rite been looking at running the frst management i have but it seems a big hassle to get it all working.

so what are the limits of the mfi system, i understand it cant fuel beyond 190-200bhp?

so other than fith injectors (not a fan) or cosworth management (which id love to do but the overdraft is only so big) is there no way round this? no bigger injectors available of some sort?

sorry for sounding daft but ive never had escort turbo stuff ive always had frst's and its just a 195 chip and beiges with that

 

Mine made over 200bhp with little in the way of fueling mods. Added a fith injector and some extra psi and it made 248bhp. I was going to chuck my KE-Jetronic in the skip and fit Webber Marreli kit but the 5th injector was a fraction of the cost and has achieved excellent results

 

I can do a little with the std mfi.

 

Plenty of MFi RST running about perfectly happy with well over 200bhp.... Mark @ MAD does a fuel mod to the metering unit that helps with the fueling, also your 5th injector can also work as Oronoco pointed out.....

AFAIK it's not the bhp level that maxes the MFi system out it's how much boost you are running....

ie: I know a guy with a 1900cvh on MFi and only running 10 or 12psi thats 240ish bhp - the MFi can cope easily with that - but try and give it 20psi on your 1600cvh to get similar power then it's gonna struggle......

As said above - Karl knows his shit - give him a bell

 

Thrush,

No its not the boost its the BHP that determines when the MFI can't cope!!! LOL

 

"And the award for understaement of the year, ladies and gentlemen, goes to........................


Kaaaaaarrrrllllll Norriiiiiiiiiisssssssssssss"

 

Ours ran 260bhp on MFI and without a 5th Injector.

 

Karl - how so? how can it be that MFi can handle 260bhp without 5th injector as C+B said, but struggles if you ask it to do 20psi on a 1.6 that will only make about 240bhp???????? Surely then it should handle the 20psi 240bhp easy and struggle with C+B's 260bhp????

 

Thrush,

I assure you it is bhp dependant and nothing to do with the engine spec. The absolute maximum I can get without a 5th injector is 280bhp but at this the fueling will be leaning at the top end. (As demonstrated on DanS car at recent RR shootout)

The most I can reliably get without leaning at the top end is around 240bhp.

The top end leaning is as a result of the MFI system being unable to detect any further increase in air flow at higher rpms. This is why we then add a 5th injector to take power levels up to and sometimes beyond 300bhp.

 

That was at 2 bar BTW.

 

You could always do the Fumes Mod........

(I am only playing by the way......Ignore that comment)

 

Christian, you can indeed add pressure to the FPR to increase the fuel pressure but as I've always said, it is not a solution to the problem, as the fueling will still lean at high rpm's. This is why we then add a 5th injector.

If I recall your engine was'nt a 7000rpm screamer and thus would have got by with this mod.

 

Indeedy, it had a standard Rev Limit whilst on MFI.

I agree with the use of a 5th Injector on MFI RST's to allow more sensible fuelling across the range.

 

Karl - fair enough dude - you know your shit more than me

I jsut thought that cos BHP and boost levels don't always go hand in hand then it would be the PSI that governs the MFi's capability rather than BHP.....

But fair enough

 

Thrush, you're getting confused mate.

Boost pressure means nothing. Its the mass air flow that governs how much fuel we need.

BHP is determined though mass air flow and thus this is why the fueling is BHP dependant, and nothing whatsoever to do with boost levels or engine capacity.

 

Ahhhhhhhhhhhhhhh....... Think I got ya now Karl

 

So, with my car spec (see siggy) what can ya do with it, power wise then fella? Granted I need to change intercooler before I run more than the current 12psi, but what we talking?

 

If it helps picture this scenario.

Typical high spec cossie engine with greys and T34. At 30psi may make 400bhp and is well within the max flow rate of greys.

Fit a T4 to the same engine at the same 30psi and the engine will melt down because the mass air flow is far higher and the greys are too small.

 

Mine was set up at PTS to run 15psi on the standard cooler (all those many moons ago ). Seemed ok but back at that point I didn't have an ACT guage to monitor things.

 

Thrush, on the std cooler around 165bhp at 12 - 14 psi.

 

I wouldn't run the standard cooler beyond 12-14psi to be honest. What are your thoughts on that Karl?

 

I don't run a std intercooler beyond 14psi. I prefer to set them to 12 psi, but most owners seem to prefer having 1 bar. LOL

At 12 psi you'll be hitting ACT's of around 50 - 55DegC so is basically as much as the cooler can cope with.

 

thanks for all the info karl hope to be seeing you soon

 

Yeah I'm on 12 now and std cooler so prob gonna change that next (and deffo change before any boost hikes) - still not sure whether to go for the GRS twin pass or the 4x4 Cossie single pass conversion tho

 

Ithink ive got a standard cooler running 15psi? is that bad then?? I think its standard? DOO, do you know??

 

Mine was running mfi with no 5th injector when it went on the rollers but the meterining unit had been tweeked to cope with the extra boost it was set up for. As a result it runs megga fuel at idle and cruise but leans out at the top end which is why i've yet to take it passed 4000rpm in 5th.

Thats all going to change soon enough though

 

Back to teh original question. Surely nobody wan't to switch an EFI to RST-management? Just remap or change the ECU completely.