ex-webby

Bob,

Thank you very much for a well informed thread.

Since I am in the market now for a Scooby (and even though I have had a small email convo with you about this, and please forgive me if this has already been covered already in this thread), but based on what you have found out what would you say is reliable for a UK MY05 STi and what would be your percieved output (or have you any actuals for TYPE UK) with your various states of modification?

1)MY 05 STI with re-map otherwise standard
2)MY 05 STI with re-map, high flow cat, after market centre section (is this part of that cat?) and after market back box and uprated panel filter

Regards,
Shaun.

Nathan L

Shaun, forget the Uk STi go the JDM route, you know it makes sense

chris's scooby

No, stick with the uk model or else he'll spend his life looking for a Shell station!

Wonder Wagon

But he's going to re-map it!!

ex-webby

lol

Unfortunately it must be a Type UK

BTW... Bob has given me some info already, but I would think Type UK owners looking at this thread would certainly find the information interesting.

Regards,
Shaun.

ARRON BIRD

Reliable tho Shaun????

Bob Rawle

OK I have a question, was out on Sunday am with someone who was interested in what my exhaust sounded like and how the car felt in the current mod state, small roundabout that I use for checking the 2nd gear pick up and third gear fast change response, eased round (damp) wellied it in 2nd, quick change, wellied it in third and both of us had foreheads against the windscreen, I have the PSi3 oil pressure input coupled to a fuel pressure sensor and the low pressure alarm was flashing indicating fuel surge, now this was not on a curve but in a straight line, fuel light had literally just come on, filled up straight away and put 48 litres in so that meant a good 15 litres still in there based on my 62/63 litres brimmed tank fill. Have had problems with uprated cars using walbro pump pick up filters which are very small but I have the oem filter installed on the end of mine and its rammed to the bottom of the tank to boot. I reckon I need to keep 1/4 tank in to avoid it.

Anyone else found this on a new age Sti ?

bob

911

No, but suffer greatly hill climbing my Sti v3, even on 1/2 full tank especially after a hard brake, 90 left kind of exercise but the cut is more a stutter rather than the face to the screen event (as in fuel-cut/overboost condition)
Takes about 2 to 3 secs to recover.
911

Nathan L

Yes Bob I have, I think I emailed you a while ago about it. Except I have the Prodrive pump.

Never let the car go below 1/4 now.

Nathan L

Bob you have Email.

marklemac

I've not encountered this. Regularly boot it when empty. (MY02 STI) (Prodrive Fuel Pump)

Bob Rawle

Cheers nathan yhm back, seems that there is a bit of an issue with the new age tank then, progressive accelleration doesn't do it but this was a snap change from 7500 in second into third and punch it hard (instant max boost) with the centre diff in auto (damp) so lots of grip from the lsd's. Normally I would have had the diff open and then would have drifted it which never seems to cause this. Tyres bit hard with no spin.
911 I used to get that effect when I had an STi2 wagon on rounda bout exits (ie right then flick left off) and was very similar to what you describe. This was very sharp and came back almost at once. Thought it was boost cut but thats set well up and she peaked at the normal level (1,55 bar) so nothing to do with that.

thanks for the input all

bob

Mark A

iTrader: (1)

Fit a small anti-surge tank. Like this

MRT had one on display for a while. Looked like a large tube of smarties and was hidden behind the boot interior panel.

Mark A

Nathan L

So does the fuel just collect in there before being pumped forwards? I.E. More fuel in reserve, opposed to just in the line.

Or does that also have a pump, like a swirl pot?

911

Mark, did you have Rob's swirl pot?

the pot Rob had on his Sti RA hill climber was from Power Station, it had it's own external pump at high delivery, the stock pump fills the pot and tries to while the tank is 1/3 or (much) less full. It holds about 1 to 1.5 ltres and delivers to the fuel rails located in the engine bay (by where the A/C bulkhead connections are).

This was VERY effective and Rob had a big weight saving from this and no pick-up issues at all during some committed runs on the hills.

Cost was £500 fitted (ish)

911

Mark A

iTrader: (1)

Hi Nathan

No explanation on the MRT site, but looking at it I can't imagine that a pump fits in the space as well. It looks like a fuel reserve. Do you really need a second pump? May be someone could explain why.

Hi Graham

No it was already sold when I went and visited him. At the last sprint I ran with > 1/2 a tank of fuel. I have since collected all the bits for an anti surge tank and plan to use the walbro as a lift pump and have a Bosch MS44 acting as a supply pump. All fitted in the boot. That's when I final find the time to fix all the problems, fit the gearbox,clutch,turbo,headers various other bits and bobs & the new engine, whilst also completing my Diploma in Management Studies and my "special" work project.

