GTR Forum banner

41 - 60 of 113 Posts

·
Registered
Joined
·
4,821 Posts
Discussion Starter #41
i think i may go for a swirl pot then... 12kgfm springs, slicks..... = lots of G's

What are the issues of a swirl/surge tank keeping up with flow?! 1 intank pump feeding it, and an external taking from it to the engine.

Heard many people discuss the twin pump external setup using a swirl pot with a single in tank... How does that single keep up with the twins?
 

·
Registered
Joined
·
1,335 Posts
fingers crossed for ya Pete...

as far as I know, swirl pots are basically the fuelling equivalent of oil pan baffles - to prevent fuel starvation under hard G forces. Nothing else really.

My second Apexi pump arrived today - sealed in oil and vacuum packed. Didn't know fuel pumps came like that. My Sard RJ fuel pressure regulator arrived - the size of it is huge compared to the Nismo FPR - maybe 3 times times the diameter? My fuel lines and fuel rail have yet to arrive though.

Pete, when you added your fuel lines, did you just add rubber lines under the car? -6AN, or what size?
I used braided lines throughout the car - top quality ptfe braided stuff (to prevent smell of fuel), i think it was twin 6AN lines for the feed to each end of the rail and then the std (feed and return) lines combined to make 1 big return line...
 

·
Registered
Joined
·
8,804 Posts
Pete - this just occurred to me. Have you ever tried running the car with the vacuum line detached? With it detached, fuel pressure should be locked in exactly where you set it. Any fluctuations would then be due to a flow or fpr issue. just a way to definitively eliminate vacuum problems as a source.

But the double pump fixed everything, right? Please tell me yes....
 

·
Registered
Joined
·
1,335 Posts
EVEN BETTER :flame:

It turned out to be the SARD Fuel press regulator - i had the lower rated one and needed a bigger item ! :bowdown1:

I have now had an SX fuel press reg fitted and the pressure hold perfectly with no dips whatsoever :) did a few full acceleration runs and one full power run on the dyno held at top revs for 50-60 seconds and it stayed perfectly where it should be :clap: :clap:

So.... i can confirm that for 600bhp at the fly on an r32 GTR the following setup definatly works:

1 x tomei 280ltr/hr pump
1 x tomei aftermarket fuel rail (fed at each end by 6AN braided line)
The std feed and return lines combined into 1 large return feed
SX Fuel pressure regulator (high bhp spec)
I also wired the pump directly to the battery with a relay to turn on and off.

Hope this helps you all ;)

Pete
 

·
Registered
Joined
·
193 Posts
Excellent news Pete :cool:

I'd just heard from Matt that they'd sorted your fuelling issues. SX regs are the norm for high power Impreza tuning, I use one on my Impreza, as they are good to at least 6 bar pressure so you can run high base pressure and still plenty of boost. They're pretty keenly priced too if you know where to get them from ;)
 

·
Registered
Joined
·
1,883 Posts
I have 680cc injectors, 255l valbro fuel pump, stock rail, stock lines, adjustable fpr.... last week my car made 450hp and 550nm at the wheels before i got a knock in the bottom end.

And we did only adjust the fuelmap, with safe ignitionmap... we did se about 60% duty cycle on the injectors....
And it was only 1.6bar on a Turbonetics Super60-5 turbo.

As soon as i get the bottom built up, we will run about 2bar boost, and do the ignmap, and i will se another 50-70 hp and nm of torque at the wheels.

Asim....
 

·
Registered
Joined
·
8,804 Posts
god, who'd a thunk it? my Sard FPR has arrived but still waiting on the other bits. I have my second pump, I think I'll put it in anyways - if one fails, the other will be enough to carry the car through. After all, I did lose an entire engine to a fuel pump failure.
 

·
Registered
Joined
·
4,821 Posts
Discussion Starter #53
some more Q's on the subject....

will a std r32 GTR intank pump be able to keep the surge tank (feeding twin 910's) full?

Twin entry rail - how does that work with pressure reg's?

I currently have a Tomei FPR - does anyone know what its limitations are? Will it have the same probs as plkettle/kismet's?

I'm going to run twin 8mm lines from the pumps to the rail, and a single 10m return.

plkettle - do you have pics of your hoses? Have you just run them in the std position for return/send lines?
Kismet - did you end up using the HICAS line for a return?
 

·
Registered
Joined
·
8,804 Posts
I imagine a std fuel pump could keep a surge tank full, but I'd worry about the age of the pump.

I've realized that fueling is a combination of having a good FPR, but most importantly, proper fuel lines and no restrictions. The stock send pipe just doesn't cut it at this power level. I found my HICAS lines but haven't quite figured out how I want to take over using them. So for simplicity's sake, I'm waiting on twin braided -6AN lines as feed lines (one per pump), and then split the return on the stock fuel pipes (as plkettle has done).

Pete, how'd you do your fuel filter? I have a pair of Z32 filters (which are huge), and I'm thinking of putting them inline at the beginning of the send towards the front (basically, the filters will be next to the fuel tank in that space where the fuel lines go down from the top of the fuel tank to the bottom of the floorpan).
 

·
Registered
Joined
·
8,804 Posts
the FPR is after the fuel rail, and there's only one exit from it, which is -6AN sized. The output from the FPR is also a single -6AN line, so dumping it into a HICAS pipe would be fine, but using a splitter block and going into the stock fuel pipes is also fine because the return really isn't under pressure (the FPR is the biggest restriction in the whole circuit).
 

·
Registered
Joined
·
1,335 Posts
i dont have any pics of the hoses but the lines follow the stock ones...

the FPR sits on the return line that is coming out from the middle of the rail (6AN fitting) and the rail is fed at each end by the 2 feed lines.

you can use 2 new braided 6AN size lines for the feeds and then combine the origional send and return line to make 1 large return feed.

I use 2 inline high flow fuel filters on the feed lines

I dont know what flow rates the tomei FPR can do so just try it and see if it can cope at full flow, its definatly worth buying a fuel pressure guage mounted permanently in the car tho to know what the fuellling is doing ;)
 

·
Registered
Joined
·
4,821 Posts
Discussion Starter #59
righto... UPDATE.

Got all the fueling sorted out in the car, mapped. It seems to be getting held back at about 500bhp, more boost just isnt doing much bar more torque. Power is still rising till redline too.

Fueling:

Tomei 280lph in tank pump
Twin Bosch 910's from Swirl pot
twin -6 feeds, single -6 return
Tomei twin entry fuel rail
HKS pressure reg
SARD 800cc twinholes

I dont think the fueling side is the concern... but the injectors are running at 80% duty with 480bhp (fly) at 1.6bar. Fuel pressure isnt cranked up though, but its not showing any problems with fuel.

Turbos - Garret GT2860-5's

Exhaust - XS power downpipes, Fujitsubo giken system

Cams - standard, but dont think this is the issue as have seen other results with standard cams.

What are peoples general experiences with bottle necks in making power?

The FMIC is standard, the turbo elbows are standard, and the filter pods are past their past. I need to know what to address first...
 

·
Registered
Joined
·
1,335 Posts
What AFM's are you running and are they maxxed out ?

check the intake temp readings from the power FC on full boost runs this will tell you if a new intercooler is required as the intake temp might be too hot resulting in a drop in power (but prob not 100hp)

cams would obviously help quite a lot but also mapping could be the issue if the timing is out...

basically you should be looking at around 600hp at 1.6 bar
 
41 - 60 of 113 Posts
Top