Hello, I have read through this very interesting thread, and I cannot remember if you used a wideband A/F to determine the A/F. If can do a WOT run from around 2000rpm to 7000rpm, then you can workout the percentage of fuel you need for No Doubt to add. I believe this piece of equipment will be a very useful investment for you. Also have you cross checked the fuel delivery limit of your injectors? Raising the fuel pressure may or may not be a good move. Stock motronic usually runs at around 43-45 psi? Raising the pressure by 20% will not give you 20% more flow, but only about 10%. If you raise it too much then there maybe issue with the injectors leaking. Currently what is the duty cycle of the injectors at max rpms at WOT (after the new chip you installed)? BTW, usually motronic injectors are of the high impedance type. You can just check the resistance component of the impedance by using an ohm meter. Chances are the F355's injectors are also high impedance. Usually the value is around 14 ohms (I cannot recall the exact value). I've installed an Autronic SMC EFI on my Alfa since 3-4 years ago and the wideband A/F meter has been very useful. However if you don't intend to run bigger cams or other radical modification, definitely stay with OEM. I apologize if this post is redundant and not useful.
2) a) Injector open time reaches max and don't forget this is not 100% time it is only intake part of the rpm's in milliseconds b) Bigger injector brings worse driveability down low, smaller injector with more pressure can help this c) if you are close in injector sizing cheap way to step up a little or bridge the gap if the next injector up is way too large 5) Not necessarily - you assume you added more air and won't know until you measure it somehow OEM with MAF reading should adjust everything for you. If you are still lean check injector pulsewidth and if they are maxed out increase fuel pressure or go with bigger injectors. If you are not using MAF and are only MAP then the fuel tables need to be redone, but also make sure you are not stuck in open loop when the MAF input is missing.
Just a few more pix-I couldn't resist Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
The wood spaces the deck lid up 1" for clearance. The pan that routes water onto the air cleaner box was removed, and the 45deg. fins on the air boxes were shortened about an inch. If I leave it like this, I'll make more attractive spacers, but the plan is for stacks, so clearance won't be an issue. The spacing is not obvious with the lid closed.
Pluzgit...where did you get the pantyhose air filters for the mafs? They aren't yours are they? Tell us the real story!
Jason is right on. Read his post again. MAF's may be the limit or the head to flow. This is a great project but maybe you are not what you think..lean. You need to meter this and not guess. He is also right on injectors. Call ron at RC engineering in Torrance and tell him you have injector 0280150731. Ask him the max fuel pressure that will take and the flow in CC/min. For comparison ask him the cc/min of the 355 inj 0280150449. Ask him the difference between the 348 and 355 inj#'s and you may find there is an impedence difference etc.. that is responsibe for the 355 no firing. Then you can ask whethere there is another injector with 355 specs that the 348 ecu will fire.
Here's one view of a few of the maps that I changed for version 0.2 of the Stooge-Series chips. We're getting awfully close to maxing out what the injectors can do via software in this iteration. Even though I'm not there with Bruce's 348, I'd think that when he installs these chips tomorrow that he's going to see slower revving-up when at low RPMs. I'd also guess that he'll be close enough to a workable A/F ratio with this 2nd version of chips so that it will make sense to use a wideband O2 analyzer + G-tech to see where to go next. If more fuel is required then drive-ability is probably going to be better if the fuel pressure is raised, rather than pushing the software maps up any higher. I'm also wondering if he needs to go to a colder set of spark plugs for this mod. Version 0.1 took Bruce up +60hp from the stock chips. If his 348 will rev up with this new set, we may see that much again compounded...but I'd think that would still be far below the potential for this mod. Gotta bump up fuel pressure. Image Unavailable, Please Login
Ain't fat-must be lean. Separate symptoms. Excellent research-thanks for sharing it. I'll call tomorrow!
"Even though I'm not there with Bruce's 348, I'd think that when he installs these chips tomorrow that he's going to see slower revving-up when at low RPMs. I'd also guess that he'll be close enough to a workable A/F ratio with this 2nd version of chips so that it will make sense to use a wideband O2 analyzer + G-tech to see where to go next. If more fuel is required then drive-ability is probably going to be better if the fuel pressure is raised, rather than pushing the software maps up any higher. I'm also wondering if he needs to go to a colder set of spark plugs for this mod. Version 0.1 took Bruce up +60hp from the stock chips. If his 348 will rev up with this new set, we may see that much again compounded...but I'd think that would still be far below the potential for this mod. Gotta bump up fuel pressure." Well said, my man!
Fat man! You know that he's not going to give you the skinny on the two young heiresses who donated their under-garments for the good of the Brotherhood!
Sorry i havent been much help on this guys,i think your faceing differant problems to the ones i had,as i dont use the maf sensors everything is run from the throttle position senser,my ecu is a programmable Omex unit and it only took a couple of hours to get the car to run properly,the hardest thing was getting the cold start right,with referance to a post much earlier i have standard valves and cam profiles and there has been no head work done the only porting was on the inlet manifold,i am running 348 injectors which i was worried about but its run great all year so i wont be changing them. Good luck andy.
Perfect. Thanks, Andy. You're running the 2.5 injectors then as I recall, same as Bruce. No head work...which is pretty well what I had guessed since there was no mention of any head work for the 348 Competiziones that run 8 tb's. That makes me think that we can get Bruce running right entirely via the software maps in Motronic. Once we get the maps right I'll make them available for free to all other 348 Brothers who want to do this 8tb mod. Just to verify, you are at stock OEM 348 fuel pressure with 2.5 injectors, correct? No head work. OEM 348 cams. OEM 348 valves. 8 tb's. 400+ hp.
Well it's about damn time Andy. You started all this madness with your fancy shmancy setup......ya big show off. This is good news, because if you are still running the stock injectors, we now know that they will handle the extra air.
Nope. Stood outside waiting, too. Watched pot, etc. HOpefully tomorrow PM I'll have them and put them in. I'll give a report. Muchas gracias!
Stooge V2 up 10% 0-4000 up 20% 4000+ 235rwhp on FBB's g-meter vs 225 originally-in the plus zone now, and still lean!
Stooge V2 up 10% 0-4000 up 20% 4000+ 235rwhp on FBB's g-meter vs 225 originally-in the plus zone now, and still lean!
Nice! OK, I've now mapped the OEM Motronic 2.5 tables to the Motronic 2.7 charts. This is important because I have identified all of the M2.7 tables as well as have run M2.7 through the 8052 emulator... So now I know what M2.5 is doing ("hey, about time I say"). M 2.5 uses multiple tables to build a final Tj time for the injector pulses (built on 3 mapped components t1, t2, and t3). Stooge chips Versions 1 & 2 bumped up some 5 tables relating to t1. For the Stooge Version 3 chips I've already bumped up an entirely new table, that of the injector pulse time based on battery voltage (t3). On the OEM M2.5 and M2.7, the injectors are kept open longer when you have lower system voltage. Well, now Stooge V3 keeps the injectors open longer at the normal system voltages. It's a thing of beauty. Too bad that I'm going on vacation now, though. Gotta go do some snow skiing with some fellow tifosis...
