Danno

"so what exactly does upgrading to a 3 bar fpr do for my car??"

Well, it would provide a 9% increase in fuel under all conditions. Simultaneously with a 3-bar FPR, you need some method of dialing back the injector duty-cycle by 9% to restore fuel-delivery to stock levels.

The primary benefit here is that in the upper-RPMs when you were hitting 100% duty-cycle previously (with the appropriate flow-increasing mods), you'll only be at 91% with a 9% overhead. But again, you need a method to dial back the injector duty-cycle.

A quick method to do this is with signal-massaging of the incoming air-flow signal to fool the computer into thinking the AFM is flowing less air than actual. The computer would cut back the injector duty-cycle, by an amount which would coincidentally or luckiy match the increase in fuel-pressure so that you would have the same fuel-flow as before. The goal is more high-RPM fuel, while keeping low-RPM/partial-throttle fuel the same.

87uk944t

signal massaging? would this be by altering the dial within the airflow meter as described in blitz951's post to make the car run leaner? there seems to be a lot of people on here running 3 bar fpr's surely all of them cant know about dialling back the duty cycle!! what would happen if i installed 3 bar fpr and did not do anything about dialling back the duty cycle??

Danno

The only thing about adjusting the AFM is that you cannot dial back a fixed 9% across the board. There was a change from the early AFM to late AFM in 85.5 with the air-volume to voltage-response curve. The 951s got the later ones which made manufacturing easier with the logarithmic response curve mapped into the chips.

If you don't dial back the duty-cycle properly and you'll get too rich of an idle, may stumble and make driving in stop & go traffic troublesome. If you do manage to dial it back to get a steady idle, you'll end up way to lean in the upper-RPMs, defeating the purpose of installing a 3-bar FPR anyway.

This is similar to people installing 50% larger injectors then reducing their fuel-pressure by 50%. You'll still end up at 100% duty-cycle at 5000rpm with the same volume of fuel injected.

87uk944t

sorry to keep going on about this danno but i am not really getting this!! you said that there was an easy method of dialling back the duty cycle so can you explain it to me so that i know how to do this and get my car to run normally at low rpm and with more fuel and power at high rpm thus benefiting from installing the 3 bar fpr

Olli Snellman

If i can understand this correctly Danno has handled dial back of the duty-cycle in his famous Chips (for use of 3 bar FPR)!
So, get rid of those Europroduct chips ! I used to have them but now i have guess what???

87uk944t

maybe i should just bite the bullet and buy the guru stage 1 map kit, danno what you think??

dmoffitt

sounds good to me - you'll get your guru chips, a way to play w/ air-fuel ratios, and reduce restriction in the intake tract. i'd add to that either a manual or electronic boost controller, and a lindsey dual-port wastegate (or a TIAL unit) - in order to use the boost controller / eliminate your cycling valve.

one thing to research tho, is MAF vs MAP. i'm very happy with my digital MAF, others have raving reviews of danno's MAP upgrade (both stage1 and stage2), but make your own decision.

btw if you want to go the cheaper route and get a manual boost controller (that can be easily changed from within the cockpit) i've got one of lindsey's boost controllers, it's rather nice, basically a **** you pull out to unlock, turn left for less boost, right for more, then push in so your settings can't be accidentally modified). i believe i paid approx $60+s/h and I'd gladly sell it for $40 incl. delivery, as i don't need it any longer... email or PM me

User 41221

David,

If he doesn't want it, I will gladly take it! Let me know.

Regards,

87uk944t

$40 dollars including delivery to the uk, are you sure you have thought thru that offer!! thanks for the offer but i think i will pass on the mbc for the moment, i am led to believe that it is a bit unsafe to run the lbe with an mbc, and having only recently fitted lbe to my car i wanna get some use out of it before i change to something else, think i will remove it and go for mbc and dual port wastegate in the future but am considering a map or maf kit at the moment

User 41221

Looks like I just bought a MBC... yippee!

Dave, you have mail...

Regards,