Well in another post I was told that I shouldnt go over 5 psi with an intank walbro pump. My question is why not? Coorect me if I am wrong but the star kit uses the same exact pump right? I have seen people running 10 psi on stock injectors with the intank pump with no problems. I have adjustable fuel pressure and I have it set at 90-92 psi at full boost (6psi). From what I have learned this pressure is more than enough. Hahn recommends 80 -90 psi. So I am actually running really rich. Does anyone here agree with me on this?

DAVE_FL
97 T-GS
HRC stageI
Stage 2 very soon!!!!!!

Well I've been told that the walbro fuel pump with my star kit isn't good enough for 10 psi. The pump I guess can't work with really high fuel pressure. I'm running about 7-8 psi and my a/f at WOT is barried all the way rich. But I've heard a few people running the same fuel pump with 10 psi for over a year or so, with no problems. But I'm still going to get an inline pump too just to make sure, better safe than sorry.

Hey Dave, I hadn't saw that you had started a new thread at the time of my initial response, so here's a cut and paste for ya...

"I don't want to go step on anybody's toes, but since you have an HRC kit, here's a post by Hoot that explains a bit why one fuel pump at high fuel pressures is NOT sufficient.

http://www.2gnt.com/dcforum/DCForumID16/259.html

This post is kind of the reason some of us think that STAR may be a bit more prone to engine detonation. I don't know for sure, but since I'm getting you those I/C pipes, I don't want you upping the boost without all info in hand.

BTW, the inline pump is VERY EASY to install. (took me two hours) I only had the walbro in the beginning as well until I learned of this. The weekend after this post, I installed my inline Accel."

As you can see, this discussion has already been addressed. Hope this clears things up.

Jason

98' Eagle Talon ESi-T
Mitsu Super 16g Turbo(HRC)/Custom FMIC


http://springfielddsm.homestead.com/JasonsPics.html

DISCLAIMER: This is purely my findings only, your results may vary, my car is a "rare" eclipse made in Oct. '94 so my fuel system may be different or more efficient. I installed the Holley (Walbro) High pressure 255lph pump because there was nowhere to mount the Accel, coz of my existing fuel lines.

Here are some Quotes from Holley (BTW these are Walbro Pumps, it even says it on the pump and box):
"at 80 PSI the standard 255 lph pump will flow around 132 liters (35 gallons) per hour" ... that means 2200 cc/min

"At that same 80 PSI the equivalent forced induction fuel pump will flow over 210 liters (50 gallons) per hour"
This is what I have... 210 lph means 3500cc/min!!!!!!

Hoot's Calculations for Walbro 255: "80 psi: 43 GPH, 2714 cc/m"

Hoot's post seems correct (by general consent) however I have a few points to note...

First as you can see above, his calculations for the standard pump are too optimistic ;-)

P.S. I quoted 80psi because that was the data I got from Holley.

----

Now MY results:
My point being that you can fine tune the final full throttle fuel pressure. The max fuel pressure that I have *ever* managed with my in-tank Holley/Walbro (High pressure edition) is about 90-105. Changes from day to day... has something to do with weather.

YET, I use gauges for tuning, no "sounds about right" tuning here (Both EGT and O2 Voltage). I had to constantly LEAN out my fuel curve on the SAFC up to 6000rpm by about 10-13% to run good (i.e. not to bog due to running so rich)....

This was fully backed by 40+ drag strip passes confirming my numbers at both 7psi and 10psi boost pressures.

I keep bringing this up and everyone "just ignores" my findings..

As I have learnt in Engineering, "Paper" calculations vary from actual physical experiments... Who knows.. maybe in my case I got a "superior/freak" fuel pump...

HOWEVER: Bigger injectors is the ultimate solution, 'coz you don't wanna have a problem with 110psi of fuel if something goes wrong!

Guy
RS_Guy

"If I wanted a 4G63, I'd have bought an EVO"



http://www.GTuned.com

I am new to this fuel system thing. I am not really familiar with the whole fuel system. I am in no way trying to put your opinion down. I am just trying to learn. I had no idea you had a walbro too. That must be really loud with a walbro AND an in line? What kind of setup do you have? I ran two fuel lines to the FPR that is mounted under my cruise control. Is that the same as yours. What I am trying to say is how is the fuel system supposed to be set up on the HRC kit 97+? Do they run two fuel lines to the engine compartment like I have mine done?

DAVE_FL
97 T-GS
HRC stageI
Stage 2 very soon!!!!!!

Actually Dave, I only run the Walbro 255-High Pressure.

And yeah, it is a WHINING bastard.. thus the DSM nickname WHINEbro.

What I was trying to say in my previous post is that the High Pressure Walbro (in my opinion, and in my case) is plenty sufficient for 10psi boost on stock injectors.

However if you do have the Accel and CAN mount it (i.e. the mounting holes are there) then do so just as a safety precaution.

The main reason that I bought the Holley in the first place is because on my Early '95 Eclipse (that has a stock fuel return line) there are no mounting holes under the car. I sure as hell wasn't going to tie-strap a fuel pump under my car!

Guy
RS_Guy

"If I wanted a 4G63, I'd have bought an EVO"



http://www.GTuned.com

So there are mounting holes on the 97's?

DAVE_FL
97 T-GS
HRC stageI
Stage 2 very soon!!!!!!

yes...they're the same mounting holes as the fuel filter. The fuel filter gets stuffed in to the place ABOVE the new inline fuel pump.


Guy, you may very well be right as to the "sufficiency" of the Walbro. I'm just bringing out all the facts.

Jason
98' Eagle Talon ESi-T
Mitsu Super 16g Turbo(HRC)/Custom FMIC


http://springfielddsm.homestead.com/JasonsPics.html

I would suggest that instead of running high pressures with an inline pump or whatever is to do yourself a favor and get bigger injectors and a Supra TT fuel pump. The supra fuel pump runs so much more quiet than the Walbro (you won't even hear it) and to me, I think it's way more reliable than any WALBRO pump I've ever used.

The supra pump isn't cheap mind you, but it's a definite must for peace of mind.





___________________________
l e o n
1995 Eagle Talon ESi-T
Star Stage 2
Boost is GOOOOOOOD!

Just in case I come across a real cheap Supra TT fuel pump, is the pump a direct bolt-on replacement, or is there modification of some kind?

Thanks,

Fly1
1998 Eclipse GS
HRC Stage 2 Turbo System

Jason: I am not trying to bring anyone down at all, just trying to add to the info :-)

BTW I have heard good stuff about the Supra pump too. Nippon Denso also makes some good pumps.

Guy
RS_Guy

"If I wanted a 4G63, I'd have bought an EVO"



http://www.GTuned.com

or you could use what I got. :)
A Aeromotive 1000hp pump that pushes over 500 gal per hour, with -10AN feed line and a -6 AN return.
Just a thought! :D

Jesus!!! Thats impressive!!!

DAVE_FL
97 T-GS
HRC stageI
Stage 2 very soon
PHOTOPOINT SUCKS!!!!!!

Supra TT pump is a nippon denso pump. Nippon denso pumps are very quiet! :)


___________________________
l e o n
1995 Eagle Talon ESi-T
Star Stage 2
Boost is GOOOOOOOD!

>or you could use what I
>got. :)
>A Aeromotive 1000hp pump that pushes
>over 500 gal per hour,
>with -10AN feed line and
>a -6 AN return.
>Just a thought! :D

Are you using a fuel cell? How'd you mate the lines to the stock fuel bracket?


___________________________
l e o n
1995 Eagle Talon ESi-T
Star Stage 2
Boost is GOOOOOOOD!