I have read a few threads about this. One had pics comparing the stock rods / pistons to aftermarket ones. Apparently there was nothing wrong with the stockers. They are good for at least 400whp. As you mentioned the problem is the big torque spike that happens before the turbo is even at full boost. Its unecessary and the people that are making big numbers "safely" appear to have tunes that push that tq later in the powerband. Take a look at the race roots page. They have the highest hp mzr that I have seen. Just look at the dyno hp/tq curves. The other problem is fueling. Not saying im right or anything. Just trying to contribute.
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Any completely STOCK engines bend/break a rod yet?
- Thread starter robin2660
- Start date
I have read a few threads about this. One had pics comparing the stock rods / pistons to aftermarket ones. Apparently there was nothing wrong with the stockers. They are good for at least 400whp. As you mentioned the problem is the big torque spike that happens before the turbo is even at full boost. Its unecessary and the people that are making big numbers "safely" appear to have tunes that push that tq later in the powerband. Take a look at the race roots page. They have the highest hp mzr that I have seen. Just look at the dyno hp/tq curves. The other problem is fueling. Not saying im right or anything. Just trying to contribute.
mars local
Member
- :
- 2008 Mazda3 S Sport 2.3L A/T
Still looking for personal or anecdotal evidence of any completely stock MS3 DISI 2.3 turbo engines blowing ....
Not looking for smart-ass comments or arguments ....
lol, then you came to the wrong place..... (wedge)
Darth Vader
Member
No he didn't. If he really wanted smart-ass mouthpieces, he would have gone to that *other* mazda speed forum....
People are alot more polite here and, that's a social skill much underrated in the modern world, especially demonstrated in the E-penis mentality prevalent elsewhere.
There ain't nothing wrong with asking around about stuff, as long as you use good judgement about what you learn. Drawing the conclusion this car is a hand grenade with the pin pulled if you don't leave it totally stock, would not be a good call, in my view but, also, disregarding the anecdotal evidence that you can break these things isn't wise either.
People are alot more polite here and, that's a social skill much underrated in the modern world, especially demonstrated in the E-penis mentality prevalent elsewhere.
There ain't nothing wrong with asking around about stuff, as long as you use good judgement about what you learn. Drawing the conclusion this car is a hand grenade with the pin pulled if you don't leave it totally stock, would not be a good call, in my view but, also, disregarding the anecdotal evidence that you can break these things isn't wise either.
Sephiroth, what OP is probably trying to find out is a real phenemenon that is being experienced and well documented on highly modded 2.3 DISI engines, including photos of bent connecting rods on this engine. It seems to be most frequently on cylinder number 3 and there is a LOT of discussion about this.
lol what?! it's a phenomenon that you blow up a modified MZR?
You're going to blow up *any* engine that is pushed beyond it's factory power numbers, the MZR isn't some miracle that has limitless capability, that's why the FS-DE blows @ around 210, and just about any factory F/I engine in the world has a limit that's 'discovered' by their respective enthusiasts crowd. It's not a phenomenon, it's an eventuality, increase the PSI with a crap tune and rods *will* fly. This thread was created to investigate the possibility of the same happening on bone stock engines, the answer is that it probably does, but no more than any other engine in the world, if Mazda were blowing stock MZR's left and right there would be a TSB for it.
obvious questions will result in obvious answers..it's the e-peen's that try to dissect it and extract results anyway that annoy me.People are alot more polite here and, that's a social skill much underrated in the modern world, especially demonstrated in the E-penis mentality prevalent elsewhere.
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Sephiroth, I think I did not make my point clear. My bad. What I'm trying to say is that inspection of the highly modded engines on tear down seemed to be suggesting that while we have forged (but not peened) rods that are theoretically good up to maybe 400 whp, a lot of the bent rods incidents were occurring under low rpm circumstances suggestive of high torque at low operating rpm -- way below the peak horsepower.
The speculation (and yes, it's just that at this point) is that when high torque is applied to the rod when it is moving slower, it is exposed to the forces for a greater length of time during each power stroke. This stress may be more than the rod can safely handle. If this is the case, the effect may be cumulative rather than from an acute application of too much power.
