virant's 2003 clunker
 

Hey,

Had a previous Miata build get stolen. Managed to track down the thieves and get it returned with at least usable parts. If someone is interested in this story, I'd be happy to post more details. Insurance company totalled it, I took the payment, stripped the car of relevant parts, got rid of it, then found a new Miata to buy.

The car as originally purchased:
https://cimg8.ibsrv.net/gimg/www.mia...74c4a99aa0.jpg

After this, I bought a hardtop because Pac NW, did some bodywork and cleanup of the car, which ended up with:
https://cimg5.ibsrv.net/gimg/www.mia...6b50609089.jpg
From here, I installed Xidas that I recovered from the old car, all new IL Rubber bushings, new alignment bolts/endlinks/etc. everywhere from SuperMiata, a MS3 pro ECU, AEM wideband, gauges, a SuperMiata rad and FM cooling shroud from the old car, FM front BBK from the old car, FM butterfly brace and associated hardware, and a HardDog Hardcore M2 rollbar.

After that, I proceeded to build the engine and throw on a 6758 with 14 psi. Enclosed is the initial dyno dynamics dyno results with a Skunk2 manifold, although I'll post a final dyno later. The interesting part to this is that 1 spacer at 14psi actually meets or beats the Squaretop at all RPMs. I was very surprised to see the low rpm behavior of the skunk2 with 1 spacer.

https://cimg8.ibsrv.net/gimg/www.mia...20a98a8c05.jpg

Interesting about the spacer, I haven't seen much data on it! Awesome to see those numbers on 14psi with a 6758, hoping for similar results in the spring

Interesting data point. Tested against the squaretop same day, tires, dyno, correction factor, etc?

We only tested N/A but it was back to back on the same day.

This is far from a standard engine. I'll be posting more details this weekend.

Everything was done within 2 hours of each other at the same place.

However, my setup is far from normal. I've dropped well into the five figures with you guys over the past six months as one example (Tell Ed I said hi and sorry for the headache with the boxmount bbk). I'll be posting more details in a post later this weekend. However, I will say we only saw this behavior occur at 14psi with my setup. We saw little to no benefit with 1 or 2 spacers when I was dyno'ing N/A (Actually, we saw negative benefit as area under the curve with 2 spacers N/A). I also suspect that with higher boost, the benefit of 2 spacers may become more apparent based on the behavior we observed with 1 spacer. However, 14psi and 1 spacer has me at 330whp, so I have my doubts on how much higher I can go psi-wise to prove this theory until I throw in the BMW tranny.

never assumed it was, I’m interested because I am just finishing up my full forged 1.8 and mild BP4W build with a 6758 and skunk2; seems like you’re working with a fairly similar build and am happy to see those numbers is all 🤷🏽‍♂️

Either way, following along 👍🏻

So squaretop dyno'd same day/conditions as Skunk variants?

And thanks for your business!

Thats 14psi directly on wastegate, no EBC or something else? I expect torque to be at least 500rpm sooner with that turbo, but it's pretty linear power after 4500rpm

Everything is done within 2 hours at the same tuner. It took me awhile to find a tuner who was willing to put up with some of my more inane requests for data.

14PSI off of a turbosmart wastegate, yes. No EBC yet, I am talking with the tuner as to how we can implement EBC best due to these results as we both had thought 14psi would be under 300rwhp and neither of us thought the skunk2 would react this way to the spacers under boost. As for the powerband, I'd be interested in further discussion about that at a later point. I suspect it is due to the engine which I built to spin all the way to 8k safely (Should've been 9k, but 949 no longer stocked the crank I needed when I needed it) and make power to 8k. I think that it is due to cams, but definitely worth discussion this weekend.

Your car is beautiful...

Your power production is outstanding at 14psi.

I'd like to see the flat tops curve on the same map as above.

Completely interested in the weekends discussion.
I'd also like to see the "prequel" with the original car.

One thing I don't agree with...

That car is NOT a "clunker"

Same as TNinja, I'd love to see the overlay with the squaretop runs taken the same day. If that's possible. TIA

Dig the fast back top and color!!!

