03 BLACKOUTSSS

iTrader: (3)

Okay, so here is the background

1967 C10, Longbed, Stepside, original inline 6 (250ci) in it. I decided to do a blowthrough turbo setup instead of putting in a SBC or doing an LS swap. Everything is in and its running (I'm friggin amazed...I don't know crap about turbo carb setups...its been a learning experience for sure). My issue now is fuel. I disconnected the lines from the stock mechanical fuel pump and put an external electric pump and a boost referrenced fuel pressure regulator inline. The reason for this is that the fuel pump needs to supply fuel about the boost pressure and the mechanical pump can't do that.

Here are the specs on the pump that I am using...

Brand:Trick Flow Specialties
Part Type:Fuel Pumps, Electric External
Product Line:Trick Flow® High-Flow Electric Fuel Pumps
Summit Racing Part Number:TFS-25004P

Free Flow Rate: 43 gph
Maximum Pressure (psi): 45 psi
Inlet Size: 5/16 in.
Inlet Attachment: Hose barb
Outlet Size: 5/16 in.
Outlet Attachment: Hose barb

https://www.summitracing.com/parts/tfs-25004p

The problem that I am having is that something is causing it to not provide constant pressure. I am trying to upload a video to show what happens. The pump doesn't make a consistent hum, it sounds like its straining and then it ...nevermind, let me see if I can upload this damn video. Its 2:30ish, so its kinda long, but I videoed the entire engine bay, everything I could get so and carb turbo experts can look over the setup and identify anything that I have done incorrectly.

03 BLACKOUTSSS

iTrader: (3)

I know there is wiring and vacuum lines everywhere...that will all get cleaned up. I appreciate any insight anyone has.

I am thinking that the pump is trying to pull fuel at a rate so that it can supply fuel at 43psi. The fuel lines are 5/16" from the tank to the pump, so I'm not sure if that is sufficient to supply fuel for what the pump is trying to do. Additionally, the regulator is bringing that 45 psi down to 5ish at idle (not under boost).

Is it possible that the pump pulling too hard and the fuel lines can't support it? I popped the gas cap off to make sure the tank isn't vapor locking, so thats not it.

I should also note that the regulator is a Non-Return style. This one...
https://www.summitracing.com/parts/sum-g3032b/overview/

Im at a loss here.

TXsilverado

iTrader: (19)

Id send the video to the pump manufacturer. Im sure they have seen it before. Cool project!

03 BLACKOUTSSS

iTrader: (3)

Thanks man, thats a good idea.

smaller_block

Did you get this problem solved? I think that I would try stepping up to at least a 3/8" feed line myself. Almost sounds like the line is collapsing.

Do you have any more information on your build?

kbracing96

iTrader: (26)

I think this is way cool! I love turboing odd ball stuff and especially a blow though carb. Been messing with one on my 5.3 swapped 69 c10. Hope you go it figured out. If not let us know.

03 BLACKOUTSSS

iTrader: (3)

Sorry guys, been off the board for a while. Figured I would update. KB...that sounds like a nasty little setup. If I remember correctly, you ran twins on a stock 5.3 for longer than anyone every expected!

I ended up changing out the fuel pump to a walbro 255 in tank and FPR to a return style, which seemed to help out alot. Spent the last two years working out the bugs on weekends when I get one free. Been struggling with a few things. I have figured out that between the intake, exhaust, log manifold, turbo and exhaust, there is about 70 lbs of metal hanging off the side of the motor with the stock 5/16 bolts. I have been chasing vacuum leaks all over the place, and I finally found some leaks at the intake to head junction. So I am pulling the motor this winter and along with getting the head drilled out for 3/8 studs, I will be designing some type of support brackets to take the weight off the bolts and hopefully I can run for longer than 30 miles without massive intake leaks. And as if that wasn't enough, I think water is getting in my tank, so that is a giant pain in the ***. So she will probably be getting bagged as well...the static 4/6 drop looks cool, but rides like absolute ****!

I got it running pretty good. Man, my little chinese turbo'd inline 6 is a monster when the boost comes in. Its waste gated at 10 psi, but I've never seen higher than 7 because the turbo is comically too large!

I'll update with more pics as I go along.

03sierraslt

iTrader: (22)

03 BLACKOUTSSS

iTrader: (3)

Honestly, I have no idea What the specs are. It was a drunken purchase off eBay 3 years ago. I used gorilla math and went off the assumption that the turbo was marketed for a Honda 4 cylinder to make between 4 and 500 hp. Figuring all engines are just pumps and my engine and a honda 4 banger had roughly the same starting point power wise, itshould be fine. The only issue is it spools too slow for my gearing and red line. If I drop the gear from a 3.73 to a 3.23, I think I would see full boost before a gear change .