Nice!
Seems like the perfect combination. Definitely a lot on the street.
I could see wanting a smaller turbo if you put lots of miles on it!
Is your car really 2550 pounds as the dyno sheet says?

That was godons car that I tuned. (EO2K)
An nb is 2350+200 delta (what I weigh).
You have to plug in the full weight for VD to calculate accurately

Ah! That makes sense. Will look up his build!

What are people doing for boost control on the internal gate EFR...I read about lots of difficulties there?
I was looking at the 2 port Turbo Smart, but I saw this
Evasive Motorsports PH: 626.336.3400 Mon-Fri, 9am-6pm PST: BorgWarner EFR Dual Port Internal-WG actuator

Any thoughts?
Jamie

The EFR5951 looks promising for the future, I'd expect TSE kits to sell like hawt cakes when packaged together. I'm very interested... VERY very interested to see what this new baby trubo can do. Gives me all the more reason to ditch this 2860 setup :likecat:

:skid:

Have you called and spoken with me yet? I could clear up a lot of your misconceptions in a ~20 minute call. :)

What difficulties? Mines been running fine for a couple years.

Horsepower is just a number, and this worries me a little bit... I'll cover this some more at the end of this post.

Its god damn amazing, It's like nothing I've ever driven. Seriously. We need to figure out how to get it on v1.4.x along with the 4 port MAC and the dual port Turbosmart WGA so I can play with closed loop, boost by gear, MS-based traction control, etc.

In all fairness you can't look at that build and compare it to 99MX5. Well, you can, but you are missing a critical component to the formula. One of those BPs is not like the other. One of those engines has $3k worth of cylinder head sitting on top of it. Boost is nothing more than a measure of resistance in the system and that specific engine makes that kind of power with 8psi less boost because it flows that much more air. Seriously. It is both a good and a bad thing.

Um, no. I'll touch more on that in a second.

Yep, that's my car! :bigtu:

Link is in my sig. You've been warned. :party:

I had a problem with the internal wastegate, but that's because I'm an idiot. It works flawlessly now. I also had a problem with the GM style 2 port EBC that was included with EFR, but I've ditched it in favor of a MAC valve and all is well. 18psi's comment about the weak actuator is because I pulled the "MEDIUM" actuator off my turbo and installed the "LOW" actuator. It makes the tuning a little weird, but lets me run less boost, and that's OK on my ridiculously flowing head.



Ok, I feel I need to address something real quick that I'm pretty sure no one has mentioned yet. Jamie, I don't know you or your son, and as such I say this with all the respect in the world, but I think you are overlooking something serious here: all hyperbole aside, a 300+HP Miata is a god damn death machine in the wrong hands. Have you driven a 300HP Miata? How about 250HP? Or even 200HP? I would strongly encourage you to do so before you get too far into this. This is not a Corvette, or a new Mustang, or a Camero, It is a radically different experience. I come from a long line of overpowered rear wheel drive V8 cars so I have had more than a decade of driving experience with tail happy beasts and my car is seriously intimidating. I've got enough fuel that I could safely run ALLOFIT on CA piss 91 with the EFR 6258 but I have to tell you, I have no desire to find out what the limits of the fuel system are, because I've reached the limits of my skill. On street tires, traction is merely the fever dream of a madman in 1st and 2nd if you are not paying attention, and at any time I can put my foot in the throttle in 3rd and 4th and the tires sublimate directly from solid to vapor state before I can even think about it. While that sounds like fun, its seriously dangerous as fuck. Driving my car in anger has a tendency to convert that rage directly into a healthy respect or even fear. Like I said, I don't know you or your son, and I don't know his skill level or driving history, but I would not, under any circumstances put say, a 20 year old kid behind the wheel of my car. I would not expect them or the car to last long.

Take a Corvette C6 Z06, put it on a 245mm wide tire, and take 16" out of the wheelbase. That's what you are building when you put a 300whp Miata together.

And his car has the 3.6FD and NT01's
With a 4.30 it would likely spin 5th lol

^^ Truth.

Someone with more smarts than me should take the coefficient of friction for an NB with a hard top, and calculate the maximum speed attainable with 300hp, 6 speed and 3.63 :giggle: Maybe I can go do the Texas Mile, or visit Bonneville. Hah!

