What have you done to your Mazda6 today?

[zinger002]

How's that? Blowing up due to what?

very low end torque caused by boost spikes are not healthy with the already weak rods the car has. it is wise to stay within stock boost specs untill about 3500 rpm as most of the zoom zoom boom guys can attest to this. 18psi over 3500 rpm's seems to be no problem, but 18psi under or up to about 3000rpm's seems to be the problem.

ask smoke_31, richard blew up his car on a stock tune with intake, and a turbo back because of the very low spooling characteristics of the k04. iirc he told me he was coming out of 5th at about 100k an hour, which is like 3000-3200 rpm.

 

[Blendercloud]

How's that? Blowing up due to what?

The idea Zinger proposes hasn't been proven and is simply a theory that has been spread around the Mazdaspeed community (MS6 and MS3). The MZR DISI 2.3 Turbo uses a long stroke and as is usually inherent with a longer stroke are longer rods. The longer rods in this engine have a tendency to bend and in some cases break completely.

These instances have led many people to assume that this occurs during low RPM boost, where the engine is moving from a naturally-aspirated behavior to a turbocharged behavior. Initially, before the turbo kicks in, atmospheric air is pulled into the engine and then compressed by the piston. Once the wastegate closes and the engine is receiving pressurized air from the turbo, the piston is then asked to further compress that air in the cylinder using only slightly increased momentum.

What it amounts to is that the piston and rod are being asked to compress an already highly-compressed charge with minimal energy. The theory is that the lower you move the instance where the process changes from NA to turbocharged, the even less energy the piston and rod will have to compress that (though it hasn't been proven and probably won't be, the fundamental basis of the theory is sound). Mazda could have reduced this tendency with several methods: stronger rod material, heavier pistons, shorter rods and stroke -just to name a few.

It doesn't mean you're going to blow your car up. It does mean that this theory points you out as being more likely than a stock engine.

 

[jdw1]

very low end torque caused by boost spikes are not healthy with the already weak rods the car has. it is wise to stay within stock boost specs untill about 3500 rpm as most of the zoom zoom boom guys can attest to this. 18psi over 3500 rpm's seems to be no problem, but 18psi under or up to about 3000rpm's seems to be the problem.

ask smoke_31, richard blew up his car on a stock tune with intake, and a turbo back because of the very low spooling characteristics of the k04. iirc he told me he was coming out of 5th at about 100k an hour, which is like 3000-3200 rpm.

How would a tune help w/low boost on rods? I don't have any tuners where I live and I haven't found a map suitable for my mods.

 

[BoostedSpd6]

about to go snap pics for my Flew Innovations Write up and ill get a few more shots of the Blow Thru from different angles for you guys too..

didnt do a whole lot with the car today, but tomorrow i gotta drain my OCC.

 

[event]

The idea Zinger proposes hasn't been proven and is simply a theory that has been spread around the Mazdaspeed community (MS6 and MS3). The MZR DISI 2.3 Turbo uses a long stroke and as is usually inherent with a longer stroke are longer rods. The longer rods in this engine have a tendency to bend and in some cases break completely.

These instances have led many people to assume that this occurs during low RPM boost, where the engine is moving from a naturally-aspirated behavior to a turbocharged behavior. Initially, before the turbo kicks in, atmospheric air is pulled into the engine and then compressed by the piston. Once the wastegate closes and the engine is receiving pressurized air from the turbo, the piston is then asked to further compress that air in the cylinder using only slightly increased momentum.

What it amounts to is that the piston and rod are being asked to compress an already highly-compressed charge with minimal energy. The theory is that the lower you move the instance where the process changes from NA to turbocharged, the even less energy the piston and rod will have to compress that (though it hasn't been proven and probably won't be, the fundamental basis of the theory is sound). Mazda could have reduced this tendency with several methods: stronger rod material, heavier pistons, shorter rods and stroke -just to name a few.

It doesn't mean you're going to blow your car up. It does mean that this theory points you out as being more likely than a stock engine.

I would think that shortening the stroke would lower the output torque, am I right in that assumption? So really the only option they had was to strengthen the rods, I love having a torquey turbo 4

 

[Blendercloud]

I would think that shortening the stroke would lower the output torque, am I right in that assumption? So really the only option they had was to strengthen the rods, I love having a torquey turbo 4

Shortening the stroke but leaving the cylinder height would have reduced compression and displacement as a side effect

It is misleading when people say that 'torque' is what breaks the rods. That isn't the case.

