Analyzing a critical engine flaw in the 4b11 by TTP
You are right, of course. But the car in stock form sucks in the hp department. Most of us, I think, just want to know what's the upper safe limit for bolt ons before you have to crack open the motor. Do you know?
We don't. They don't take 4G63's past 400 - 425 tq. And Yes we need to talk about the max Torque a 4B11 can take, and not HP. Torque is the Force of the engine, HP is the Force of the engine Times the RPM it occurs at divided by 5252.
Thread Starter
Account Disabled
iTrader: (465)
Joined: May 2005
Posts: 8,824
Likes: 2
From: Central FL
We also have stock engined 500-600whp Evo X's yet 300-400whp Evo X's we've seen with the issues.
Evolving Member
Joined: Mar 2009
Posts: 182
Likes: 8
From: Seattle
""But the car in stock form sucks in the hp department""
Agree
"Most of us, I think, just want to know what's the upper safe limit for bolt ons before you have to crack open the motor. Do you know?"
a general rule of thumb (guess) would be 1.5 times stock. I have no clue what the hard number is.
""And Yes we need to talk about the max Torque a 4B11 can take, and not HP. ""
Agree
""We have Evo 8-9's at 550-605whp and 500+tq on stock motors and rod bolts.""
the iron vs. alum block might have something to do with it, different expansion rates
""We also have stock engined 500-600whp Evo X's yet 300-400whp Evo X's we've seen with the issues. ""
I think what you may up against is production tolerance stack-up. Say some of the gaps are coming in at the tight end of the tolerance, within specs and it works stock but goes past the margin with mods.
It's not a weakness of material but a weakness of design/adjustment when modded. At least it's just an adjustment and not an upgrade of parts, labor expense but no part expense.
The proof of the whole deal would be to start adjusting the gap and see if it stops the grenading.
Agree
"Most of us, I think, just want to know what's the upper safe limit for bolt ons before you have to crack open the motor. Do you know?"
a general rule of thumb (guess) would be 1.5 times stock. I have no clue what the hard number is.
""And Yes we need to talk about the max Torque a 4B11 can take, and not HP. ""
Agree
""We have Evo 8-9's at 550-605whp and 500+tq on stock motors and rod bolts.""
the iron vs. alum block might have something to do with it, different expansion rates
""We also have stock engined 500-600whp Evo X's yet 300-400whp Evo X's we've seen with the issues. ""
I think what you may up against is production tolerance stack-up. Say some of the gaps are coming in at the tight end of the tolerance, within specs and it works stock but goes past the margin with mods.
It's not a weakness of material but a weakness of design/adjustment when modded. At least it's just an adjustment and not an upgrade of parts, labor expense but no part expense.
The proof of the whole deal would be to start adjusting the gap and see if it stops the grenading.
Recall, problem solved, glad it was found and fixed WELL before it became an issue for anyone I've come across on these forums, have you heard of anybody who actually had the fuel line crack from vibrations and being improperly supported?
TEN dollar fix
Same problem, no? Sucks for track junkies, but if you're a track junkie get yourself a surge tank. More often than not, that's killing two birds with one stone to support higher power fueling needs
"other tuners" should learn them some more 4B11T, IMO
And I agree with anybody who says that turbolancer02 Mitsu tech makes a silly argument... Mitsubishi built the Evo and tuned it to its threshold... lol. So if I beat the **** out of the car in completely stock form at sea level, -20 degrees F outside, then the car should grenade because it was already at its threshold when I was driving it up in the mountains on a 75 degree bright and sunny day?
TEN dollar fix
Same problem, no? Sucks for track junkies, but if you're a track junkie get yourself a surge tank. More often than not, that's killing two birds with one stone to support higher power fueling needs
"other tuners" should learn them some more 4B11T, IMO
And I agree with anybody who says that turbolancer02 Mitsu tech makes a silly argument... Mitsubishi built the Evo and tuned it to its threshold... lol. So if I beat the **** out of the car in completely stock form at sea level, -20 degrees F outside, then the car should grenade because it was already at its threshold when I was driving it up in the mountains on a 75 degree bright and sunny day?
Evolving Member
Joined: Aug 2008
Posts: 404
Likes: 0
From: NI
Recall, problem solved, glad it was found and fixed WELL before it became an issue for anyone I've come across on these forums, have you heard of anybody who actually had the fuel line crack from vibrations and being improperly supported?
