New guy post.... How reliable are turbo miatas?
 

Hey guys, my name is Tom, and i am a supra owner.
Recently i have been debating giving up the supra game and transferring it over to something small and light with a turbo. But since i was looking at these cars, i have noticed that 1, they have a small rear end, and 2 that some people don't even use engine management.
How reliable are these things for this kinds of car, and what can i expect with these cars in term of any other problems.

I am not gonna even attempt to answer that, you should know better than to ask such a noob question...
You should know that your budget will determine how reliable any build is.

Bone stock, you cannot kill a Miata unless you neglect critical maintnance, with boost come problems, how many and how big depends on how much boost and all other supporting mods.

Make a proper introduction in a proper forum and your stay here will be much more welcomed. We don't spoonfeed people here.


Now, Pics or BAN!!!
You cannot storm in here talking about turbo supras and not give us any pictures...or vids. If you have neither, nude wifes or girlfriends will do.

Since you already have experience with turbo vehicles, I'll go ahead and assume you understand that as your goals (and boost pressure) become more lofty the need for sturdier hardware and more comprehensive engine management increases. :)

The block is good for around 15 psi (debatable and there are other factors, of course) on the factory internals, the rear in the 1.6 cars blows fairly easily even at low-boost and in some cases at stock power, but it is easy enough to swap to the later rear from a 1.8 car (6" gear versus 7"). Transmissions are also a known weak point.

Fewer and fewer people around here rely on something other than a replacement ECU for engine management, or at least it seems that way. Most NA owners use a Megasquirt and many NB owners use a Hydra EMS.

If you are looking at a 90-97 car, in a nutshell, the small (6") rearends are not good for boosted cars. They are on 90-39 cars. The 7" (94+, especially torsen LSD are fine to about 260-270 WHP, maybe more depending on driving habits.

There is really no reason to run without engine management with Megasquirt plug and play and other ECU's are available for about $700. Yes, you can spend more (Hydra, etc) but not necessary. And, you can run with band-aid fixes, but the total cost is about the same as MS.

EDIT: Whoops, I was slow.

Done well they are pretty reliable. I'm going on to 30k miles, relatively trouble free. Haven't really needed anything that I can't call "maintenance" on an old car.

Engine management, and not running more boost than your management is capable of controlling, is key.

or just drop in a supra engine :D

reliable. mine's had a diy setup on it for over 3 years and 10s of thousands of miles. i dont push the limits and haven't had any problems. 250 rwhp give or take, depending on the dyno.

what boost level are you running your car at, and with wich e/m? I also clicked on link in your profile looking for a mod list, and havent found one. really interested

I drove mine for 4 months straight without an issue. I'd say that's pretty good......for me :)

who me?
https://www.miataturbo.net/forum/vbg...do=view&id=391

Shit, I must be blind....Thanx for that link man

*edit- DAMN your car is nice man, all that power/torque at only 9psi geez....wanna trade? :D
ill give you my white one and a bottle of vodka for yours :giggle:

wow....did everyone get laid last night? or have we turned over a new leaf? you guys typically flame people for questions like the OP had. man, this place is getting too civil.

i'm gonna agree with nick, you guys are getting soft. kinda like hustler around a girl :p

Sheesh, Hustler finally gets going, and you guys declare open season on him.

hahahahah, seriously whats up with that? Havent we determined that he doesnt exist? And yet every other thread gets jacked and his name is brought up :D

he posted one time and asked what he wanted to know. had he posted 10 times and been a jackass, we would have beat him up some.

18: if your vodka makes you blind, I dont want it. try some cirrus vodka.

and i spent a lot of time on my car to get it this way. I bought it new in 01 and have been molesting it ever since. http://gallery.y8s.com/miata

:jerkit:

Tell me please it at least has a six speed....

(Sadly I just noticed its RHD...)

OMG, it's RHD....this isn't gona turn into THAT thread is it?

Hey did you know it was RHD?

How reliable is a turbocharged Miata... haha. Well to be honest, your better off with the highly reliable Eaton MP45 or Eaton MP62 superchargers. The reliably is through the roof, the power is predictable, all in all more bang for the buck... ;)




(Hehehe, like driving a Import to a Union meeting (Did that, done that, do it again), I shouldn't be discussing superchargers on Miataturbo.net, unless its taking a shit on one)

if you build it right, you will have little to no issues.