I'll ask my dyno tuner when we figure out the path to take with EBC and get him to give me a dyno sheet of flat top, skunk2 w/spacer iwg, and skunk2 w/spacer ebc. However, I have a pdf of someone else doing the same thing of a flat top vs. skunk with spacer on these forums and got the same results I did. I have attached it, however, I was not able to find the thread it was from. Hopefully two people independently arriving at the same data point adds credence to this, @emilio700 .

Thank you.

Thanks. Not same day, correction factors didn't match so weather was different, but still useful info. I presume no other changes.

As I understand, this is correct. Trying to find that thread, only had the .pdf since I downloaded it to take a look and realized it was the same pattern I saw with the skunk2.

Another .pdf I ran across that I downloaded earlier from the same thread. It seems to support my psi theory. Still trying to find that thread.

Found the thread finally. Here you go, @emilio700 https://www.miataturbo.net/dynos-tim...unk-2-a-99000/

Back from a track day. Exhausted, but even at 7psi the car is insane.

Spool...

Current engine:
CNC SuperMiata VVT head, SUBs, supertech dual heavies, +1mm ss intake, +1mm inconel exhaust
Tomei VVT cams (Love these so much, their lift is just after when the BP head starts flowing decently)
FM Pistons (9.0 turbo 84mm)
Eagle rods (Shoulda been Carillos but Supermiata was out at the time I needed them)
SuperMiata oil pump
SuperMiata BHJ damper for now (Fluidampr soon)
Skunk2 mani w/spacer and TB
Kraken efr manifold, downpipe and full 3" exhaust
ID1050X, truck LS coils, 80psi returnless fuel to radium fuel rail
EFR 6758 with turbosmart IWG and BOV
Stock crank because SuperMiata didn't sell the moldex crank when I needed it


I'm open for ideas on why my spool is poor. My best guess is due to the powerband moving to the right. As it is, I have close to a 4k rpm powerband with the engine setup to go to 8k rpm, but I certainly wouldn't mind some lower range grunt. Any ideas based on the above engine list? Also, should I worry about spinning the above to 8k rpm? Heard some mixed information on this and was hoping for someone like @emilio700 to chime in.

What are the cam specs?

Sometimes altering the exhaust cam timing can have effects on boost threshold.
Usually you need to be on a dyno and try different settings on your car.
It's not a "one size fits all" thing, your set up might like something different than another.
Also need an adjustable exhaust cam gear for this.

Are you still on wastegate only?
If so I would not worry about anything else before getting EBC set up.
A stock waste gate has a "cracking" pressure where it starts to open much earlier than the "boost" setting it's set up for.
EBCs can delay this "cracking" big time. Lower boost threshold is result.

I would also want to see what pressure was in the exhaust manifold versus boost level.
I'm guessing your set up will have lower TIP than BOOST. This is why you are making serious power at 14 psi.
Besides the cam specs and timing (unknown right now) everything else looks like a strong 400+ hp recipe.
Wild cam profiles will push the effective power range to a higher RPM.

You probably just need EBC...
And Emilio is GOD on this type of stuff so listen to what he has to say.

Thanks! Good tips, yeah, I am only on an IWG. No EBC yet.

VVT cam specs are here: https://www.tomeiusa.com/_2003web-ca...cam_BP-ZE.html

Also, totally agree about Emilio. It's why I buy almost exclusively from SuperMiata.

All of those look like NA (naturally aspirated) profiles.
There were three different set ups listed in your list.
Which one did you get?

Altering exhaust cam timing MAY help you because you may have too much overlap now.
If you had a poorly flowing exhaust manifold and turbo (you have the best flowing stuff NOW IMO) this late boost threshold would be substantially worse.
I think you have "too much" cam for the compression and application but I could well be wrong and I am very interested in Emilio's take on this.
It's easy to alter exhaust timing to test this theory. It's a PIA to purchase different cams.

Putting big camshaft profiles into a turbo application is tricky.

EBC will make everything better...

