evolution2147

I have owned an Evo 9 now for about a month. I have not been in the 4G63 world since the DSM days with an SAFC. I am trying to understand how these Evos work. The car I bought has a dual map tune, one for E85 and the other for pump gas. It is currently running about 32PSI on E85. I would really like to turn this down preferably to the lower 20's but I am not sure how involved that is. Back on my DSM I had a MBC that you can easily turn. This looks to have an electric solenoid, and it looks to be factory. Does the ECU control the amount of boost on these cars?

The car has basic supporting mods. Hard intercooler piping, upgraded FMIC, full 3in exhaust, fuel pump, cold air intake. I have not inspected the fuel injectors yet but I would assume the car was tuned in its current state.

L888Apex

iTrader: (94)

You most likely have a 3 port of some sort, so you can't manually turn it down. Go get it retuned for whatever you like, even though 26-28psi is perfectly fine. and maybe even the 32psi you have now depending on the mods you got. Most stock block evos run low 20's on pump gas 91/93oct and 27-30psi on e85.

Jahtoot

agreed definitely get it retuned for the boost levels you want.

evolution2147

Thank you for the replies. I would like to turn the boost down because i get a misfire/cut out around 5k RPM at full boost. I really bought the car as a pleasure car so there is no need to be pushing everything to the limits.

How does the retuning process work? Does it require the stock ROM?

Jahtoot

Hey man. Im new here in arizona too. I got a evolution 9 MR.

Ive been talking with Moon Performance. I heard UMS is a good shop too. Based on my little experience so far, i think i will be going to Moon Performance for tuning / engine building.

You could reach out to him and inquire about costs to get your car retuned, or even serviced.