If this is true it becomes a concern for all of us regardless of degree of mods and points to a possible issue with application of WOT at low rpm, just when the engine is coming up on boost in the 2,500-3,000 rpm range. With little to no mods these engines are producing close to or sometimes exceeding 300 pound feet of torque in that rpm range. This may not be a healthy thing and may explain why some stock engines have failed. It's just something to think about and a reason to drop down a gear before hammering WOT.
Race Roots race MS3 MZR (running low 12's) is producing about 400 whp, I believe. But they are using a bigger turbo and modified fuel system that moves the power curve further out to the right so the power comes on later in the rpm band. They are running on the stock bottom end without any problems.
And yes, every stock engine has a power limit. Modding pressed the limit and modding above that limit will result in short engine life or outright failure. That's not what I'm talking about. Sorry for not being more clear.
The speculation (and yes, it's just that at this point) is that when high torque is applied to the rod when it is moving slower, it is exposed to the forces for a greater length of time during each power stroke. This stress may be more than the rod can safely handle. If this is the case, the effect may be cumulative rather than from an acute application of too much power.
If this is true it becomes a concern for all of us regardless of degree of mods and points to a possible issue with application of WOT at low rpm, just when the engine is coming up on boost in the 2,500-3,000 rpm range. With little to no mods these engines are producing close to or sometimes exceeding 300 pound feet of torque in that rpm range. This may not be a healthy thing and may explain why some stock engines have failed. It's just something to think about and a reason to drop down a gear before hammering WOT.
Race Roots race MS3 MZR (running low 12's) is producing about 400 whp, I believe. But they are using a bigger turbo and modified fuel system that moves the power curve further out to the right so the power comes on later in the rpm band. They are running on the stock bottom end without any problems.
And yes, every stock engine has a power limit. Modding pressed the limit and modding above that limit will result in short engine life or outright failure. That's not what I'm talking about. Sorry for not being more clear.
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Darth Vader
Member
I haven't heard, here or elsewhere, of ANY stock engine failures in the MZR, except 1 that was cause the dealership didn't tighten the oil drain bolt and all the oil leaked out, killing the engine.
This engine, despite it's high specific output, is pretty choked-up safe from the factory. The gawdawful intake, the despicable DP and second cat, the pinner turbo, cork this thing up hard mechanically and the ECU's standard calibration is fatter than a diesel under power.
This engine, despite it's high specific output, is pretty choked-up safe from the factory. The gawdawful intake, the despicable DP and second cat, the pinner turbo, cork this thing up hard mechanically and the ECU's standard calibration is fatter than a diesel under power.
Sephiroth, I think I did not make my point clear. My bad. What I'm trying to say is that inspection of the highly modded engines on tear down seemed to be suggesting that while we have forged (but not peened) rods that are theoretically good up to maybe 400 whp, a lot of the bent rods incidents were occurring under low rpm circumstances suggestive of high torque at low operating rpm -- way below the peak horsepower.
The speculation (and yes, it's just that at this point) is that when high torque is applied to the rod when it is moving slower, it is exposed to the forces for a greater length of time during each power stroke. This stress may be more than the rod can safely handle. If this is the case, the effect may be cumulative rather than from an acute application of too much power.
If this is true it becomes a concern for all of us regardless of degree of mods and points to a possible issue with application of WOT at low rpm, just when the engine is coming up on boost in the 2,500-3,000 rpm range. With little to no mods these engines are producing close to or sometimes exceeding 300 pound feet of torque in that rpm range. This may not be a healthy thing and may explain why some stock engines have failed. It's just something to think about and a reason to drop down a gear before hammering WOT.
Race Roots race MS3 MZR (running low 12's) is producing about 400 whp, I believe. But they are using a bigger turbo and modified fuel system that moves the power curve further out to the right so the power comes on later in the rpm band. They are running on the stock bottom end without any problems.
And yes, every stock engine has a power limit. Modding pressed the limit and modding above that limit will result in short engine life or outright failure. That's not what I'm talking about. Sorry for not being more clear.
