HarleyTechTalk

 Tried searching around, contacted S&S and have not gotten a answer to my question. What is the flow rate for the S&S injectors that come with the 58mm throttle body kit? Plan to use this kit on my 04 softail with a 124ci motor.

I have that kit installed on a 124LC.  I was told by the S&S tech support that they flowed 5.1 gm/s @ 58 psi.

whatever it is i can tell you my 4.9 hit 85% on my 120. i just ordered some 5.3 from hpi.

I have 53mm injectors in a 58mm throttle body on my 640 cam S&S 124 motor.



Seems to be a nice combination, runs great & is easy to ride around town.

~John

Thank you guys for the info.

Looked in my packaging today and the injectors are 34.5lbs/hr flow rate. This being the case that is 4.3 g/s which isn't enough flow. So these won't work for my build as I need the 5.3 or 6.2 instead. Also for a different TB setup looking for recommendations. Seen the HPI 62mm tbc setup. Thinking this may be a better choice.

Is there a drawback using 6.2 gms/sec vs 5.3 gms/sec on a built 110? I assume it will be making about 120+ HP and 125 TQ. Won't see over 6200 RPM.

I'm concerned about my duty cycle as the injectors will be running at 86%.

I don't see a drawback using 5.3 but feel the 6.2 might be too much for what you have described.

Fuel droplets from bigger injectors will be bigger, this may effect gas mileage and possibly low speed performance if injector timing cannot be adjusted..

either the 5.3 or 6.2 will work and no downside to either.. Over running the inj a bit is not what the net makes it out to be. 6.2 would cover it without issue if you are buying new ones. No down side to that as you will need to tune it any ways .  At some point I hope HPI comes out with a higher PSI fuel reg for the newer bikes. Would be a great option as the 5.3 then would be fine for higher HP engines and the 5.3 is widley used in many of the HD kits ..


Max you had to bring that up..  HA HA

So the injectors that came with my throttle body kit from the info I am gathering here is not gonna work? 34.8psi

You need to run the conversion on them if they where tested at lower PSI than 59.. Most inj are tested at 43.5 but not sure why cars today all run different PSI and there is no real std pressure any longer.. 

If I understand what you wrote you have a inj that is rated at 34.5lbs/hr  and the test PSI was 34.8 correct if that is the case

That means you have a 45.4 lbs/hr  @ 59 PSI convert that to GPS =  ( 5.7 GPS at 59 PSI )   

All I have is what the package is labeled as 34.8lbs/hr. So I am not sure if this is tested or max psi. Will have to call the manufacturer.

What conversion formula are you using?

Several formulas as I have to first figure out the CC at the PSI you posted then I can get the lbs hr then go back again.. I am sure they are other ways just the way I do it..  HD is the only one that I know of running 59 PSI so that throws a curve at you if you have something that is not right out of the HD world.. Not that it will not work just its larger than you may think..

http://www.witchhunter.com/injectorcalc1.php

http://www.translatorscafe.com/cafe/EN/misc/unitconv/mobile.asp?m=cvt&c=flow-mass

RC injector is another ,

I'm going to do with the 6.2 gms/sec if they have no ill effects on the bottom end and tunability because I might end up going yo a 124 next year anyway. I have more than I mentioned before. 110 SE at 10.5 and 0.030 gasket with a Woods 408-6 and head work.

so I used the 2 calculators posted in this thread and came up with 4.4g/s on 34.8lbs/hr.

GMR am i missing something here? Maybe you have used these before being in the industry? S&S P# 55-5052

I'm guessing these are pretty close to the SE 4.9 injectors as what Harley publishes and what the injector manufacture publishes can be a little different.

you recommend using these on a 124?

No I would just go ahead and get the 6.2 injectors

Quote from: joe_lyons on January 03, 2016, 08:04:47 PM
No I would just go ahead and get the 6.2 injectors

I agree.  I have the 5.3 in my  HC 124"/ 58mm throttle body & it runs great, but I didn't buy these-they came with the bike when I bought it (It was a 117" motor at that time).

If I was buying a new set, I would definitely get the 6.2 size (there is no real downside to that)

Does anybody know where I can buy a set of 6.2 that are plug & play for an 07 EG?? (cable throttle/correct electrical plug etc.)  I am building a winter project for a buddy & need a set, & would prefer not to use the electrical conversion adaptors etc.

~John

Jason at C&S has everything you need for the conversion.  Billet fuel rail, connectors, and 6.2's around $300.

I used the data you posted and that was 34.8 PSI .. is that incorrect??

There is a 6.2 that fits the plugs for an 07 no problem.