fuel starvation, with and without Verus door

[gen3v8]

Had my fuel pump recall done. All good. I took the car to the track and proceeded as normal. Bigger sticky rubber, new coil overs and a new pb. No more fuel surge/starvation. It loves the long left hand sequence now.

[ZDan]

I have since discovered that it wasn't fuel starvation! I installed a header and got a custom tune, which cut power above some low rpm when oil temp reached 274F! It just so happened that at NHMS and Palmer it *always* happened ~5 laps in just after the extended left-hander! Tuner bumped the cutoff oil temp up to 285F and no problemo after that...

[gen3v8]

Yeah its strange that it went away. Nothing else was changed and its summer here so definitely not a temperature issue. Maybe I was just soft cocking that part of the track? but my lap times showed otherwise 1/2 a sec quicker.

[ZDan]

Originally Posted by gen3v8

Yeah its strange that it went away. Nothing else was changed and its summer here so definitely not a temperature issue. Maybe I was just soft cocking that part of the track? but my lap times showed otherwise.

How low was fuel?

I have had *real* fuel starvation, a few years back at Palmer. Was running ~3/8 tank and 1st timed lap in my time trial lost power coming out of Turn 2. Luckily for me, someone went off (he was fine!) and the session was black-flagged, so I was able to duck into the pits and get fuel

Since then I just make sure I have >1/2 tank which I need to for time trials anyway to meet weight.

[gen3v8]

Originally Posted by ZDan

How low was fuel?

I have had *real* fuel starvation, a few years back at Palmer. Was running ~3/8 tank and 1st timed lap in my time trial lost power coming out of Turn 2. Luckily for me, someone went off (he was fine!) and the session was black-flagged, so I was able to duck into the pits and get fuel

Since then I just make sure I have >1/2 tank which I need to for time trials anyway to meet weight.

It would do it before even at 3/4+. Now it`s fine still just under 1/2 tank. I don`t have to worry about weight we just play with cars of similar times.
Lately they have been throwing some professional cars and drivers out near me. Great fun seeing them have to use the straights to pass and slowly meander away through the rest.

[Ultramaroon]

Originally Posted by rice_classic

Is there an eloquent example of this somewhere? I've been searching this site but can't find one.

Leaf switch with a slug glued to it. Mount it so the pump only runs on left handers. Or maybe arduino and accelerometer to filter out the bumps. Do we know how to get that data from the can bus?

[NoHaveMSG]

Originally Posted by Ultramaroon

Leaf switch with a slug glued to it. Mount it so the pump only runs on left handers. Or maybe arduino and accelerometer to filter out the bumps. Do we know how to get that data from the can bus?

Wouldn't it be easier to just run a second fuel pump controller to drive it. Power to controller to be feed to pump off of it's own circuit but piggy back the signal from the existing controller.

Asking for uh............a friend.

[Ultramaroon]

Originally Posted by NoHaveMSG

Wouldn't it be easier to just run a second fuel pump controller to drive it. Power to controller to be feed to pump off of it's own circuit but piggy back the signal from the existing controller.

Asking for uh............a friend.

Oooo... *dives into wiring diagram*


edit: A couple unknowns here.


I can't figure out what the DI signal is between ECU and FPC.
If the impedance of the FPC input is too low, running two in parallel would drag down the signal from the ECU. It's just a few steps of DC voltages to set the duty cycle of the pump.


I'm liking the idea of a pump in the right side dumping fuel into the cup during left-handers. It's what I would try.

[gcranston]

Jumping on this thread because I also get fuel starvation at the NHMS oval under 1/2 a tank. I'm on 225 Falken Azenis RE660s (that is, less grip than ZDan). Stock engine/header/tune, but Walbro 485 pump WITH the Verus door. And yes it's annoying because to keep over 1/2 tank, I run out of fuel in my 5gal jugs and have to pay gouging track pump prices.

The second fuel pump seems a little over my head, and I've not seen a really clear tutorial. Ditto a surge tank. Mixed results reported from Hydromats. Can anyone help get me pointed in a good direction here?

Thanks.

