Braineack

iTrader: (62)

great, can you idle them?

mattsmiata

what?

Braineack

iTrader: (62)

exactly.

bripab007

Brainack, you are at the top of your game, sir! Good work!!

mattsmiata

i am not the only one doing this project. my dad and other people are helping with it. i just thought i would get some input on parts.. so i don't know everything about it and i will admit that but that is why my dad is helping with the project.

Braineack

iTrader: (62)

I think you need to consider one of these kits instead of a TSI kit:

http://www.bellengineering.net/Pages...bosystems.html

Call Corky Bell, designers of the system and author of "Maximum Boost" for the best way to acheieve your goals with his system. Look at the comparison between the S1, S2, S3 & S4 in regards to power output, turbo size, fuel controllers, etc.

Throwing 20psi at your system is not a simple task. Believe us, if we all could we would. Yes internals will be needed after around 250rwhp (12-15psi), but it takes a lot to get to that point. But then you might need to find a larger turbo and sacrifice lots of low-end and "lag" to run larger boost levels. You'll find a lot of us are plently happy with systems between 190-250rwhp.

samnavy

iTrader: (7)

Matt, STOP!!! I absolutely guarantee if you buy that kit, within a month, you'll be spending an extra $1000 dollars just to fix what you've broke or what came in the kit that's already broken or wasn't right. That kit was just discussed at length in another thread... https://www.miataturbo.net/forums/showthread.php?t=4801

DUDE, SERIOUSLY, YOU NEED TO SPEND A FEW WEEKS AT LEAST DOING RESEARCH. WE'RE CAN GIVE YOU GOOD ADVICE HERE!!!!! DON'T BUY ANYTHING YET. DO YOUR HOMEWORK. LEARN FIRST, SPEND MONEY SECOND.

First, have you decided on a horsepower goal?
How much money total do you have to spend?
What are the current modifications to the car? List ALL of them... even the bling stuff if there is any.

And PLEASE DON'T SPEND ANY MONEY YET!!!!!!!!!!!!!!!!!!!!!!!!!!

mattsmiata

i figured that i want to get around 200-250whp out of the car... i don't really know how much i want to spend i guess i will spend what ever it takes. it is stock right now but i am going to redue all the guts. any requests on the guts?

Mach929

iTrader: (3)

well a stock 1.8 motor in good condition will have no problem handling 200-250 whp as long as tuning is decent. If that's all your goals are just do a stock rebuild, aftermarket internals for the miata are very expensive, you're looking at over $1000 for pistons and rods alone.

With that said what is your reason for building the motor, miata motors are pretty tough and even higher mileage examples still show great compression numbers.

Ok so now we know you want 200-250 whp. since you have a 1.8 the way i see it you have 2 reasonable options.
1. build yourself a diy kit
2. look over the bell kits and pick one

mattsmiata

the motor has around 120000 miles and i just want to strengthen the internals just to be sure that i only have to do this once. it is eaiser to pull the motor to do the turbo so once it is out it is easy to rebuild. just going to do it all at once. I know the internals are over 1000 i want to only spend
3000-4000 prob is a good est.

Joseph B

The engine dosen't need to come out to bolt on a turbo setup. You should do a clutch, flywheel, and catback first to build up your mechanical ability (these are nice supporting mods). Next, I would install the kit and learn how to conservatively tune it on your old engine. If you blow it up, you're not out thousands of dollars on your nice, new rebuilt engine. Lastly, like most of us, you have a finite amount of money. What are you looking to spend? If I knew little about cars and FI, I would just pick up a Bell or FM kit since all of the homework is already completed.

Mach929

iTrader: (3)

with a 3000-4000 budget there's no way you'll be able to build the motor and build/buy a kit that will take advantage of it.

samnavy

iTrader: (7)

Matt, you don't have to strengthen the internals unless your power goals warrant it. There is an ENORMOUS difference between 200 and 250 hp in these cars. I'm headed for almost 200hp and my motor has 140,000 miles on it. I expect to go to near 200,000 miles before replacing the motor, and even then I'll just get a someones low mile donor from a wreck.

Now, 250hp is approaching the need for internals... but not at all mandatory. You can buy several used motors for the cost of one built one. You say you only want to do this once, but once may be all you need. To start, what are the compression numbers on your current motor?

Again, you need to pick a more specific number for your power goal... everything you buy will depend on it. What is your horsepower goal?

