Boost is not linear. There is not a proportional gain in HP related to boost pressure. It is entirely feasible that an engine making 200whp at 10psi will only make 250 at 20psi. Turbine curves play a large part in this.

There are many more factors at hand than "turn up the boost, turn up the hp!"

 

Right, but there is this arbitrary limit set in mt.net legend that limits Miata rods to 250whp or ft-lbs depending on who you ask and I've never seen concrete evidence that says that is the absolute failure point of this motor.

I don't think 350 is out of the question on this car, I'd absolutely say between 3-350 with the current setup and I'll stand behind that guess

In response to the non-linear boost curve, I definitely don't think the turbo is running out of steam. It's a little oversized for this motor and I think its within its efficiency range.

 

What turbo is this again?

 

Well, a lot of it has to do with our history.

 

Same as brain.

T04E 50 trim .64 a/r exhaust

 

Well, its theoretically possible to hit 350 on that turbo.

 

Well, maybe I should clarify. Extended time beyond 250whp leads to bent rods. If you turned up the boost yesterday, then sure maybe you are making 350whp, but I doubt it will last long (say for the next year for example).

Just to be clear, the suggestions on here (and on just about any other website) don't mean instant implosion at 251whp and perfect reliability at 249whp. We are talking about pushing parts beyond their reliable limit. Take that anyway you want, but babbling about how **** didn't explode based on your gestimate (or someone else's experience) is short sighted. This is the same for 5-speed reliability. They don't explode at 225 ft-lb torque, but failures become more regular at that point (especially depending on application). I know 1-2 guys who have had a 5-speed last more than year at that power, doesn't make it a good idea. Its generally called an "exception".

What I don't have is concrete evidence on expected life of stock rods. Its your responsibility to figure that out (either by reading, or by testing).

 

IOW, you haven't looked hard enough. I've seen multiple sets of bent rods posted on this site from 260-270whp cars with no detonation on the pistons. People make more, but not for very long.

e: Track said it better.

 

Well said Track.

The bottom line is none of us are claiming any definite limits, but when you CLAIM to exceed what most of us normally call "the limit" by 100whp and are pulling that estimate straight from your prolapsed colon, you bet your *** we're gonna call you on it, and you better believe we're gonna get hard and tag team you when you start crying like a prison sister with your pathetic excuses and flawed logic.

 

[leafy]Rods don't bend from horsepower, they bend from torque[/leafy]

Go ahead and check every thread from members who blew up stock motors. Sure some of them had det that caused it, but there were plenty who just threw rods with no signs of det at all. Hell 99mx5 did it at like 12PSI with his EFR6258. It's not a law of the universe, nor is it a myth. It's just a (rather large) amount of significant data which shows that stock rods don't last north of ~250wtq.

 

Just use virtual dyno and make a street pull to get a ballpark figure for where you stand. It is free software and you should be able to backup your claims tonight to some extent. The program has proven to be very reliable if used on a flat road in normal conditions.

 

fixed

 

ar·bi·trar·y
ˈärbiˌtrerē/
adjective
adjective: arbitrary

1.
based on random choice or personal whim, rather than any reason or system.
"his mealtimes were entirely arbitrary"
synonyms: capricious, whimsical, random, chance, unpredictable; More

Had to share that since you don't seem to know what the word actually means. Many members here with well-tuned cars have had their engines fail around that power level. A few have gone higher, but typically not for long. Sometimes, sure. But we like reliable, see. Repeatable. Freaks need not apply.


It's not just the turbo. What about the head? Did you end up doing massive headwork with oversized valves? No? 8k rpm? no?

I think you're full of it, sir. 18psi said it very well:

 

BBBBBRRRRRR!!!! I'm a TRUCK!!!!! BBBBBBRRRRR!!!!

 

Mesmerizing.

I really need more to do at work.

 

^^^ Thats the coolest thing in this thread until we see a dyno plot.

 

I just spent 20 minutes writing an elaborate post explaining my life. It told me to sign in when I hit post and I lost the whole post.

I blew my motor up. It over heated (really bad). No water pump belt. whoops

I put a new used motor in.

I'm going to the dyno January 9th

I have problems with coolant leaking out the motor at the headgasket. IDK why

CAS needs a dedicated ground (found out the hard way)

Here's my motor, it uses e-85. neat. Running 1.6bar.




Here's me putting the best oil ever in my motor.




Here's my car, because I know you like drift cars.

 

where the heck is the dyno sheet!!????

 

 

That's the 1.6 stock motor? Holy ****