fiestaturbo.com

[stu@mdevelopments]

FAO Stu,

Im having grief with some tuners over my cars management at the moment, OFAC. Infact Karl at NMS didnt want to touch it as he finds OFAC/OFAB to temperamental and frustrating. Is this something you would agree with?

I have also been warned away from pushing it much further than a chip and tune up as they dont respond well to the larger injectors and still underfuel at the top end. Again would you agree with this, especially given the spec I listed above?

If not, how much would you charge to carryout the fitting of some 701's, reflashing a chip to next phase and supplying and fitting a bigger I/C? As this is somthing i am considering having done in the new year and want to start budgetting for it I am happy to travel the distance from Newbury, Berks to have to it all set up properly by yourself

Has anyone else found this when enquiring about work at tuners, as i always believed the fiesta rst engine was one of the most tunable

I dont want to get involved in "He said / She Said", so this is my professional view of the situation.

OFAB / OFAC is a very complex management based largely on an american base that most UK mappers are totally unaware of and find it most frustrating to get it to work correctly. Most uk chips even bring up a ROM Failure/Error when plugged in.

Worked correctly, both the standard and the 701s can be made to fuel perfectly well, with plenty of fuel on boost, if that wasnt the case, we wouldnt sell them. Ask around and see if you can fine any of mine (Evolution Chips) that have been damaged due to insufficient fuel? Its simply not the case as long as its done and monitored properly, which sadly, many tuners are not equipped to do.

What is problematic commonly is:

1) The standard fuel pump HATES excess pressure. Up the boost / fuel pressure more than i reccomend and expect a dead engine for your tinkering.

2) The OFAC system is mapped with a dead fuel map at around 17psi. I have yet to find a tuner that knows how to solve this, other than ourselves. You will commonly hear tuners tell you the OFAC system is crap. In fact, technically a little better, they just dont understand it.

3) People insist on adding 3 bar map sensors onto OFAB systems with a 2bar based chip. Say Goodnight to your Pistons as soon as you shift to 5th gear.

4) Cooling. The Fiesta bay is AWFULL for keeping things cool, especially with a big I/cooler up front. Sort it before asking for power or i simply WONT let you have any as an overheating engine on power, is a piston nipping gasket destroying engine.

5) DIY conversions from 1AFA etc bases. These are usually brought to me with totally bolloxed up wiring. Sort it out properly eh? It will never work with the map sensor input wired to the CO adjuster.

As for big injectors, we do conversions with OFAB & C up to around 380bhp. They will all return virtually factory fuel economy and will all be perfectly safe on boost as hard as you like. From that power upwards we recommend aftermarket management.

I dont really wish to discuss prices on here as im not here to tout for work, i do it as i enjoy the forums as most of you will know, i spend most my spare time on PF. If you need to know anything about cost, either ask on here or feel free to E-Mail me.

Hope this answer helped.

[stu@mdevelopments]

Whilst browsing i come across a perfect example:
http://www.fiestaturbo.com/phpBB/viewtopic.php?t=115408

No offence to the chap intended at all, hes just unlucky i spotted it there tonight, but what makes people think you can do this?

[OrionRst]

A great response Stu, much appreciated

[Jur]

@ Stu

I have myself a FSE PBV fitted.. with the fuel pressure turned up a little (1/4 of a turn) Other specs are further up this topic..

just a question in common about the pro's and cons of turning up the fuel pressure.

I intended it to have some extra fueling on boost preventing pinking. (More pressure, same injection time = more fuel)
But you wrote down it could damage the engine.. can you tell us some more about this ?

thanx

[stu@mdevelopments]

I intended it to have some extra fueling on boost preventing pinking. (More pressure, same injection time = more fuel)
But you wrote down it could damage the engine.. can you tell us some more about this ?

thanx

There are 4 main problems with excess fuel pressure.