Last one, intake duration: 252° exhaust duration: 256° intake lift: 10.8 exhaust lift: 10.0

Emilio actually spoke positively about these in a turbo application.

This is all you need!

I wish those cam specs showed what lift the duration readings were taken at.
If those are total timing they're not nearly as "big" as if they were taken at .050 lift like domestic stuff is.
The specs didn't list duration at XX lift anywhere.

It's also interesting that the 16 lifter "kit" is $50 more than ordering 16 lifters individually.
This seems backwards...

How did the shims work out?
Did you assemble, measure, then order shims?
Or did you just have Super Miata supply the head complete and assembled?

I'm envious of your build.
It looks like it should be super reliable at the power levels you are at.

That Tomei profile is the shortest duration they offer and why they work pretty well for both N/A and forced induction. Increase the duration much more than that and they require really high revs to make any power and the motors don't last very long. The lift is also in the range that is pretty easy to get the valve train to survive. Start getting into the .450 to .500 lift and the valve train doesn't last very long.

On an N/A engine, they usually bump the torque peak up 4 to 700 RPM depending on what else you've done to it. For Rotrex, it's just like adding big valves more power everywhere. For a medium size turbo, the torque hit will be a little bit more abrupt than it would be with the stock cam. You might actually make more torque down low than stock cams but because the hit is a little bit more abrupt it can make the bottom a bit feel soft in comparison. Anyway for a BP that's going to be driven on the street I always recommend keeping the duration as short as possible.

Thanks Emilio! Thoughts on my current engine revving to 8k and the reliability of such?

Should be fine up to 500whp or so. Keep oil pressure above 45psi under boost, preferably 55psi and <240°. Sometimes that means shimming pump, adding oil cooler or running higher viscosity oil. Assuming no cat, run race oil, lots more zinc. When a BP goes bang at high revs/boost, it's almost always rod big end. If you can source billet main caps, I'd add them next time you're in the motor, and line bore it. 6258, I wouldn't bother. We made 450whp with a similar setup on a 6258 so I think yours could hit 550whp.
Might need the HB studs if you run E85 and lots of boost and timing. Mots of the builds running regular ARP studs run less timing that I did (21°) so less peak cylinder pressure.

Stock crank is fine at that power level provided you aren't also spinning it to 9k. The BP's that break cranks are going above 9k. Plenty of 500-700whp BP's surviving on stock but blueprinted, polished, balanced cranks.

@technicalninja Honestly, I just bought the supermiata sub kit and took it to a head shop, then cut them a check. In hindsight, I wish I had asked SuperMiata for their shop and just had them ship everything to their shop, then ship me a fully assembled head. That would have been the best result for everyone.

This is an important tip!
Rip your valve cover off and check valve clearance YOURSELF! if you haven't already.

Shim under bucket (best IMO) takes a real competent technician to get right.
You yourself are MOST LIKELY more competent than the head shop.
There are very very FEW machine shops that are really competent.
They exist but it's 1/50 in my experience.

Machine shops usually try to hit a "range" around a specific target clearance.
Commonly the range is +/- .002 so a total range of .004
When I'm setting up an appliance car, lots of everyday Toyotas and Korea cars have SUB or SIB (shim IS bucket), I'll try to hit +/- .001 with a total range of .002.
For something like you have there (world class stuff) I'll try to hit +/- .0005 with a total range of .001.
This is a PIA but worth it in the long run.
If your valve adjustments are all over the place then your cam timing events are also all over the place. You can have significantly different compression readings with a range of .004. It doesn't matter on an appliance car with wimpy duration numbers.
It WILL matter on a 400+ HP BP build with nice cams.

You need to EITHER be a freaking Wizard at cutting the valves to hit the shims that came in the kit OR (far more common) have a bunch of the shims for your set up in different thicknesses...
Another way to "skin the cat" is to start with shims that are too thick and grind the shims INDIVIDUALLY on a little surface grinder. This works great (+/- .0005 is EASY) and may be what your head shop did.

The OEM seem to love specing shim diameters different than each other so having a bunch of working shims is rare unless...
Mazdas are what you do. Like Super Miata. I'd bet they have a shim box for SUB stuff, a fairly heavy box with lots of different thicknesses.

