https://www.evolutionm.net/forums/sh...d.php?t=166886

Above is a link to all the issues i have been having. Tapering 6psi being the top one. Well after multiple pressure tests, MBC testing, boost gauge testing i finally removed my HKS intake and swaped it to the stock box.

The results.......The HKS intake filter caused all of my problems!!!!! The second my stock box went back in my boost came on quicker, i am now holding 21psi SOLID all the way to redline and NO MORE TAPER!!!!!!!!!! YES!!!!!!!

Everyone listen to WARRTALON when he says intakes are junk without a tune. As much as i like the sound of my turbo spooling i like being pined to my seat at 6000k much better!!!!

Hope this helps someone else having tapering problems....

My evo is back baby!!!!!!!!

 

sooo why did you install it and not get tuned

 

typical newbie jack@ss. I was a 2jz and B series convert so i thought "its just an intake..." Boy didnt i feel like a jerk.

 

So i guess it's time for you to change your sig!

 

So get it tuned.

 

Is the taper being caused because the intake filter is acting as a restriction? If so, how would a tune help the situation?

 

It's tapering because the ECU is factory programmed to do so (to preserve the life of the turbo). Untuned this is the case irregardless of intake type. Sounds to me like the MAF was taking a "beating" and the car was running in "safe" mode. Tell the ECU what the hell is going on *via a tune, and problems solved (oh and more power too)

 

I have been running the hks rs intake on my 05 without a tune for 8k now with no problems. Not saying its the best thing to do but I don't have any tapering problems.

 

LOL more reading less posting! Get a ECU re-flash, you can have your Intake noise, eliminate the factory programmed taper, up boost, extend fuel cut, lean A/F's... you get the idea.

 

irregardless? ;\

Glad you got your issues worked out.

~brian

 

Throw a manual boost controller on there then...how could the ECU possibly cause the turbo's output to taper if it has no control over boost? I've always understood the taper was caused by the stock WG actuator and solenoid. The only way I could see the stock ECU tapering boost would be to dump TONS of fuel and kill EGT's and/or pull a significant amount of timing. I'm asking, not stating

 

Did you change your mbc install, like isolating the solonoid? it seems odd that the stock intake fixed it cause your other post said it did this with the stock intake in also.
if that fixed it, odd... but good for you

 

The ECU had no control over his boost, because he had (and still has) an MBC. The ECU was not running in safe mode. Neither of those suggestions made any sense.

 

I have a feeling something was loose or something and by replacing it with stock it fixed that leak or whatever it was.

 

He said he re-installed the stock MAF pipe, but he called it the "intake." He didn't fully re-install the stock intake (plastic MAF pipe and stock airbox) until this thread...