[NoHaveMSG]

Originally Posted by gcranston

Jumping on this thread because I also get fuel starvation at the NHMS oval under 1/2 a tank. I'm on 225 Falken Azenis RE660s (that is, less grip than ZDan). Stock engine/header/tune, but Walbro 485 pump WITH the Verus door. And yes it's annoying because to keep over 1/2 tank, I run out of fuel in my 5gal jugs and have to pay gouging track pump prices.

The second fuel pump seems a little over my head, and I've not seen a really clear tutorial. Ditto a surge tank. Mixed results reported from Hydromats. Can anyone help get me pointed in a good direction here?

Thanks.

It would be something like this except our fuel tank is plastic so a magnetic solution isn't going to work. Our fuel pump and basket are on the left which is why it starves on lefts. There is a fuel sender unit on an assembly on the right side similar to the fuel basket on the left. So if you could swap the right side sender unit for another basket, and feed the left basket with it you would be in business.

https://www.z1motorsports.com/z1-pro...it-p-9558.html

https://www.z1motorsports.com/z1-pro...it-p-9558.html

[gcranston]

Originally Posted by NoHaveMSG

So if you could swap the right side sender unit for another basket, and feed the left basket with it you would be in business.

https://www.z1motorsports.com/z1-pro...it-p-9558.html

I think I follow the idea. Basically both pumps run together, and the new right side pump just moves fuel into the left side basket. This seems safer than adding a surge tank. Mounting the hydramat will certainly be a challenge in the plastic tank. There's a fuel level sender on both sides, right? So getting a second basket wouldn't mess up the fuel gauge?

EDIT: any reason I couldn't use a pump like this on the right side: https://www.pegasusautoracing.com/pr...sp?RecID=30036

[NoHaveMSG]

Originally Posted by gcranston

I think I follow the idea. Basically both pumps run together, and the new right side pump just moves fuel into the left side basket. This seems safer than adding a surge tank. Mounting the hydramat will certainly be a challenge in the plastic tank. There's a fuel level sender on both sides, right? So getting a second basket wouldn't mess up the fuel gauge?

EDIT: any reason I couldn't use a pump like this on the right side: https://www.pegasusautoracing.com/pr...sp?RecID=30036

Yeah, no reason you couldn't use that.

I elected to buy another used OE fuel basket off ebay, I think I paid 65 bucks. I was going to check out the in tank senders as there is one on both sides, I bet they read in the same range and I may be able to use the sender on the second fuel basket in place of the one on the right side unit. I also plan on driving the pump with a cheap PWM DC motor controller since it probably doesn't need run at 100% all the time.

Something like this.
https://www.amazon.com/RioRand-7-80V...NsaWNrPXRydWU=

[gcranston]

Originally Posted by NoHaveMSG

I also plan on driving the pump with a cheap PWM DC motor controller

Electronics and I do not get along. As long as I can think of it as legos I just need to plug together I'll be OK, but beyond that it's risky.

I emailed a couple boneyards last night for the whole pump & sender assembly. Swapping that in and just having both pumps run together seems easiest to me. The cheap facet pump from Pegasus was attractive if I had to cobble something together, but I'd rather just drop in the whole assembly. I'm ok with the risk of burning out the 2nd pump faster; I'll just replace it if/when that happens.

Thanks!

EDIT: thinking through it a little more though... you'd use that motor controller just to turn on and 'throttle' the second pump, what, track by track? It might make sense for my use case to at least have a switch so I only enable the second pump at the track, or even tracks where I have a problem, and not run it on the road.

[NoHaveMSG]

Originally Posted by gcranston

EDIT: thinking through it a little more though... you'd use that motor controller just to turn on and 'throttle' the second pump, what, track by track? It might make sense for my use case to at least have a switch so I only enable the second pump at the track, or even tracks where I have a problem, and not run it on the road.

Yes, that is the idea. I only have a couple tracks that I have an issue. Running the pump all the time at full power will also wear it out quicker. Even on tracks that have corners that cause issues, probably don't need to run the second pump at full power.

The factory fuel pump controller changes pump speed based on demand. I looked at possibly running a second factory pump controller and tying it into the signal from the ECU to run both pumps, but as looking at it in the above posts, not sure it will play nice so decided to try something simpler.