See I am planning on doin a build soon, because my the car used 1 quart between oil changes when I bought it last year in March, and it had 103,000 miles on it. Now it's boosted, and it takes 2 quarts between oil changes, and it has 123,000 miles on it. I wanna keep it low boost, cause I like the way it's set up now...it is dependable, very dependable....and I drive it to work everyday and I get around 26 MPG while beating on it. I think it is fast enough for my liking, but I figure, if I do a rebuild, what are my options to keep it pretty much stock, but strong enough to handle boost, but at the same time tame enough for everyday use? It doesn't smoke or leak oil, so where is the oil getting used? Think it's time for new rings? I wanna keep stock injectors and stock computer, so lets keep this thread mechanical please.

This is what I read:

FAIL FAIL FAIL FAIL :blah:


rods are for strength. low boost shouldn't need rods. your rings are leaking so you'll want to in the least rering. (unless your boosting into crankcase). You're make more power on low boost with HIGHER compression pistons. in the least, that will net you the most gains.

On v8's we would mill the heads for more compression. It is a big bang for the buck. The only time you wanna lower compression on a race motor is "boost"

LAYMEN TERMS:

Non-boost: Low compression = vagina
Boost: Low compression = ability to boost more.

Non boost: High compression = Trojan Stallion
Boost: High compression = Lower boost capibilities

It is pretty much that simple. Something has to make more bang. If the bang is less. Less power.

See I am all about efficiency...balance, weight distribution, etc. You could have a perfectly balanced engine with very low rotating mass, boosting, lets say, 12 psi...and have a heavy rotating, shitty balanced engine boosting, say 15psi, and I feel the 12psi would make more power, be better on fuel, and last a hell of a lot longer. Correct me if I'm wrong, but it's not all about simply turning up your boost.

I can see wanting dependable. 1 quart on a oil change is nothing. Are you driving the piss out of it?
I would drive it till it started smoking bad, not in-between shifts, I mean bad. I would just keep check on the oil everyday.
It is an excuse to look at your turbo anyway.

no it's not, and it's exactly why my 1.6L looks better on a dyno than most 94-05s.

but, if you want the motor to make more power on lower boost, raise the compression. since you'll run less boost, your knock threshold should be fine, you'll make more bang for the buck. coupled with increasing the flow it will be a monster.

Plenty of 200+ RELIABLE 1.6's. That's not pushing it very hard.


"Around", meaning "half of" :-P



Seriously, 200 hp out of a stock stock stock NB motor is nothing. Just throw it together, don't worry. If you're going to take it apart, put in better rods.

On my own 2000, I put in rods/pistons from a 97, for 9.0 compression. It's been dandy at 10-12 psi for a while. It's good to be cautious, but that's more than you need, you're killing your gas mileage, etc.

Your magical 12psi motor isn't going to do what you want on the stock ecu. You're right it's not all about simply turning up the boost. It's about building a good sealing motor with a strong bottom end, and tuning.



It's hard to find a heavy rotating, shitty balanced miata motor, unless you make it that way.

You're a perfectionist. So am I. You could easily make 250whp on a stock motor with a good tune and maintain reliability. This is old news. Turbo, Megasquirt, tuning, and 12 PSI you're their. Or you can be a perfectionist and try to optimize everything to make that same power at less boost. Option 1 is more bang for the buck. Option 2 is prefered if you're an engineering type that enjoys tuning, tweaking, and spending time and money as much as driving and passing people.

I read you wanna keep your stock ECU. I'm sorry.

built low compression block + major headwork + stock ecu = nonsense

Thirdgen, I'll ad in another tidbit for you...
You are a victim of believing in Voodoo.

Here's what you do.
Plan on having your car "down" for a month.
Pull your motor.
Take the motor to a reputable machine shop in the local area.

For the head, tell them you want "the works" but rebuilt with a new stock valvetrain. About $1500

For the bottom end, tell them you want a standard rebuild kit but supply them with a set of CAT forged rods you buy from Ben, and you want a tri-coat on the pistons. You also will need a new water and oil pump, and a new timing belt. They will hone the block and balance the crank, reassemble the motor and you'll be out around $2k total.

Take that motor back to your car and re-install it.
Sell SR20det T25 and purchase GT2560.
Then remove the Voodoo Box and get either the Xede or Hydra and some 550's. Or you can wait patiently until Begi has their new ECU ready for the '99-'01 cars.

This is gonna run you in the neighborhood of $5-$6k, but 11-12psi on a good tune for about 250whp and it should last 100k miles. Turn boost down to 7-8psi and run 200whp for as long as YOU live.

I consider myself part of this crowd. If I were thirdgen, and I had to do a rebuild anyway, here's where I would spend my money on a 100% reliable build (in order of importance, excluding turbo parts):

1) Standalone ECU, and lots of dyno time.

2) Oil cooler

3) Coolant reroute

Rebuild the bottom end with stock parts, keep the stock pistons if you want to daily the car, trust me it's not fun HAVING to warm up the car completely before driving it, and you must let it warm up fully on forged aluminum pistons if you want the rings to last.

Do a port and polish on the head, valve job, you can do more to it but with low boost you won't see much gains. Put it together and have a cheap reliable motor and just drive it.

If you insist on keeping the boost low, or alternatively, maximizing the power with a given boost, you should consider spending a lot of time on the dyno playing with cam timing, along with the usual fuel/spark tuning. This is what I intend to do when I can afford it.

building a motor for low anything is crap crap crap!!

my 01 made something like 190 rwhp at 4 psi. bone stock motor. it probably would run hundreds of thousands of miles like that--with half ass tuning.

I ran 40+ hours of track time last year.

let's play a game: which one is the stock 01 at 9psi and which is the stock '93 at 12psi????

Touche.

Tell me which turbo was on each motor, and I'll tell you.

2876 with a .63 T2 A/R on the 01.
T3 Super 60 with a .48 T3 A/R on the 1.6.