Long post... I was on a roll.
 

Cryo... welcome to mt.net... I noticed you've been a member here for awhile but never posted... place your location in your profile and place your Supra plus short mod list in your profile. Do not anchor on Zabac's post in your initial reply in this thread. We have a NOOB hazing ritual and you are prime fodder by being a Supra owner. The mods around here run a tight ship, don't tolerate bullshit, and wield the most often used bansticks on the internet.

You'll find the answers to all your questions are met with immediate and good to-the-point information as long as it's very obvious you did some research yourself before asking the question. As Zabac said, we do not spoon-feed. Forums that spoon-feed end up with an endless amount of THE EXACT SAME TYPES OF THREADS that are impossible to get reliable and consistent information out of for the NOOB who shows up and actually knows what the search button is.

Hints for all NOOBs:
Put location in profile.
Put short list of mods in signature.
Visit all companies websites in the Vendors Forum and be familiar with everything they sell.
Use the SEARCH button liberally (title searches limited to appropriate forums are best).
GOOGLE has been proved since it's creation to the best source of information about anything on the internet. If you type in any question relating to turbo Miata's into GOOGLE, quite a few hits will be links to threads in this forum.
Always visit th USEFUL SAVED POSTS forum before asking questions.
READ THE FAQ.
A PIC/VIDEO/SOUNDCLIP IS WORTH A THOUSAND WORDS AND WILL ALWAYS GET YOU BETTER HELP THAN ANY AMOUNT OF DESCRIBING THE PROBLEM.

Other things that will help you on all forums everywhere:
Have a digital camera with video-capture capability.
Have a Photobucket account.
Have a Youtube account.
Have Microsoft Image Resizer Powertoy installed (or another super-easy resizing program for creating forum-friendly quick-uploading pics).

NOW, I will spoon-feed you this one time, but never again:
1) Rear-end.
90-93 cars come stock with a 6" ring gear and 4.30gears. People have broken the dif on stock (100whp) power. It can however last a long time at 200whp+ with good fluid, no drag's/drizfiting/burnouts/etc... A good guess is that if you're gentle, it's probably good to about 250whp accelerating in a straight line and waiting for WOT until the clutch is fully out. Above that, you're gonna break it doing anything short of a 5th gear gentle roll-in. The majority of 90-93 dif's were open. There was a VLSD (viscous) option and most of those difs lasted about 50k before they were no longer effective at limiting slip.

94+cars all have 7"difs. They are good for over 300whp with moderate to extensive abuse. 4.30/4.10/3.90(6-spds) are the 3 factory gear options. Many cars came with a Torsen LSD depending on trim/options. Currenlty, you can get a 3.636 or 3.308 rear-gear that is the mod of choice for 300whp cars... makes 1st gear useable again. You can take any 90-93 car and install the driveshaft/dif/carrier/axles from any 94+ car... direct plug-in.

2)Engine management
The quickest/easiest/cheapest way to get your Miata boosted is to use a RRFPR (rising rate fuel pressure regulator) to increase fuel-rail pressure when in boost. 5-6psi boost and 70-80psi(limit of stock fuel pump) pressure in the fuel rail, in conjunction with 6* base timing can be done non-intercooled forever. The 90-93 Miata Greddy turbo kit (sold by the thousands) gets you 145-150whp in exactly this manner. Base stock timing is 10* BTDC so you're hurting your low-rpm performance out of boost... and it's a little laggy due to the small DP, but it's easy and proven. The current shit-hot non-intercooled AFPR (adjustable fuel pressure regulator) system on the market is the BEGi"S" system... leaps and bounds better than the Greddy and easily upgradable.

^These systems we call "bandaid" systems as there's no EEM. You can add an electronic timing retard box (Bipes), 02clamp, slightly bigger injectors, fuel pump, intercooler for the ULTIMATE bandaid setup and run about 12-14psi... maybe 220whp before the limits of the stock ECU catch up to you. This is how a lot of people get started into boosting Miatas. It's cheap, parts are plentiful used, and the corporate knowledge will not let you make mistakes.

