qwiketz

Hi guys. Well the title is sort of true. Here's a little info on my fuel systems over the years.

My 2007 setup when I changed over to the ysi head unit, I previously ran a 255 in tank to a vortech 50/70 pump to the 60's. I was running out of fuel with that setup. this was at 11 maybe 12 lbs off boost. I tossed a boost a pump on the external and I was still running out of fuel by 4600 rpm. I don't know what the deal was with that setup because on paper it should have done better.

My current setup is a dual walbro 340's in tank, 60lb injectors, a fmu at approx 1.5lb to 1 ratio. It worked great while it worked. I upped the boost and wasn't running into any issues on the upper end.

The car sat for a while and now it appeared that the 2nd pump isn't running or that something is wrong. I have no clue what happened since I changed the trans but didn't mess with the pump or electrical. Last time I drove the car, it was going lean as I went into boost. Perhaps a line came loose on the 2nd pump or it isn't going on.

Rather than mess with the system, I'm pulling the dual 340's and tossing in walbro 465lph e85 pump. I figure I'm going to have to pull the sending unit to inspect anyhow. I will also be using the boost a pump as well. Eventually, I'll go to 80lb injectors. Pump technology has come a long way.

It's a cheap and simple solution that many guys are going to. It should be a ton of fuel; especially at 17 volts when in boost. I'll post some photos when I do the install.

For you guys just going turbo or s/c, if this works, it's a one and done solution. Get a hot wire kit and this pump and you'll be set.

qwiketz

Got the pump out today. I found the source of my poor performance. I didn't understand how the car could go from running awesome to having fueling issues. Well, when I installed the second walbro fuel pump, two of the hose clamps I used were cheap ones and not stainless. They were so badly rusted that when I tried to undo them after removing the sender, they basically disintegrated.

My laptop died so I'll post the photos tomorrow. I am going forward with the new pump install though. Photos to come tomorrow.

mnstrlt1

I'm interested to see what you figure out. I've always admired the massive blower hanging off the front of your c4, let's see what this darn thing is capable of! E85 "is" the "it" fuel these days, and I've even been bit! My 12' GT mustang ran on it, and I really want to swap my fuel system to E85 as well.

qwiketz

Haha! Yeah, I'd love to see what it's capable of as well. I'd like to go E85, but the nearest station is about a 40 minute drive away. Logistically, it'd be a pain in the butt but the performance would probably be insane. One potential problem would be the size of injectors I'd need to make it work. I'm already considering going up to 80's on pump gas. I currently have 60's.

Here's some of the photos that I took. Here's a shot of the bad hose clamp and how the dual 340 setup looked.

qwiketz

here's some pics of the new pump/setup. On the first photo, I noticed that the metal tubing goes down from 3/8" down to a smaller diameter. I bypassed this section to minimize any potential restriction there. I don't know if it'll do much but it didn't cost me anything.

mnstrlt1

Wow, those clamps are definitely toast. I think you already need 80's. These days 100's aren't a stretch. Injection dynamics seems to have some top-notch injectors, but with a hefty price tag. Of course, I've been told they behave very good to tuning.

E85 will need 30% more by volume to truly extract the benefits of the fuel. This would mean big fuel pumps, big injectors, big lines (for your power level)

Orr89rocz

E85 is nice if its available in your area and you monitor ethanol content for seasonal blends but you can make a motor make big power on pump gas and esp with meth inj

Fyi i am making 1018 at the tire thru th400 and 4500+ stall on 93 oct regular pump gas no meth with good intercooler and cold winter day summer air may cause me to back off boost and timing but ahould still make 900's.
just a dual walbro 255lph setup -8 feed -6 return, 40 psi base fuel pressure no fmu all ls1 ecm controlled 401" sbc with FIC 127 lb inj. They work and tune great! Injector tech has inproved greatly these days

How much bigger is the walbro 465 vs a 255?

BrianCunningham

qwiketz

the difference in flow is about 80% more for the 465. I don't have the chart in front of me, but I believe that it flows 465 lph @ 40psi. With a boost a pump, these things can support way over 1000 hp and right around 950-1000 without a booster.

Orr89rocz

Yeah just becareful of the drop off in flow at higher pressures. 1000 hp usually is 20 psi or so depending on the setup so actual fuel pressure would be closer to 60 with boost referenced reg

qwiketz

You're correct. It would take about 20lbs of boost to make good power remotely in that neighborhood. The pump does flow over 100 gallons per hour at 60psi. If I did want to up my base pressure to compensate for my small injectors, it woud still put out right around 90 gallons per hour at almost 80psi. These numbers are at 13.5 volts but I'll be running at 17 volts under boost. That should increase the figures by about 25% or so.

qwiketz

got the car back on the road. The new pump is working great. I need to get it on the wide band to see how the car is really running.

qwiketz

well, good news and bad news. Upon firing up the car, I knew it was rich. The question was how rich.

I got the wideband on the car last night and it was reading about 10.7-11.0 at idle! The good news if any is that it was running fine under boost, in the low 11's. So, there is a bottleneck that is causing fuel pressure to spike under idle and part throttle conditions.

I have a cyberdyne fuel pressure guage that isn't working currently so I can't see how high the fuel pressure is spiking.

I spoke to another member prior to installing the pump and he said it worked fine in his l98 setup. On mine, I'm not sure if the regulator or the fmu is the bottleneck. The other member said that his worked fine with the stock regulator and lines so who knows.

This pump flows a little more than my dual walbro 255's by a very small amount, so I guess I've found (or am super close) the limit of the stock fuel system.

What to do now?... I can possibly trim the fuel at idle and part throttle. Another option is to install an aeromotive rail mounted lt1 regulator and a -6 or larger return line to the tank. Obviously the tuning would be the cheapest method although it's probably a band aid.

BrianCunningham

<----

I did a permanent mount Air/Fuel Gauge as well as a boost gauge

New pump probably puts out more fuel under the same pressure.

rcrflyby

I know this is several months old but do you have anymore pics of this pump setup? what year car?

ANTI VENOM

What did you end up doing? Bigger AFPR and return lines?

qwiketz

Actually, nothing.... Yet.

For the time being, I'm going to trim the fuel tables at part throttle and idle. I'm still learning about tuner pro so I haven't done it yet.

I wouldn't doing the fuel lines and regulator but hopefully this will get it done for now.

djxib

I installed a new FP on mine and it overwhelmed the stock regulator (FP at idle was over 50). So I now have an aeromotive AFPR, holds nice and steady.

qwiketz

Here's an update guys.

First and foremost, the car was running rich after installing the big pump. I hooked up a fuel pressure guage off the sending unit and it appeared to be normal, which I thought was weird. However, once I hooked up a fp gauge at the rail, sure enough, it was at 55 psi at idle. So, it looks like it's time for a new fuel pressure regulator.

Also, I burnt up the stock sending unit wiring using the big pump. It was either the pump or who knows what, but the bulkhead on the sending unit was burnt pretty good. I've since gone to a zr1 sending unit that spreads the current over 2 prongs instead of 1 on the lt1 sending unit. Hopefully this will work good. In addition, the zr1 unit had very, very little use on it and was in great condition. I put the death wheel to it and cut it up, but it's installed now and works.

Next up, racetronix wiring kit install which I should have definitely done already. My car does already have a wiring setup for the 2nd pump using a relay but it's 16 years old and I'm not going to trust it.

qwiketz

ordered the aeromotive 13106 fuel pressure regulator today.... that should fix it according to another forum member using a 500 lph pump.