Left Hand turn fuel starvation on WOT

[zdr93523]

Originally Posted by AyJay

1st time i ran at Thunderhill after switching to E85 i experienced this problem at Turn 8 (high speed left hander). It started out as a sputter when my tank dropped below 1/3 on the gauge. It behaved much like the traction control fuel cut for a brief second. I kept running laps that session since I wasn't sure what the hell was up and eventually it had to limp the car back onto the paddock as it would just sputter as if it was in some sort of limp mode.

My solution was simple. Never start a session with less than 1/2 a tank of E85 and replenish after every session. Haven't had an issue since.

I could get my car to fuel starve when starting with a full tank on lefts, rights, and even long straights in only 3-4 laps. 365whp and 265 non-DOT slicks do not agree with the OEM fuel system at all. I have it sorted now but it has been a massive process.

[redlined600]

Originally Posted by zdr93523

I could get my car to fuel starve when starting with a full tank on lefts, rights, and even long straights in only 3-4 laps. 365whp and 265 non-DOT slicks do not agree with the OEM fuel system at all. I have it sorted now but it has been a massive process.

Care to share your solution?

[zdr93523]

Originally Posted by redlined600

Care to share your solution?

PM me. Those who have understand why I don't want to post it. Messing with a fuel system can be dangerous and it is a pretty big undertaking.

[dave-]

@zdr93523 solution is interesting, great to hear it works.

But bit much for me as I don't have the technical knowledge to pull it off myself. Don't wanna be a local shops test dummy either.

[lutfy]

Anyone tried the Velox Fuel Starvation Door? Seems to be a solution:

http://www.ft86speedfactory.com/velo...l#.WYsq1VGGPIU

[Ultramaroon]

@VeloxEric, brilliant! Bravo, sir. Take my money, please.

[Tcoat]

@Lunatic if you haven't resolved this yet take a look above ^

[VerusEric]

Please keep in mind that this solution was designed for 90-95% of track guys. A simple solution for the typical track day enthusiast. A surge tank (or other) is still a more complete solution to fueling needs for competition or those that want to run the car dry.

@The Racers Line can comment more on his experience in the Harrop equipped white car they take around tracks in California.

Thanks,
Eric

[GT86Dan]

Already on its way !! Will be testing this fix at New York Safety Track. Will post results !!

[The Racers Line]

Originally Posted by VeloxEric

Please keep in mind that this solution was designed for 90-95% of track guys. A simple solution for the typical track day enthusiast. A surge tank (or other) is still a more complete solution to fueling needs for competition or those that want to run the car dry.

@The Racers Line can comment more on his experience in the Harrop equipped white car they take around tracks in California.

Thanks,
Eric

So although I had nothing to do with the genius, simple design of this little flapper, myself, and 2 other drivers (in one of my shop cars) did perform the testing.

Drivers:
I'd call myself an advanced novice, I don't have more then maybe 2 years of experience on track, but I do relatively well, and put down respectable lap times. Driver 2 has been drifting and tracking for 5+ years, and knows how to get around a racetrack quite well. Driver 3 is an animal in basically any car you put him in, and currently holds the fastest unoficial 86 lap at Thunderhill West,in this car, with the Velox Fuel Flap installed. He also drove this same car, with our old JRSC, to a Second place in the Continental Sports Car Shootout a few months back. Bottom line, he can drive. A licensed, professional racing driver will be piloting this car in October at the Thunderschleif(5-mile) in October, just to really round out the testing.

Anyways, I did approach Eric with a completely different design for a "fuel system fix", just before he came up with the Flapper! My goal was to keep the complete stock fuel basket, with some add-ons. It likely would have worked, but for the money I estimated it would cost, you'd be half way to a surge tank, and that would still be a better setup in the long run.

This fuel flap, ended up being even better then I imagined. It seemed to simple to work, and I was absolutely skeptical. I know Eric was too, but after some bench testing, he mailed it to me and I tossed it in our Harrop car. Until this point, we couldn't even run full e85 in this car, because it would starve with a full tank. The NA shop car would starve at 3/4 tank, and it was frustrating as all hell, to have to bring 60+ gallons of fuel, to every track day.