2017 World of Speed is in September this year, I can maybe have the car working by then.

https://cimg5.ibsrv.net/gimg/www.mia...bc06894618.png

CD is 0.36 with soft top, so guessed 0.35.

Brb, need new speedo...

Just ran the gearing numbers. With a 6 speed and 3.636 rear, you would need to spin the engine at 8400rpm.

Get a GPS speedo. At those speeds, I bet the tires expand a bit, making a regular one read low. :P

Supertech heavy doubles should be able to do 8400rpm sustained, ayyyyy?

Oddly enough, tire deflection ends up making the tire shorter, at least in the 140-150mph neighborhood. Maybe 180+ would change that, but the data I have says you need about 6% more RPM than you think you do to reach a gear-calculated speed.

The EFR internal gate gave me fits too. My problem ended up being a combo of needing to clock the CHARA a little and also needing to bend the wastegate mount in order to get it to move freely through the whole range. I didnt feel like having to fight with it again to nudge and tickle it to be just so for my next setup and the EWG only IRL 7163s came about at just the right time so I went that way. I'm sure TSE checks each one for alignment before it goes out the door on their kits.

Actually, that makes sense thinking about it. The amount of torque being applied just to over come the drag probably rotates the rim ahead of the outside edge of the tire. Something like a wrinckle wall drag tire.

I don't, yet. I was thinking about it last week after the chat in Aidan's thread. I would have to add something to the cost of each kit due to the time it would take, but I'll probably start doing it.

Could be, but that would surprise me since it's a radial tire. It's a substantial reduction, over an inch of circumference loss IIRC. I don't actually have a good theory for why the GPS speeds are lower than the calculated speeds, but I do have a bunch of repeatable data that shows it to be true :)

If you already clock the turbos you wont be adding much time. A gauge would be pretty simple, a block with 2 pins the major diameter and spacing of the actuator studs and 1 long pin with a little play in it to the block and just slide the flapper through its motion over it.

If you ever have a chance to get more data, a dot on the rim with a dot near the edge of the tread on the tire, a bight sunny day and a camera with a fast shutter speed will give a great data point.

How fun it'd be to use digital image correlation on a tire to measure full field strain and deformation. Just need Vic2D/3D and one or two high frame rate cameras Photron SA1 etc.

That makes sense, we use 3.636 in Europe and every car i know makes 10km/h aprox. less than the gear calculator gives @7200rpm 6th gear. Never understood why.

Theseus had a 7400rpm limiter, 3.909s and a 6sp. Gear calc says 153.7mph at redline in 6th, GPS said ~146.2mph every time.

I wonder if it's a result of intentional unilateral tolerancing. Ever notice how every car's speedo tends to be a little too optimistic? I have to think it's driven by liability concerns of the manufacturer which make them tolerance the speedo to over report speed rather than under report speed. Perhaps the gear ratios and therefore top speed of a gear at a given RPM is also slightly unilaterally toleranced to avoid exceeding the limit of the design envelope. Just an armchair conspiracy theory.

Speedometers lie, but this is a comparison between a gear calculation and the GPS measured speed. The ECU's RPM signal doesn't lie (not the tach, but the one that drives the rev limiter), because it has to be accurate for the engine to run properly.

You can't really tolerance a gear -- count the teeth and that's the ratio.

I don't know how accurate GPS measured speed is, though.

--Ian

(edit): One other thought, if you're getting a few percent of tire slip, then that would account for some of it.

My data is from a 10hz antenna fed into a Racepak, then extrapolated to 20hz. More than accurate and repeatable enough to clearly show a discrepancy between "what is" and "what should be"

Not yet Andrew! I gave you a call when I had a free moment the other day, but you were busy.
This wont happen for another year or so...I am not in a huge hurry.

We are going to bolt the suspension/safety stuff together and he is going to spend the spring and summer doing HPDE, autoX and, spending the rest of his money on instruction.
The plan is to allow him time to establish solid control of the car before adding power. If that takes two years so be it.
I would also like him to get some wheel to wheel experience before the turbo, but that is still being discussed.
Once the turbo goes on the plan is to run it at lower boost until he connects with the power and feels good control over it. (one of the reasons I was talking about a dual port boost solenoid).
I suppose a smaller spring could be supplemented.

