how much boost
 

how much boost can the stock engine in a 99 miata handle befor breaking lots of parts

as much as you want. provided you tune it proper, and know when to stop pushing it

With stock internals most people don't push past 15 psi, 12 psi is considered the "safe" limit. I am speaking very, very generally. Too many other factors.

psi on one turbo is different than psi on another

He isn't referring to the amount of power the turbo is capable of producing airflow for. He is referring to premature ring wear. As far as HP (or airflow as you are thinking) the general thought is that the stock rods might give way sometime soon after the 275ish HP mark. Not to say that you might not be able to run 300whp on them but people generally have a build motor that you see running 300whp or up.

Try the search function:
https://www.miataturbo.net/forums/sh...ighlight=power
https://www.miataturbo.net/forums/sh...ighlight=power
https://www.miataturbo.net/forums/sh...tock+internals
https://www.miataturbo.net/forums/sh...ighlight=power

NEO, how did you deduce he was referring to "when will my rings blow" from that post. Do you know him from another forum? It sounds like a typical "newb" question to me.

The question of "How much boost" is not a good question since different turbos flow different amounts of air per psi of boost. You might run 12psi on a T25 and make 180rwhp, or 12psi on a T3 and make 250rwhp. You can break your engine on 2psi by screwing up the tuning. You can run 20psi or more for short periods of time with proper tuning. Assuming the best tune ever, somewhere between 250-300 rwhp is the place where stock internals start to have shortened lifespans. Remember, the B6 motor was an OEM turbo motor in the 80's (or something)... it's set up internally for forced induction.

The rules for both the 1.6 and 1.8's are pretty much the same as far as limits. Your '99 internals are the same as every other 1.8 motor from '94+ I believe (someone confirm or correct me here).

Welcome to the forum. Do us a favor and fill out your signature. A couple lines with the info on your car/mods/goals written in your sig will help people tailor their responses to your questions. There's also a section called the vbGarage where you can upload pics and give a full list of mods. TRUST ME, this will make you friends around here.

So, now that we're on the subject, what are your goals with your '99?

thanks for all your help