The most popular aftermarket ECU choices are as follows:
Megasquirt (currently available PnP 90-97 and lots of guys running 99+ cars with MS in parallel to stock ECU)
Hydra ($2k, it's the best you can get PnP).
Xede (extremely capable piggyback, great choice for 99+).
Emanage (regular/blue/Ultimate... +Boomslang FTW)
Link (90-93 need so find used, 94-97 still for sale, for a long time it was the only PnP choice)

ZOOM3 (will be released any day now, might be the tits for 99+guys depending on how big an injector it will idle)

Less popular/capable but still used in decent numbers: AEM/SAFC/Voodoo/other similar piggys all doing the same thing.

:bowdown::bowdown:Samnavy...Your patience and lenghty posts never fail to amaze me :bowdown::bowdown:

dude, how do you know about that!!! argh!!!! Its all mental. Its not you, I'm just really stressed out right now.


















I have a baby dick.

Since we are all being generous, one hint you get from me is:

Do not ever ask where the 1998 Miatas are and why no one has one boosted. You will get banned even if nude pics of the significant other are provided.

They do not exist, at all! Mazda slept through 1998.

I bought a torsen swap from an idiot who claimed it came out of a 1998. At $300 for it, I knew I had either a crook or a moron.

Did it atleast turn out to be a torsen?

why would I buy it if it weren't?

Thought maybe it was an internet deal...

Was it a type I or a type II?

I...aren't they stronger?

As far as i know...
reason I was asking, if it was a 99, he might have mistaken it for a 98 production year maybe, but if it came out of an NA, then there is no excuse for the idocricy.

Also, the 6-spd transmissions are significantly stronger than the 5-spd transmissions. :)

I hear this a lot but I take it with a grain of salt since it's pretty much anecdotal evidence supporting the claim. plus, my 5sp hasn't died yet! :)

:fawk: Just stating that it was RHD. First glance the left hand (USDM Drivers side) was missing all the normal equipment. Then at second glance I noticed it was on the wrong damn side. Really I don't give a shit what hand drive it is to be honest. ;) FWIW I think people who want to convert their USDM LHD car into a GAY-DM RHD are fucking morons who should die in a fire. :jerkit:

Riiiiight.....

1. Belt Slippage
2. Boost adjust ability
3. COST

Did I mention Belt slippage?? I'm not even attempting to start this debate, but its been proven more than once an MP45 @ 8psi made less peak power and torque than a properly sized turbocharger @ 8psi...

Friend has an MP45 on his miata. In the stock 5psi form it made 147rwhp. After a 250$ high flow cat, longtube header, exhaust, 8psi pulley, more timing and more fuel.. it made 158rwhp. That was over 700$ in upgrades to get that extra 2psi along with supporting mods and it didn't do dick.

Isn't the 6 speed the same design aisin unit from the RX8?

If so, it fails under stock power in RX8s.

Well, im putting down far more power than a torqueless RX8 and have no problems..... and that's WITH hard driving. Though, I blew up two 5-spd Miata transmissions... which have a lot in common with NA FC RX-7 transmissions...which were HORRIBLY WEAK.

But back to the original question... i don't think the NB 6 spd has nothing in common with the RX8

I am sorry for the noob post, but with these miata's i will not lie that i am.
I am very aware of old car maintenance, and that is always the 1st thing i do when i get a car. Replace most hoses and gaskets. A modded POS engine won't hold up or keep up to a properly running one.

I don't know if anyone appreciates the older supras but here is mine.
Attachment 212315

Cool that is what i was looking for. I am under the assumption that the block is aluminum as well as the heads?
Wow. 1jz Miata, i like! haha. Oh and there was no 1jz in 6 speed, only the mark 4 2jz.
I hope that is the case, getting lucky puts everyone in a good mood, even to a noob ;)

Thanks for everyones post's so far, it is helping me inquire more about these cool little cars :)

No... Miatas have a cast iron block,closed deck and alum. head.