I'm currently building a 2UZ V8 Toyota 32 valve engine. I'm working with a new machine shop but he's used to doing Korean stuff which requires very expensive buckets to adjust clearance. He cuts the valves to hit proper clearance with the buckets that came in with the head.
He is the first machinist I've worked with that I think has a chance to hit it right but the juries still out until I bolt the heads on and check clearances myself. I'm hopeful as the freaking shims themselves are $15 each!
He goes +/- .002 normally.
He tried to hit +/- .0005 for me.
If he did he will get fully assembled heads from me and I'll let him do everything from now on.
I haven't taken assembled heads to ANY machine shop in 2 decades...
The 2UZs were fully dissembled when I took them to him.

But it's super easy to verify you're fine or you're screwed.

Just check your valve adjustment yourself...

Ouch. Serious question, I get a tick on startup with solid lifters that I'm having trouble explaining. Could this be from misadjusted valves?

I am seriously eyeing the valve covers now.

Another tip (here's where I disagree with the almighty Emilio whom I respect HIGHLY!)
Screw the CAT...
If you have one.
That critter NEEDS race oil ONLY.
Aftermarket cats are cheap and EASY to change.
Internal engine wear on what you have built is NEITHER cheap or easy.
Run oil high in ZDDP or add ZDDP to the oil you are running.
Replace $300 cat every 25K if you have one installed.

I'd check the valve clearances anyway.
Significant noise on a build like that would "Dead Line" the engine for me.
No more operation until noise issue diagnosed/fixed.
Too loose makes noise...
Too tight eats wallet and time...
Death is silent here.

Gotta have a cat unfortunately, but I could care less about replacing them every 25k.

Got it. I'll give a call to a shop I seriously respect on Monday and have them take a look.

Thanks.

Mr Ninja, you sir are a rare perfectionist in the auto mechanics field. I'm sure your paying customers greatly appreciate that quality.

BTW, only set lash with head onto block. Doing it on the bench will end in tears.

I could be wrong on this but I believe metal core cats stand up to zinc better than OEM ceramic cats.

Yep, agree 100% on the bolt head on BEFORE.
I very interested if my new guy can pull off the impossible and hit the numbers.
Here's the real KICKER. He did it WITHOUT the springs holding the valves in place...
Juries out but I'm hopeful. He does a bunch of stuff that requires competence.

I've never encountered a cat that died early due to ZDDP.
American cats die early (100K), Japanese cats seem to live forever 3-500K

I'm seeing more and more engines damaged (mildly) by lack of ZDDP.
Even wimpy stock spring 4 valve junk, super mild cams and baby springs suffering scuff damage.
Big cams and especially "heavy doubles" require increased scuff resistance, full speed ahead with cat killing additives, and automatic replacement of the cat early.
I'm fine with using cats on my stuff but I will not shortchange an engine to make their life easier.
Nice to hear about heavy metal cats being more tolerant, Thanks Emilio...

What do you recommend as a ZDDP additive?

One disquieting thing I ran across...
I needed a couple of Toyota shims for a 4 runner I did a while back and I "tooled up".
I took a couple of dozen kolaches and donuts to my local Toyota dealer and offered them up sacrificially.
I WANTED in to their mechanics "shim box". Every dealer I have worked for has had one.
The service manager told me "We don't have one, we don't adjust valves, we just wait until there is a problem and replace the heads or the engine, Most of the time it's a whole engine and we make more money that way".
Holy sheep shit Batman!
When you no longer do shim style valve adjustments you no longer need that level of technician...
This is the FUTURE gentlemen.
Get used to it.
You all are better than the local dealer wrench...

I use Lunati's stuff but any cam manufacture stuff will probably be fine.
Amsoil makes a dedicated race oil with excessive ZDDP. That's what I would spec for your car Virant.
Where do you live? Update your profile. I wanted to know this to determine your level of emissions enforcement at your loaction.
If you're in California you have an uphill battle.
Wyoming, Texas, or Florida not so much...

