I recently run my Evo 7 on a Dyno and they told me it was running lean.

They said that it could be either 3 problems:
1. Fuel pump is going bad or not good enough (which i heard is a common thing in Evo 7's)
2. The MAF sensor is dirty. Which I havn't cleaned yet anyway.
3. A bad customize tune.

Now, I decided to buy a new Fuel Pump because I know that it's priority upgrade on 7's. So I did some research and got a Walbro 400LHP. Instead of the Walbro 255LHP which is good for awhile, but not forever with my plans.

After purchasing it, I found some links that said it was over-kill and to much unless it's a modified machine (not aimed at Evo's, but at all over types of cars AKA 180sx, 350z, etc).

My 2 concerns are:
1. Flooding/pushing through the injectors
2. Having the fuel heat up in the fuel rail because of the pressure.

So I know it's 400 Litres Per Hour and it's 40 PSI pressure. if the stock fuel pump is also 40 PSI, then there shouldn't be an issue with flooding/pushing through the injectors?

Anyone have any advise or first hand experience with this fuel pump? Did I go too big?

 

Bumping for advise!

I really need some advise, or pointed in the right direction to get advise! thank you!

 

The FPR should keep the pressure where its supposed to be. What are your HP goals for the car? Turbo/fuel?

 

I've done alot of research on what the EVO 7 needs modifying first. I knew it needed a fuel pump because of this, but after I purcahsed it, I found information that I may of gone too big..

Over the next 2 years, Id like to hit 400HP at the wheels.

I am using the standard TD05 turbo at the moment but plan to upgrade in the next 18 months.

I used 98 OCT with a octane booster that should bring it up to 100.2 - 102
(In Australia 99% of places only offer 98 OCT and not 100 OCT or E85)

 

400HP is easily achievable esp if your upgrading the turbo. That pump is bigger than what you would need but i dont think its too big. A single walbro 255 can do 400hp

 

You could easily hit 400 with a single walbro 255lph HP. I don't think you've gone to simply because once you hit 400hp you'll want more. With that pump you left yourself some headroom to break into 500s

 

I just made the change from a 255 to a 400(E85). I also installed a 6an feed line. I have a FIC rail and FIC 1250 injectors with a Fuel Labs reg. My pressure went to 90lbs at the rail. Somewhere in the 60's was as low as I could go. I had to drill out the siphon on the stock hanger. That got me to 55psi. I added a 6an to the return now all is good. 44psi with the vac line off and 36psi at idle. Bought it all from MAP.

 

That just confused me and scared me...... is the 400 on a stock EVO 7 too much then? :S

your post didn't help give me any answers :/ what do you personally recommend after using it!

 

I would say the 400 is fine. I forgot to add some very important info. Most of my issues started when I hooked up the rewire kit. With no rewire you maybe ok.
For peace of mind I would cal MAP they have seen it all.

 

What makes you think it was the rewire?

 

The 400 will overrun the stock FPR when rewired due to voltage. That may be what you're experiencing.

 

^ Yep my walbro 400 over ran the stock FPR. It was terrible with the rewire kit, not soo bad when I ran it off the stock wiring.

 

im prob gonna be going with a rewired 340 looking for a hair over 500hp with e85, that should still be within what the stock FPR can do?

 

running a rewire kit reqiures a re-tune and aftermarket FPR.

 

im tuning the car now thats not an issue. Why the FPR? Ive always heard the stock one is good over 500