Here... have some motivation...
Attachment 212312

Attachment 212313

Attachment 212314

shit man, that car is gorgeous...great color as well

I did some research and it appears it was a modified NB tranny and was fragile in comparison. So scratch that same tranny bit.

off topic, but here

http://www.rx8club.com/showpost.php?...2&postcount=16

Mazda claims the Mazdaspeed MX5 (NB) six-speed transmission has shot-peen-hardened gears... Any bets its an identical trans to the standard Six-speed NB Trans??

I just beat up on my NB this weekend at 7 psi. Drove it 1 hr there and back as well after the race. Its running great, I love megasquirt. No dyno tune for me either, MLV 4 life.

That reminds me off the supra I had to let go of due to the wiring harness falling apart if you looked at it wrong.

Nah. But there is a reason more people choose turbos. Power and preference

spark, negguh.

Porsche has proven how reliable turbos can be......with that being said, I don't think there is a supercharger on record winning Enduros or even LeMans for that matter.

don't tell that to the dallas crew.

flat, low torque curve > lots of torque and power.

Yep, Gary is very dissappointed in me.....

i hear about it all the time from everyone, and when they find out my motor is 8.8:1 static, they tell me it will be a slug even though I'm not twisting a supercharger off boost. When you look at the money side on a blower, $4200 gets me 200whp at the most, with no intercooler that actually fits because I have a swap car, and I'd have a power card for a 99 when I would need it for a 1.6. My $4k in turbo would take me to well over 300whp, and its a bolt-on affair, exactly the way I wanted it.

I've heard nothing but horror stories about turbo miatas in Dallas...hopefully I can change that with mine or I'm going to be really, really pissed.

Maybe you should just keep your mouth shut and not tell them anything and all...let them assume what they will, it's more fun that way.

Or maybe you should just start cursing a random times when around them pretending something broke and make comments such as: "stupid piece of shit, will you last one day without breaking something?"
That will encourage your locals to stay slow for sure...

With you there on the horror stories....but 99% of the job is prep work and I think you've done your homework. Dealing with an issue before throwing the grenade might have saved a few failed local or two.

HaHa! Better advice for sure. :)

guys you're doing it all wrong: its all about the NAWSSSS:D

holmez you saw paul's absurdflow 2560 spooling at like 900 rpm, rite?

after I realized that everyone who cried about it was using a blower, I drove a blown car and it dawned on me...it was super sluggish because they were turning a blower at 2000rpm.

:)

EXACTLY! Let them keep their 4500$ 200whp car with piss poor EMS.. Just let them cry when you put 15 - 20 cars on them before you hit 60mph. ;)

The supercharger guys are really stoked about the 150lbs of torque at just 2500 rpms and how it stays flat all the way after that. My turbo system is making 150lbs at 2500rpms too. Difference is mine keeps climbing to 200lbs at just over 3000 rpms before it starts to flatten out.

They don't really make torque faster. It just tops out quicker!

I'm the first to admit that supercharged cars are fun because power delivery is linear and ascends all the way up, acceleration faster and faster. Where we embrace the less exciting, but more desirable quadratic delivery, but faster in the long run typically.

I remember when I switched from a vortech blower to a turbo in my old vw. Even with 150whp more, the turbo car felt slower until ran a few cars.

dude your turbo is on the wrong side of the car.
15 psi my ass i believe it was markp who said past 20 psi oringing was useable but still overkill these are cast iron blocks guys and cast cranks. throw some rods billet oil pump gears and build the head and you can make enough HP to truly see the limits of the stuff we like to call transmisions and rear ends half shafts etc. Swap in a 6 speed and a good lsd with a 1.8 rear and keep wheelhop down and there is a drag miata at 616 whp that ran in the deep 10's with stuff like that. Yes he had a storker crank but mostly for more displacement than anything else. There is a enthusiast in japan who before he sr20 swapped his car kept 330 or so whp as a DD out of his 1.6.

I know these hp numbers dont seem like shit to a supra but please consider the fact that the miata wieghs 2500 lbs with you in it and a full tank of gas. Getting a supra that light is alil tougher. Even then miatas have been taken down to 1900 lbs even on many ocasions. The limits will all fall upon your $$ and your brain power. You will need both but some stuff will take more of one than another from time to time. GL man