What inj const to start with for the new Mototron 60/65# injectors?

[2QUIK6]

Just got some new Mototron injectors, some call them 65# because they flow 65# at 100%DC and others call then 60# because they flow 60# at 90% DC.
What should the baseline injector constant be set at to start tuning with these injectors?

Just loooking for a ballpark to start with then I'll increase decrease as I tune. I'm guessing I'll start out around 57.0 and go up from there based on the BLMs.

 

[ijames]

I don't think anyone can give you a closer guess than your own, and it should only take a few iterations to get it happy with your fuel pressure, anyway.

 

[2QUIK6]

Originally posted by ijames
I don't think anyone can give you a closer guess than your own, and it should only take a few iterations to get it happy with your fuel pressure, anyway.

Yeah, I was figuring that. Was hoping for at least a ballpark since there seems to be some confusion as to what these injectors really flow and at what DC. Normally for 50's, 40's, etc, the injector const would be set just under that amount. For these injectors, some call them 65#, others call them 60# and the difference is the DC the injectors were flow tested.

I guess a good question is traditionally, what DC are injectors flowed at for their advertised size/flowrate?

 

[ijames]

Static at 3 bar, 43.5 psi, is the most common. Course then you have to spec the fluid, which is why we have the 55/57 business since they are flowed with both test solvent (55 lb/hr) and gasoline (57 lb/hr) from Siemans . People seem to keep using 55 for the low impedance version and 57 for the newer high impedance ones, but really they flow the same. I'm not sure what the full explanation is for the 60/65 naming, though.

 

[Joe Lubrant]

Originally posted by ijames
Static at 3 bar, 43.5 psi, is the most common. Course then you have to spec the fluid, which is why we have the 55/57 business since they are flowed with both test solvent (55 lb/hr) and gasoline (57 lb/hr) from Siemans . People seem to keep using 55 for the low impedance version and 57 for the newer high impedance ones, but really they flow the same. I'm not sure what the full explanation is for the 60/65 naming, though.

Hi Carl

As far as PTE calling them 65's, I will just say that based on numerous injectors flowed on our bench at static, we had 62.8# as low, and 66.8# high. So based on this we decided to go in the mid...65 was a good a call as them old 42.5#???? why not just call them things 43's or whatever?

When we flow match injector sets, unless they changed procedure, they are done at 90% d.c.
From what I have seen lately sets under those conditions were in the order of 56+# to 59+#. We then code/mark & separate them in bins within close tolerance.

As I said in another post, I wouldn't buy these Injectors unless they were flow matched sets. They have the same spread just like the 50#'s some may flow 46-47, and some 50-51, and the rest in the middle.
It troubles me to see people get large injectors unflowed out of a bushel basket if you know what I mean

 

[bruce]

I'm old fashion, I just use what the manufacturer says they are, and then fire up the WB, and start adjusting the MAF tables, then go for the finer points.
Once I have the 1-2, or 1-2-3 MAF tables figured out, it doesn't take too much to get the last few really close.
Then fire up the ecm bench, and get the DCs to say 90% intially at WOT from 3K up.

That way I wind up with a calibration that's really close to being correct.

Doing it that way, means that even the stuff that might not be in use, would still be correct, if implimented.

BTW, so far, doing things that way, has never left me with any of the problems some guys have. ie *fat* injectors, or non-linear, yada, yada, just don't exist for me.

This approach just seems to make sense to me.

 

[2QUIK6]

Originally posted by Joe Lubrant
From what I have seen lately sets under those conditions were in the order of 56+# to 59+#. We then code/mark & separate them in bins within close tolerance.

Hey Joe, the ones I just recv'd from PTE have a different code/mark scribed in each one rather than the same marking. Should I just assume these are all flow matched or how should I interpret the markings?
They have numbers like 30157/24204 scribed on them.

 

[ijames]

Thanks for the info, Joe. I knew PTE was one of the "good" vendors that supplies flow-matched sets, but I didn't know what all info went into your 65 lb/hr rating. Is PTE going to Salem, OH this weekend (or are you, personally)? I enjoyed the little time we got to spend talking in KY.

 

[Joe Lubrant]

Rob,
The markings/code etc, is done also for traceablity. I don't have the exact breakdown here with me at home. I believe it does contain a date, batch#, flow code etc. But rest assured they are flow matched sets at approx. 1% tolerance as tested.

Carl,
I was planning to attend at least on Sat., but might have to cancel. Just put engine etc into my new TSO set-up car. Still plenty of mock-up stuff to get done. We hope to debut the car at the US41 Morocco Buick Race in Sept or possibly at Norwalk.

Regards,

 

[2QUIK6]

Update: Got the injectors in and got the air/fuel tuned, the injector constant that worked best for me was 65.5. Starting with the stock MAF tables, I had to adjust every value lower than 30g/s to be leaner and every value above 30g/s to be richer. Runs great and BLMs are 124-132 in all cells.