shiv@vishnu

iTrader: (20)

Hi guys,
Just figured I'd spread the news as it look everyone by surprise. This past weekend, during the CO dyno days, at least 3 EVOs experience fuel pump issues. That is, the inability to consistently provide stable fuel pressure. All three cars exhibited this sudden "leaning out" after 20 or so dyno pulls. Whether this is due to the high altitude conditions or not, it does appear that upgrading pumps for anything higher than Stage 1 is a cogent idea. In fact, even a Stage Zero+ car exhibited this problem. For some reason, we have not seen such behavior at sea level and God knows we've been known to do a lot more than 20 runs in one sitting Just thought i'd mention it...

We were fortunate enough to retest one of the troubled cars on Tuesday with an upgraded fuel pump freshly installed. We could not replicate the problem which, needless to say, is good. Even after 50 runs.

We are ordering a bunch of upgraded fuel pumps ASAP so expect us to have them 1st week of January. This we become a part of our Stage Zero and up kit. Especially important for those who live in conditions like we saw in Colorado (cold and high evelation).

Best Regards,
Shiv

chronohunter

iTrader: (1)

I can highly reccomend the pump since I had the "troubled car."
The pump is very easy to install and also not at all noisy (you can barely hear it with the seat out and cover off!). Stage 1+ rules!!
Thanks again Shiv!

DynoKing

So are you going to be mapping the 1+ cars now for this pump? I am not going to do the pump until I have a map because I don't want to be pig rich.

chronohunter

iTrader: (1)

You usen' them fancy words again? You know how I get all confused

chronohunter

iTrader: (1)

Shiv can correct me, but I don't think you need to re-map because of the pump upgrade. It just seemed to stop the lean condition after 18+ consecutive runs. I don't think he changed the map due to the pump from what I saw looking over his shoulder FWIW

shiv@vishnu

iTrader: (20)

Correct. Adding the pump won't change your mapping. Not doing it is a bad idea, IMHO.

Shiv

DynoKing

What pump do I need to install?

shiv@vishnu

iTrader: (20)

We've been having good luck with a high capacity Walbro. Simple direct replacement. Shouldn't take more than 20 minutes to install. I'll make up direction when the time comes.

Shiv

DynoKing

Sounds good man and thanks!

slowTsi

Does the 255 pump over run the stock fpr at idle? I know the dsms have this problem. Also, the 255 pump is noisey, I can't imagine how this would be different on the evo. Only with the ac and radio off with the windows up can you really hear it though. You definately know it's in there.

MP5

iTrader: (4)

I never noticed my 255 walboro in my WRX. I also think the EVO FPR is different IIRC

chronohunter

iTrader: (1)

No noise, no "pump over run" no problem and no lean out Just get the pump, cheap insurance...

Chris in HB

iTrader: (3)

So would I need an FPR or not? I was told by RMR early on that an FPR is a good thing to have... I could probably mount it side-by-side with the oil catch can along the firewall. I know Denso has one as does Stillen (RMR's recommendation - probably has something to do with Rhys being Steve Millen's nephew... LOL). Any comments?

MalibuJack

iTrader: (5)

I think the stock FPR Is a rising rate regulator.. Which means it will adjust accordingly, from what I've gathered from others "In the know" an aftermarket FPR is not required like it might have been with earlier DSM's

shiv@vishnu

iTrader: (20)

Typically, the term "rising rate regulator" describes a regulator that doesn't follow a 1:1 manifold to fuel rail pressure rise. That is, it will increase fuel pressure by say, 6psi, for each additional 1 psi of boost pressure. These regulators, sadly, are used often in applications where injectors are undersized such as in poorly designed aftermarket turbo kits. The factory regulator, like most factory regulators, simply maintains a constant pressure differential between fuel rail and manifold pressure (1:1).

Just my 2c,
shiv