 

[BoostedSpd6]

How to for the FI grounding kit is up

http://www.mazdas247.com/forum/showthread.php?t=123778757

batou i posted over on 6 crew about it as well.. check my post over there and get back to me.

 

[mglavina]

Has anyone had their turbo replaced under powertrain warranty? I'd love to have a copy of someones work order showing this..

I haven't had my turbo replaced or anything, but however I do remember bringing it up when I was buying my car (because it was used, and the regular 50,000km/3-year warranty was up). It was the main thing I was concerned of buying the car and the dealer said "everything under the hood is covered by the powertrain warranty". I even questioned again, does that include the turbo if it smokes (after I explained the main problems with the blue smoke and bad k04's) and he said, "yes, if the turbo does smoke, if there is something wrong with it, or if it has to be replaced, we will cover it under the power train warranty".

I don't have this on paper or recorded on a mic or anything lol, but that is what the dealer told me. Not sure if that's just what he said or if it was part of the Mazda policy with the warranty.

 

[event]

Shortening the stroke but leaving the cylinder height would have reduced compression and displacement as a side effect

It is misleading when people say that 'torque' is what breaks the rods. That isn't the case.

well not actually torque on the rods, but force being applied from the pistons which the crankshaft experiences as torque. The rods should experience very little torque, just compression and very little tension. excess compression forces will cause them to buckle, and a longer rod has a greater propensity to buckle, esp being as thin as they are. They experience more compressive force if the crankshaft gives more resistance due to having too little mechanical advantage to the wheels

I could be wrong, don't know all that much about engine physics, just more general physics

 

[event]

I haven't had my turbo replaced or anything, but however I do remember bringing it up when I was buying my car (because it was used, and the regular 50,000km/3-year warranty was up). It was the main thing I was concerned of buying the car and the dealer said "everything under the hood is covered by the powertrain warranty". I even questioned again, does that include the turbo if it smokes (after I explained the main problems with the blue smoke and bad k04's) and he said, "yes, if the turbo does smoke, if there is something wrong with it, or if it has to be replaced, we will cover it under the power train warranty".

I don't have this on paper or recorded on a mic or anything lol, but that is what the dealer told me. Not sure if that's just what he said or if it was part of the Mazda policy with the warranty.

so if your windshield washer reservoir breaks its covered by powertrain?

 

[zinger002]

The idea Zinger proposes hasn't been proven and is simply a theory that has been spread around the Mazdaspeed community (MS6 and MS3). The MZR DISI 2.3 Turbo uses a long stroke and as is usually inherent with a longer stroke are longer rods. The longer rods in this engine have a tendency to bend and in some cases break completely.

These instances have led many people to assume that this occurs during low RPM boost, where the engine is moving from a naturally-aspirated behavior to a turbocharged behavior. Initially, before the turbo kicks in, atmospheric air is pulled into the engine and then compressed by the piston. Once the wastegate closes and the engine is receiving pressurized air from the turbo, the piston is then asked to further compress that air in the cylinder using only slightly increased momentum.

What it amounts to is that the piston and rod are being asked to compress an already highly-compressed charge with minimal energy. The theory is that the lower you move the instance where the process changes from NA to turbocharged, the even less energy the piston and rod will have to compress that (though it hasn't been proven and probably won't be, the fundamental basis of the theory is sound). Mazda could have reduced this tendency with several methods: stronger rod material, heavier pistons, shorter rods and stroke -just to name a few.

It doesn't mean you're going to blow your car up. It does mean that this theory points you out as being more likely than a stock engine.

Well where does the car make all of its torque? i use the word torque because nobody associates force with a dyno or when they speak, and im just generalizing. i have never herd any car person say look how much force my car laid down. You are correct with saying the forces at work are totally to blame for problems, it was just easier to point it out as a rpm and torque reference.

just going to refer to this graph as a reference as to why the theory of low end power is fairly sound. Not to argue, im just tossing the idea out there as i doubt you or anyone else wants to spend a few grand replacing your block. imo if the car comes with a forged crank, they should have they upgraded the rods.

 

[Blendercloud]

well not actually torque on the rods, but force being applied from the pistons which the crankshaft experiences as torque. The rods should experience very little torque, just compression and very little tension. excess compression forces will cause them to buckle, and a longer rod has a greater propensity to buckle, esp being as thin as they are. They experience more compressive force if the crankshaft gives more resistance due to having too little mechanical advantage to the wheels

I could be wrong, don't know all that much about engine physics, just more general physics

You're absolutely on the right track with this post. The idea just isn't as black and white like most believe.

