So far I've only seen one failure on the 4B11 out of over 75 tuned so far, about 15-20 of those on E85 and 26-29 psi. I have yet to see the infamous "common" piston chunks, that is not to say it isn't happening elsewhere.

The one failure was a rod bolt snapping, of course this created alot of carnage. This 4B11 was producing 450whp on our dyno on E85 at 29psi straight across. This is 220 whp over what the car made stock.

The stock rod bolts are interesting, I would urge people not to make it a habit of revving to 8k or beyond with them.

There has also been a bunch of FP relay issues I have caught on dyno in time. A local threw a rod because of a FP relay issue on the street. Car had stock tune with small bolt on mods.

In all honesty I would recommend a wideband to all Evo 10 owners that like keeping their motors in one piece. The 4B11 is interesting in that it doesn't seem to fall over on itself when it goes really lean. Without a wideband it's hard to tell if it's lean or not.

- Bryan

 

I think it's important to point out how important a wideband is... I think this will be my next mod.

 

well you can always try, it doesnt hurt and you never know!

 

My dealer told me anything in front of the maf and behind the cat can be changed. So I'd at least go try.

 

I haven't seen many blown engines, but I find it interesting that in many cases, one piston has signficant meltdown while the others are all prestine. Is this typical of an overly lean condition? Wouldn't all the pistons show carnage if generally lean?

 

Sounds to me like the main problem is that there are too many shops (I don't mean the good ones of course) & owners ecu tuning these cars that don't know what they or doing.

 

Completely agree.

 

That is interesting considering one of the largest threads on this subject of bridged spark plug gap and broken piston rings is tuned by AMS Performance.

https://www.evolutionm.net/forums/ev...ml#post8030830

Read the above linked thread.

 

Ah yes the thread you played a part in getting temporarily shut down. Even the best tuner shops are going to blow engines and I don't believe I ever pointed fingers at any shop in particular. The fact of the matter is that cars running stock or simple tunes like Cobb Stage 2 aren't blowing up. We already know the 4B11 isn't capable as the 4G63 at making big power on stock internals which means that shops are still learning the safe limits on these engines and the margins are a lot smaller than they were on the 4G63. Also remember that 2008 was year one of the 4B11 turbocharged engine, hopefully 2010 models have some minor assembly changes if your theory of incorrect assembly is correct.

 

I have seen three 4B11 failures with my own eyes, which is why I don't like it. Two of them had turbo upgrades (Dom1 and a Red). OK, makes sense.

But one was a local friend, with slight mods (test pipe and cat-back), and a really mild tune: 23psi tapering to 17, conservative timing. It ran great for a year on all those parts, logged no knocksum, then just started knocking like crazy out of the blue one day. We tried literally everything to fix it, but in the end, the only fix was going to be pulling the motor. THAT car scared the crap out of me. Because it was much more mild than even my own car, and I could not figure why it would fail like that. This guy is a dad of 3 kids, the car was treated well. He was the original owner, and that should not have happened IMO.

 

Every car brand/type will have it's bad motors, that is inevitable. I am sure the mods made that one go faster. Especially in a performance car will this happen. Most people don't expect sports cars to be super reliable, but us Evo guys expect everything from it and it typically delivers.

I know what you are saying, but there are plenty of people running excessive amounts of power with no problems.

 

The 8/9's need head studs to run any decent boost level. The local guys don't trust their blocks much beyond 450 without building them. It doesn't seem much different to me.

 

I agree the levels seem similar, in fact the 4b11 seems to have people going higher. But if anything they are very comparable.

 

Sometimes I wonder where people come up with some of the **** they punch on the keys with such great confidence. People can blame tuning all they want but you have to remember that most of the guys self tuning their cars have probably been tuning longer than a lot of the shops. Somehow tossing a car on the dyno for an hour for a "full custom tune " is the professional way and tuning the car continuously for various types of driving and changes in weather is the HACK way Don't be so easy to discredit everyone's tuning abilities. You'd be surprised the abuse most engines can take, and being a tad lean isn't going to destroy all these engines. Some of the most retarded unsafe tunes I have seen are from the Pros.

You guys that think you are having rod bolt failures....are you sure it wasn't the rod and the bolt broke as a result of other **** flying apart? I know my rod bolts are fine, but my rods are snapped clean in half (except 1 has murdered bolts) These all seem to be pretty clean breaks in the same spot.

 

Not that I really have to (or should) mention this but I'm a "self-tuner" first starting with the 4G61 then into the DSM 4G63's, then the Evo 4G63's and now the 4B11's. Just because I have a vendor name attached to me doesn't mean you should view me in a different light, and of course vise versa. I'm not saying you are, just want to mention it. I have the utmost respect for the "self-tuners" because I know my roots.

Anyway.. I'd love to see a photo of your snapped rod. The one failure I've seen and mentioned above also had a snapped rod that had (looked like) impacted the sleeve after the bolt failed. I'm not an engine builder by any means, I just tap keys on a keyboard with my eyes closed and hope for the best (joking on that last part.)

- Bryan