The Chances of blowing my motor.

[GOGRANDE]

have you gone to meth? is so what have you noticed ?

[Sanch]

There is a section all about meth and fuel on this forum. I would look for the link but I am lazy. Anyway Devils own i think is the company that makes them specifically for out car just google them and bam.

[ms3=evokilla]

I do worried about blowing my motor. But i am happy that i don't have subbie. My buddy works at ams performance he said that a brand new sti blew it motor on the dyno and it was all stock.

[socks]

Do not be fooled. You cannot replace the rods from the bottom without taking the head out.

Do not be fooled. It is easier to take the motor out than to pull the head with the block still in the car. Ask someone who has tried... oh yea. thats me.

[08_ms3_gt]

Originally Posted by GOGRANDE I am just now learning about meth injection. I just got a MS3. So I now know what it does...but whats the set up? Where can I get it? Can you give me a little more info?

if your engine is stock, you don't need it.

meth injection involves:
1) meth (water-methanol mixture)
2) pump to move the meth from its storage tank to the nozzle
3) nozzle mounted somewhere on inlet side of engine, prolly the intake manifold

adding meth injection reduces the intake charge temperature, effectively increases the octane rating of the fuel, and 'cleans' the engine. meth can reduce the potential for knock retard and allow for timing advance. it can be useful either as a knock reducer, power adder or both.

but, like i said, if you're stock then worry about things like an intake. especially if you want to keep your warranty since meth requires drilling a hole for the nozzle. you can buy it @ various places, i think both streetunit and protegegarage have kits.

[08_ms3_gt]

Originally Posted by ms3=evokilla I do worried about blowing my motor. But i am happy that i don't have subbie. My buddy works at ams performance he said that a brand new sti blew it motor on the dyno and it was all stock.

the latest-gen STi's have had ECU management issues. basically a lean condition that occurs upon fuel cut at the rev limiter, so the engine knocks like crazy at those high RPM's/boost.

the issue has caused STi's to blow their compression or the engine altogether, and it's more due to the management than the engine itself (or so it would seem). sure as hell sounds a lot like the MS3 and its own tuning issues.

[smakdown61]

Modern Ecus are primarily designed for two things:

1. Emissions
2. Gas Mileage

Performance is an afterthought and sometimes gets compromised b/c those two things above HAVE to come first.

[Sanch]

Thats is very true. Well anyway I think for now just to be on the safe side I am just going to shoot meth. Building my motor is going to be costly and I really don't want to have put in 6g's in this car.

[GongShow]

FWIW, I chatted with my local Mazda service manager. They have yet to see a MS3 come in with a blown motor. I know that doesn't mean a lot, but I think these are still VERY limited cases.

Don't be shooting that meth man. That stuff'll kill ya!

[Tomas]

Originally Posted by Darksun280 you guys should try it for your selves instead of listening to all the internet hype. Your car doesn't flip from closed to open loop part throttle once you get over 3k like everyone thinks. Just watch your DH in the bottom right. Fuel System Status (C = Closed Loop, O = Open Loop, L = Open Loop due to Engine Load, F = Open Loop due to a Failure/Trouble Code, P = Closed Loop with Problems, - = Data not available, U = unknown status) When this value is displayed on the screen or on the PC from a data log, the following values are used: 0 = Unknown 1 = Open Loop 2 = Closed Loop 4 = Open Loop due to Engine Load 8 = Open Loop with Fault 16 = Closed Loop with Fault Personally I'd be more worried tooling around part throttle or off throttle in the 3k range closed loop then going full throttle all in a sudden. That could lead to a boost spike during a quick transition from open to closed loop IMO. Just monitor for your self and come to your own conclusion.

Are you sure about the low/mid rpm range issues with closed loop boost leading to con rod failures? . Even with spikes in boost, I would think the reciprocating force on the big end rod bearing at 5.5 or 6K rpms would be higher than a spike of a few psi in boost at mid or low rpms. Knocking is a different story.
How much are these closed loop spikes in pressure? up to 17 psi or so? Knowing the weight of the piston/rod assembly one would have to get down on the math to calculate psi on the big end rod bearing. Without that though, I think one can say that the pressure on the big end bearings at 6K rpms should be 2x as high as at 3k rpms. That means if you have 10 psi boost at 3k rpms = x psi bearing pressure. So no boost at 6k rpms = x as well.
How much boost pressure at 6k rpms for the ms3 under continous acceleration from about 3k rpms? Anyone got a cure?

[Tomas]

Originally Posted by Tomas Are you sure about the low/mid rpm range issues with closed loop boost leading to con rod failures? . Even with spikes in boost, I would think the reciprocating force on the big end rod bearing at 5.5 or 6K rpms would be higher than a spike of a few psi in boost at mid or low rpms. Knocking is a different story. How much are these closed loop spikes in pressure? up to 17 psi or so? Knowing the weight of the piston/rod assembly one would have to get down on the math to calculate psi on the big end rod bearing. Without that though, I think one can say that the pressure on the big end bearings at 6K rpms should be 2x as high as at 3k rpms. That means if you have 10 psi boost at 3k rpms = x psi bearing pressure. So no boost at 6k rpms = x as well. How much boost pressure at 6k rpms for the ms3 under continous acceleration from about 3k rpms? Anyone got a cure?

