Boost Joose

Don't worry, if you decide to downgrade turbo's I can find a safe home for yours

Savington

iTrader: (31)

-intake manifold
-exhaust manifold
-knock control
-transmission cooler
-differential cooler
-bigger oil cooler
-overpowering factory LSD
-transmission failures (assume one 6sp/yr unless you run a $4000 Quaife box)
-more engine internals (BE gears, ARP main studs, SS/Inco valves all required @400whp)
-exploding CV joints
-significantly increased brake/tire/bearing wear
-heat management

Maybe $20k is a low estimate...

Nobody breaks stock cranks, ever, at any power level. It's a forged steel crank.

hustler

iTrader: (6)

How did you do at nationals? Do I owe my NASA classing hate to you?

A 400hp reliable Miata racecar is not rare because of a lack of engineering, it's rare because most people who have $20k to drop don't drop it on a Miata because they can already afford Vette tires and brakes.

Boost Joose

A racepak or AIM system would be nice......

nickt93

iTrader: (5)

I bought a well built 400 horsepower Miata for $13.2k. It was a steal at that price, but was SIGNIFICANTLY more needy than my ~200hp FMII Miata. I still drive to the track, so an unreliable underthehoodbetweeneverysession Miata just wasn't what I needed. I was more than happy to go running back to my FMII car after getting zero track time at the one event I took the 400hp car to. Part out pending.

Savington

iTrader: (31)

So it was "well built" but you were under the hood every session and you got no track time at the only event you went to?

hustler

iTrader: (6)

Driving your car home from the track requires a level of preparation and monitoring that exceeds anything this side of professional, big-budget endurance racing. The 10' view of my engine shows a typical, expensive turbo Miata. Grab a mirror and get in close and you'll see things like safety wire on anything and everything attached to the engine, anti-seize on every bolt in the car, thread-lock and safety-wire on the bolts without thread-locker, break-away plastic stuff under the car, fancy greases and lubricants on every friction surface, and heat wrap on every single wire and hose in the car. I laugh at people who don't hide their fancy SS hoses in fire sleeve these days. It makes me feel pretty bad *** at annual tech when the garage stops and every tech comes to look at what I've built/bolted together. Then, they look inside and see an interior that's held together with clear duct-tape and a heavy-layer of filth.

jbrown7815

iTrader: (1)

Huster I want you in me. If I brought you my Miata with 1.8L in it and everything for turbo kit would you help me do a full tune on it?


/threadjack

hustler

iTrader: (6)

I was really afraid of building a turbo car with the bad reputation our cars had 3-years ago. Today, the turbo Miata is more reliable than the supercharged cars;l the secret is the thought and a holistic understanding of what it takes to race a car for 20-hours, all season long, and never put a wrench on the car. A good example is when people ask what a reliable turbo Miata costs, "price the turbo kit, then double it for items like hoses, cooling parts, and attention to detail among a number of items of which I've forgotten more than I remember.

nickt93

iTrader: (5)

Yeah, maybe I should have put "well built" in quotes like you did. What probably would have been more accurate to say is that it had "all the right parts" - Carillo H beams, Wisecos, a Quaife in a box waiting to be installed. My point was really just to say that a 400hp car is likely going to require more attention and tinkering than a 250-300hp car.

And, just to set the record straight, I said above that I only took it to one event but didn't get any track time due to a turbo with a bent shaft that locked up. Hard to say who is to blame there - Garrett? It was a low mileage brand new 3071.

Anyway, good luck to the OP. Hopefully he'll have better luck in the world of 400hp Miatas than I did.

Savington

iTrader: (31)

Fair enough. You have a good point - "all the right parts" doesn't mean the car is put together correctly.

We've been doing R&D at 350whp for 18 months now, which means that we can put together a 250whp package and it will be pretty reliable. 400whp? Call me in another year or so, but bring an oversized novelty check and a ",000" stamp.

mr_hyde

iTrader: (4)

You can get a reliable 400whp from an LS3...

An acute interest in making the grid for every session and finishing said session and still being able to drive the car onto the trailer at the end of the day under its own power has kept my goals in the ~275 range. The Corvettes and other high end hardware will pull on you a bit above 120mph but you will still be able to out brake and out corner them if you spend time and money on the non-hp half of the list.

Faeflora

iTrader: (2)

I will answer what I know:

-Do I need to get upgraded oil pump as I was told the stock one will fail? I was told to get this form Boundary Engineering .

Yes

-Is my Turbo to large and if so what size would be recommended for my goals?

No. GT3071 is a fun turbo. GTX3071 will probably get you to 400 more quickly than GT3071.

-I still have a stock intake manifold and throttle body. What do you recommend for the upgrade on this if it is necessary?

Yes ARTech is making intakes and I recommend his work.


OK intake is not necessary. I would run knock control on ANY boosted miata over 180hp. Transmission/diff cooler? Why this? Are you running one? I haven't read of anyone running one on a miata

Oil pump gears, studs, valves aren't that much more in the big picture

Why CV joints sexplode?



OMG!!!! A garrett turbo shi the bed? Inconceivable!!!!!!!! This surely has NOT happened to anyone else in this thread!



Alternative I would recommend that I am doing is to build for 400+++ HP and then run 250 at the track. I ran a GT3071 for 3 years on a stock block at 10psi or so for 240HP (Ed's Dyno for you locals) and it was still quite fun.

Right now my car probably puts down well over 400 at 25psi and I'm going to tune for 40psi. For the street. But... for track day I will turn down boost to 17ish psi and drop timing...

mr_hyde

iTrader: (4)

That's the best way to be reliable. Build for 400whp with maps tuned to crazy boost numbers and then turn everything back to sane levels. Set the boost at 15 to 17, pull a degree of timing or two to back away from the razor's edge. Proper ducting and cooling, good hardware like inconel studs and a little common sense will keep it running. Just avoid the red mist that happens when you could catch that viper with another 20 or 30whp. Paradise is just a few MBC clicks away!!!

Savington

iTrader: (31)

Yep, for about $20k in parts

Savington

iTrader: (31)

Intake is necessary if you want to track it. Without it, you have to run more boost to make the power, which taxes the intercooler and the cooling system, and increases backpressure, which will make the motor knock more easily, which means you have to run less timing, which means you'll need more boost, do you see a pattern here?

Tranny and diff coolers because they run hot as ----, nobody can keep a transmission in one of these cars yet, and I suspect that the fluid heating up to unreasonable temps is why.

CV joints explode because you're putting 4x the rated torque through them, constantly, the entire time you're at WOT. If you compare the amount of time spent at WOT, every 30 minute race I do is the equivalent of 50 1/4 mile passes, in a row, without letting the CV grease cool at all.

I'm not talking about 400whp on the street, that's easy as hell TBQH. 400whp on the track is an entirely different ballgame. IMO it's easier to put together a 400whp street car than it is to put together a 250whp track car.

Buzz

Well thanks again for all of the help. I think I have decided that I do not want the headaches associates with 400 whp track Miata and I will be contacting all of the vendor who helped to finish this build the only question now is if I want to stay in the 300-325 range is my GTX3071R going to big and laggy or can I keep it and turn down the boost? Or do I go for the 2871? Thanks

Boost Joose

If that's your new plan I would definetly go to a gtx28 housing. I personally like the specs of the new GTX2867, great spool, great top end power(more than the 71) or you could always look at the new borg warner efr's. With the 3071 you wont get full boost until around 4200-4400 rpms. with one of the 28's or borg's, could get it before 3500.

emilio700

iTrader: (3)

This

Braineack

iTrader: (62)

All I want to say here is that the stock cap is 13psi.