To get back on topic and help the new guy out... Fuck guys come on.

I installed mine over the winter, so like 6 months. Year of car?? I run NGK BKR7E plugs gaped to .028 though(stock 94 coils). I also have mine tuned to 12.2 - 12.0 in boost(wot)12psi... I run regular synthetic oil. 10w30 i think. Watch your intake temps, and coolant temps. It doesn't take a genius to figure out what's to high. I usually run 10F above ambient temperature. Keep the boost down, drive the piss out of it, when it breaks. Fix it with better parts.

You haz the answer.

Does anyone know if Jared ever pulled apart that stock MSM block that he was running like 23psi on for months and months... ??????

He sold it to someone... i wanna say Pusha. I thought it was a 94 block, though.

I'm building a bottom end over the winter, so after i get back from the 6000 mile wedding trip next summer, i'll be putting the 250 "limit" to the test. (I still don't buy it. The Escort/Protege guys have been going well over that for years.) I'm also reasonably sure my car spent at least 50k miles making quite a bit more than 250wtq. It made 238wtq on FM's dyno, and the car is WAY slower at that point than it was prior to bringing it to them.

Ya, hopefully i can continue to learn and if money is right get my hand on another longblock this winter to shove money into. Also thanks Sav for the info.

I like flyin miata's NGK race plugs gapped to 20. They don't misfire at 36psi. That is win to me.

Run rotella synthetic cus it is nice

AFR. I run 10.5-11:1 AFR with meth. 11.3ish AFR without. Again. This is for 25+psi.

For up to 15psi I would run 11.3-11.5 AFR. Yes, a tad richer for just in case your AFR gauge is off.

Also. If you decide to tune yourself, know that your knock sensor is god.


It is very useful IF you are naturally aspirated. Do not follow this guideline if you are boosted. It will at best, cost you power and at worst, your engine.

How is "11.3-11.5 AFR richer than 10.5-11.1"?

You're hitting 10.5:1 at 25psi WITH meth? I was under the understanding that would burn up rings, valves, ect.

I also don't see how running 14.7:1 at cruise in "econ" driving is bad. Or how 12.0:1 @ 12-15psi WOT is bad? Chance of going bang goes up, but i also don't like the idea of burning up rings and valves... I don't run super high boost, but i can't see how that would change much.

I think he was saying 11.3 - 11.5 is tad richer than Sav's recommended 11.8.

Oh okay. Well i recommend 12.1... So i guess it's richer than what i said as well.

12:1 in boost is ok on good 93 oct but risky on crap 91 oct.
10.5 will not do damage like you think. lower than 10.0 for extended periods of time might though.

Key word being "might." (But probably not, it'd have to be MUCH lower.)

Ahh okay. The 93 here in Detroit is some pretty dang good stuff, with marathon being right in my back yard.

You're not going to burn valves by running rich. You burn valves by running retard timing and a lot of power. Or by running a B series honda head.

Rings also don't burn up.


12:1 in boost does make good power on a miata. When I was tuning for 400hp on my GT30 I found about 30!!! hp by going from 11:1 to 12:1. No it didn't detonate. Yes it was on decent 93 octane. No I don't recommend that AFR.

As 19psi says, 10.5:1 will not break anything. It can even make more power than 11:1 at high boost.

I will always recommend run low 11 AFR because those extra few HP really aren't worth motor boom. Note that motor boom on lean AFR is because lean AFR runs hotter. Closer to stoich you get the higher your EGTs are. The reason why you don't blow motor and burn valves at cruise 14.7 AFR is because there really isn't much fuel going through the motor at that AFR. The more fuel, the more fire. Literally. At WOT with boost, there's a SHIZLOAD OF FRIKKEN FIRE pouring out of the valves. Hence valve burn risk and melted piston risk.

You just contradicted yourself.

I said high boost. Gt30 ran at 20-25psi. Thats not high boost nugga