TEN dollar fix
Same problem, no? Sucks for track junkies, but if you're a track junkie get yourself a surge tank. More often than not, that's killing two birds with one stone to support higher power fueling needs
"other tuners" should learn them some more 4B11T, IMO
And I agree with anybody who says that turbolancer02 Mitsu tech makes a silly argument... Mitsubishi built the Evo and tuned it to its threshold... lol. So if I beat the **** out of the car in completely stock form at sea level, -20 degrees F outside, then the car should grenade because it was already at its threshold when I was driving it up in the mountains on a 75 degree bright and sunny day?
TEN dollar fix
Same problem, no? Sucks for track junkies, but if you're a track junkie get yourself a surge tank. More often than not, that's killing two birds with one stone to support higher power fueling needs
"other tuners" should learn them some more 4B11T, IMO
And I agree with anybody who says that turbolancer02 Mitsu tech makes a silly argument... Mitsubishi built the Evo and tuned it to its threshold... lol. So if I beat the **** out of the car in completely stock form at sea level, -20 degrees F outside, then the car should grenade because it was already at its threshold when I was driving it up in the mountains on a 75 degree bright and sunny day?
Actually I never said that it was tuned to its threshhold..I said with any performance car you can expect to be close to its limit in terms of trying to get every bit of power out of it by the manufacturer , when you mod it and it parts werent designed for the hp your trying to get its your own fault, not mitsu's
Mitsubishi has not "put out a performance vehicle and maxed it out." I do not care that you are a Mitsubishi tech. You can keep coming in here spouting that off over and over again, but the fact of the matter is that I will argue with you until my fingers fall off.
Servicing and working on are an entirely different thing. Oil changes, fuel line fixes, relay switches, ecu updates are an entirely different thing than what we are talking about here. Someone who has no master tech certifications can follow a Helms manual or a TSB and do what you do.
Even you yourself said it in this post; Mitsubishi did not design the car to work at the power level they took it to. Why is this? I thought you said Mahler made quality parts. Well, apparently their quality parts cannot function under extreme situations. In another post you said they had been a company before we were all born. Why then, did they not see this as a possible issue? Everyone knows these cars are going to be modified. Why would they not beef it up just to ensure a reliable product?
A fundamental rule is to build the motor for your application, but it appears to me that you are saying that you would need to build the motor to make any change from factory spec (i.e. IC piping, Exhaust, Intake, Tune, Upping Boost). That, to me, is just a joke. I really don't think you know what you are talking about.
Servicing and working on are an entirely different thing. Oil changes, fuel line fixes, relay switches, ecu updates are an entirely different thing than what we are talking about here. Someone who has no master tech certifications can follow a Helms manual or a TSB and do what you do.
Even you yourself said it in this post; Mitsubishi did not design the car to work at the power level they took it to. Why is this? I thought you said Mahler made quality parts. Well, apparently their quality parts cannot function under extreme situations. In another post you said they had been a company before we were all born. Why then, did they not see this as a possible issue? Everyone knows these cars are going to be modified. Why would they not beef it up just to ensure a reliable product?
A fundamental rule is to build the motor for your application, but it appears to me that you are saying that you would need to build the motor to make any change from factory spec (i.e. IC piping, Exhaust, Intake, Tune, Upping Boost). That, to me, is just a joke. I really don't think you know what you are talking about.
...Most everyone I know who is a tech builds there own engines and stuff in there own garages ,my last car was a twin turbo mustang lx that easily nailed off 1000hp and I do build my own stuff including that engine and guess what I know a stock 302 block cant handle that so I upgraded and I didnt sit around and complain that ford sucked...the block was good til a level , thats what Im getting at
I said that if you want 700 or 600hp ex. or whatever out of any engine designed for a safe 400 ex. you need to build it to handle it, instead of pushing it and grenading it then crying about it and sayin mitsu dont know what there doing...
Do you honestly think mitsu race evo's are running stock production blocks, pistons etc.? No because they know the stock stuff wont handle it, pretty much common sense
And just to let you know its mahle piston not mahler
Last edited by turbolancer02; Mar 22, 2010 at 12:58 AM.
