savior

Hey my name is Jon and I own a 2.4 Cobalt SS.

Recently I've looked into the miatas. There are many mods that support a miata and I just want a little more information.

Which route would you prefer; turbo, or 5.0L swap
- (i assume the answer is going to be a turbo, but why?)

How strong are the stock internals?
- If you wanted to reach 250 hp, would you need to replace any internals? Also, would the car still be drivable?

How much would a total installation of a turbo cost to reach 250+ hp?

what is everyone's 1/4 mile time?


***I have yet to come across any of these thread, I've tried looking but havent found the answers I have been looking for, therefore, I came to this forum for some answers

greenday3437

iTrader: (2)

I all depends on your goals really..

Basically the main reason people go with turbocharging over a 5.0 swap is because:

1. Its much easier and takes less time/money
2. You can still get pretty good gas mileage on the highway

250hp on a stock engine is do-able with a really good tune, but thats gonna be a pretty fast car with 150% more hp

savior

my goal is to have a very very fast sleeper. I wouldnt mind taking down stock cars like and STi or Evo (AWD drivetrain loss hurts on the top end)

but yet I'd like to be able to drive my GF around without having to yell over a loud rumbling car

samnavy

iTrader: (7)

Jon, start here:
https://www.miataturbo.net/forums/showthread.php?t=4288
This should tell you everything you need to know to get started.
One thing to keep in mind with your power goals. 250rwhp in a 2200lb car is a better power to weight than a C6. Unless you're looking into that kind of performance, you might want to dial down the goal a little. In that HP range, the biggest limiting factor is getting enough rubber to hook up, especially as you seem to be a drag racer. There simply isn't a lot of room to run big wide tires without bodywork.

A nice even 200rwhp is a good place to start. Any number of sub $2000 setups will get you there easily if you don't mind buying used parts and can do all the install and minor work yourself. I think you should probably be able to squeeze out a 13.5-13.7 1/4mile with the right tires and that power. This power can be done on simple mechanical fuel control and a basic ignition retard device.

With a goal of 250rwhp, to do it right, you're looking at standalone engine management in the form of EMU, FM Link, Hydra, etc... properly done for somewhere between $1500-$2500 depending on sensors and injectors.
No reason to skimp on the rest of your setup, a T28 pushing 15psi would see 250rwhp easy. That plus decent IC and piping, BOV, mani, DP, and exhaust, would run about another $2500-$3000 assuming you buy new.

Properly managed, the stock motor should be safe and reliable on the stock internals up to the 250-270 range. The stock internals will run up to about 300 but will not last long, and after that, you need rods and pistons at a minimum.

There are two main competing companies that sell full Miata Turbo KITS. They are www.flyinmiata.com (FM) and www.bellengineering.net (BEGI). Visit both of these websites and go through them thoroughly... they offer a lot of info other than just trying to sell you stuff. Both offer complete mechanical and full standalone TURBO kits in different power ranges. There are a few other companies out there, but with the technology and service FM and BEGI offer, there's really no reason to go elsewhere if you've got the money.

The place to ask about V8 swaps is at miata.net in the V8 forum. They require a full driveline swap, motor/tranny/dif/rear/wiringharness/etc... and you'd better be intimate with your TIG machine. A basic V8 swap with the 5.0 and using tried and true methods will take you a year to finish, will weigh 200lbs more, cost twice as much, and will give you less power than a 15psi turbo kit you could install in a week.

If you want to follow my build from start to finish on a '93 with a 180rwhp goal, read this... it's pretty much all inclusive, every part, every reason why, all options, and where to buy... I'm still tuning, but that's just as fun as the build: https://www.miataturbo.net/forums/showthread.php?t=4455

kotomile

iTrader: (24)

A turbo is your solution. I have no idea what you need to do to a Cobalt to prep for one, but a turbo will make you hella fast and will be quieter than fast NA and SC'd cars.

Ben

iTrader: (33)

I thought that was a really well done post, except for your take on the V8 swap. There are several "Monster" Miatas running very close to stock weight and putting down 300-500 hp. 200 extra pounds doesn't mean too much with 500 hp anyway. The GM LS-x motors are very popular, powerful, and lightish (for 8 cyls). The type of grunt you get from a V8 does not compare to a turbo 4; it's a different machine. Oh, most people are reporting spending $10k+ on their build. I have a Ford 3.9 V8 from a Lincoln LS tucked away. It was only $300 for the _complete_ motor, so maybe I'll head down this road one day...

savior

the cobalt turbo, which has yet to come out, will be in the ballpark of $3500, plus a new clutch which will be expensive.. all in all, the cobalt is a very expensive car to mod (which is why i am looking at miatas)...

