V7 STI Fuel Surge

[TNHSTI]

Hi guys - I'm guessing most people who own a WRX/STI have come across the fuel starve/surge issue when hard cornering on right hand turns, well it has been annoying me and I want to do something about it.

 

after doing some research i came across this http://www.ludicrous-speed.com/wiki/index.php?title=Shanes_impreza_fuel_slosh_mod

I tried it but didn't seem to work still getting the same problem, can anyone recommend a fix or state what they have done?

 

Only other option is to buy the Spec C/S204 pump here - but obviously - an expensive option! https://www.japanparts.com/parts/detail/2209

[hunter951]

yip my first v7 sti would surge when under 1/4 tank after i put a dw200 fuel pump in. I used the fuel filter that dw supplied.... removed that and replaced with the factory one and the issue dissapered.

 

are you using the factory pump? what condition is the filter in? the dw one i had was very sloppy where in joined to the pump, i am assuming when i cornered hard the fuel would be held in the sock but the pressure would suck air through the connection... hence surge

[loner]

For a road car there is only one solution... an external fuel pump and swirl pot. @GC8E2DDhas a really nice bit of kit for that.

 

It's either that or never let your tank go below 1/2 full.

 

 

Edited October 25, 2016 by loner

[TNHSTI]

Very interesting thanks yes - my pump is completely stock - I thought that the factory sock was pretty small? - what pump and filter would you recommend?

[hunter951]

Just now, V7STI1992 said:

Very interesting thanks yes - my pump is completely stock - I thought that the factory sock was pretty small? - what pump and filter would you recommend?

if i can remember correctly some of the aftermarket ones are smaller? my tuner recommends DW over the others. Just use your old fuel filter sock or get a new replacement one. 

 

3 minutes ago, loner said:

For a road car there is only one solution... an external fuel pump and swirl pot.

 

It's either that or never let your tank go below 1/2 full.

 

 

I personally think a surge tank on a road car is over kill... and so is keeping it above 1/2 tank. I know someonerunning big power, 1000cc injectors with factory fuel setup and just a drop in fuel pump with no issues... 

[loner]

3 minutes ago, hunter951 said:

I personally think a surge tank on a road car is over kill... and so is keeping it above 1/2 tank. I know someonerunning big power, 1000cc injectors with factory fuel setup and just a drop in fuel pump with no issues... 

 

The stock system should be good enough, but if he has the right sock and is still getting surge, then he must be driving it pretty hard... in which case he needs to keep the tank full or get an external setup... or stop driving so hard on the road and do some motorsport.

Edited October 25, 2016 by loner

[TNHSTI]

nope not driving it hard at all its a known issue - do some research and you will see 

[hunter951]

9 minutes ago, loner said:

 

The stock system should be good enough, but if he has the right sock and is still getting surge, then he must be driving it pretty hard... in which case he needs to keep the tank full or get an external setup... or stop driving so hard on the road and do some motorsport.

 driving hard or not the factory system should be fine cornering. my v7 has never had a problem since i used the factory sock... and the injectors are maxed. If the fuel pump and sock is fine it must be something else, fuel reg etc... a external setup would be the last thing id look into.... unless your pushing 350+ hp 

Edited October 25, 2016 by hunter951

[GC8E2DD]

The factory system just isn't fine for hard right hand cornering when low on fuel. We have too many real world motorsport experiences to believe otherwise.

[loner]

10 minutes ago, hunter951 said:

 driving hard or not the factory system should be fine cornering. my v7 has never had a problem since i used the factory sock... and the injectors are maxed. If the fuel pump and sock is fine it must be something else, fuel reg etc... a external setup would be the last thing id look into.... unless your pushing 350+ hp 

 

Fuel surge when cornering can not be the regulator or even the pump... they are not affected by lateral g forces. Fuel surge is air being sucked by the pump because there is no fuel around the pickup.

[TNHSTI]

2 minutes ago, loner said:

 

Fuel surge when cornering can not be the regulator or even the pump... they are not affected by lateral g forces. Fuel surge is air being sucked by the pump because there is no fuel around the pickup.

 

exactly what i thought

[loner]

16 minutes ago, V7STI1992 said:

nope not driving it hard at all its a known issue - do some research and you will see 

 

So your first post when you say that you have surge when hard cornering means what exactly?

[Andy_Mac]

Surely there's something like this but cheaper for that age STI

 

http://www.radiumauto.com/Fuel-Pump-Hanger-Subaru-P706.aspx

[TNHSTI]

7 minutes ago, loner said:

 

So your first post when you say that you have surge when hard cornering means what exactly?

 

Okay so not grannying around - taking a roundabout at normal speed and pinning it on exit - but this only happens on right hand turns

[pl0x]

I have one of the below and car seems fine until 1/8 of a tank. Was surging below 1/3 on road prior. Koom made these a few years ago but believe I got the last one.

[loner]

Just now, V7STI1992 said:

 

Okay so not grannying around - taking a roundabout at normal speed and pinning it on exit - but this only happens on right hand turns

 

I'm betting you have the wrong sock on the pump... the stock sock is pretty big and has an extension on it bent down so the sock sits right into the fuel tank.

Check it and then come back and update us.

[TNHSTI]

Sweet, you sound about right mate - it does seem very small - I will pull it out and post a pic and update you guys

[TNHSTI]

OK so the Fuel pump and sock are stock, I cant work it out, i can do everything to make it surge on a Left hander but not right handers and this is happening on anything less than half a tank, of course if I drive through a right hander without pinning it i dont get surge - but that's no fun on a windy gorge lol - I'm thinking I may just have to get one of these? http://www.ebay.com/itm/GENUINE-Subaru-Impreza-GDB-Spec-C-Anti-Surge-Fuel-Pump-STI-S202-S203-S204-RA-R-/142125555516?hash=item211757df3c:g:JZsAAOSwPCVX-WAs&vxp=mtr

 

The car is stock except the following

 

turboback exhaust

Tuned to 200kw

HKS BOV

 

And don't anyone tell me its the tune causing it cos it was doing the same before the tune as well

[SpeedySub]

11 minutes ago, V7STI1992 said:

I'm thinking I may just have to get one of these? http://www.ebay.com/itm/GENUINE-Subaru-Impreza-GDB-Spec-C-Anti-Surge-Fuel-Pump-STI-S202-S203-S204-RA-R-/142125555516?hash=item211757df3c:g:JZsAAOSwPCVX-WAs&vxp=mtr

 

Holy smokes thats expensive!

[TNHSTI]

Yep - slightly cheaper here  https://www.japanparts.com/parts/detail/2209

[Dairusire]

10 minutes ago, V7STI1992 said:

Yep - slightly cheaper here  https://www.japanparts.com/parts/detail/2209

 

it's about half the price.

[PBMS]

Hi guys, the GP N rally cars we build that are based of a Spec C have have little issue with fuel surge, so those pickup units are a good (albeit expensive option). The Radium pickup's look like really good quality. I believe JTune are the NZ distributor of them. 

For the money, I think it'd be cheapest to knock up a hand fabricated enclosure like pl0x has posted.

 

[loner]

Or use a plastic fuel tank around the pick up... I made one years ago from one of these. https://www.rchobbies.co.nz/results.html?q=fuel+tank 

Edited October 31, 2016 by loner

[TNHSTI]

6 minutes ago, loner said:

Or use a plastic fuel tank around the pick up... I made one years ago from one of these. https://www.rchobbies.co.nz/results.html?q=fuel+tank 

 

did it work for you?

[Dairusire]

5 minutes ago, V7STI1992 said:

 

did it work for you?

 

tbh I'd expect that to work better than the metal ones.