 

[BoostedSpd6]

this is the reason why i have my WGDC Table set to 0 untill 2500 rpm and 37% throttle.. still makes alittle bit of boost before then but nothing over 1-2 psi normally, gotta thank Taylor for giving me that bit of info..no more boost going up hills under high load in any gear.. woot!!

this is what my table looks like

its alittle blurry but you get the idea

 

[event]

Well where does the car make all of its torque? i use the word torque because nobody associates force with a dyno or when they speak, and im just generalizing. i have never herd any car person say look how much force my car laid down. You are correct with saying the forces at work are totally to blame for problems, it was just easier to point it out as a rpm and torque reference.

just going to refer to this graph as a reference as to why the theory of low end power is fairly sound. Not to argue, im just tossing the idea out there as i doubt you or anyone else wants to spend a few grand replacing your block. imo if the car comes with a forged crank, they should have they upgraded the rods.

torque is absolutely the right term when comparing to RPMs and power to the wheels. Its just that the rods don't experience any torque, the crankshaft is designed to convert force from expanding gases into torque. its torque from the crankshaft on out, but the rods really only experience compression forces.

 

[Blendercloud]

Well where does the car make all of its torque? i use the word torque because nobody associates force with a dyno or when they speak, and im just generalizing. i have never herd any car person say look how much force my car laid down. You are correct with saying the forces at work are totally to blame for problems, it was just easier to point it out as a rpm and torque reference.

just going to refer to this graph as a reference as to why the theory of low end power is fairly sound. Not to argue, im just tossing the idea out there as i doubt you or anyone else wants to spend a few grand replacing your block. imo if the car comes with a forged crank, they should have they upgraded the rods.

The engine uses forged rods and piston from the factory. The issue with the factory rods is their length is not compensated for with higher grade forged steel or, more explicitly, the rod's design.

It isn't the engine's torque output that doomsday the stock rods. It is the extreme compression they experience during low rpm boost. If the engine was 1 litre with a comparable stroke, boost levels, and rod design and only made 100 ft. lbs. of torque it would most likely still occur. My argument is only that it is not the torque that causes bent and broken rods. It is the compression without sufficient energy experienced by the rods that causes it.

 

[event]

The engine uses forged rods and piston from the factory. The issue with the factory rods is their length is not compensated for with higher grade forged steel or, more explicitly, the rod's design.

It isn't the engine's torque output that doomsday the stock rods. It is the extreme compression they experience during low rpm boost. If the engine was 1 litre with a comparable stroke, boost levels, and rod design and only made 100 ft. lbs. of torque it would most likely still occur. My argument is only that it is not the torque that causes bent and broken rods. It is the compression without sufficient energy experienced by the rods that causes it.

for clarity, do you mean compressive forces? or compression of the fuel/air mixture? I assume you mean compressive forces.

if so I disagree about an engine of the same design putting out only 100ft-lb of torque being subject to the same design flaw; this engines rods can easily survive 100ft-lbs at low rpm, unless you're scaling everything down, then its a different story

 

[Blendercloud]

for clarity, do you mean compressive forces? or compression of the fuel/air mixture? I assume you mean compressive forces.

if so I disagree about an engine of the same design putting out only 100ft-lb of torque being subject to the same design flaw; this engines rods can easily survive 100ft-lbs at low rpm, unless you're scaling everything down, then its a different story

Yes, I meant compressive forces. By my example I am trying to illustrate that it is the cylinder pressure experienced without the rotational energy or momentum to properly aid in further compressing an already highly compressed gas that causes this. Not an engine's torque figure.

 

[mglavina]

so if your windshield washer reservoir breaks its covered by powertrain?

Lol... I didn't fully explain but he meant everything under the hood that makes the car move forward... as in the turbo is covered. Things like the clutch, brakes, and other stuff obviously aren't.

The point is that in my case the turbo is covered by the powertrain warranty.

 

[jdw1]

Yes, I meant compressive forces. By my example I am trying to illustrate that it is the cylinder pressure experienced without the rotational energy or momentum to properly aid in further compressing an already highly compressed gas that causes this. Not an engine's torque figure.

Good info guys, you're both correct really. I drive it right most of the time so i'm not too worried about it. Sounds like you should design us some better rods and make some money.

 

[dave_PEI]

had it down the drag strip for the first time... i hadnt planned of racing, so i stopped and filled up on our way to the track... so with my inexperience with the car, and the weight of a full tank of fuel i got down to a 15.3 @ 93mph

so, once i do a bit of maintence, and get the launch down pat (and show up to the track with much less gas in the car) hopefully i can get some much lower times