Is that $3k-$4k all the money you have for everything you intend to do to the car, or just for the motor alone?

What about the other things in my first post. Throwing 250hp at an otherwise bone-stock Miata is a bad idea. What about tires/wheels/suspension/roll bar/chassis/exhaust/etc...

MORE HOMEWORK!!!

bripab007

Also, do yourself a favor and drive/ride in a boosted Miata to get a feel for how fast it is. Running a mere 6-7 psi provide 50-60% more power than stock, and is a huge kick in the pants. Running 200-250rwhp in these cars is ridiculously quick. A stock S2000 makes about 205rwhp, and it weighs 500lbs. more than a Miata...I certainly wouldn't call it a slow car.

mattsmiata

no i plan on spending around 4000 in just the motor alone i already have eveything else i need for the car.

samnavy

iTrader: (7)

YOU MUST START BY HAVING A POWER GOAL!!!!!!!
JUST GIVE US A NUMBER!!!!!!!
ANY NUMBER WILL DO!!!!!!!!!
JUST PICK A LEVEL OF HORSEPOWER YOU'RE LOOKING FOR AND TYPE IT!!!!!!!!

Then list the "everything else" you've already got for the car. Seriously, LIST THEM!

$4000 will get you a 200rwhp NA motor. (if that's all you want then no need to turbo) But you'll need another $2000 in engine management to run it, plus upgrading most of the fuel system. And why build that motor if you're not going to turbo it. How about a nice big T4 running your 20psi. You can have over 400rwhp... but nothing about the stock drivetrain will handle that much power. Transmission/DIF/Tires/Wheels/Chassis/RollBar/Suspension/Exhaust

You're talking about $12k-$15k dollars. If you've already got most of it, that's great, but then just tell us what you've got.

Come on man, help us help you, you've gotta answer our questions before we have enough info to answer yours.

bripab007

I really don't think $4000 will get you 200rwhp naturally-aspirated.

It might cover most of the work and parts to build out a high-compression motor with worked head/valves/cams for ~150-170rwhp...but the you still need to budget for an ECU to control it.

A 200rwhp NA would be close to unstreetable...you'd probably have to live with a lopey, 1800 RPM idle. There's a reason Honda created VTEC :-)

mattsmiata

hey guys, truth is my buddy started this up for me a few days ago while i was away just to help me get my bearings before i start this project. thanks for the advice so far. i read through it last night and im definately open to all suggestions. im hoping to get a little over 200hp outta my miata and i figured a turbo would be an upgrade i could do that would help me get there fast. i was a little afraid of running a turbo on my engine with as many miles as it has so i was looking into changing the internals, but if you say i dont need to, that could save me some money. also, if that kit i was looking into isnt worth buying, i'll just hold off and get one of those kits from BEGi. before i spend any money though, what psi should i look into running, what should i do to get about 200hp out of her, and is there anything else i should consider doing. again, im open to all your suggestions and thanks for what youve done so far.

Mach929

iTrader: (3)

do a compression test on your motor to see where you stand. for 200hp and normal sized turbo you're looking at running probably 10-15psi, so many other factors come into play so psi really doesn't mean all that much. can't really go wrong with picking a kit from begi. Though this board kind of caters to the do it yourselfers, hackers, and tweakers.

Efini~FC3S

iTrader: (4)

I don't mean to rag but stop worrying about how much psi you want to run. If you want around or just over 200hp that's good, now you need to select a turbo that fits your needs and budget. After selecting a turbo then you will know how many psi you need to run to get 200hp.

The thing is boost pressure doesn't mean anything by itself, how much air the turbo is flowing is what really matters. For the same boost pressure (psi) a T3/T4 will be flowing a lot more air than a t25. To make 200hp a 1.8 miata engine has to flow a certain amount of air (cfm).

I'm new to Miatas so these numbers aren't warrented but for an example 200hp on a t25 might require 18psi (way out of it's efficiency), on a t28 it might be 15psi, 13psi for a GT28, 11psi for a Super 60 T3, and 9psi for a T3/T4.

Also if you're worried about turboing a high mileage engine just do a compression check first. If it turns out ok than you don't have much to worry about as long as you tune everything carefully and safely. I turboed my 175k mile KA24DE on my Nissan and it's ran fine for 10 months now (over 5k hard miles).

With the right parts and tuning your 140k miata engine could put down 200whp daily for another 30k+ miles (or more who knows).

Hope this helps