I think pretty highly of my tuner and he also complains about the knock detection on our motors. He has seen phantom knock from upgraded pistons/rods as well so I may be setting myself up for a bruising. Should find out this week.
So there are pictures from 2 cars with busted ring lands, both modified, and that is enough to start a giant hoopla about the ring gap being too tight and causing this? Completely destroyed cylinders are you are positive there was no p2v contact? These valve springs are VERY soft for what we are doing.
Isn't subaru having a similar issue, but on stock STIs because they moved the top compression ring too far up to the top of the piston for emissions?
I tossed my nitrous motor in there just to show that I have no problem with the ring gap after a LOT of nitrous usage and TONS of heat with only .005 ring gap on some cylinders. I think you are looking at the wrong issue here.
Isn't subaru having a similar issue, but on stock STIs because they moved the top compression ring too far up to the top of the piston for emissions?
I tossed my nitrous motor in there just to show that I have no problem with the ring gap after a LOT of nitrous usage and TONS of heat with only .005 ring gap on some cylinders. I think you are looking at the wrong issue here.
Last edited by DRAG; Mar 22, 2010 at 08:26 AM.
Actually I never said that it was tuned to its threshhold..I said with any performance car you can expect to be close to its limit in terms of trying to get every bit of power out of it by the manufacturer , when you mod it and it parts werent designed for the hp your trying to get its your own fault, not mitsu's
I said that if you want 700 or 600hp ex. or whatever out of any engine designed for a safe 400 ex. you need to build it to handle it, instead of pushing it and grenading it then crying about it and sayin mitsu dont know what there doing...
Do you honestly think mitsu race evo's are running stock production blocks, pistons etc.? No because they know the stock stuff wont handle it, pretty much common sense
Do you honestly think mitsu race evo's are running stock production blocks, pistons etc.? No because they know the stock stuff wont handle it, pretty much common sense
Again I ask how many of these broken piston failures have been seen on cars that had stock rev limiters?
I still then Piston to valve contact is higher likely. But I am not engineer or pro engine builder.
Another thing to think about. Maybe somehow the Mivec (to aggressive) changes people are making are allowing the P2V contact.....
I still then Piston to valve contact is higher likely. But I am not engineer or pro engine builder.
Another thing to think about. Maybe somehow the Mivec (to aggressive) changes people are making are allowing the P2V contact.....
Thread Starter
Account Disabled
iTrader: (465)
Joined: May 2005
Posts: 8,824
Likes: 2
From: Central FL
Again I ask how many of these broken piston failures have been seen on cars that had stock rev limiters?
I still then Piston to valve contact is higher likely. But I am not engineer or pro engine builder.
Another thing to think about. Maybe somehow the Mivec (to aggressive) changes people are making are allowing the P2V contact.....
I still then Piston to valve contact is higher likely. But I am not engineer or pro engine builder.
Another thing to think about. Maybe somehow the Mivec (to aggressive) changes people are making are allowing the P2V contact.....
All of the ones we have seen are on stock limiter.
I'm not sure that you realize how easy it is to tell when a piston has hit a valve. It distinctly marks the valve relief, leaving a clean aluminum mark on it.
I do not see any way whatsoever that any MIVEC programming can cause piston to valve interference. I do not believe that Mitsu has provided a MIVEC range of control that will cause interference under any circumstance.
They have to allow for failures in MIVEC oil pressure solenoids and so on without there being valve interference.
Furthermore any nitrous oxide use and input has no place in this thread as there are many variables including intake air temps that come into play. On top of that the engine with nitrous blew apart two pistons altogether which is much more damage than colliding ring ends.
Last edited by TTP Engineering; Mar 22, 2010 at 10:07 AM.
It wants to be pushed
Are you saying that Mitsubishi created a high performance car with a safety factor of less than 2 for the engine. Rule of thumb for engineers is to not design parts that have a safety factor that is greater than 2 in an application. If it can only withstand application's operation state then it's closer to safety factor of 1 which means it can break if the limits were ever surpassed. What you are saying is Mitsubishi engineers designed the engine where it ran the pistons and rings to their limit where it's at the verge of retaining safe power or catastrophic failure.
So I guess that all those $100,000+ drag race and Formula One engines that fail so gloriously were all designed poorly and used inferior parts?
In fact I can't off the top of my head think of ANY racing engine that hasn't had a failure. Does that mean that ALL engines are poorly designed?