Parallel vs. dead head

[TT302Z28]

MSI in Roseville, CA. Modifies C6 Z06 Corvettes all day to 600+RWHP without having to modify the fuel pumps or tanks.

What does the LS7 in the Vette's come with?

[CarlC]

That Russell hose keeps coming back to haunt you JP!

[parsonsj]

I know! I thought I'd seen the last of it, but nooooo.

Anyway, I hope this fixes the problem.

jp

[ss dave]

Up date, I pulled the Aeromotive pump and replaced it with the largest Bosch pump made, 300lph, more than enough for my LS7. In fact Holley states it would be good for over 800hp.
Now, with limited test time, I'm not starving the pick-up, but get fluctuations at 3/4 WOT. The pressure will drop 8-10 psi.
We think a vacuum regulator will help, as opposed to my current Weldon, but I won't know for probably two months, when I finish upgrading the rear suspension and stuff!

The stock 2008 LS7 pump flows minimum 188lph @ 52.9 psi @ 12v
Walboro GSS340 255lph = 67gph = 404 lbs good for 800hp
Bosch 044 300lph or 80 gph @ 72.5 psi better yet.
Quieter than my A1000, probably cooler too.

[parsonsj]

I got the new elements yesterday and installed them. Last night, I did a test of the pump that tells me the filter made a huge difference.

I disconnected the fuel line in the engine bay, and ran the pump. Fuel shot at least 10 feet in a huge glug of fuel. Before, it would just gurgle out of the hose.

OK, I didn't actually mean to coat my garage in 93 octane (I forgot the hose was over at Brown & Miller), but the test showed how much restriction the filter was.

Here's a pic of the new BMRS hose (PTFE inner liner, polyester outer braid, and guaranteed on pump gas indefinitely):

[camcojb]

love a happy ending...............

[John McIntire]

So John, would it be safe to say that the experince that you and others have had with their cars running poorly after extended periods is due to a dirty outlet filter? The outlet filter being so dirty that the fuel pump was trying so hard to push fuel through it that it started to cavitate and in turn heating the fuel up and the cell, and the car running poorly because of the lack of volume and pressure at the rails?
This is a good find on your part! Hopefully when you get it all back together and running you can give us an update as to how the car runs on long trips. I have put off converting my car to EFI for awhile, well one for lack of time, but I wanted to see what came of this topic because I really didnt know how I was going to plumb it. I'd rather go with the traditional setup with the regulator up front by the fuel rails and run the return line all the may back.
Thanks for sharing this info with us!

On a side note, I used Russell line on my old carb'd SBC and after a few weeks of running it I noticed that my fuel pressure was low, and I cleaned the filter and everything ran fine for a few more weeks, then the same problem. I couldn't even go WOT. I don't really remember any black particles in the filter screen, as it was a stainless mesh type, I think 10 Micron. Doesn't look to be that Russell hose is up to snuff, does it?

[parsonsj]

So John, would it be safe to say that the experince that you and others have had with their cars running poorly after extended periods is due to a dirty outlet filter? The outlet filter being so dirty that the fuel pump was trying so hard to push fuel through it that it started to cavitate and in turn heating the fuel up and the cell, and the car running poorly because of the lack of volume and pressure at the rails?

I can say that that was my problem. And I can that Aeromotive told me that this is a common condition. So yeah, all the guys with custom EFI and high dollar pumps should definitely check their fuel filter, even if the car only has a few hundred miles on it.

A good lesson learned. I'll take my car out for an extended drive tomorrow. I'll post back about how it runs.

jp

[Van B]

So John, would you think I would be best off to plumb mine with hard line all the way to the engine bay and make sure to use teflon braided line everywhere else?

[parsonsj]

would you think I would be best off to plumb mine with hard line all the way to the engine bay and make sure to use teflon braided line everywhere else?

Absolutely. That's my setup now. Hardline all the way to a fender bulkhead (and back since I'm using a rail-based regulator), hardline in the rails, and just some teflon inner lined flex line from the fender bulkheads to the rails.

Bonus: no gas smell. (that is, once the gas that ended up on the floor during my pump test evaporates)

jp

[CarlC]

Same here except for flexible teflon lines at the tank as well. Zero gas smell in the garage.

[andrewb70]

Teflon lines are the only way to go. Seriously!

When I worked at Holley they were doing some testing on various hoses to see how they stand up to everything from race fuel to E85. Race gas was actually easier on the rubber hose than street fuel. In the end it was found that all of the fuels deteriorated the rubber hose to some extent. The Teflon hose is impervious to just about all fuels.

Andrew

[Vegas69]

love a happy ending...............

[parsonsj]

I gotta get my car back on Mike Norris' dyno. I swear it has more power. Maybe this lack of gas has been a problem all along.

Anyway, hours of driving later, no fuel pump problems.

What will I do all day now?

jp

[CarlC]

Breath in the aroma of latex paint being chewed up and stained by 93 octane.

[B Schein]

Those are some nice looking hoses.John did you get to meet Wade and the guys from BMRS at PRI.

[parsonsj]

No, I just called them up. I talked to Penny on the phone, and Scott made the hose.

jp

[Fuelie Fan]

Teflon? Do you mean nylon hose? Pretty sure the OE's use nylon-12

[parsonsj]

The liner of the hose is PTFE. See more about it here.

jp

[JRouche]

The liner of the hose is PTFE. See more about it here.
jp

Hey John, I have literally hundreds of feet of stainless braided hose in various sizes with teflon liners. I would like to use it for the car. It was for another project and its just sitting around. What I would like to know is what fittings to use. The teflon looks to be pretty thick, maybe a lil over a 1/32", close to 1/16" just by looks, and its stiff. Can I use AN type compression fittings with it for fuel?? Whadda you think. I know the liner is pretty slippery and would hate to have the fitting pull out. Any advice would be great. JR