Just completed a total rebuild of my 3.0, but no performance upgrades were done except a new set of "S" cams. Exhaust manifolds remain stock Alfa, although I plan to eventually get a pair of hi-flow cats mated to custom down pipes.
Next up is an MS conversion, for which I am now gathering parts (and knowledge)! I plan to totally remove the original AFM and install larger intake hoses.
My car is a STREET car...therefore it will never see long periods of wide open throttle. However, my objective is to tune the MS for maximum power, and revert the system to Bosch AFM and ECU every two years for smog certification. My question is this: will I need to upgrade my stock injectors to higher flow rate ones, or will my stock units be fine for the application I'm proposing? I have read that stock injectors are barely adequate for 190 hp, and I assume that my engine, less the restrictive AFM, plus MS, will be able to deliver well over 200 hp, right?
If I need new injectors, I have some Bosch 0-280-150-201s or -360s ( 22.5 lb @ 43 psi) to mount on a separate fuel rail. This way I can easily go back to the stock injectors if the Bosch ECU cannot tune the larger injectors out and pass emissions testing.
But, do I really need larger injectors to gain max hp and not risk burning out my stock ones at WOT?
Thanks,
MilanoMan
Milanoman,
All you need is to put the stock intake hose & AFM back in place. The AFM doesn't even have to really be connected. I mean, just make sure the wiring is connected but it goes to ...nowhere.... if you know what I mean. As long as the tech guy sees proper wires you should be set MS will still run your car.
All you need is to put the stock intake hose & AFM back in place. The AFM doesn't even have to really be connected. I mean, just make sure the wiring is connected but it goes to ...nowhere.... if you know what I mean. As long as the tech guy sees proper wires you should be set MS will still run your car.
Milanoman,
Have a look at my 3.0L conversion in the Technical section. I have larger inlet runners, no AFM, larger air inlet, S cams, Pace extractors and running MS. Stock injectors are more than adequate with MS showing relatively low duty cycles on the injectors.
David
Have a look at my 3.0L conversion in the Technical section. I have larger inlet runners, no AFM, larger air inlet, S cams, Pace extractors and running MS. Stock injectors are more than adequate with MS showing relatively low duty cycles on the injectors.
David
1985 GTV6 3.0 Zender Body Kit - Red
Zamani, David:
Thanks for the replies.
Zamani: Good idea! However, the issue of connection to air temp sensor is one I will have to figure out. With the original AFM in place, I can use the one in there for MS. I can plug the cable in for my smog inspector, pin the flap wide open, tune MS for lowest emissions, and be done. For "track use" (he-he) I pull the AFM out, use a separate temp sensor mounted somewhere in the intake pipe and tune for maximum emissions, er...power that is.
David: That is good news! I do wonder exactly what % duty cycle you are seeing at full load and WOT? And...what kind of HP increase have you seen from having MS on your car? I assume it is tuned for max power? Ever dyno it, or use a G-meter to estimate power gains?
Thanks,
MilanoMan
Thanks for the replies.
Zamani: Good idea! However, the issue of connection to air temp sensor is one I will have to figure out. With the original AFM in place, I can use the one in there for MS. I can plug the cable in for my smog inspector, pin the flap wide open, tune MS for lowest emissions, and be done. For "track use" (he-he) I pull the AFM out, use a separate temp sensor mounted somewhere in the intake pipe and tune for maximum emissions, er...power that is.
David: That is good news! I do wonder exactly what % duty cycle you are seeing at full load and WOT? And...what kind of HP increase have you seen from having MS on your car? I assume it is tuned for max power? Ever dyno it, or use a G-meter to estimate power gains?
Thanks,
MilanoMan
Milano Man,
I have Greg Gordan's stage II injectors, a 3" tube intake with no AFM, a 3" exhaust, s-cams, s-pistons and you know what, I don't think my duty cycles get over 40-50%. I don't think you need bigger injectors for what I have, but then my stock injectors were trash and the decision to go to stage II wasn't too difficult.
I'll try to look up some datalogs to see what my duty cycles at high loads are. Right now I'm not doing a lot of high load runs though while I work on my ignition.
Good luck,
Bill in Maryland
I have Greg Gordan's stage II injectors, a 3" tube intake with no AFM, a 3" exhaust, s-cams, s-pistons and you know what, I don't think my duty cycles get over 40-50%. I don't think you need bigger injectors for what I have, but then my stock injectors were trash and the decision to go to stage II wasn't too difficult.
