If I was to Sell My Turbo

[kmh001]

We had a lengthy discussion here a while back about what causes these engines to pop, but the truth is that no one knows why, there's only a bunch of theories and speculation. My view is that there is a flaw in the programming of the ECU that raises it's ugly head when the adaptive part of the ECU is making the transition from highway mode back to high-boost mode. I think that ECU flaw causes short but severe detonation that is survivable with a stock engine, but less so on a highly developed engine that runs higher cylinder pressures.

So the moral to the story must be to stay on the boost and don't let your ECU go to sleep.

[240MPS]

I might pass all this info to the boys at Allstar Tuning, I have great faith in these guys they really know there shit,even TG was impressed when I took him there when he was up with me for a few days..... The boys go over my car like its the race car when issues arise on the race car they will check mine for the same reasons...... Maybe the guys can give me a stronger turbo with ballberaings and bigger shaft and tune it so it won't break with the other gear they want to do, I have no idea when it comes to turbos.... They tell me they can make my car go faster then the race car because of their restrictions and any work they do on my car I should be covered with Mazda Grand Prix because of there contacts.... I will be in meetings with them maybe in the new year now because I've being umming and arring....

[LittleredMPS]

I personally think that the zoom zoom boom boom comes from that little spike at around 3k-3.2k revs on boost.

Ive noticed in a lot of the tuned mps's that the dyno shows a boost spike above 19psi around that rev area.

Seems kind of a weird coincidence that thats also where most mps's go pop

[240MPS]

I have attached my my last dyno the red line was the last Dyno upped to 14.5Psi and the blue Line was the previous Dyno at 13Psi means jack shit to me and would of liked to have gone to the Chiptorque Dyno day to get my figures from them to see difference...... I would assume there is no spike in there someone help me out..... He is doing the air box and a switch to flick from 14.5 to 18psi before the turbo upgrade to see how it goes?????

[DISIMS3]

I personally think that the zoom zoom boom boom comes from that little spike at around 3k-3.2k revs on boost.

Ive noticed in a lot of the tuned mps's that the dyno shows a boost spike above 19psi around that rev area.

Seems kind of a weird coincidence that thats also where most mps's go pop

Won't a boost controller prevent spikes?

[Doug_MPS6]

DISIMS3, Hi. No, not necessarily, as it depends on how well the PID loop is configured, the purpose of which is (partly but not solely) to tame departures from the designed graph path - known generally as "spikes". PID = proportional–integral–derivative is a generic control loop feedback mechanism (controller) widely used in industrial control systems. A PID controller attempts to correct the error between a measured process variable and a desired set-point by calculating and then instigating a corrective action that can adjust the process accordingly and rapidly, to keep the error minimal. The manual that comes with the CP_e Standback has a very good section describing how this is done.

Even though you might have an electronic, vacuum or pressure actuated controller, there are various events or conditions that bring about either a lag or an over-run in their response. This might be due to age, wear & tear, crap design, or merely an inability of the system to keep up with rapid changes, such as someone stamping suddenly on the go pedal, a diving plane suddenly changing altitude, a sudden change in temperature, etc.

The PID loop is a feedback system used to rein these variances in to an acceptable level, just as your own body works (you hold your breath, the CO2 builds up in your blood, a sensor mechanism kicks in to force your diaphragm to pull down to fill your lungs so you take in air until the CO2 stabilizes, and so on - and this is less than half of the respiratory cycle autonomic response.)

In any event, no one should be running over 18psi on a stock turbo due to its inherent inefficiency above that level. And as someone else has noted here, any more than that should be accompanied by some serious attention to the engine internals.

In my view, a certain improvement in performance is nice, fun and a good thing, as it often denotes or is attended by improved efficiency. But serious mod's that threaten the longevity of an engine clearly not designed to perform above a certain level is just plain dumb, unless you are prepared to commit lots of $$ on structural reinforcement.

Brings to mind the famous quote by Bill Gates "256Kb should be enough for anybody"

[DISIMS3]

And I suppose even that could fail under extraordinary circumstances...

[LittleredMPS]

I have attached my my last dyno the red line was the last Dyno upped to 14.5Psi and the blue Line was the previous Dyno at 13Psi means jack shit to me and would of liked to have gone to the Chiptorque Dyno day to get my figures from them to see difference...... I would assume there is no spike in there someone help me out..... He is doing the air box and a switch to flick from 14.5 to 18psi before the turbo upgrade to see how it goes?????

Not sure about the bottom graph..almost looks like its showing boost in Bar (I think) but doesnt look right for that either.

Have a look at the chiptorque dyno tunes page in the chiptorque section.

That will show you what I mean about boost spikes.

You will see a large boost peak around 3k rpm.

[lazydog]

I don't mean to scare anyone, but as one of the few in Australia to pop an engine I have a little knowledge about this.

I've seen 2 engines that have gone bang now, and both have had the same thing happen. Bent conrod 4.

One bent and we stopped tuning it, the other bent and ended up coming out of the block.

Both cars blew on the dyno, but funnily enough one (mine) was making 185kw atw before it blew and the other was making 175kw atw.

The second car blew when it was only running 15psi!

All this crap about there is a problem inside the ECU and stuff is simply rubbish! The sheer fact of the matter is that they are not designed to push big power like the EVO's/WRX's(although the 2.5L WRX has serious limits too..).

Most people here are not really pushing big power, just bolt on bits and peices(exhausts intakes etc..), but when you start changing the turbo you really start to effect the load on the engine and how the car operates.

I was talking to the guys @ MPS Garage and they advised me that 180kw on a MPS 6 is the max they would go, and 200kw on a MPS3 is safe. Anything above that is getting to the limits of the engine.

Having said that, I know there are people running around with 200+kw in a MPS3 with no problems, but it really comes down to the dyno that it was tuned on(some dynos produce higher readings than others).

The point i'm trying to make is if both engines break the same part of the engine then it highlights the weakpoint of the engine. If you want to go for big power or above what i've quoted be prepared for things to go wrong.

As doug put above, you run the risk of damaging the longevity of the life of the engine the more power you put through them. There is also other things that can help, like not thrashing the crap out of it on a hot day, letting the engine cool down for a bit after going on a run and other things to protect the car's life.

Also, from my experience the standback was the only engine controller that cut it for me. Not saying others didn't work, but for me it was the only one that actually did everything I wanted it too.

[kmh001]

The problem with the ECU is not rubbish. Mazda have produced several ECU updates specifically to address this issue and if you've ever experienced the severe detonation that is unique to operation with the cruise control on (during map transition) you'll know what I'm talking about.

It's no surprise that your engine blew on the dyno given that there isn't a tuner on this planet who actually understands what's going on inside the Mazda PCM. The operating parameters of DI engines are so unique that to my knowledge there isn't a tuner on the planet that truly understands what's going on inside any DI engine, whether it be Audi, Toyota, Lexus, Mazda, Ford, Holden or whatever. The fact is they are still guessing, they are treating these engines like PFI engines and unsurprisingly they are not having the greatest success. Even the manufacturers are still coming to terms with DI technology, and still making mistakes, so no small time aftermarket tuner could possibly claim to have a better understanding of the technology.

I've rebuilt plenty of grenaded engines and I know the difference between a rod that is inherently weak and one that was subjected to cylinder over-pressure. I still maintain that the pictures I've seen of broken DISI engines do not indicate any structural weakness. The problem is that people are playing with these engines without understanding how they work.