1+
hold back on the feathers and tar

 

Good news is you have a reason to build a built motor now.. Good luck man

 

You guys making these brash statements are honestly kinda off-base IMHO. Yea boost is a little high and yea lugging it in 5th gear is probably not hte best, but 45-50mph is NOT 1500rpm, it is 2000rpm which really isn't that low when you think about it. Yes if the car loads up and starts bucking you need to back off, but general cruising and light accel at that speed is fine. The only thing it could really affect is the trans imho more than the motor.

Plus I don't think the OP ever said, 'yea I drive around at WOT *ALL* the time in 5th gear at 45mph.'

 

Usually it's not the final event that sends a motor over the edge, but a series of conditions that weaken the motor over time until it's ready to let go from just about any trigger condition.

Usually I like to tune the Evo X's at 26 PSI tops on the Stock turbo because any more at lower RPM's below 4000 seems to be trouble on these engines. You can tune for zero knock and get mad torque which feels great but really is incredible stress when you hit 29 psi at the boost threshold in 4th and 5th gear. Because the boost tapers from 25 psi at 5500 down to 20 psi at 7000 anyways, you really don't lose any top end pull by running 26 psi peak boost, just some low end torque that won't be enjoyed anyways once you start rowing the gears during racing conditions since you will be between 5000-7000 rpm anyways. While that extra 3 psi might feel good coming out of a slow speed corner, the engines just don't like it all that much and it's not worth the extra risk in my book.

Hopefully you will figure out what to go with, Buschur has some nice options for rebuilds from 2.0L to the mighty 1BAMF 2.2L that we're dropping into Dr. Seto's Evo X for the 2012 One Lap event.

 

+1 you usually don't even feel that big torque hit unless you go around flooring it at 2k rpm

 

Using too high of a gear is definitely a problem... You should be in 4th gear at 45-50. I don't think that was the only factor in this situation though.

That dyno graph shows how inefficient the stock turbo is at 29psi. Also, that's not a very smooth graph either.

OP: Good luck getting your car back on the road. If there's anything Vivid can do to help, let us know.

 

I haven't dabbled with tuning X's yet, but is the problem that in a low RPM/high LOAD situation the ECU can't reference a correct part of the table or what? Can the car not account for low RPM/high LOAD situation? Excessive knocking? Can't be tuned out by adding fuel or pulling timing?

 

^+1

 

Good luck on the rebuild

 

45 mph in 5th gear is perfectly fine and efficient for this car. If the car is properly tuned you should be able to floor it in 5th gear and have no damage. The boost levels should not be able to reach 29 psi at that rpm if properly tuned for the right load/rpm cells/and throttle position. The only way to tell would be to look at the tune. It could surely be possible his car was tuned correctly! There are so many variables on a cars condition. Something as simple as a bad sensor could cause a big problem.

 

45 mph in 5th gear is perfectly fine and efficient for this car. If the car is properly tuned you should be able to floor it in 5th gear and have no damage. The boost levels should not be able to reach 29 psi at that rpm if properly tuned for the right load/rpm cells/and throttle position. The only way to tell would be to look at the tune. It could surely be possible his car was tuned correctly! There are so many variables on a cars condition. Something as simple as a bad sensor could cause a big problem.

 

Ahh no, definitely not. I don't care how "well tuned" you are but going WOT in 5th gear is just asking for your motor to blow, especially at low RPMs.

 

29psi.. i would keep it lower than that.

 

One or a few people have had this problem before with the 4b11 motors, and there's a LONGG thread on here somewhere explaining the weakness of these motor, the rod bolts or something I think? One person did have the same issue though while just cruising in 5th also....I wanna say TTP engineering knows this problem to the T, the story I remember reading was a guy felt a loss of power so he did a compression test, found cyls 1 and 4? with low compression and the guys on here was saying thats ok nothing to worry about and ttp said pretty soon this and this is going to happen, everyone called bs, then later it happened just like ttp said. It's a common thing on these motors. I'll look for the thread later if I can.

Either way you should post the tuner and bring it back to them or tell them what happened, it was probably caused from the tune, maybe not happened when the car was in the shop but the more aggressive tune was the reasoning. I've seen lots of "Pro work" look like a 6 year old did it too.

 

It's the rods. there have been several cases of people replacing their rods in a 4b11t that appeared to been running perfectly fine, only to find out that the one of the rods was horribly warped. Like several people have been saying, the damage that caused the engine to break may have happened long ago.

This reportedly came out of an evo x that was running just fine:



edit: another similar example: