saving Stock rods by keeping peak torque low ?
 

Id really like to end up somewhere close to 240-250whp with my setup. its a stock 95 engine with good compression (180psi), Exhintake mod, GT2560r and I will be running MSpnp

its my understanding that the big killer of rods is torque is this correct ? my plan is to set the timing to keep peak torque low (210-220wtq) Assuming a good tune this should make it less likely that I will bend a rod right ??

Yes torque, but also revs... and how much torque is being made at how high of revs... in other words, POWER.

A lot of bent rods are the result of detonation.

Basically. Keep boost and timing down (but not low enough to melt stuff) to keep torque down. Also keep stock redline.

Yes was planning to rev it to 7k with a limiter set at 7100. I want to beable to beat on it pretty hard on the street. If I take it to the track boost will be lowered to the 190-200whp range

A friend of mine runs 15psi on a large 16 with stock BP. Wastegate spring only, no boost controller. He absolutley rapes his car on the street every day, and its still just fine.

From my previous experiments, wastegate spring only is MUCH smoother onset from mbc. I think that's the difference between straight and gay rods.:giggle:

You know... i never really thought of that.

This is also why DISIs like to bend rods... it's the ridiculously fast spool up and sudden onset of torque that's the issue.

HRM.

That's also why they blow balls on fuel mileage.

What is DISI ?

my wastegate is a 7psi non adjustable unit. I guess when it comes time to up the boost maybe ill just get a new wastegate actuator

Mazda's Direct Injection technology.

Its cars like your friends that make me want to run 250whp but then I hear of people bending rods making only 230whp/wtq

I see plenty of 250whp stock engine dyno graphs on this site but havent seen much talk about how long people have ran at that kind of power and with what kind of abuse

^detonation

A street machine could probably make 300 without bending rods if there is absolutely zero detonation.

On the track youre building up so much heat, for such an extended period, that detonation can happen even with conservative boost and tuning. That why most well sorted setups are not even hitting 250 on a stock bottom end, and why shitty setups blow up way before that.

You never told us what you wanted to do with the car.

I like to beat on it pretty hard on the street and go out on curvy back roads and push it.

If I were to track it id lower the boost to get close to 200whp. I might even end up lowering the boost to that level when I go drive back roads since im pretty freakin hard on the car when I do that

Where is Paul when you need him...
All I can say is: stock block, gt2560, 18ish psi...319whp.

I made 280 whp with a holset hy35 on a stock BP until the oil pump blew. another guy on clubprotege made 300hp on a stock BP. he had an aem stinger with a good tune that motor lasted for two years and then the oil pump gears shattered. I could probably list a dozen who have been around 300whp with stock internals granted some of them didn't last that long. its all in the tune.

I could probably list 5 dozen people who claim they want 300whp, but have never ridden in a Miata with 240whp. 240whp is pretty damn fast.

I wasn't satisfied with 280whp it is never enough. I got used to it and it seemed slow. I wouldn't even worry about blowing it up with 250 lbs torque if you have a decent tune.

hasnt he been at that level for over a year ? dont know how much he drives or beats on the car though.

I take that car/setup/numbers with a grain of salt. I'm not doubting the numbers, or the fact that its held up at that power level for a long time, but find me a handful of others that did the same: you won't find any more than 1 maybe 2. Which makes me think that car is the exception, not the rule.

Remember when leatherface made well over 300 and ran something silly like 27psi on stock block? Yeah, same thing.

That car also made the smallest amount of power i've ever seen huffing that kind of boost.

Impressive that it held together... not impressive in the power it was (or wasn't) making.


There has been numerous Escort GT/Proteges in the past living for a relatively long period of time over 300whp on stock motors.


My Miata spent at least 50k miles over 250whp before i paid FM to tune it and they hamstrung it.

How did they F$%& things up ?