I just got my 05 MR a week ago. I know the owner before me beat on the car a little bit because he autocrossed it. He also but on a TBE and i noticed that when i first got it it took off like a bat out of hell. im familyer with fast cars. i have a 93 TT RX7. when it was pulling strong like that i noticed that it would boost 1.5 at peak then hold 1.4. This is on the stock gauge which i know might not be the most acurate.

But my Questions is. what boost levels did a stock MR run in 05? because this seems higher then normal. he has never messed with the boost level so im not sure where its coming from. But most of all my concern is that over the past few days its been feeling slower and ive noticed that boost levels have droped. it still peaks 1.5 and then drops all the way down to 1.1! Why would this be?

Should i be concernd, and how to i fix it?

How much boost can u run on a stock engine and still be safe? ive heard 20 pounds AKA 1.5.


Also what should be the first mods to do since i already have a TBE.

 

First off, 1.5 is a little higher than 20 psi. More like 22. The stock gauge has been known to be quite acurate. At least for a stock guage that is.

Stock boost is around 1.3 bar, but it will be a little higher from the TBE. IMO 1.5 bar is ok, but should be tuned. The worst part is you don't know if the ecu has been flashed/tuned. The only way you can be sure things are safe is to be logged.

First thing I would do is get a wideband and a tactrix cable. This way you can log your car and tune it via ecuflash and the tactrix cable. Then I would do a drop in filter and turbo outlet. If that still isn't enough power do cams. You will be surprised how quick the car will be before you even get to cams though.

About the taper to 1.1, You first have to find out how it is hitting 1.5 bar. It maybe possible from the TBE, MBC (manual boost controller), or some flashes can alter your boost. The cars do get taper, but usually not that much. Without knowing what is controlling the boost though, I don't thing anyone can give you an acurate reason.

 

well 1.5 bar is about 22 psi (1.5X14.7=22.05). stock the cars are set at about 18 psi and taper off to 16. there is no way that that guy didnt mess with boost levels if its bossting to 1.5. and the boost all varies with temperatures outside. in short, the colder it is, the higher you'll spike (lower density air) and vice versa. 1.5 bars is safe boost. that's what i'm set at right now.

 

what are all the mods on your car?

i think stock boost levels for the 05 were 19.5 psi. are you still running the stock boost control solinoid or a manual boost controller (electric boost controler)? if you are still running the stock boost control solinoid that may be the reason why you are tapering so much. 1.5-1.1(21psi-16psi) is about right for a stock solinoid. but you can check for possible boost leaks and if you are still running the stock plastic bov, change it to a jdm mr bov, or evo 9 bov.
as for the feeling of loss of power this may be directly attributed to the temperature. car is going to be slower in 90 deg. afternoon heat as apposed to 60 degree evening temp.

 

with the stock boost control solenoid, cool temps and a tbe, you could spike to 22psi

 

I spike to 24psi and hold 20psi to 8k daily on 93 octane, it's all about the tune.

If I were you my next mods would be, intake filter, fuel pump, manual boost controller and a tune to make the most of the mods. If you want more after that, cams.

 

It is the stock Boostconrtoler. The only mods on the car is a drop in K&N and TBE with a highflow CAT. Im aware about how tempetrue afects a car sincer warmer air is less dense, But will that also afect boost levels? shouldnt the turbo be putting in the same amount of air regardless?

I agrea a boost conrtoler should be the next step. Which way should i go though manual or electronic? is it true that on electronic you can set up different boost levels for your car and change them on the go?

Also which brand is the best and where should i look for one?

If i do swap out the BOV is JDM the best replacement? and if so where can i find one.
Thanks for the help