Car Setup:
Stock Motor
Harrop SC 95mm Pulley (estimated 300whp on e85)
Custom Valved Tein Street Flex w/ swift springs
EDFC Active Pro/GPS
Voltex Type 1S Wing
Varis Vented Hood
Delicious Tune/FF/FPS
Deatschwerks 300c/700cc
Velox Fuel Flapper
235/40/18 Maxxis RC1

First Test:
Thunderhill West, 2-Mile, Corner 2 is a long 70+mph left hand turn, it was very easy to replicate fuel starve in this turn. We started the day with a full tank. 3 sessions later and I was getting excited as the car wasn't hitting its fuel cut(delicious fuel pressure sensor was keeping an eye out for dropped pressure). Driver 2 had been in the car all day, so we decided to switch. I tried a couple different lines through turn 2, and as the car approached a quarter tank, the FPS detected a slight dip in pressure and the ECU pulled power. If this car hadn't been running the pressure sensor however, I believe we could have continued accelerating out of that turn without issue. I never like to run the car this low on fuel, but we did, and it worked. At the end of the day, Driver 3 took the car and managed to set a stupid 1:23.xx lap. Driver 2 ended with a 1:25 (first place in SuperMod class) and myself with a 1:27 (first place in Mod class)

Second Test:
Thunderhill West, 2-Mile not much change, other then the 113F ambient temps. The track was not fast, so we spent the day doing as many laps as possible. No hiccups, and we refilled the car at 1/4 tank. The new advantage was, we did not have to bring nearly as much fuel as last time. I think 30 gallons for both cars, and I was refilling the NA car to full, because it did not have the flapper.

Third Test:(before the official product release)
Sonoma Raceway, this is not a track known for causing fuel starve issues in the 86, but if there was going to be an issue, it would be the Carousel. Its a hard, downhill left turn the g's out at the bottom. Purely by accident, running on the blissful ignorance that the car no longer starved, Driver 2 ran the car down to the empty line. Needle buried in the the red. No issues to report. Again, I would NEVER run a car that low on track, especially because of the embarrassment that would ensue from having to get towed for running out of fuel.

Bottom line, this little simple device works, and we will continue testing it at the trouble tracks. Is it a replacement for a surge tank? Absolutely not, and no one would ever claim that. What I love though, is that this fuel flap, took care of an issue that a large majority of 86 Track enthusiasts deal with, and it did so without costing an arm and a leg, and without compromising any safety.

I have to publicly give Eric and Paul a huge thanks for developing this, and allowing me to be involved in the testing!

Also, I apologize for the long post, but I don't get on the forums much anymore, as I am either on track, or actually working on cars in my shop, instead of just talking on car forums...

[VerusEric]

Originally Posted by The Racers Line

So although I had nothing to do with the genius, simple design of this little flapper, myself, and 2 other drivers (in one of my shop cars) did perform the testing.

Drivers:
I'd call myself an advanced novice, I don't have more then maybe 2 years of experience on track, but I do relatively well, and put down respectable lap times. Driver 2 has been drifting and tracking for 5+ years, and knows how to get around a racetrack quite well. Driver 3 is an animal in basically any car you put him in, and currently holds the fastest unoficial 86 lap at Thunderhill West,in this car, with the Velox Fuel Flap installed. He also drove this same car, with our old JRSC, to a Second place in the Continental Sports Car Shootout a few months back. Bottom line, he can drive. A licensed, professional racing driver will be piloting this car in October at the Thunderschleif(5-mile) in October, just to really round out the testing.

Anyways, I did approach Eric with a completely different design for a "fuel system fix", just before he came up with the Flapper! My goal was to keep the complete stock fuel basket, with some add-ons. It likely would have worked, but for the money I estimated it would cost, you'd be half way to a surge tank, and that would still be a better setup in the long run.

