Left Hand turn fuel starvation on WOT

[Sapphireho]

I don't track my car, but the other day I was driving in the hills and my car started cutting out wot up the hills. I am JRSC running e85. I was going up the hill with about a quarter tank. I freaked out, turned around and gently made it down the hill and filled up. I did a couple pulls on flat land and it seemed fine. I went for a drive in the hills yesterday (same road) with a full tank and the car ran perfect.

I bought the flappy thingy a couple months ago. I think it's time to get off my ass and install it.

[Turbo]

Does Toyota run a transfer-pump in these cars? That is, a pump which sends fuel from the passenger side of the saddle-tank to the driver's side, where the fuel pump and pickup are located?

If not, how do they ensure both sides of the saddle get drained during normal useage?

[Ultramaroon]

Originally Posted by Turbo

Does Toyota run a transfer-pump in these cars? That is, a pump which sends fuel from the passenger side of the saddle-tank to the driver's side, where the fuel pump and pickup are located?

If not, how do they ensure both sides of the saddle get drained during normal useage?

Just one pump but the system uses a venturi-effect device to suck fuel out of the right side. It's described near the bottom of this page. Look at my sig line for the top link to the manuals. (not mine)

https://demos.starbase7.net/t3Portal...0558G001X.html

[Turbo]

Thanks for posting that tech diagram. I looked through it and it seems like a pretty simple system that would work well enough when driving in a straight line.


However, it sounds like the 'venturi effect' which is being used to suck fuel from one side to the other is pretty ineffective when cornering -well- at least when cornering hard.


Which begs the question - why don't we just install an auxilliary transfer pump? Mount a small pump externally, and have it pump fuel from the bottom of the passenger side of the fuel tank through a hose that feeds right into the fuel pump/pickup basket on the driver's side?

My 1988 Mazda 323 AWD GTX used this very system to move fuel from one side of it's tank to the other. Why re-invent the wheel?


Installation of the flapper-door solution, may work, but it's entirely possible that if an upgraded fuel pump is used, the basket won't have enough fixed volume to supply the engine during the longer corners anyway. A transfer pump that constantly feeds the pickup basket seems like an easy and complete solution.

[VerusEric]

Originally Posted by Turbo

Thanks for posting that tech diagram. I looked through it and it seems like a pretty simple system that would work well enough when driving in a straight line.


However, it sounds like the 'venturi effect' which is being used to suck fuel from one side to the other is pretty ineffective when cornering -well- at least when cornering hard.


Which begs the question - why don't we just install an auxilliary transfer pump? Mount a small pump externally, and have it pump fuel from the bottom of the passenger side of the fuel tank through a hose that feeds right into the fuel pump/pickup basket on the driver's side?

My 1988 Mazda 323 AWD GTX used this very system to move fuel from one side of it's tank to the other. Why re-invent the wheel?


Installation of the flapper-door solution, may work, but it's entirely possible that if an upgraded fuel pump is used, the basket won't have enough fixed volume to supply the engine during the longer corners anyway. A transfer pump that constantly feeds the pickup basket seems like an easy and complete solution.

Check out post number 84 in this thread, I think that may answer some of your questions or thoughts? https://www.ft86club.com/forums/show...2&postcount=84

Multiple people have tried the dual pump method without the fuel door (before we developed this solution) with limited success. This is because there is still a gaping hole in the bottom of the basket releasing all the fuel that you are pumping into it on left-hand turns. I think what @sfruski has done is a step above the OEM setup which uses a jet pump to siphon from the passenger side. His solution of a pump from the passenger side into the driver's basket with our fuel door keeping fuel in; may be the best solution for an in-tank, near OEM type install. It's pretty cool to hear it works so well and I can definitely see how it would be better than the OEM jet pump.

Thanks,
Eric

[Turbo]

Thanks, Eric! I didn't see that post. That looks like the IDEAL solution.

I had thought about the possibility of using your flapper door in conjunction with a transfer pump, but as I haven't taken my own basket out to see it's construction I wasn't sure if that would work.


Any thoughts on offering a complete easy-to-install drop-in kit? Maybe packaged with the flapper door?

[VerusEric]

Originally Posted by Turbo

Thanks, Eric! I didn't see that post. That looks like the IDEAL solution.

I had thought about the possibility of using your flapper door in conjunction with a transfer pump, but as I haven't taken my own basket out to see it's construction I wasn't sure if that would work.


Any thoughts on offering a complete easy-to-install drop-in kit? Maybe packaged with the flapper door?

Had not even crossed my mind, it has now though! We'll start looking into it. That makes sense as the next iterative step in solving this problem. It will raise the price a decent bit though; but for those not wanting to put a surge tank in the cabin (or trunk) it makes a lot of sense.

