So I read that the EVO IX has boost taper....and so at higher RPM, boost tapers downwards.

Why is that?

And when people modify their cars, do they prevent this? Seems sort of sucky to me.

I'm looking into ECUFlash.
Does anyone know whether ECUFlash can change this boost taper so that it stays constant?

NEWBIE

 

Boost taper is a safe, but unnecessary annoyance. Get a manual boost controller and set it at 21 psi, or just get the reflash. Enjoy the extra power!

 

The chances of detonation increase at higher RPM.

 

You wouldn't happen to know which options you would adjust to get rid of the taper in a flash would you?

I am not a fan of other people's maps.

And do most people get rid of the taper? I think I read somewhere that people keep the taper when modifying.

 

You can get a flash by jester tuning.

 

What's jester tuning? Another tuner?

EDIT:
Nevermind, i found him by search.

No thanks.
No generic flashing for me. If you have the tools to do it ($90 cable) why would anyone use a generic flash made by someone else?

I can see getting a flash by someone if it's extremely expensive...I come from a world where if you want to turbo your car, you absolutely have to go with a standalone. So after spending over 1k on a standalone, you'll need a custom made map.

The advantage of this car is that in order to tune your own car, it only costs 90 bucks, not a few thousand. So I'm not planning on paying someone to just send me data. Data that may or may not work perfectly on my car.

 

I hate to say this, but if you don't know why boost tapers at higher revs, tuning your own car may not be the greatest idea.

 

I've tuned my other car which started at 168rwhp to 390rwhp and am currently building it for almost 600 rwhp.

I don't taper boost nor see the need to on a properly tuned car with effective timing.


I realize that at higher RPM and cylinder pressure, the likelyness of detonation is higher. From what I've read, the evo has a good knock detection/retard system. So why not just have it run stable boost pressures until redline?

Tapering the boost makes me thing that there is a definitive weakpoint in the motor or combustion chamber.

The evo is a new world to me, but turbo'd cars are certainly not.
I'm not sure what your background is, and why you would make that comment. Regardless. No disrespect. I'm not a retard. Tapering boost in stock form on a car which people put down over 500awhp on a stock block doesn't make sense.

 

I'm well into my third decade of being around tuned automobiles and have seen my share of mishaps.

None taken. Good luck to you.

Longevity and reliability are a couple of factors to keep in mind.

 

simply put:
If people are modifying their cars to run higher boost, they are pushing the envelope more than someone who is simply not tapering at higher RPM. I'm trying to finger out whether it's safe or not.

 

Not to sound like a smart-as$, but define safe. I don't think it's safe, as I plan to keep my RS for a very long time, so my car is stock. I drive it on the street and can hardly use all I have as it is. You have to evaluate your own priorities - ie. driving style, comfort level with repairs, and expected time of ownership - and then prorate your personal risk factor. I realize that I'm probably telling you something you already know, and by doing so I'm hoping to illustrate the general inability to answer the question without better definitions of the constraints at play. You're asking a Yes or No question when the answer is open-ended. I hope that made sense.

 

well get jester to do a custom tune, thats what i have and im will have the motor and head done with a 35r this weekend and when he comes back to NC, ill get him to tune it again. Im pulling to put down the highest numbers on a stock mass air sensor. does anyone know what that number is so far? i think i seen 570.

 

Very little in modifying cars is a simple yes/no
but I really do think the question of boost taper is. Everyone has it from the factory...I'm wondering what people do with it. If a lot of people get rid of it and drive around successfully, I would consider the answer yes. If not, then no. Again, it's a newbie question. I simply don't have the experience and reading through some of these posts or threads is just distracting.

Example: people who's answer to everything is "go get a flash" by this guy or that guy. Sorry. I think that's a easy way to spend money for mediocre results and no opportunity learn.



Thanks for the advice. 570 is a buttload on a small car like this. Congrats.

I don't think i'll be taking it to any tuner. I actually expected people on this forum to be more hands on simply because the car is so easy to mod. What I'm finding is that people are tending to give everything to the tuners.

If I decide or run into major problems, I'll take my car to a tuner and consider Jester. But I will be tuning myself. I'm a DIYer.

 

Yes, many people drive around with a MBC and no taper, relatively speaking. With a MBC and a flash the boost will still taper slightly relative to its peak. Many people also encounter various mechanical issues down the line, and some don't. That's why I cited the constraints in an earlier post. Seeing how the IX has been out for any about a year - with a 4 year total for the IX and the VIII - there's no way to predict the long-term consequences of any of the mods. One thing's for sure; your 10/100K warranty will be gone. Whether you think of that as successful is up to you.

 

Eh. I consider that successful. Warranty concerns are always going to be there.
I thought that you could control the stock wastegate solenoid to prevent taper with one of the ecu settings?