This fuel flap, ended up being even better then I imagined. It seemed to simple to work, and I was absolutely skeptical. I know Eric was too, but after some bench testing, he mailed it to me and I tossed it in our Harrop car. Until this point, we couldn't even run full e85 in this car, because it would starve with a full tank. The NA shop car would starve at 3/4 tank, and it was frustrating as all hell, to have to bring 60+ gallons of fuel, to every track day.

Car Setup:
Stock Motor
Harrop SC 95mm Pulley (estimated 300whp on e85)
Custom Valved Tein Street Flex w/ swift springs
EDFC Active Pro/GPS
Voltex Type 1S Wing
Varis Vented Hood
Delicious Tune/FF/FPS
Deatschwerks 300c/700cc
Velox Fuel Flapper
235/40/18 Maxxis RC1

First Test:
Thunderhill West, 2-Mile, Corner 2 is a long 70+mph left hand turn, it was very easy to replicate fuel starve in this turn. We started the day with a full tank. 3 sessions later and I was getting excited as the car wasn't hitting its fuel cut(delicious fuel pressure sensor was keeping an eye out for dropped pressure). Driver 2 had been in the car all day, so we decided to switch. I tried a couple different lines through turn 2, and as the car approached a quarter tank, the FPS detected a slight dip in pressure and the ECU pulled power. If this car hadn't been running the pressure sensor however, I believe we could have continued accelerating out of that turn without issue. I never like to run the car this low on fuel, but we did, and it worked. At the end of the day, Driver 3 took the car and managed to set a stupid 1:23.xx lap. Driver 2 ended with a 1:25 (first place in SuperMod class) and myself with a 1:27 (first place in Mod class)

Second Test:
Thunderhill West, 2-Mile not much change, other then the 113F ambient temps. The track was not fast, so we spent the day doing as many laps as possible. No hiccups, and we refilled the car at 1/4 tank. The new advantage was, we did not have to bring nearly as much fuel as last time. I think 30 gallons for both cars, and I was refilling the NA car to full, because it did not have the flapper.

Third Test:(before the official product release)
Sonoma Raceway, this is not a track known for causing fuel starve issues in the 86, but if there was going to be an issue, it would be the Carousel. Its a hard, downhill left turn the g's out at the bottom. Purely by accident, running on the blissful ignorance that the car no longer starved, Driver 2 ran the car down to the empty line. Needle buried in the the red. No issues to report. Again, I would NEVER run a car that low on track, especially because of the embarrassment that would ensue from having to get towed for running out of fuel.

Bottom line, this little simple device works, and we will continue testing it at the trouble tracks. Is it a replacement for a surge tank? Absolutely not, and no one would ever claim that. What I love though, is that this fuel flap, took care of an issue that a large majority of 86 Track enthusiasts deal with, and it did so without costing an arm and a leg, and without compromising any safety.

I have to publicly give Eric and Paul a huge thanks for developing this, and allowing me to be involved in the testing!

Also, I apologize for the long post, but I don't get on the forums much anymore, as I am either on track, or actually working on cars in my shop, instead of just talking on car forums...

Neal,

We enjoy working with real enthusiasts/owners/community supporters like you .

Thanks,
Eric

[Lunatic]

Originally Posted by Tcoat

@Lunatic if you haven't resolved this yet take a look above ^

Will do.

[Anarki101]

Thanks for all this information, it's awesome to be a part of a community that strives for solutions.

Before buying my BRZ, I was in the market for a 818c; which is also plagued by fuel starvation issues. One of the solutions they use to alleviate it is the use of the Holly Hydramat.

https://www.holley.com/products/fuel_systems/hydramat/

I've never personally used it, but the guys on the factory five forums have had good luck with it.

I wonder if this is something that could be adapted to run on the 86 platform?

[CSG Mike]

Originally Posted by Anarki101

Thanks for all this information, it's awesome to be a part of a community that strives for solutions.

Before buying my BRZ, I was in the market for a 818c; which is also plagued by fuel starvation issues. One of the solutions they use to alleviate it is the use of the Holly Hydramat.

https://www.holley.com/products/fuel_systems/hydramat/

I've never personally used it, but the guys on the factory five forums have had good luck with it.

I wonder if this is something that could be adapted to run on the 86 platform?

It's already in use. It works!