has anybody fitted one of these fse power boost valve things? im trying to overcome my cars tendency to run lean with all my mods, so will this do the trick? or are they are total waste of time? anyone had any good/ bad experiences with these things in any capacity?

also, how much of a pain are they to fit?

thanks,
matt.

 

Dunno bout FSE, but there is often talk of uprated fuel pumps around these parts.

 

Stick the word pump into Search and you will be spoilt for choice

 

funny, i was just reading about a chap that had put a newer bigger pump on from mark at lateral performance. doesnt a bigger pump mean i have to get an ecu remap though? are all ecu's able to be adjusted or will i have to buy a new ecu before i can run a bigger pump? also, will this mean new regulators injectors and assorted other sundries? plus i assume ill be p*ssing away optimax at an even more alarming rate?

matt.

 

matt,
i have been told to steer away from the fse boost valve on the imprezza as it may cause detonation of the engine.
it was designed for the pug 205 and worked very well on them.

i would do a fair bit of reserch about it before you go ahead and fit one.

 

just done a search, and long story short your right. certainly seems like the general consensus is that theyre at best a detrimental mod, and at worst a way of making my precious car go boom.

so, should i be exploring the likes of a bigger fuel pump? will this help me increase my fule air ratio? can somebody give me some facts about ecu reprog'ing?

thanks for all the advice.

matt.

 

There seems to be some confusion here.

I'm not a fan of rising rate reg's, but they have their place.

The first thing that you MUST do, is replace the fuel pump if you want to run higher boost. The pumps have been proven to be marginal at being able to produce the fuel pressure required.

An up rated fuel pump should't cause a problem with the stock ECU. It's closed loop lambda control should be more than capable of dealing with any increases. Cars running just stock boost, mat find they run richer at the top end, but then stock cars are unlikely to need an up rated pump.

Now, the main reason for increasing fuel pressure, is because the injectors being used are really too small to safely supply enough fuel for the power. So you have a choice. Either fit larger injectors, or, increase the fuel pressure, will allow the current injectors to flow more fuel.

If this is being done with a re-mappable ECU, it's far easier to map when things are linear, and the "shape" of the map remains the same.

A rising rate reg' will bias fuel towards the top end, where it's really needed, where you don't have the luxury of mapping it correctly.

If you increase fuel pressure, you are asking the pump to work harder, and we already know the stock pump struggles to do this.

Now, if you run a standard type fuel reg', set at 3bar at atmospheric, and run 1.3bar of boost, the pump has to be able to sustain 4.3bar of fuel pressure (3bar set + boost) at full boost.

If you use a rising rate reg (1.7:1) and run the same 3bar at atmospheric, and 1.3bar of boost, I believe you could be running as high as 5.1bar fuel pressure (it's not something I've tested).

This is where people fall foul. No fuel reg', in it self, is going to cause "DET".

Mark.

 

thanks mark, thats a big help. ive just looked at the ecu and its a PROVA super type that one of the other blokes on here has just said he runs with mega boost etc. so, with an aftermarket ecu, is an uprated fuel pump (which id want to get from you on strong recommendation) going to be as effective as on the stock ecu? long story short, im happy to run higher boost induction mods etc, but i dont want to go bang, and since putting on the blitz filter the afr has been green and occasionally yellow a lot more than before, so i want to be safe rather than sorry, and have the capacity to up the power again after the new clutch goes in. i do tons of miles a week now, so if an upped fuel pump is gonna do the trick then thats great. whaddya reckon mate? also, how hard is it to fit, and how much do they cost?

thanks for all your help all of ya.

matt.

 

Matt, the fuel pump is easy to fit mate..took about half an hour to change..
What AFR gauge are you using?? yellow aint so good when on full boost.. afaik yellow on most gauges means stoich... personally i would definately only want to be seeing greens on boost...
Rob

 

using a dawes afr, and i know what you mean about the yellow, though i have to say, its only just flicking to it occasionally, and as soon as i see it i back off. so what fuel pump do you rate?

glad its a quik fit though. makes a nice change!!!

matt.

 

just so i know ive got this right (im not the sharpest tool in the box) if i uprate the fuel pump, the yellow light syndrome will go away yeah?

matt.

 

My first concern would be a Japanese market ECU, is more than likely mapped on a higher octane fuel, so I'd recommend getting someone to check it out with det' cans, if you don't have a Lambda Link.

Personally, I'd be running it with octane booster.

The only sure way to know if your fuel pump is coping, is to get the fuel pressure checked.

Running rich is no guaranty that the pump is working correctly, or your injectors aren't running very high IDC's.

Mark.

 

hi mark,

sorry to be a pain in the ***, but what are high idc's? BTW i am running on octane booster and optimax already so im being as careful about the fuel as i can, as i am aware that im probably mapped for high ron fuel. the thing is, all the garages at my disposal that will even look at a car like mine are big bucks to do anything, or i will have to travel 200 miles to go someone more specialised, so it might well be that its cheaper in the long run just to source a shiny new badass pump, from someone like yourself (if memory serves, the thread i read recently quoted about 120 quid). as i understand it this would do the trick, and then i would have plenty of fueling accross the range, rather than waste a hundred or so notes just to find out that, inevitably, i need to increase fueling across the range. i understand what youre saying about doing some form of diagnostic first, but this is really about prevention rather than cure, and if my memeory is okay, this seems like an affordable way to do it, seems diagnostics are gonna be as, if not more expensive.

thanks again for your help, sorry to go on.
matt.

 

idc is injector duty cycle.

anything over 85% means the injector is working too hard.

As mark says, if you need to supply more fuel, you eother fit larger injectors or increase fuel pressure to allow the IDC to be lower.

 

thanks adam. im going to call mark in the morning and order a pump just to be on the safe side. from what ive read doing a search it certainly cant hurt, and at best will make a really nice difference, and with luck will provide ample fuel for me to up the boost a little further safely. going to get a knock link thing too. it never ends does it?

thanks again mate.
matt.

 

Matt,

I guess Mark will explain when you talk to him, but the uprated pump will just ensure you're getting as much fuel as the ecu's map asks for.

Regardless though the map is expecting you to be running higher ron fuel and you may still have problems. I recommend the knocklink as a priority, as well as getting someone to listen to your engine with det cans to confirm all is OK. Once you *know* you have a stable environment, you can begin pushing things in 'relative' safety

Richard