evo over boosting possibly cured

Well anyone who was at bobs on Saturday will have realised how annoyed I was when I realised my evo had an issue with overboost  hitting 1.4 bar when it should be 0.8bar


So today I started investigating  the issue and it looks like I've found it ..  If I blow into the vacuum lines you can hear a hissing as it's coming out somewhere. .  
A little more searching led me too the actuator.  
If I blow into the vacuum port on the actuator you can hear it leaking from inside ..
So that has possibly found the issue.   Won't know for certain till  a new one arrives tomoz. .

I've also De modified abit more .  For some reason it had a tubular manifold fitted.   I've removed it and fitted a standard manifold ..
Also noticed the tubular manifold had cracks in it .

It's good you've found the problem so quickly but that's often the trouble with aftermarket parts...

Not up to the required quality..

I wanted to get rid of the manifold anyway ..
It had only two parts on The car that made it non standard ..
The manifold amd other one is an alloy radiator ..

So with the manifold gone is nearly a standard car .  Really can't be many standard examples left

Well done Rob! I do get why you want it standard as that's why I'm happy with mine because it has a few nice modifications!

I had the opposite problem with my mates evo 4 that was here Saturday. It wasn't going over 12psi and was the actuator too! Now replaced and hit 1.5 but quickly backed off until I have time to set up on the dyno

App the evo can go either way ..
Actuator spring can fail so it doesn't close waste gate . Less boost
Actuator diaphragm gets a hole in it so it doesn't get a vacuum . More boost

What is the stock boost guage like on the Evo I take it you hadnt realised it was over boosting so bad?

^ Surprisingly they don't have one !

Mr B wrote:^ Surprisingly they don't have one !

Seriously? Lol I know the R one is not great but at least its something.

Just shows it might be worth one as I know I always check mine regulary. Glad its shown it up for you Rob and will soon get it sorted.

Yeah they don't have any gauges at all

shroom wrote:

Mr B wrote:^ Surprisingly they don't have one !

Seriously? Lol I know the R one is not great but at least its something.

Just shows it might be worth one as I know I always check mine regulary. Glad its shown it up for you Rob and will soon get it sorted.

R one is fine for boost reading within scale & surprising they work at all at 25 years old & bad spanner monkeys playing with wiring, people complain about R oil temp & pressure not accurate but a lot of supposedly better/modern cars have nothing more than oil pressure warning light :-O cost cutting as usual :-/
Least the 3 R gauges can be good if maintained or allow easy fitting of better gauges.

Mr B wrote:

shroom wrote:

Mr B wrote:^ Surprisingly they don't have one !

Seriously? Lol I know the R one is not great but at least its something.

Just shows it might be worth one as I know I always check mine regulary. Glad its shown it up for you Rob and will soon get it sorted.

R one is fine for boost reading within scale & surprising they work at all at 25 years old & bad spanner monkeys playing with wiring, people complain about R oil temp & pressure not accurate but a lot of supposedly better/modern cars have nothing more than oil pressure warning light :-O cost cutting as usual :-/
Least the 3 R gauges can be good if maintained or allow easy fitting of better gauges.

Subaru impreza is the same.
When I bought mine I fit a boost gauge right away. And it was boosting 1.1bar so not standard.
Very strange that a performance car like subaru and mitsubishi don't have the gauges as standard.

Definately is strange Stu cost cutting?

I know my Astra VXR I had didnt even have oil temp pr anything was very basic and handled like a cart horse

My stock boost gauge is poo but Is better than nothing I suppose.
It doesn't sit at 0 it's slightly off centre and it's incredibly slow to react compared the the aftermarket one I have fitted.

You would think Mitsubishi would of put a boost gaugr in the evo though, more gauges to keep an eye on stuff can't be a bad thing

yeh shocking they don't have one. more surprised at Subaru though as they normally not so penny pinching & more engineering over accounting.
Boost & oil gauges are engine savers or at least get you on to a problem before it a recovery truck problem ...

Just goes to show how good the R is :-)