Hi,

i am completly new to the Miata and have a question regarding the stock rods. Can anyone tell for how much power and torq the stock 1.8 NA rods good for?

At what stage it makes sense to change the rods and do you have any advise?

Regards

 

I think the generally accepted value is about 250wtq if tuned properly with no det. Of course at that power level transmissions and other things become more prone to break.

 

Man this question really does come up weekly. Brain, can we have a little writeup on things like this and make the question(s) you have to answer before you can get a membership be a quiz on the questions that come up constantly?

 

Not worth the trouble.

 

Sorry, i didnt know that this questions is coming every week cause i dont find anything with the search...

@hochkis
thx for your answer, but what is 250wtq for a unit?
Can you tell me the torq and bhp?

background is i have a NBFL engine which should run in my NA for trackday use. The engine have already 323 GTR pistons with a reduced compression, i guess 8.2:1 or so and a turbo. At least the engine have 230 bhp (not proven yet cause i dont have it on a dyno already) but i want to boost them a little bit more... so the questions is as long as the engine is out of the car, does it make sense to spend some extra money for new rods or can i run 300bhp with the stock ones?

Thx in advance for every helpfull answer.

 

It means 250 wheel torque as in the torque applied through the wheels.

If you already have the motor apart, upgrade the rods, it's cheap insurance even if youre only planning on making 300hp at the crank.

 

And you'll be back here in a month asking "my 5 speed blew up, what's a good replacement upgrade for it?".

 

with that CR level, you'll never need to worry about the rods; not enough torque.

 

I think he does not know if you mean 250 newton-meters or something else.

 

3389544870 Ergs at the wheels

 

0.125 ft-tons

 

3000 in-lbs.

 

But how much Work is 250ft lbs?

 

250 lb-ft.

 

caveman level.

 

There is a thread that covers all noob power questions. Even if it doesn't answer all it gives more info to search on https://www.miataturbo.net/diy-turbo...k-links-56507/

 

I'd be like over like 1500lbs if I were 250lb per ft. I'm sure I'd break the rods by then. Must be right. Like. Like. Like.

 

Yeah, quiet funny.... but in Germany we have other units compare to the US. So sorry that wtq, lbs etc. dosent ring a bell.

Neverless, thx for the helpfull answers and the rest comments.

 

With a small T25 I would say about 10, maybe 12 psi. With a T3/T4, no more than 7-8 psi, and pray for no detonation.