For those that asked?
I have a 580hp Sunbeam Tiger, and used to have a 740hp Cobra...Not to mention a host of scary fast longer wheelbase cars.
To me the 350hp Miata I drove was edgy and a sporty ride, but was completely predictable....A long way from the Tiger.
My son of course is not in the same boat....and there was no way he was going to drive that car.
See my above comments to Savington, but the plan is to work him into the power as slow as it required.

Eo2k,
If it was me I would have to know how much power I could make.
There has to be some curiosity there? :)

Thanks for all the comments as always!

Jamie

I have tempted him to come down and do a "ALLOFIT" tune on e85 dozens of times now.

If he ever bites, I will be sure to share the videos :D

Haha!
That would be awesome!
The torque would be insane!

Psssht! Who needs a turbo? 300hp N/A BP. Suck it, Trebek!

Pretty sure both Emilio and Savington have debunked their HP claims in this thread here.

sarcasm is hard to convey in a post

"A little shy of 350hp".....A little short!
I am a little short of 12 inches....I am closer to 12 inches than they are to 350hp!

Your link didn't work for me Shuiend.
I would enjoy that read! :)

For a while now, this forum has been reformatting urls so they do not link properly

https://forum.miata.net/vb/showthread.php?t=630740

Emilio: "Cutting edge K Series 2.5L spun to 11k in drag cars are just hitting 395whp on VP Q16 gas. A stock K20A2 head flows a bit over 40% more than a BP4W."

Or said another way....

Savington: "350bhp from a naturally aspirated BP on gasoline is a monumental pile of BS."


Priceless! :)

Any update on the 5951 from SEMA this year?

Still a mid-2018 release?

No 5951s on display at BW this year. Rep said they are still in progress, no ETA, definitely not a mid-2018 release.

Any updates on the 5951?
I haven't seen anything recent about it.

I would also like to know about what happens with this turbo. Seems to fit exactly with what my goals are.

Yeah I've got a stock VVT Exocet that is an autocross toy. I want the most responsive turbo possible.

So i dont know why not get the TSE kit with the EFR 6258 that has been proven countless times.

Have you actually driven a well tuned vvt 6258?

Asked a rep about it at SEMA 2018. It's shelved indefinitely, no ETA. They are focused on Gen2 EFRs (8474, 9274, 9280) instead.

If you want response, buy a 6258 kit from me.

This ^^^^^^^

That was my plan before I heard about the 5951 and now it is my plan again :bigtu:
Do you know if anyone has installed it in an Exocet? Fitment issues?
I hadn't seen that info from SEMA 2018. I've got megasquirt, flex fuel, and clutch done. Injectors, exhaust, gauges, ignition, intercooler still on the to do list.
What are people using those ridiculously large turbos for? It's surprising that there's more demand for those than the 5951.

A quick search will get you the exocet answer. As for bigger turbos people run the 6758 to get into the 450hp range and a handful of insane people run the 7163 to get all the horse powers

They use them for six and eight cylinder engines. My buddy with the rb26 GTR is giddy about them.

But those engines have two turbos! Is 1000+HP really necessary? I guess this is why I drive around cones in a parking lot instead of playing with the big boys. Haha.

Yes that power is always necessary. There is never enough power.

I know, I guess I forgot which forum I was on.
My goal is to have enough power to be traction limited up to 70mph in 2nd gear on 200TW tires (5spd, 3.6 rear end).

ftfy

At least they're cheap to replace! Remember that I've got a front heavy car that only weighs about 1500lbs. I was thinking tune for a flat 200lb-ft and it would be ok?

You may want the 6258 to hold 200 to redline

200lb-ft at 7200rpm is 274hp so a smaller turbo would probably be optimal. From what I gather though the EFR6258 is better in every way compared to smaller turbos like the GT2554R.

Correct

274 at the wheels, you have driveline loss to account for. Sav's e85 CNC VVT looks to be pretty much 200 @7500.