Hello,

I have gotten some PM's regarding the fuel pump in the Evo X so I want to post up some quick facts or at least things I have seen when you are going to do this so it may make it easier for people in the future.


First off the standard Evo 8&9 Walbro GSS342 does NOT bolt right up! It is too large to fit in the housing. So if you are buying one please be aware you do have to modify the housing to get it to work. This is what we did to get it to work is just mill out the inner part of the fuel pump housing and just took some of the plastic off to get it to fit.


The other big kicker is with the way the housing is set up you have to eye ball the top of the pump into the top of the housing and you HAVE to be careful when you do it or else you will destroy the O ring on the pump. If this happens you will cause a lean condition under boost. A good indicator that you messed up is the car will start harder than usual. So if you put a pump in and go to start it , get it started then shut it off and try and start it again, if it is hard to start the install is wrong.

I will post up some more stuff as I get it but I just want people to be aware of this.

Thanks,

Mitch Mckee
Vivid Racing

 

Mitch, a few questions:

1) You mentioned in another thread that a car you mapped started to go lean at high power levels on race gas, but the X has larger injectors than the IX. Is it the pump only or both the pump and injectors that are the issue? Even on a pump gas map when Dyno4mance EcuTeK'd my car, I saw almost 90% IDCs.

2) Do you think there will be a better fitting aftermarket pump available soon? I would rather wait than modify something to fit.


Thanks for all your contributions!

 

1. I think it is the fuel pump. The injectors are supposed to be 650cc or something along that line and just calculating a very basic BSFC will show that we should not be near maxing them out.

2. I am sure there is a pump out there that would fit. Just need to look through some stuff and see what can be found. A bosch stlye pump may work better or they make something that will work as well.

Time will tell. I will look into it as soon as I have a bit of free time.

Thanks,
Mitch

 

Thanks for the info. I do think Bosch has something, I will also try and look into it.

 

I don't think I can handle another Walbro, so any alternative is actually a blessing.

 

x2.
Wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeeeeeeeee. I hate the whine they make. The fact they don't fit is the nail in the coffin. I'll pay double for something that doesn't suck.

 

Mitch, its under the back seat like the rest of them? Do I have to go under the car? I'm gonna throw it in in the next day or 2

 

Steve,

It is under the seat on the drivers side.

Mitch

 

do I have to go under the car

 

No.


MM

 

Thanks for the thread Mitch!

 

thanks for the info

 

Good to know! Thanks for the advice Mitch. :thumup:

 

I would much rather put in a Bosch pump then a Walbro, for the quality and reliability as well as the weeeeeeeeee.

When I sold my VIII the guy who bought it called me as he was driving home (came in from out of state) after the fuel had run a bit low. He said that something in the rear was humming or making a noise. Had to explain to him what the damn noise was....

 

Ok I just finished tuning another X. This one has the fuel pump in it. I require there to be fuel pumps for people that are doing close to 300hp for safety reasons.

It worked flawlessly on this car and lowered the IDC but a substantial amount.

I am going to make a new thread for this car but check it out I will post graphs of the differences.

And on a side note it is around 110F here. It has been between 104-108F in the dyno room all day lol. I am not a happy guy.


Mitch M