I've adjusted my fpr which now I completely regret,

I thought I could tweak a bit more power out of my car but instead has made it worst, I have now connected the gauge up to my sard fpr and adjusted it to 3 bar ideal pressure with no boost hose attached.

The car just isn't as aggressive so bit by bit I've tuned the pressure down, I am at 2 bar currently and the car feels a lot better but still judders under heavy boost which I don't know if it's the fuel pump pulse or not enough pressure being retained.

I've spoken to the previouse owner (John) who is a wonderful bloke and has tried to help me, basically he has said the car runs at 1.8 bar boost and the fuel pumps limit is 5 bar so at iddel you want about 2.5 bar and at 0% vacuum it should be 3 bar, I've tried this but the car runs slow and sluggish.

Is my fpr f@cked or the fuel pump ?

The spec is as follows

447 BHP

Closed deck block
New under piston oil squirters
Wiseco 92.5mm forged pistons
Manley forged H beam rods
STI V3 heads polished and ported
3 angle valve seats
Supertach valve stem oil seals
Brand new API supplied genuine subaru V4 STi crankshaft
ARP head bolts and rod bolts
Cometic 1.3mm head gaskets
ACL race spec big end and main bearings
RCM modified oil pump
740cc injectors
Parallel fuel rail conversion using stainless steel braided hoses
Sard FPR
Forge dump valve
MD321T turbo with custom 3" intake and air filter
RCM headers, heat wrapped
Harveys special up-pipe, heat wrapped
HKS 3" bell mouthed decat downpipe
HKS silent hi power 3" exhaust system and backbox
Autobahn88 FMIC with custom candy red pipework
Magnecor 8.5mm HT Leads
Mocom Racing oil catch can
Underdrive pulleys
Blue autobahn 88 silicone hose kit (coolant)
PPG straight cut gearbox in a P1 housing with kazz plated front diff
Exedy API clutch and API lightened flywheel
P1 rear diff and drive shafts
Redline shock proof gear oil
whiteline drop links
pink powder coated anti roll bar
cusco front H brace
STI carbon fibre strut brace
Hard race uprated engine mounts and transmission mounts including the dog bone gearbox mount
MAC 3 port boost solenoid
NGK PFR7B with gap down to .65mm
Silkolene Pro S 10w50 oil
Bilstein prodrive suspension.
Rota torque alloys with TOYO T1R tyres.
Autronic SM4 ecu with antilag (off) and launch control (on) (removes the MAF)
Car mapped by B Rawle
D2 8 piston braked calipers and 330mm discs
STI V6 carbon fibre rear spoiler
PIAA wipers
STi ally bonnet (much lighter than uk steel version)
Jap spec water bottle
RCM carbon bonnet vent
Guages & pod - boost, water, oil

 

Get someone who knows what they are doing to set it up for you, 1 lean run will be enough to cost you an engine rebuild

 

+1

 

Without meaning to be rude, you have no idea what you're doing, and if you keep doing what you're doing, you're going to BLOW YOUR ENGINE UP !!!!

I would expect your fuel pressure to be set to 3bar with the vacuum hose off as a MINIMUM.

STOP driving it, speak to whoever mapped it, and find out what pressure it was running before you started messing around with it, and set it back to that.

 

Oops. Leaning it out had probably made it faster, if not too much to cause misfires and hesitation. But it would have been mapped over rich than that required for maximum power in order to help the engine last more than 5 seconds at full load. There are no gains to be made from adjusting the fuel pressure without sacrificing any safety margin that was mapped in. A lower pressure would risk damaging the engine fairly quick and higher pressure will reduce HP even further.

You should find that the fuel pressure should increase in line with the boost pressure, and (if it was set up as normally would be) will go from 3bar to 4.8 bar when the boost goes from 0 to 1.8bar. Generally this would lead to a fuel pressure of about 2.5 bar at idle with the hose attached. 2bar is almost certainly not enough and I would turn it up until you get it checked out by someone who can check the car with a wideband lambda

 

Ok thanks for your help, I think bob Rawls mapped it originally so I'll contact him, am unemployed at the mo so money is tight but don't want to brake my pride and joy,

 

You don't need Bob, any local who can monitor the AFR can restore the correct fuel pressure.

dunx

 

Did you not make a note as to what it was before you started playing with it? As above you must not play with the FPR pressure once it has been mapped. You might think it feels a bit quicker, which it probably might be, (leaner to a point makes more power), but road cars are mapped at a safe level of richness to withstand a lot of use and minimal wear and tear. Leaning this out will start the count-down to early failure due to heat and potentially detonation.

Problem is now it will probably need setting up again, which I wouldn't blame Bob for charging something for as it's not just a quick 5 minute setup, but the good news is it isn't as long as a mapping session either!

Graham

 

I've spoken to bob and we are trying to arrange a day to sort it, thank you for all your advice, I didn't note the pressure before as it didn't have the gauge attached, my own stupid fault,

I wouldn't expect bob to work for free, that's madness, ��

Oh and great work graham with ur test mule, brilliant thread.

 

Where are you located?

Maybe worth ask Rich@FB tuning about this and maybe help you too


Jura

 

Am in dagenham but it's fine I'll sort it with bob, his price is very reasonable, thank you tho,

 

Near to you is Neil@Slowboy racing which will able to help and he have very good prices too.

http://www.slowboy-racing.co.uk/inde...d=2&Itemid=120


Jura