particularly with BE pump gears. We started this engine project two years ago, before I was confident we could get VVT management working smoothly. Now of course, it's easy. But the head is done and has a lot of work in it. So we'll run it as is and just give up some torque. C'est la vie.

Oh yeah, ARP head and main studs.

what is the bracket between the radiator and engine supporting, an oil cooler of some sorts? or?

plenty of room for the Rotrex

Oil cooler

So, what kind of power are you hoping to generate with fi?

I've noticed that you list 300 whp as a safe limit with the 85.5 mm pistons, but with the use of e85, I'd wager you are hoping to get to 400ish?

Flat timing above 6500?

I'm not set on a power number. To reach the lap time and race goals I have for the car I think it will need 350-400whp. If we have a bore related problem we will build another one with smaller pistons, 11.0:1 and a VVT head.

Oh how Id love to see this thing mated to a borg on e85.
Also, and this may be a dumb question, but: what is the big dip in hp/tq at 3800ish?

I have an 11.5:1, knife crank, 85mm bore, ported 99 head in the garage. It's really sad because it needs a car, VVT head, and MS3x. I should also note that its not "my engine", lol.

It will be interesting to see what my stock VVT engine does on sweet, Texas 93-octane. I wonder how it will compare. Are you det limited or did you see MBT at peak efficiency range? I love peak-efficiency at ~6000rpm, lol.

Sleeves ftw!!!

No, it ramps just a little bit. I think that flat power on the top end is more airflowc related than anything else. Probably intake manifold but possibly cam timing too. Steve did not give me recommended lobe centers so my starting point straight up could be way off.

For those asking questions about the tune, power band and such, it only has a rough tune now. It will get some other hardware and a lot more tuning so don't read too much into where it is now.

This thread burns my ass. If we had the knowledge we had today when I bought all this turbo ----, I'd have a 10-11:1 bottom end, VVT head, and probably 180whp rather than another $5000 in turbo stuff so I can turn the boost down to ~210whp.

I know. It has me debating buying a cheap roller and building a VVT track car instead of pursuing a turbo TTB-A car. I got the chance to drive a CSP car with 150whp and it was amazing to drive. The simplicity and reduced thermal load of a NA car is very tempting given what my track budget may end up being.

I'm not so sure a 200hp NA car makes less heat than a 200whp turbo car.

True. I should have worded that better. I could live with 150-170 whp if it meant keeping inside the confines of a budget and reduced maintenance costs.

Wrap the 400 dollar header. Notice the size of the radiator?

There are too many variables. Does the manifold really return that much more heat through the head?

Emilio, do you know of a source for vvt cams other than megacycle? I have found no other place.

How much do you have in the current head? What did you have done to it?

I think I too am part of the crowd that would rather have a 200HP NA rather than a 300HP turbo for simplicity sake. However, I am where I am, and that is what I will continue to run.

Emilio do you think a 6258 will reach your 350-400 power goal estimate? I'm excited to see the fi direction you go in.

Hey gays did you notice that the car has 272 cams??? They are prob worth 20hp. My point is that this is a very NOT STOCK MOTOR na build.

Enough with the tech talk. What real car guys want to know is what stops the passenger side headlight from vibrating?

Who said it was? It's an expensive built motor and I make no pretenses to the contrary.

Maruha

Mazda Motorsports had blanks a little more than one year ago, I'll give the last known one to a cam designer/grinder tomorrow.

Mazda might find a new foundry for VVT blanks sometime. Otherwise you have to weld/grid the stock one.

I hope to get my build just behind Emilios numbers in the end, although using 84mm ST and only going to 7500.
But I have Jenveys on the shelf and a decent header would also be needed (Staal looks good). But I will start with a squaretop and a RB header (I have them, not mounting issues, and they work for run-in purposes).

Maruha makes my wallet scared. Are those cams better specs than the integral:megacycle cams? For powerr.

I suppose that would depend on the application. Maruha only has one grind and looks like something that would still idle nicely, nothing too radical. Call Megacycle for more info on their stuff. Be warned, the folks at Megacycle are not consumer oriented and have no real interest in helping Joe Retail select cams.

Good Miata cams aren't cheap. Get used to that if you want big n/a power :)

Niklas, my motor would likely benefit quite a bit from IRTB's but its not part of the overall plan.

Building all these n/a motors recently has me wanting to do an all out build and aim for 220whp or something. 14.0:1, IRTB, sequential fuel with individual trim, honkin big cams, 9000rpm. I won't, but its fun to think about at least.

OTS supertechs? Stroke length remains unchanged to make it a square 85x85 motor?

Yup.

Cool, thanks. Shopping list is coming together nicely now.

I'd phrase it slightly differently. Good Miata cams are not OTS, you need to go custom.
And custom Miata cams are not any different from any other custom cams.
For my case it's $125 per blank, $200 for the design and $200 per cam for the grinding (taxes removed for comparison), so $850 for a pair of cams for exactly the goals I've set.
You might get the job done for more or less but knowledge cost.The Jenveys scares me a bit with airbox design, moving the ABS for space, throttle cable linkage etc, so I'll run with the squaretop from some time getting the grips with the VVT and the new cams etc.
I want the cams to loose breath at 8000 to have some room for changes in rules/purposes (hard rev limit at 7500 now), so I plan to get "on cam" as early as possible, maybe even as early as 3500. The VVT might make it possible.

I bet it could benefit from a Skunk2 manifold at this point.

I have a feeling Hustler and many others don't really appreciate how true this post is. lately every other post about n/a track cars is:
"you could just pick up a vvt motor, and make eleventy billion horsepowers on it n/a with this awesome new technology we have
I'm not downplaying this car or motor, and we do have some better parts (specifically engine management) nowadays, but it is nothing groundbreaking and mindblowing from what I can see: just a well planned/executed VERY expensive motor.
lol

You should consider looking at our website in a month or two.

You just have to pick one of the plentiful 2L BP4W to start from... :D

I'd not call it "VERY expensive", it cost some, but there is still nothing special. It's just a balanced setup.

Lower BSFC on the NA car means that by definition it makes less heat than the turbo car. There's also the matter of the turbo car breathing through a very, very tiny restrictor (colloquially called a "turbine housing") instead of a set of big 4-1 primaries, and then there's the matter of the intercooler cutting down on the airflow going in the front of the engine by a fair amount. It's the price we pay for 200ft.lbs at 3500rpm ;)

This is pretty bitchin' cool, Emilio. I am loving the flat power at 8k+. I wanna drive :)

Wow we actually agree. Lotto ticket time