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have you run a wideband on it? Posted by jak [Email]  (#195) [Profile/Gallery]
(more from jak) on Mon, 18 Oct 2004 19:46:24
In Reply to: Re: 24 lb will work with a rrfpr and fuel eprom (perfor, drupchen, Mon, 18 Oct 2004 15:57:55 Members do not see ads below this line. - Help Keep This Site Online - Signup |
the best advise I could give anyone is to get on a dyno with a wideband so you realy know whats up we all have just guessed at it & its the sheer strenth of our engines & usualy modest HP levels which keep our pistons from melting from leanuot
the deal with a more progressive fuel curve is that we are trying to make the ECU hit 100% injector on time later as the stock curve hits 100% on time way too erly 3000RPM-4000RPM
that said the only way to make a small injector flow more fuel when its allready wide open is to turn up fuel pressure
high FP is nice in that the fuel is better atomized but 80 PSI is realy high & the higher the pressure the less volume the pump can move (you can run out of pump)not to mention have pump failure from overworking I wouldent go higher than 70 PSI
the 30s I mentioned above hit 70 PSIish but by the rev limit was about 60-65PSI & this was making a 13:1-13.5:1 AF at about 16-17 lbs boost this is borderline but Ill bet many of us myself included (in the past) have run much leaner at the end of the RPM range but because we dont sustain high RPMs our engines manage to live
most of us dont drive like me using the rev limit as a shift indicator actualy holding 19+PSI boost at 6200RPM with a realy good flowing setup
if your car is setup to act like mine which hits 12.5:1 AF near the rev limit with the 31.5HR volvo injectors at 65-70psifp & you are using #30s you are definatly leaning out acording to what Ive seen
if you are running FMS #24s which are like 25 lbhr at 3barfp you are still probably leaning out up top so stay away from high RPM for any extended period
the other thing is that boost in our cars usualy even with perf APCs & whatnot tapers, allot of which is just the engine outflowing our smaller turbos, so one may have high FP in the mid range but later in the RPMs when its realy needed boost is down & thus so is FP but since the RPMs are up so is airflow so we lean out & with boost & RPM up you are realy moving allot of air & probably runing even leaner
so the better thing to do is upsize injectors & tune the ECU so that 100% on time is later to get rid of that rich spot & if the injectors are big enough you can run them below 80% on time which is how its suposed to be done because when you run an injector over 80% the coil gets hot & the injector can actualy close a bit & flow less
I have completed a chip (one size fits all) made for #30s which uses a 3barfpr & is best used with a upgraded IC (at least a tallon unit) & a bigger turbo,exhaust & free flowing intake this makes the best possible use of this size injectors
Im also working on a chip for the trionic injectors in the 2.2 & 2.4 LH ECUs (also one size fits all)
so I say for relyability of the fuel system mechanicaly speaking lower FPs are better using injector size to add more fuel is the rite thing to do
have a great week
JAK
posted by 68.119.228...
, Sat, 16 Oct 2004 11:54:36, Sun, 17 Oct 2004 19:12:31, Mon, 18 Oct 2004 08:17:37, Mon, 18 Oct 2004 19:46:24 <-- Viewing This Message
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