1) The fuel pressure increase will increase the fuelling GLOBALLY.
This means that where she was once fine, she is now too rich. This is not ideal, although its better to be safe on boost than economical off, unless you can get the best of both with a decent map.

2) What many people dont realise is your fuel pressure regulator is a 1:1 rising rate type. This means that for every 1psi of boost you have, you get 1psi of fuel pressure to offset the pressure differential at the injector nozzle. When you raise the fuel pressure AND teh boost you make the pumps job harder. Example: If you set the pressure on your FRST rail to 3.5bar with pipe the pipe off you are running around 3bar at idle, and 3.25bar while cruising. However, once at a bar of boost you are at 4.5bar pressure. At 1.5bar boost you are at 5bar. Now think of that 5 bar in real terms Thats 73psi. Do you know how much pressure that is? This is why the seals, on the standard pump just start to leak and starve the engine and fuel lines start to leak under the car. Now what happens if someone tweaked the pressure another bar to start with? 6bar? Do you think the pump can deal with this? Can the injectors even open the nozzle with this pressure behind them? Will they open SLOWER? Think about all that.

3) As mentioned briefly above. The standard pump is notorious for blowing its seals out at 4.5bar fuel pressure or sometimes less. No more needs to be said on that subject i expect, other than, ive seen engines with 13psi run fine, till the owner gave it "Just 1/2 a turn for safety" and blew the seals in 5th. £3K damage to his motor.. expensive lesson learnt. Lucky he admitted it to me, or he would have LEARNT NOTHING. LOL

4) Fuel pump rating.. a pump is rated to flow x amount of fuel at x amount pressure. As the pressure goes up, the FLOW goes down. So, as the boost goes up, the flow goes down, are you followuing this at the back? More boost = less fuel FLOW potential. So does MORE PRESSURE

4) Wiring. I keep going on about this pump dont i? LOL
An average pump at say 5bar line pressure will draw for arguments sake, 8amps. Now 6 bar, while flowing less fuel, will draw about 10/11 amps. Can your 13yr old wiring supply that? Or will it starve the pump of ciurrent and... yes... you guessed it.... FLOW EVEN LESS THAN IT DID BEFORE YOU MESSED WITH IT

Hope that helps and im not boring you folks...

[Jur]

totally clear to me (-:

Thanx (-:

[Jur]

totally clear to me (-:

Thanx (-:

[stu@mdevelopments]

[DaveRom]

Great posts Stu.

I now have the seeds of doubt planted into my head about my fuel lines. Along with the wiring they are the oldest thing on the car. I'm a little worried about em as i don't fancy turning into a Nikki Lauder style fireball when booting my car.

Are they something you can replace if needs be?

I only ask as shortly i'll be buying a 195 chip off you anyway and giving you the job of setting it up. Just thought while its there why not. IMO they don't look great and i don't particularly want to mess with that side of things.

Thanks

Dave

[JamieFRST]

Very interesting read Stu, you should post more often

[RS_Rawli]

note to self, take car to stu before driving

[stu@mdevelopments]

Great posts Stu.

I now have the seeds of doubt planted into my head about my fuel lines. Along with the wiring they are the oldest thing on the car. I'm a little worried about em as i don't fancy turning into a Nikki Lauder style fireball when booting my car.

Are they something you can replace if needs be?

I only ask as shortly i'll be buying a 195 chip off you anyway and giving you the job of setting it up. Just thought while its there why not. IMO they don't look great and i don't particularly want to mess with that side of things.

Thanks

Dave

Sorry its been ages, i dont get notifications from here, dont know why but im SURE BT are to blame

We are not geered up for the replacement of fuel lines front to back in all honesty so if you are really worried, id advise you have a local garage with a ramp change them. However, if there are no visible flattened areas and no major corrosion, i wouldnt worry too much. If there IS a problem i will spot it on my fuel analyzer within 1mile of leaving the building.

As for posting more often, ive always enjoyed it over here, its a great site, i just dont remember to visit as often as i should due to running PF and starting to hate forums in general. lol