Haven't seen much posted on this topic in the last few months. I have a faulty one (low flow) which is not responding to ultrasonic cleaning. I've heard of the brand Five-O, but not sure if they match the originals https://www.ferrarichat.com/forum/threads/355-upgraded-fuel-inj.489075/#post-144075811 https://www.ebay.com.au/itm/373696020376? Bosch part number is "0 280 150 449" (15.9 Ohm Dual Spray, 267 ml/min static flow at 3 Bar) according to Miro: https://www.ferrarichat.com/forum/posts/147247696/ Another source says 240.7 cc/min: https://www.ferrarichat.com/forum/posts/144263767/ On eBay there is only a second hand one available. Any suggestions, gents? Thankz
My mistake. They are not a brand, but simply a US company who sells (among others) Bosch injectors. My tech appears to have found some Bosch replacements (different part number). I'll report back on what part number he used. I understood that all the injectors have to match, but I didn't realise that the same ferrari part number was insufficient. You have to buy a balanced set of 8.
Five O Motorsports has a good reputation for selling OEM and upgraded injectors. I bought a set, last year, for my Porsche and am very happy. Here is what they offer for the 355 https://www.fiveomotorsport.com/makes/211s-ferrari-maranello-355-456-550-porsche-911/
^ Not sure why they list a 28lb/hr injector as a replacement for a 23lb/hr injector. Can't see any way that would work right.
My independent tech’s fuel specialist is also recommending an injector with a similar fuel flow increase of 12%. I am concerned, too, especially during open loop operation (warm up, full throttle and >4000rpm on the 5.2 car). I don’t know how much that will equate to in unburnt fuel in the cylinders, increases in cat temperatures and cat degradation. I guess we will see as we took a record of the cat temperatures prior to the change.
Idle and part throttle trims will compensate for larger injectors to a point. So if everything else is correct and you install injectors that flow 12% more, you'll see fuel trims learn back to negative 12%. (and may code bank1/bank2 rich) Everything else I've worked on from this era has no wide open throttle fuel trim adjustment however, so would probably be running rich at that point. I would probably buy the used injector and send them out as a set to be tested/flowed.
I got 2 sets of "Five-O" injectors for my 348. Was able to flood it with fuel to lean it out and every bit powerband in between Cant remember I settled on something around the flow rate of a 2.7 355 where I got the best powerband. If you need custom made RC in torrance rocks
I actually found a new injector and bought it. There was one available at Eurospares, but I'm not sure why it was being sold alone. There is no guarantee that it will match the flow rate of the others. They have to be within a certain range to be considered matched. I could get lucky, but I think my tech is already in the process of installing some Bosch 0 280 155 931's with a flow rate of 300.1 ml/min (Vs the standard 267... although some spec tables show 240.7 cc/min. That's a 24% greater flow rate)
Here's an extract from the WSM on fuel injector open time, although it's not 100% clear. Image Unavailable, Please Login A t5 value of 1 seems to be suggesting that no correction is applied.
Yes, T5 value of 1 in open loop would mean closed loop fuel trims are not applied to open loop. (best as I can tell). Without having the ecu calibrated to the new injector flow rate it will be very rich under hard acceleration.
I don't normally do extended, hard accelerations, so I may be relatively ok in this respect. To be honest, I'm more worried about the warmup period with lots of fuel going into the cylinders, washing the bores with fuel. My indy reported that his fuel guy is quoting these values for the old and new injectors: 150-449 sprays 252ml/min 155-931 sprays 269mls/min That's a more reasonable 6.7% increase in fuel flow. The data sheets found on various websites for Bosch injectors quote fuel flows based on a particular type of fuel. The above quoted values may be based on real world measurements with a typical Australian (hopefully high octane) fuel. Unfortunately, I don't have a "before" long term fuel correction, so it's not something I can compare after installation.
There's much more to calibrating the ecu to a specific injector than just the flow rate. Many other parameters, specific to the injector itself. Also spray pattern/angle. I wouldn't deviate from the original injector if the ecu can't be calibrated to the new ones but it's your car to do as you like with.
Never really thought about this but with my group m and capristo would my 99 not be likely leaner than stock because of the reduced back pressure and the more open air intake? It has always seemed like it ran hard and Dyno graphs show it was making 30hp more That being said it should have run richer stock then. I think this makes sense
Grouppe M induction, if it does anything shouldn't lean it out as it's going through the same maf sensor, which is the smallest point on a 5.2 induction. And to a degree will compensate as higher airflow through the maf will results in more fuel delivered. If you dyno it again most shops have the ability to check air/fuel ratio.
