nice job all. perfect timing mid April....

 

I spoke with Justin at STM about things before I ordered mine, and they found the following details, which still seem unclear up to the last few pages:

-They maxed out the pump with the STM rewire kit at 560whp on their Mustang Dyno on E85, which is about 620ish Dynojet.
-With their rewire kit, they were STILL USING THE STOCK FPR without issue.

I don't know why that information hasn't gotten in here yet, but they seem to have tested the pump through and through and didn't have any issues.

 

I've watched (logged fuel pressure at the rail) as a rewired Walbro 255 overrun the stock fpr. Hard to imagine that a Walbro 400 would not.

 

Sorry, Justin may have mis-spoke.

Both cars that we maxed out the rewired walbro 400 on last year ( a 2G DSM on E85 making 588whp on our dyno and an FP Red powered Evo on E85 that made 572whp ) both have our STM Fuel Pressure Regulator Return kits on them and NOT the stock FPR.



-Brian Gleason
www.stmtuned.com

 

Ah, I see now. Makes sense. Welp, sucks for me.

 

Anyone care to guess limit on 93 with rewire and after market FPR?

 

Roughly 30% more. 750 on their dyno, 820 on a dynojet. Something in that vicinity.

 

Any updates on the E85 compatible pump?

 

I just put two of these on my Buscher Doube-Pumper. I think I'll have enough fuel now

 

You guys need to check out this link. It was sent to me by the guys and Injector Dynamics. In the upper right hand corner all you have to do is click on the box of the fuel pump and it will chart the flow vs. pressure ratio of each fuel pump listed.

This really out to have a thread of its own. If anyone wants to do that it would be cool.

http://webpages.charter.net/hybrdthr...mp_web_app.htm

 

I would hope lol!!!!!

 

Before you put a "roll eyes" icon in your response, you would do yourself a favor and read the info at the link in the post above yours. Look at the flow data of the Walbro 400 at 85-90psi....

Now, consider that it will take every bit of these two 400s to make 850awhp on the Mustang dyno my car is dynoed on. We know for a fact this car will make 850 since we just made 780awhp running out of fuel with two Walbro 255s in the tank. This isn't some happy-numbers dynojet dyno.... 850 on this dyno would be about 1k hp on a dynojet.

 

Those charts are fun to play and I played with that one for a few minutes.

Take this fact, a single modified Walbro pump with 1,000 cc injectors on OUR dyno will make just about 500 whp. I know our dyno reads about 13% lower than a Dynojet and as far as I am concerned a Dynojet reads close to flywheel horsepower, that's from the article in Hot Rod a few years ago and the facts on their dyno. That chart is in brake horsepower.

If you just take the simple fact of the injector and pump I just posted and double it all........well it's 1000 whp. Two modded pumps on gasoline with 2,000 cc injectors. This of course would mean you needed the correct size fuel lines to flow that too.

My car currently makes 725 whp at 33 psi, two modded pumps, single 3/8" SS line on E98, duty cycles are in the low 80% range.

Let us know how it goes with the two new 400's in the tank and the new lines, I'm guessing you are going to have plenty of extra fuel.

 

after logging 18:1 afr at 7,500rpm and 28psi on my sti i decieded it was pretty stupid to run fuel pumps at the ragged edge. i wouldnt run a single walbro past 475 whp on a boosted car. spending $100 more on a better fuel pump can be the difference between a blown engine or a dead reliable setup.

 

also, looking at many of the flow results i dont understand why people buy many of these pumps. 600 ltr/hr at 40 psi and 200 ltr/hr at 80 psi.