No emissions where I am at. And if they decide to start trying to enforce them, I own a lake cabin that I can register it at that will never have emissions.

Ditch the cat...
Better yet, put that kitty up in storage for when it becomes a problem.
Replace with "test pipe" with matching flanges to the cat so change out is a 10 minute proposition...

On a 2003 if you have any visual emissions inspection you will need both the cat and a down stream O2 sensor to appear compliant.
It doesn't usually mean they have to actually work, they just have to be on the car.
Full OBD2 emissions means the upstream and down stream O2s have to work and the cat has to pass an "effective" test called a "monitor".
I don't think your car could pass a full OBD2 test and I have no idea what ECU you are running right now.
Only way to skin the full OBD2 test is with a piggy-backed ECU with the stock ECU still doing it's monitor tests.

It's one of the reasons I moved to Hood County. No OBD2 at all. I was in Tarrant and screwed for doing anything to 96 and newer vehicles.
If I do it for myself, misdemeanor, if I do it for a customer.
Federal Felony...
There is multiple reasons I operated an automotive air conditioning shop. This is one of them.
I like doing stuff, I just don't want to go to Federal prison for it.

Photo of the latest paint. Fresh out, house of kolor jet black. I love their jet black so much.

More incoming, finally figured out a way to work in power steering. A double hairpin made me regret not having power steering a lot.

https://cimg4.ibsrv.net/gimg/www.mia...807351fdd4.jpg

Seats just came in. Marrad LX2s, they feel great even to my fat ass.

https://cimg3.ibsrv.net/gimg/www.mia...4b055b4740.jpg

Couple of updates.

Not happy with the FM depowered power steering, so I'm adding in https://kpower.industries/products/e...r-steering-kit Yes, I'm a wuss. I like how it feels, but it's just too much for my wife at low speeds, and considering I agreed with her as part of financing this build that she would be able to track it too, the choice is out of my hands.

Also decided to try to adapt https://www.flyinmiata.com/ND/nd-fm-...ooler-kit.html to a NB. Bottom fitting should be fine, and the fill plug on the 6-speed is just 1/2 npt, so should be pretty easy.

In the middle of building a diff with an OS Giken with 3.3 R&P and a rx-7 rear housing.

Interested on your impressions of the PS kit, I've been eyeing it for when I swap my depowered rack in.

After going through the data on my last track excursion, my tranny is clearly getting way too hot which lit a fire under my butt to do something about it quickly.

Decided to adapt https://www.flyinmiata.com/ND/nd-fm-...ooler-kit.html onto a NB 6-speed as noted in the previous post.

So far, the only things that won't work is the tranny fill plug and the mounting brackets. Since the tranny fill is a 1/2 NPT/BSP fitting, it was trivial to adapt it. Will post further updates/observations on it as things go, but things went going super smooth once the fill plug was sorted out. Initially was planning to mount it in the nose, but I am thinking that won't work. Too many coolers in the nose. Time to figure out a better place to mount it.

Update....

Found out the head guy screwed up with the head. Fresh build, leakdown of ~20% and valve lash was more than double the spec.

Sent it all to @technicalninja to fix. Hopefully he'll be creating a thread on what he does to fix this situation.

@emilio700 Hey, my current builder and @technicalninja have uncovered some massive problems in previous work. Would you be willing to let technicalninja post a thread on how he is going to fix my Supermiata CNC head? technicalninja is worried about any proprietary information related to your head and wanted your permission before he posts a thread on what went wrong, and how it will be fixed.

Crap... i just did this while my shortblock is in the machine shop. Is this just to make sure that you don't bend a valve while turning the cam.

At first I did manage to not realize what was happening when I was turning the cam and the head was lifting... but I assumed that I didn't hurt anything. Should I be worried?

Head distorts a teeny bit when torqued onto block. Same reason proper bore honing requires a deck plate. Stuff flexes.
Set lash off the block and the clearances will be off when you torque it to the block.

well, hopefully I have enough shims now that I’ll be able to account for the true lash measurements once the head is on the block