Shit, typo. I meant anyone got a curve on stock boost?

[Sanch]

So I got my car back from the autobody shop. Man I am worried to get on her. I drove in the rain last night in s.f. And i was thinking to myself if i had my cai i would be fucked. I converted my mazdaspeed cai into a sri. It works really well. Anyway the car runs great. I am still a little worried about blowing the motor. I am buying meth soon just to be on the safe side.

[Grim]

don't even worry about blowing the motor,i beat my car hard like a redheaded step child and it has given me no problems.you are getting too paranoid man.

[Phantomspeeds]

Are the Rods the only weak point of our cars?

[ms3=evokilla]

Originally Posted by 08_ms3_gt the latest-gen STi's have had ECU management issues. basically a lean condition that occurs upon fuel cut at the rev limiter, so the engine knocks like crazy at those high RPM's/boost. the issue has caused STi's to blow their compression or the engine altogether, and it's more due to the management than the engine itself (or so it would seem). sure as hell sounds a lot like the MS3 and its own tuning issues.

Yea i guess. But I also heard that they have crappie rings from the factory that why there loosing compression stock. Its not only tuning issues. But we have weak rods no one wins, except the new evos there blocks are rated at 450whp.

[Sanch]

The rods are a pretty weak point in the car. He ms3=evokilla did you get the pnp yet. You got to give me an update. I know its out of my hands but I want to make sure everything went good. LMK! anyways I am just scared of throwing a rod pretty reasonalbe reason to be paranoid haha. 20 people have done it just on this forum.

[Sanch]

Not exactly 20 but you get the jist of it.

[pidass]

<20 people out of 2,800 members. You'll be alright, if you're that worried mod lightly so you can return to stock if needed.

Otherwise quit bitchin and drive it like you stole it.

[Grim]

Originally Posted by Sanch Not exactly 20 but you get the jist of it.

And about most of them were caused by something that either made them do that like SU marks car or it was a factory defect.i mean there was a guy that blew and was completely stock.Quit worrying about man,just drive it like it was meant to be,you didn't buy all those mods so you could pussy foot around town.

[bova]

SU marks wasn't a factory defect, he was running a bigger turbo and the hose popped off the wastegate which sent the boost soring to high levels thus blowing the motor.

[08_ms3_gt]

Sanch, dude, calm down. your car's not going to explode. or @ least it's extremely unlikely.

but you do want to avoid hydrolock... so good call on that one.

IMHO you can avoid breaking the engine or @ least avoid defects if you:

1) maintain rigorously. oil changes, spark plugs, etc.
2) modify carefully. including logs of relevant variables - KR, fuel pressure, etc.
3) allow the engine to properly warm up and cool down.

the three above are what i do, and also what i have done in past cars. the ms3 seems to have a fuzzier line in terms of exactly how or when these engines find their limit, but oh well. i try to avoid going WOT below 3k RPM's but otherwise i just enjoy driving.

being paranoid is going to ruin the driving experience. @ worst, you'd end up selling the ms3 and buying another car, which is a mistake i've made before. and guess what, odds are you'll discover that a small minority of those cars blow their engines, too. Evo's are capable little bastards, but i know a guy who blew the shit out of his with less than 400awhp. he kept a piece of one of his pistons on his keychain...

[Grim]

Originally Posted by bova80 SU marks wasn't a factory defect, he was running a bigger turbo and the hose popped off the wastegate which sent the boost soring to high levels thus blowing the motor.

exactly.i said it was either something that caused it OR a factory defect.

[bova]

he didn't put a clamp on the hose i believe.

[Grim]

yea i know,then the hose popped off and hi boost skyrocketed.

[Sanch]

Yeah you guys are right but if i come back today and a rod went flying out i am killing all of you. jk

[Grim]

Just dont be stupid and you will be fine.Like dont got WOT in 5th or 6th.

[wassup61]

Originally Posted by Grim Just dont be stupid and you will be fine.Like dont got WOT in 5th or 6th.

lugging the motor that is, I have gone WOT in 5th and 6th but that was in "mexico" on a high speed run.

[Grim]

Originally Posted by wassup61 lugging the motor that is, I have gone WOT in 5th and 6th but that was in "mexico" on a high speed run.

so have i,but i mean if your crusing in 6th at 70mph then go wot is bad

[bf360]

Originally Posted by Grim so have i,but i mean if your crusing in 6th at 70mph then go wot is bad

yea, just like dont put to much load going up hills etc

[Lex]

Originally Posted by bf360 yea, just like dont put to much load going up hills etc

This no WOT at low RPM business doesn't add up. You are putting a lot more "load" on the rotating assembly when you're WOT at high rpm. So unless someone intelligently explains this low RPM load issue instead of the usual regurgitating it because someone else said it, I wouldn't buy it.

