I had an ECUTEK Dyno tune on the IX wagon. The car pulls a lot better with much smoother power delivery and acceleration. Boost builds up quickly and you can feel your back being planted into the seat during acceleration. I have posted the Dyno sheet, note the Torque figure is out by some factor. Final result:
315whp @ 5900RPM
Peak torque @ 4400RPM
Peak boost 24psi @ 4000RPM tapering down to 16psi @ 7500RPM
Mods: SS O2 housing, Custom 3" Turbo back 2 x mufflers & 2 x resonators (no cat), Drop in high flow filter, Walbro drop in fuel pump, GFB Deceptor BOV.

The HP peak is at around 5900RPM and then there is a drop in boost and torque. I am looking for ideas as to the next stage in mods to keep the HP rising above 5900RPM.
As well at high load (4th gear from 2500RPM up a hill) the boost rises sharply and peaks at 28-29psi and stays there for a while. Is this a problem and is the ECU reacting to this high boost?

 

I'd invest in a boost controller and turn down the boost to control it. 24psi on pump gas is not a good idea!

 

Isn't pump gas in Japan around 98-100 RON?

 

I'm actually in New Zealand and we have 98 RON available on pump.

 

I had one and I removed it because the boost was oscillating and it seemed like the ECU was not happy with it. I had the factory boost controller reconnected and it definitely controls the boost better and smoother. Even with the boost controller and boost set at around 23psi it would still taper down to 16psi at redline.

 

Not sure why I read Japan instead of NZ. Either way, the point is the same.

 

I don't think that is the correct solution to the problem. The ecutek should be able to control the boost, theres no reason to add a MBC.

 

Y does it taper so much though? 24 tapers to 16?!

 

Maybe they were very conservative with the tune? maybe a boost leak? I honestly don't know.

 

It goes down to 16psi because that is the max boost that the stock turbo (with stock intake and stock intercooler piping) can hold at that flow level. The tune has a fixed boost level of 24psi, but from about 5000 RPM the boost starts to fall off.

 

with double mufflers and double resonators your stock exhaust probably flows more!

 

That’s bull Dude, these are strait through mufflers which are an unrestricted 3" pipe with a gas expansion chamber around it. The car was spooling better and going faster after the muffler was done even before the tune. It is the stock rear muffler that is the biggest restriction in the system.

 

I got 10 hp untuned from a tanabe DP, high flow converter and Greddy Ti cat back. I dont think anyone would notice 10 peak hp, especially with the way the stock ECU pulls back when it realizes slightly more flow. Only after a tune is the curve corrected.

I also have the Ecutek flash and dynos to proce the exhaust effect on the IX Ecu - they all do it untuned with high flow exhausts. The sound and psychological effect might add up to a feeling of more speed / power but its false. Now on the VIII its a different story, a TBE you can feel on that car as the ECU does not pull back with the increased flow.

https://www.evolutionm.net/forums/sh...d.php?t=173129

 

If you are using the ECUTEK flash to control boost ( which IMO is the cleanest way to do it) you need a larger restrictor pill in the vacum line to hold higher boost levels without taper.

24 PSI is a lot of boost, even with higher octane gas, but no knock, no worries, I guess.

Cams will help the top end as well and they are nice and hassel free once installed.