Thanks,
Eric

[Turbo]

That sounds awesome, Eric! Was hoping to spur you in that direction

I'll see if I can find my old 323 GTX shop manual and send you the exploded diagram of their system. I know you're more then capable of engineering your own solution, but there may be something there of use. I probably have the part number for the Denso motor too - I remember they were dirt cheap as they sent me one of those instead of the in-tank fuel pump in error once. Never heard of one failing.


In the mean time, I should probably get one of your flapper doors if I'm going to track my beast.

Nosed around your site. Maybe even add a few other parts too like the cam cover and throttle pedal relocator.

Do you ship to Canada?

[VerusEric]

Originally Posted by Turbo

That sounds awesome, Eric! Was hoping to spur you in that direction

I'll see if I can find my old GTX shop manual and send you the exploded diagram of their system. I probably have the part number for the Denso motor too - I remember they were dirt cheap as they sent me one of those instead of the in-tank fuel pump in error once. Never heard of one failing.


In the mean time, I should probably get one of your flapper doors if I'm going to track my beast.

Nosed around your site. Maybe even add a few other parts too like the cam cover and throttle pedal relocator.

Do you ship to Canada?

Sounds good, please shoot it our direction.

Yes, we do. Email us for an accurate quote though as international shipping through our website is hit or miss.

Thanks,
Eric

[HSV Guy]

--edit-- This post can be largely ignored as I had opened up the right side instead of the left side. I'll leave it here to stop someone else from making the same mistake. What made me realise was googling the part number (116010-0021) and find a picture of two 'baskets' in the one picture - the one that I found (on the right side) and the one that I should have found (left side). :-)

Has anyone tried to do this in a 2017+ BRZ? I bought one of the Verus flaps as I have been having this starvation issue (NA, but running e85) and just went to install it, only to find that in my MY2017 BRZ Subaru have removed the basket and pretty much everything attached to it, except the float and fuel level sensor.

According to this service manual page for the 2017 86, it seems that 2017+ 86 models have the old setup, but it looks like Subaru have changed it for the BRZ.

As you can see from the following photos, the first difference is that the fuel line no longer comes in via the 'lid' of the fuel basket - it would normally come at the yellow circle of the first picture.

As you can see in the second picture, the 'basket' now only has the float/fuel gauge sensor. You can't see it, but other than a spring the column on the right is empty. The fuel line clips in to what is left of the 'basket' where I have circled in red. The fuel pump itself is no longer in this area and must have been relocated somewhere 'upstream' on the fuel.

So has any else opened up a MY17 or new BRZ 'fuel basket' and if so what setup did you have. More importantly, as suggestions on how I might be able to overcome this issue in my car?

[prandelia]

Ran my car to fuel light on E85 w/ flappy door mod at Road America. It doesn't really have any long-duration left handers, but there are some at home track, NCM, which we will be testing at soon as well.

[ka-titties]

Originally Posted by prandelia

Ran my car to fuel light on E85 w/ flappy door mod at Road America. It doesn't really have any long-duration left handers, but there are some at home track, NCM, which we will be testing at soon as well.

At a recent event at NCM I ran my last session with < 1/4 tank and had the E light come on during the session. I didn't have any starvation issues and I do not have any fuel mods. I think the lefts at NCM are low enough G to not cause issues.

[VerusEric]

Originally Posted by HSV Guy

--edit-- This post can be largely ignored as I had opened up the right side instead of the left side. I'll leave it here to stop someone else from making the same mistake. What made me realise was googling the part number (116010-0021) and find a picture of two 'baskets' in the one picture - the one that I found (on the right side) and the one that I should have found (left side). :-)

As you noted, you opened up the other side of the fuel tank. Glad you got it figured out though. The side you showed photos of is the pickup/filter for the jet-pump system which resides in the main fuel basket.

Originally Posted by prandelia

Ran my car to fuel light on E85 w/ flappy door mod at Road America. It doesn't really have any long-duration left-handers, but there are some at home track, NCM, which we will be testing at soon as well.

We have had a lot of people respond with positive results overall though certain tracks still cause the car to starve with a decent amount of fuel in the tank still. They are generally extremely long left-hand turns (10+ seconds).

That being said, we have continued to develop a fully in-tank solution we think will allow track goers to run significantly less fuel than with the fuel door alone. We obviously need to test it still (and finalize the design) but we have continued to further the development!

[David G 23]

Originally Posted by VerusEric

.
That being said, we have continued to develop a fully in-tank solution we think will allow track goers to run significantly less fuel than with the fuel door alone. We obviously need to test it still (and finalize the design) but we have continued to further the development!

I know this thread is a bit old now. Just wondering if this is something you are still working on? Thanks!