[pidass]

Originally Posted by Lex This no WOT at low RPM business doesn't add up. You are putting a lot more "load" on the rotating assembly when you're WOT at high rpm. So unless someone intelligently explains this low RPM load issue instead of the usual regurgitating it because someone else said it, I wouldn't buy it.

it all boils down to the high pressure fuel pump can't supply the needed fuel pressure at low rpms.

[bf360]

Originally Posted by Lex This no WOT at low RPM business doesn't add up. You are putting a lot more "load" on the rotating assembly when you're WOT at high rpm. So unless someone intelligently explains this low RPM load issue instead of the usual regurgitating it because someone else said it, I wouldn't buy it.

all the torque our engines make at such a low rpm with the tiny snail we have stock makes it easy to put a lot of load on the engine down low
a ton of torque thrown at the engine down low is a lot worse than the high rpm hp

also the problem also arises that the ecu doesnt change from closed to open loop and the engine could run lean while boosting too low or at the wrong time

[y2kc0wb0y]

lean fuel pump conditions don't bend rods...they fry pistons or burn valves

[badams118]

i thought lean fuel would cause detonation, stressing the internals.

[Sanch]

So what exactly bends rods.

[08_ms3_gt]

Originally Posted by Sanch So what exactly bends rods.

i can't be 100% since i've never bent one, but a few ideas:

1) detonation --> shoving the piston down before it wants to
2) too much power --> too much stress/strain can result in the failure of the weakest point in the engine, which appears to be the rods in the ms3
3) oil starvation --> which could also break most anything

Lex - yes, you are putting more load on the engine at higher RPM's, but you also have more RPM's. it's been 2 years since i've taken physics, so i'm a bit rusty, but i'll take a crack @ it:

the itty bitty k04 on these cars spools easily. so easily, in fact, that it's making a bunch of boost a low RPM's. all this extra air causes a torque spike because of all the extra air being shoved in. this air is 'independent' (kind of) of the rotating mass of the engine.

the rotating mass of the engine relates to the torque thru it's RPM's. torque has units of (mass*distance^2)/time^2. essentially, the engine can put the torque to work by rotating itself (RPM's) and the wheels. thus, extra torque is why the ms3 has power @ low RPM's.

the engine must rotate to put the torque to work. if it is rotating at 3000RPM, it has one revolution every 0.02seconds to handle the constant force of torque. at 6000RPM, the engine has more revolutions (once every 0.01seconds) to handle the torque.

so the bent rods are related to the engine having a limited number of RPM's to displace the force of torque. too much torque means the engine can't keep up and the weak point (rods) fails.

[GongShow]

On a side note, the hydrolock concern is usually unwarranted as well. Unless you plan to submerge your filter while creeping along in a swamp, it's not easy to do. If you're moving at regular driving speeds and hit a substantial puddle, you MIGHT get a sudden hiccup at the most.

I've owned several cars with CAIs in some of the nastiest, wet weather. I've never and have yet to hear of someone hydrolocking their motor without doing something stupid. If you plan on driving on flooded streets or fording rivers, then you might want rethink the CAI thing.

Besides underdrive pulleys, hydrolocking a motor due to a CAI might be the most overhyped topic on car forums.

[y2kc0wb0y]

Look leave it stock if you're worried. If you wanna play, realize this is not the only platform out there that has weak rods. Hondas, EVO's, Subbies, all the same gangster...at some point you're going to pop it. If you're a crackhead and don't know when to say when, I suggest you build your engine because unless you really know what your doing you're going to eventually FAIL EPIC and you'll have no one to blame but yourself with a lot of people saying "I told you so"

[Lex]

Originally Posted by bf360 all the torque our engines make at such a low rpm with the tiny snail we have stock makes it easy to put a lot of load on the engine down low a ton of torque thrown at the engine down low is a lot worse than the high rpm hp also the problem also arises that the ecu doesnt change from closed to open loop and the engine could run lean while boosting too low or at the wrong time

Physics say high RPM by itself puts more load than cylinder pressure alone ever can. The acceleration of the piston as it changes direction at the top and bottom of the stroke place the most load on the rods.

08_ms3_gt, the combustion takes place during the power stroke no matter how quickly you spin the engine ... so the same amount of force is applied to the rotating assembly at the same time in the cycle. At higher RPM it just happens more frequently. Don't mistake the fact that at higher RPM the car feels better for what is going on with the forces inside the engine. It feels better because the combustion events happen quicker resulting in smoother acceleration.

The derivative of torque does cause transients. However, if you build the torque at 2000 or 4000 RPM, it can only be worse at 4000RPM in terms of the forces. Diesels live at high torque at very low RPM.

Yes, there is something to be said about the rotating assembly spinning quickly at high RPM and having more inertia to begin with resulting in less "shock" on the components than at low RPM when a large acceleration is induced.

Another note, the fast onset of boost can cause detonation rather than a slow onset because the cylinder pressures change so quickly. This has more to do with the turbo size and fuel delivery however.

That being said, I would like to be proven wrong. Show me cars that die at low RPM.

[bf360]

Originally Posted by Lex Physics say high RPM by itself puts more load than cylinder pressure alone ever can.

high rpm as in what, 8000rpm?
so your saying 300hp at 5500rpm puts more load than 350ftlbs at 2500rpm in a high gear