The new (single) OEM injector I bought was from Eurospares. I emailed them and asked them if Ferrari sold a full set. I'm not sure I understand their reply: Why would Ferrari need the old unit? It's not like they could match the fuel flow of their injectors to the broken unit. Do Ferrari only sell single flow rate injectors (a fixed precise value) and every F355 is exactly the same? This might explain their exorbitant price for a single injector (8 times a matched Bosch set on eBay).
I have not seen OE/OEM injectors being sold as matched sets by any car manufacturer (parts supplier). It seems that the "matched sets" are only offered by the suppliers of "refurbished" or "upgraded" injectors, i.e. by sellers who are dealing with large numbers on injectors (used-refurbished or cheap new China-made) out of which they can put together matched sets through selection using an injector flow testing machine. New high quality injectors (Bosch, Denso, Hitachi etc.) do not need to be specially matched and sold as sets since their manufacturing tolerances are very close so they are all practically matched. I matched injectors on my Jaguar V8 engine (to be reasonably close, not necessarily spot-on) using the existing 8 injectors (~75 k miles) and another 8 used injectors that I bought and my injector cleaning and flow testing machine (China made, not too expensive). I first did ultrasonic cleaning of all 16 injectors, then checked and recorded their flows and selected 8 with closest flows. I have read that 2-3 % flow difference between injectors is acceptable (https://www.knowyourparts.com/technical-resources/fuel-system/fuel-injector-servicing/). The write-up on this website also states that "Most OE fuel injectors are held to a +/-2% variance".
I really hope this is the case, Miro. My indy just told me that the new injectors have about 7ml/minute greater flow rate than the old ones which is actually not too bad (just over 2.7%), but the spray pattern is different (4 hole vs the OEM 1 hole). He's going to talk to his fuel guy again on Monday. I'm rather hoping that my OEM one arrives soon (FedEx says it has arrived in Sydney, but it will probably take a day or two to go through customs). I'd like to compare it and see. Not sure if you can call 20 year old Bosch injectors "new" I wonder what the tolerances were back in those days.
They are supposed to be more efficient for a given flow rate. However, if injector opening time is determined by ECU internal maps during full throttle, high rpms and warm up operation (i.e. "open loop"), will you still be getting the correct air/fuel ratios? Does your Porsche have the same fuel control logic as the F355?
The injectors I bought from Five O Motorsports were the same 19 lb as OEM except with the 4 hole pintle. Can't imagine that the spray pattern would have any effect on air fuel ratio? My car idles perfectly and runs great. ECU management is Bosch LH Jetronic which has some similarities with F355 but is different.
They are probably need as cores for the next customer—- the older systems are not being supported by vendors as much now a days Bosch is more focus on GDI which is in most ICE cars to date so stock of older tech is going to be effected manufactures are only bonded by law to provide 20 years of replacement parts to their products—- we are hitting that and more with these cars so Ferrari is probably trying to keep a product in stock to supply us but at a price aka TAX I have not needed to replace mine yet (knock on wood) but if they day comes I will be looking in to modifying my intake to a new injectors that should be serviceable for years to come and have talked with my Machine friend and he said it’s a lot of work but can be done Sent from my iPhone using FerrariChat
I can't get my head around it. If an engine runs perfectly on less fuel because of spray pattern, what does adding more fuel than required do? In "open loop" mode (with no O2 sensor input), the injector open time is designed for the old injectors, so the ECU will be supplying more fuel than required for optimal operation (even though the flow rate is the same). Do you just get more power with the same fuel usage (because of the better burn) and the stoichiometric ratios remain the same... or are you adding too much fuel for an ideal burn (for a given amount of air), affecting the ratios. Thanks, makes sense. Just wondering how I got a new injector without trading in my old one. And what part is considered to be the "core"? The possibly broken bit (on my old one)? And how can Ferrari sell refurbished ones as "new".
I have no empirical evidence, but I "believe" your comment above. I don't "think" there is any added fuel.
The spray pattern affects transients/start up more than absolute air/fuel ratio at say cruise or higher rpm. Generally oem stuff targets fuel spray at the back of the intake valve(s). With a different spray pattern you have more or less fuel hitting port walls and then evaporating off the walls. The spray pattern chosen originally wasn't by chance.
Contact OSide Tiger (eBay selller) for direct replacements. They can even set you up with some that have better flow. Four hole also makes for better atomization. And, yeah, what Tim said, RC in Torrance is AWESOME! They will make you whatever you want for very good pricing. Plus send them your stock pieces for cleaning and repair to keep as a back-up. This is what I did with my 2.7 348 injectors.