I'll try to look up some datalogs to see what my duty cycles at high loads are. Right now I'm not doing a lot of high load runs though while I work on my ignition.
Good luck,
Bill in Maryland
Bill in MD
'88 Alfa Milano Verde x 2
'77 Fiat Spider
'88 Alfa Milano Verde x 2
'77 Fiat Spider
Hmm, Milanoman I found something quite different, my stock injectors ran out of duty cycle before 6k rpm on the 3.0, I had to put bigger injectors in - and did. (3.0, cams, headers, MS, no AFM, Greg inlet etc).
On a hot 2.5 the stock injectors will be OK, but on a warmed over 3.0 I think they'll be borderline at best.
Just make sure you have an O2 sensor linked to your MS and datalog to ensure you don't go lean at high load high rpm !
reagrds
On a hot 2.5 the stock injectors will be OK, but on a warmed over 3.0 I think they'll be borderline at best.
Just make sure you have an O2 sensor linked to your MS and datalog to ensure you don't go lean at high load high rpm !
reagrds
83' GTV6, 3.0 24v supercharged
Steve:
Sorry for my slow reply, I have been off this board for a while, summer holidays and other things...
Thanks for the info. I assume you discovered this via O2 sensor readings off the MS program, right?
Your findings concur with those of Greg...that stock injectors are borderline, even with a slightly warmed up 3.0. My only concern about using larger injectors is making it through California SMOG testing. My plan was to bolt on all the original L-Jet stuff for the smog checks, then revert to MS hardware "for track use only" after the test is passed. I wonder if L-Jet has a broad enough range of control to keep the larger injector output down for acceptable emissions performance? Nobody has had this direct experience, I would imagine.
What replacement injectors did you use? I have a couple of Bosch P/Ns that are supposedly a bolt-on replacement to the original fuel rail. I have a spare rail, so if worse comes to worst, I can always swap out the entire rail and injector setup every 2 years for smog checks.
Life in California is a pain for us engine tweakers...
MilanoMan
Sorry for my slow reply, I have been off this board for a while, summer holidays and other things...
Thanks for the info. I assume you discovered this via O2 sensor readings off the MS program, right?
Your findings concur with those of Greg...that stock injectors are borderline, even with a slightly warmed up 3.0. My only concern about using larger injectors is making it through California SMOG testing. My plan was to bolt on all the original L-Jet stuff for the smog checks, then revert to MS hardware "for track use only" after the test is passed. I wonder if L-Jet has a broad enough range of control to keep the larger injector output down for acceptable emissions performance? Nobody has had this direct experience, I would imagine.
What replacement injectors did you use? I have a couple of Bosch P/Ns that are supposedly a bolt-on replacement to the original fuel rail. I have a spare rail, so if worse comes to worst, I can always swap out the entire rail and injector setup every 2 years for smog checks.
Life in California is a pain for us engine tweakers...
MilanoMan
Hi Milanoman,
No problem, I've been off forum for a while too (holidays, changed jobs & home PC screwed up!)
We don't have the same level of vehicle checks over here so I can't really relate any useful experience. A thought though - if I faced a detailed smog check including visual I would remove my inlet pipe & filter, replace it with the factory inlet pipe + airbox + AFM and leave the Megasquirt running. Apart from one inconspicuous extra vacuum hose (easily concealed if necessary) from the plenum no-one would EVER be able to see the car isn't running L-jet.... because my megasquirt is built into an old L-jet box...and plugs straight into the ljet loom
I also can't put the ljet ECU back in either - without swapping injector rails (not a big job) as I'm running Greg's stage 3m's. I looked at bigger low-z injectors, but couldn't find anything that was either new at a decent price or 2nd hand and trustworthy.
Steve
No problem, I've been off forum for a while too (holidays, changed jobs & home PC screwed up!)
We don't have the same level of vehicle checks over here so I can't really relate any useful experience. A thought though - if I faced a detailed smog check including visual I would remove my inlet pipe & filter, replace it with the factory inlet pipe + airbox + AFM and leave the Megasquirt running. Apart from one inconspicuous extra vacuum hose (easily concealed if necessary) from the plenum no-one would EVER be able to see the car isn't running L-jet.... because my megasquirt is built into an old L-jet box...and plugs straight into the ljet loom
I also can't put the ljet ECU back in either - without swapping injector rails (not a big job) as I'm running Greg's stage 3m's. I looked at bigger low-z injectors, but couldn't find anything that was either new at a decent price or 2nd hand and trustworthy.
Steve
83' GTV6, 3.0 24v supercharged