fueling, tuning & injectors

[John_Hudson]

Im currently running 850 primaries, im mapped to .9 bar running 436 FWHP at around 74% duty on a stock block.
im thinking about going back to 550 primaries as it seems to eat a hella lot of gogo juice

1.) If the compensated duty cycle was pushed up to 95+ % what would the estimated power loss be roughly at the same psi if any

and

2.) If i did go ahead and change the injectors, and changed the injector size and % on the PFC would i still be able to drive normally under the current map untill a re tune ie. off boost, im guessing it will just run super rich on idle.
Im not clued up on maps unfortunatly so im not really sure on what goes into it or how much can be changed / altered before things start to go pear shaped

cheers

J-

[John_Hudson]

urgh.. no one?

[karl_tate]

95% duty is a no no really.

if your using to much fuel then put the 550\'s back in and get bigger secondaries but you map would need tweeking.

you will be fine driving the car, just off boost is the safest option.

[John_Hudson]

I use to run 95 all the time on my old map, never had a problem, not like I was WOTing 100% of my journey and maxing them out, however thanks for the reply Karl good to know I can drive it about on the smaller injectors when on route for a re map

[karl_tate]

ah right ok, me personally wouldnt like them running at that kind of percentage. (just me lol)

no problems

karl

[AtomicRex]

Can you adjust the fuel pressure?

[John_Hudson]

not 100% sure how to lol :p

btw did you find another vent and did you get my PM last week regarding the Vmount

[BlitzBoy]

changing back to 550s wont change your fuel economy, only a remap of your cruise zone of your map will better your fuel economy.
Plus you dont want to change you fuel pressure as it will make your existing fuel map useless.
Just get someone with a "wideband" to do you a proper cruise map to give you better economy

[AtomicRex]

Vent was a no sorry....we did look
 
Do you want to ring me about the V-Mount?

[John_Hudson]

aye can do but i cant now till wednesday arvo bud, im working solid from tomoz and busy this evening =/

[John_Hudson]

only a remap of your cruise zone of your map will better your fuel economy.

Just get someone with a "wideband" to do you a proper cruise map to give you better economy

are you free bud?

[gmogle]

Do you find the idle is rich also with the 850 primaries ?

Would changing to bigger secondaries help this ? MOT tends to be a nightmare usually.

[SiH]

I\'m running about 340bhp atfw on a totally stock fuel system and the injectors are hitting 93% duty - this was mapped by Pip.

However, this is with the stock pump wiring - Everything i\'ve read or been told tells me there\'s potential for another 20-30bhp with upgraded wiring.

[clive]

changing back to 550s wont change your fuel economy, only a remap of your cruise zone of your map will better your fuel economy.
Plus you dont want to change you fuel pressure as it will make your existing fuel map useless.
Just get someone with a "wideband" to do you a proper cruise map to give you better economy

Mark is right the 850\'s are only putting in the amount that they were mapped to put in and would not be dumping the fuel in like they would if they were sitting in the secondary rail like normal,


Best way is to get somebody who really knows what they are doing and get the fuel cut down only when driving on partial throttle on the road


This may save a small amount of fuel  "BUT", you then if you have to pay say 2/£250 for somebody to do this so you will have to wait a while to reclaim from your "economy"

Don\'t forget, the bottom line is, you can\'t have power by not putting fuel in, so if you want better economy put 850\'s and 550\'s back along with the stock ECU,  !

[John_Hudson]

nice one, thanks for all the replys guys, its just seems like its gotten alot worse lately, i dont know why but even when driving normally it just sucks down the fuel so damn fast its not funny