I am entering college right now so of course ill be short on money, however I am going to study mechanical engineering and a miata would be a great project car! With turbos under 1k that could get a miata near 200 hp, I am dreaming about modding one!

--- so far what I have learned is the following:

sub 200 rwhp is easily attainable and for CHEAP!
- This will give you a pretty peppy car
(anything over and you'll have to invest a little more money)

v8 is probably not the way I want to go unless I want to invest a lot of time and money

and that I hatea cobalt-aftermarket companies

samnavy

iTrader: (7)

When budgeting for this project, don't forget about the rest of the car. If you're going for a 200hp build, the turbo is probably the last thing you want to do.
At a minimum, when considering your other modifications, think about a rollbar, brakes (pads/lines), shocks/sways, tire/wheels.

Throwing 200hp at an otherwise stock Miata isn't a good idea. You will overpower the suspension and tires. The rollbar debate goes on forever, I'm a fan, get one. Adding a set of braided lines and street compound Hawk or RPS pads makes a HUGE increase over the stock brakes (OEM rotors are all you need for a street car). A good set of used KYB AGX shocks and good Swaybars will run you $300. When you think wheels, think lightweight 15" (16" if you must, but there's no handling advantage, maybe bigger contact patch at the expense of unsprung weight to handle more power), and for tires, do your homework, I'm a Toyo guy, but there are half a dozen other "popular" performance tires the Miata community sticks to.
Bottom line, you really should upgrade some basic stock pieces before upping the power. Watch the classifieds here and at m.net... good stuff always for sale.
http://www.miata.net/cgi-bin/isc/cla...revaction=show

I think you're convinced unless you're up for a serious investment in time/money/labor, a V8 swap is out so I won't go there again.

savior

yeah but how long will a turbo'd engine last?
what are the stock internals rated to?

(miata mods are still much cheaper than cobalt mods)


BTW:
what are some 0-60 mph times for a 190 hp engine?

samnavy

iTrader: (7)

I already said that in my first post: Properly managed, the stock motor should be safe and reliable on the stock internals up to the 250-270 range. The stock internals will run up to about 300 but will not last long, and after that, you need rods and pistons at a minimum.

Properly fueled and sparked (ie, standalone), stock internals should handle up to about 15psi (depending on turbo) and be relatively long-lived (I would think 60-80k miles is common at that power). The Miata engine originally came in the 323gtx, which was a factory turbo car. There is a whole host of things this motor has engineered into it that makes it turbo friendly out of the box. Used COMPLETE motors and tranny's go for as little as $200. At that price, why worry?
The stock 5-spd tranny's will hold up to about 300hp no problem, the 6-spds have had luck up to about 400hp.
The stock dif's in the 1.6 litre (6") can be broken with stock power, but have also been known to hold decent boost with responsible driving.
The stock dif's in the 1.8 litre motors (7") have shown to be reliable up to about 400hp with abuse.

Again, if you haven't read Braineaks FAQ in the DIY turbo forum, go there and read the whole thing... a lot of the questions you're asking or will ask in the near future are already answered there. BTW, unless you're interested in a Greddy turbo kit, make your new threads in the DIY forum.


Somebody may correct me, but at 190rwhp (with an appropriate clutch, rubber, pavement, etc...) should put you into the very low 5sec range.

magnamx-5

iTrader: (7)

yeah 300 whp has been done by alot of people on stock motors. The buy in for turn key kits is pretty steep with begi's going from 3500 + and Fm's about the same, the greddy for a 1,6 is pretty good but you will need a intercooler or WI and some way to get your fuel right. I clutch is also needed at this hp level but the ebay stage 3 F1 racing cluthc is just fine south of 230 or so whp and has a nice soft pressure plate, but becouse of this lighr pressure plate it doesnt like clutch drops, but then agian neither does the 1.6 dif wich is said to be fairly weak i hope i dont find out if it trully is or not until i upgrade though. All miata parts pre 06 interchange pretty regularly and there are alot of tricks you can use stored here just browse around for a while and you just might surprise yuorself.