Mark A

David_Wallis

Id personally have a lift pump and a decent feed pump..

I use two walbaro's in tank currently.. changing to surge tank and two bosch 044's as well when i pull my finger out.

David

LitchfieldImports

Bob we fit the Spec C fuel assembly which stops the straight line fuel surge, you can get surge from cornering with anything under 1/2 a tank if your really trying

Iain

www.litchfieldimports.co.uk

JohnS

iTrader: (1)

Even standard new age cars suffer from this under the right (wrong ?) circumstances, with around 1/4 - 1/3 of a tank of fuel left in the tank. If you know it's likely to happen, you can drive around the problem by short shifting to 3rd, or only using part throttle in 2nd as you come out of the corner to give the fuel supply a chance to recover.

STi actually make a fuel assembly to combat the problem, as well as an uprated fuel pump. I'll need to look out the links, but I remember the parts were quite expensive.

John

Bob Rawle

Ian tried that and it still will do it, think if I'm really bothered I'll need to spec something up, bear in mind that the car is sticking 375 ft lbs down almost instantly. I have never had a problem cornering even on less than 1/4 as she normally drifts the rear out.

David I've found that the Bosch pumps are as "bad" for reliability as the Walbro's but have you found they deliver better flow into pressure? I know what the specs say but more interested in the reality. Sticking with the devil I know for now but trying to find something else that is as compact.

cheers

bob

carlos_hiraoka

uhmmmmm what about installing two Walbro pumps in parallel ?

Carlos H.

Bob Rawle

Won't help with surge though, the single delivers more than enough fuel at this level. Need a plan.

bob

Pavlo

And to think people (not Bob mind you) scoffed at me at having a swirlpot!

P20SPD

iTrader: (1)

Can you not have 2 walbros in the tank (or even just 1) with some sort of baffled area at the bottom of the filter pickup point(similar to the sump)?

Or just a swirl pot as Paul suggests, although i wouldnt really want one in the boot.

Dont powerstation do a swirl pot and pump combo?

P20SPD

iTrader: (1)

Bob Rawle

That will screw up the oem ecu's fueling strategy which relies on being able to pwm the pump to differing duty levels according to engine load, I really only need to contain fuel under shock accel. loadings. Suppose I could rewire the fuel pump controller to that new pump but it will be a pita to do unless the swirl pot is located at the rear of the car. So thinking is on the lines of refit oem puimp to tank as the lift pump and relocate walbro to buffer tank in boot, rewire walbro to fpc and hard wire oem via a switched relay from ign.

bob

JohnS

iTrader: (1)

I found the part number for the STi swirl pot thing that installs in the fuel tank. It keeps 5 litres of fuel "inside?" for times when there is little fuel in the tank and extreme G forces are encountred resulting in decreased acceleration:

ST420214S000



There's also an uprated/competition fuel pump that you can use with it:

ST420214S010



Translated text reads:

For in presser
The Subaru Technica international corporation sets for in presser "advanced fuel pump (for competition)" the commodity, we sell the Subaru dealer of entire country, via the STI shop.

The advanced fuel pump is the fuel pump which guarantees the fuel flow which is necessary for the output improvement of the engine. Fuel flow 180 L /h (at the time of emission pressure 300kPa), is increasing injection-valve open pressure to 650 kPa. As for part constitution with the fuel pump and set of the filter, exchanging the pump body part of standard fuel pump ASSY, you use.

It is installing possible in domestic rally, concerning the application of various competitions, with competition vehicle rule, but concerning the application of other various competitions, you cannot use with competition vehicle rule because there are times when, at competition vehicle rule or the competition group please verify. In addition this advanced fuel pump the fuel pump for STI make competition which designates the deviation prevention of the fuel as purpose (ST420214S000) is applicable.

Tim W

iTrader: (1)

Hmmm...where can one get ones mitts on that Powerstation Swirl Pot, without any of the other bits they sell it with (already have 'em) and for sane money?

Bob Rawle

John it never holds 5 litres does it, looks too small for that. The 180 pump is "ok" but not as good as the Walbro at 255 litres. Basically most of this stuff is related to Group N car perfomence which falls well short of most modified road cars today.

bob

911

MRT Rally do an 'in tank' baffled pump inlet for running hard on a 1/4 tank similar to the Sti part.
911