[7158sean]

Originally Posted by Autobahn335i

Common scenario: cruising on the highway at 80 mph in 6th gear. Then I want to overtake a few cars, stomp on it and I would get a limp mode at around 110-120 mph mostly. So you're saying this is normal? Although it doesn't happen in stock mapping, with less power?

Yes, this is what happen to me

[7158sean]

Originally Posted by Kalud

From wikipedia, Taiwan: 92 RON, 95 RON and 98 RON are widely available at gas stations in Taiwan.

98 RON is 93-94 AKI, so you should be good.

so it should not be a octane quality problems right?

[Kalud]

Originally Posted by 7158sean

so it should not be a octane quality problems right?

Correct, it would need more logging that doesn't finish during boost, and also maybe a good full 3rd gear pull going into 4th to see overall if the car runs well in "normal" conditions.

For sure WOT at 2000 rpm in 5th / 6th gear should be avoided, if you need passing power, just downshift into 3rd / 4th depending on actual speed, it accelerate much faster, its a lot more fun and much less stressful on the engine.

[7158sean]

Originally Posted by Jeff@topgearsolutions

Sorry for the confusion, no it doesnt sound normal necessarily but normally this car only makes about 8 PSI stock. What I was speaking about is how bad it is for the engine to load up high boost in low rpm in high gear. What happens is you create a large amount of boost and usually boost spiking. There is a strong load on the engine which in turn creates a lot heat. As the engine is lugging in that low RPM high load range the pistons can start moving horizontally in the engine. It's just really not good for an engine. Imagine going up a hill with a 10 speed bike in 10th gear, its pretty hard on your legs right?

The best way to to accelerate is in the proper gear, in most cases I would have dropped to 4th or 5th and maybe eased in about 5 psi. If I pass anyone on the highway it doesnt take much speed in this country, another 5-8 MPH is all you need which can be done with about 5 psi from any gear, instead of WOT.

In our country we can't really get up to 110-120 legally so I doubt many people can replicate it. Usually if they were to replicate those speeds they would drop down to the best gear for the most power (i.e. 3rd and 4th).

The reason I brought up the mazdaspeed 3 is because that engine is notorious for blowing on high engine load, low RPM scenario. It cant combat the excess load torque and boost. I think the rods let go if I recal correctly.

Its a lot more strenuous on an engine to perform those tasks believe it or not, compared to high HP, High RPM.

My best advice is to simply adjust driving habits, but I cant say I had a problem on my personal car but I've never done WOT in 5th or 6th unless I was already at high RPM. I would imagine if I did try, which I wont, the car would respond just like everyone elses. At stock boost levels I'm sure it can handle it.

I only do WOT above 3000 RPM and again never in 5th or 6th.

yes, if I kick down to 3 or 4th gear and everything is fine, the reason I hold at 5th gear and do the log is because limp mode happen for sure.

If I drive in D and just want to pass few cars slowly, limp mode happen radomly. That's why I hold at 5th gear WOT and do the log.

[7158sean]

Originally Posted by Kalud

Correct, it would need more logging that doesn't finish during boost, and also maybe a good full 3rd gear pull going into 4th to see overall if the car runs well in "normal" conditions.

For sure WOT at 2000 rpm in 5th / 6th gear should be avoided, if you need passing power, just downshift into 3rd / 4th depending on actual speed, it accelerate much faster, its a lot more fun and much less stressful on the engine.

I will do a 3rd gear pull when I can and I think downshift is the only way to avoid the limp mode otherwise the car runs ok!

Thanks to everyone and I will do the 3rd gear pull ASAP to see if the car runs well in normal conditions

[Joshboody]

Hey OP, i don't even know how to rename an extention with windows 7 now... Much easier for us to view a log pic. Do a typical 3rd and 4th gear log for reference and post more of the 5th gear pull then whats already posted. Include fuel correction also to the log

[Kalud]

Originally Posted by Joshboody

Hey OP, i don't even know how to rename an extention with windows 7 now... Much easier for us to view a log pic. Do a typical 3rd and 4th gear log for reference and post more of the 5th gear pull then whats already posted. Include fuel correction also to the log

I can make the csv file pretty. In Win7, just open folder's options and uncheck "Hide extensions of know file type" or something like that...

[Kalud]

More comments later, in a hurry, out of town for the long weekend.

[7158sean]

Originally Posted by Kalud

More comments later, in a hurry, out of town for the long weekend.

Thanks for your time, wait for you.

[Murph335]

What was the resolution?

[kanecvl]

Install new parts or even better upgraded parts and try again...

[WedgePerformance]

Although this thread is really old, OP had an issue with fuel pressure drop. Any time you stand on the throttle in a high gear, it puts a heavy load on your HPFP. If your E content is higher and you're HPFP cannot keep up, you car will buck and throw codes. You can increase fueling for the HPFP, but ultimately the best way to resolve this issue is to reduce gears and stop going WOT in a high gear at LOW RPM.