Getting dyno tuned and noticed that my car started getting lean around 735hp on a DYNOCOMM dyno. Which is weird because i thought the br double pumpers on modded 255 were good for 800+ from what i have read in previous threads. Am i really going to need to upgrade my pumps already or even add a 3rd inline pump? Please any advice is greatly appreciated at this point. Willing to try anything before i spend big $$ on new parts.

I have done the following
-swapped out to an aeromotive FPR and gauge (to test)
-changed the FPR boost reference to the the turbo
-re checked all my lines and fittings for leaks or kinks
-pulled out the hanger to inspect the pumps (everything was fine)
-cleaned out the injectors and fuel filters (not dirty at all)
-Fuel tested the e85
-checked that the hobbs switch was connected correctly

A Quick run down on the supporting mods:
-2.1L LR
-6466
-ID2000
-mini fuel lab fpr with gauge (43psi)
-8AN teflon feed
-6AN teflon return
AMS fuel rail
fuel pump rewire (10ga)
BR double pumper
modded 255s (second off hobbs switch 12lbs)
e85
stock ECU

 

How old are the pumps in the double pumper? This still on the stock hard line? If so you can upgrade to a -8 feed line, or perhaps upgrade to dual 450s...

 

you've got a solid fuel system, well except you didn't mention the fuel filter. should easily suppoert 800 whp if the pumps are in good condition. what base pressure? what fuel filter? since you have a fuel pressure gauge, are you tracking fuel pressure to make sure that rail pressure equals boost plus base pressure? if its not, then you have an issue.

 

ya thats definitely wrong. you can make 900whp on dual walbros. Im at 810 which is probably closer to 840 on a real dyno and im at 82% IDC.

The only thing buschur on my double pumper is the housing. I replaced everything on it. Make sure the fuel pumps are modified, they sometimes dont come modded anymore.

That will change the fueling result big time.

 

also a double pumper on a dynocom is probably capable of 1000+ since that dyno reads high as hell.

 

I'm running a compact filter, pic in link
https://www.anfittingsdirect.com/an-...fbd66485b588c6
43 base pressure

i wasn't able to view the gauge that well when doing the pulls because of the placement of the gauge. But should i be seeing ~76psi if I'm on 43 base pressure and 33 pounds of boost??

yea i pulled the pumps off to make sure that they were and it looked like valve was pushed in all the way, not sure if its pushed in TOO much since i can't really see the silver valve anymore. Im going to try and swap those out to see what happens

hmm interesting

 

Correct, rail pressure should be 76 psi for 43 psi base at 33 psi of boost.

40 micron element isn't much of a fuel filter. Suggest you consider the Fuelab E85 compatible 6 micron filter:

http://fuelab.com/products/performan...uelab_filters/

Fuelab claims less than 1 psi pressure drop across the filter for something like 800 whp worth of E85 fuel flow.

 

They are all pushed down from walbro, I doubt its modified. it isnt easy to tell sometimes.

One of the best inline fuel filters ive tested was Fore innovations with the 10 micron SS filter.

I've got a bunch of inline filters if you want to buy one message me.

I tested a bunch on my car. fuelab, kinsler, fore, etc.

You could refresh the pumps, filters, also and start from scratch. I can supply you with all the stuff from walbro if you want also.

 

i was going by this thread that was started on how to modify a walbro..

https://www.evolutionm.net/forums/ev...ng-walbro.html

i just looks black in the hole, unless i had a different version of 255s not sure

Also, would fuel filter brands really make that big of a difference in the flow?

i appreciate all the help guys, just trying to make sense of it all and understand everything before i just throw money on parts

 

I posted at the end of that thread with a picture awhile back. It should be helpful to you.

I haven't flow tested anything fuel filter wise, but i let it get filled up with e85 then drained it, then checked how hard it was to blow through. Fuelabs get very hard to blow through once wet. The kinsler not so much, the fore was the best / most easiest to blow through.

 

i would rather get a pump/pumps that work better at a higher pressure ratio, than run a filter that does not filter as well but is less restrictive.

way too much at stake with fuel being improperly filtered.

 

Which of the Fuelab filter media did you test?

 

what pump/pump replacements would you suggest going with to replace the walbros

 

The filter I use (fore innovations is found on some 1800WHP GT-R's. It is still a 10 micron SS so its plenty enough to protect the injectors.

The one im using was the easiest to blow the fuel out of. The 2nd one was the kinsler paper element filter thats included with buschurs double pumper system.

3rd was kinslers monster mesh.

I fully understand what you're saying though.

 

All of them. All their paper, fiberglass, etc.

Once 40 micron, it blew through nice and easy. 6micron was like trying to blow through a brick wall.

40 micron is not safe enough to protect the injectors though.

whos to say one brand might be more conservative in regards to filtering elements then the other though.

I know a lot of cars running 40 micron with no issues, but when you call and ask around you will be recommended not to ever run over 10 micron with injectors.