Go with MSMS3's previous 2 statements. It's a function of low-end torque being applied at too low an RPM. There is a HUGE thread here that describes this in great detail if you search for it. It's on one of the blown-engine threads I think. Rule 1 is to downshift before romping on it into high boost levels to extend overall life and prevent slowly bending rods. See the other reference links here. A slight change in the way you might ordinarily drive the MS3 compared with another small-block turbo will go a longer way, in the long run, should you have rods with minor impurities in the metal (another theory, which combines over time to slowly bend the rod if you are at high boost in low RPMs). The big thread has scads of information relating to the rod structure, forged vs cast rods, the thrust washer change in 2008, high torque 2.3 DISI that has boost coming on in low RPMs, etc. etc..... combinatorial effects that "could" cause the engine (and maybe only "some" engines) to blow. You have to have "all 3 factors over time" to raise your probability of blowing. Othwerwise, there would be a TSB about it.
6
60181
Still looking for personal or anecdotal evidence of any completely stock MS3 DISI 2.3 turbo engines blowing ....
Not looking for smart-ass comments or arguments ....
keep in mind you're on an internet forum....that said, there are posts here about those that have gone BOOM in stock form. However, wh knows what they have or had done to their cars or if they even know how to properly drive the MS3. you can bend or weaken the rods simply by applying too much throttle in too high of a gear out of poor driving habits. too much of a load by not driving in the proper gear will over time take its toll.
axisboldaslove
Member
- :
- 07 MS3 GT Heavily Modified
Sephiroth, I think I did not make my point clear. My bad. What I'm trying to say is that inspection of the highly modded engines on tear down seemed to be suggesting that while we have forged (but not peened) rods that are theoretically good up to maybe 400 whp, a lot of the bent rods incidents were occurring under low rpm circumstances suggestive of high torque at low operating rpm -- way below the peak horsepower.
The speculation (and yes, it's just that at this point) is that when high torque is applied to the rod when it is moving slower, it is exposed to the forces for a greater length of time during each power stroke. This stress may be more than the rod can safely handle. If this is the case, the effect may be cumulative rather than from an acute application of too much power.
If this is true it becomes a concern for all of us regardless of degree of mods and points to a possible issue with application of WOT at low rpm, just when the engine is coming up on boost in the 2,500-3,000 rpm range. With little to no mods these engines are producing close to or sometimes exceeding 300 pound feet of torque in that rpm range. This may not be a healthy thing and may explain why some stock engines have failed. It's just something to think about and a reason to drop down a gear before hammering WOT.
Race Roots race MS3 MZR (running low 12's) is producing about 400 whp, I believe. But they are using a bigger turbo and modified fuel system that moves the power curve further out to the right so the power comes on later in the rpm band. They are running on the stock bottom end without any problems.
And yes, every stock engine has a power limit. Modding pressed the limit and modding above that limit will result in short engine life or outright failure. That's not what I'm talking about. Sorry for not being more clear.
race roots traded their ms3 in for a evo x and parted out there turbo kit to MadVillan
I have read a few threads about this. One had pics comparing the stock rods / pistons to aftermarket ones. Apparently there was nothing wrong with the stockers. They are good for at least 400whp. As you mentioned the problem is the big torque spike that happens before the turbo is even at full boost. Its unecessary and the people that are making big numbers "safely" appear to have tunes that push that tq later in the powerband. Take a look at the race roots page. They have the highest hp mzr that I have seen. Just look at the dyno hp/tq curves. The other problem is fueling. Not saying im right or anything. Just trying to contribute.
I thought the testing said they were good for closer to 500WHP...it was a while ago so not sure...
that curve looks like that because the turbo they used...not trying to discredit your post BUT calling the low end torque "unnecessary" doesn't make sense to me. it is what it is... low end torque is a big part of this cars appeal... that's what makes this car pin you to the back of your seat when you hit the go pedal! Its that quick spooling turbo that makes this car so raw.
I am not sure we can say people are making big numbers safely yet either. But for those making big numbers (for this platform anyway) their torque and HP curves have to do more with the turbos and mods they are using IMO. A bigger turbo will spool later than our lil guy.
i do think that our rods should be a little beefier due to the potential for LOTS of low end torque at low rpms (lugging)...but i also believe there is some sort of design flaw here too...
Again not trying to argue just trying to add to the discussion.
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race roots traded their ms3 in for a evo x and parted out there turbo kit to MadVillan
Thanks, I did not know that. So we may never know what power level they may have reached or how their tune might have ended up if they had stayed with the project.
Oh, well. I'm always interested in what we can learn from those willing to push the envelop to the point of crash and burn, tear down and root cause analysis. That's the best way to find out where the weaknesses are. I'm not that brave and not that willing to abuse my daily driver.
