I just bought a nice evo x, the owner said it was professionally tuned with cobb. Boost spike quite high and drop stable at around 22psi. Spike is higher in 2nd gear(29psi), and 3rd gear (27.5psi).. and so on......being a newbie to evo x, is this ok? Air fuel ratio is always stable at 10.2 at full throttle. I just want it to be safe.......thanks

 

Depends all on what its tuned for, but 10.2 is really really rich, how are you reading AFR?

Post mods too, always helps

 

It has a greddy exhaust, an aftermarket exhaust manifold, cai, bigger intercooler. The ex owner told me that it was tuned rich by purpuse as we only get 90 octane here so it would be safer.

 

I read the afr with ams afr gauge

 

I cant comment on what afr should be on 90 then, but with those mods 29 PSI doesnt sound too crazy, Id get the tune looked at and possible consider a retune, at least that way you know exactly what should be happening as it will be to your liking

 

Meanwhile i want to lower the boost a little bit. I have a mbc from turbo xs, how do i connect it? Do i have to disconnect the grimspeed 3port or run tees to go thru it as well?

 

Your tuned for a certain PSI you cant just lower it by taking out the ECBS and puting in a MBCS

 

Your very best bet, as it sounds like you don't have local access to a tuner, is to get working with an e-tuner. wtftuned.com is a great e-tuner that is cheap and can get your car safely tuned remotely. There are other good e-tuners as well you can find. Don't cut corners or you will have a big repair bill!

 

Ur right. I have no access to a tuner, how does the etune work? Im not in USA, im in a small carribean island, just need to lower boost a couple of psi to be safer...... Why cant i use the mbc along with the 3 port?

 

Etunes are easy, that site I suggested will work with you to ensure you are successful. You just need a cable (they tell you which one) and a laptop to work with. They will check your tune, ensure it is safe, then work with you to tune your car.

https://www.wtftuned.com/collections...alliart-e-tune

Requirements: (there are hotlinks to all the parts in the link above)

Laptop / netbook w/ Windows Vista / 7 / 8 / 8.1 / 10 Installation
If using a Mac, a dual boot installation of Windows will work
Tactrix 2.0 Cable - reflash adapter not required
EvoScan v2.9+
EcuFlash 1.44+
Wideband gauge w/ serial or USB logging configured (AEM UEGO, AEM Wideband Failsafe, Innovate, Zeitronix)

This is accomplished by having you run your car in various ways (they will tell you) then log it with the laptop. Send them back the results and then they send you back a tune. You will put that latest tune on, run some more logging, send back to them.

After a few back and forths you will have a perfectly running and tuned car that was accomplished without you ever leaving your island

Good luck, hope this helps!

 

Because your tuned for a certain PSI, so if the car doesnt hit target boost it will adjust other things to try and get to target boost, which could mean more air which could be VERY VERY bad. 29 PSI is not thaaaat much. I was on 28 psi completely safe on my EVOX with fp green