Mopar 550 cc injectors.

[jrotten]

This thread got bumped on DSM Talk, so lets try it here. Mopar Super 60 fuel injectors. Mopar part# P5249452. They are 550 cc, they are low impedence, best of all they are 175 bucks a set! The catch is that they are rated at 550 cc at 55 psi, not the standard 43 psi that our cars (at least 1G's) love. They also require some MINOR trimming to get them to fit our rail. So this begs the question, why could you not bump up the base fuel pressure and use these? Has anybody done this? A pump upgrade is one of the first things we do to our cars anyway. In my case I even have an adjustable regulator (Spoolinup.com). Less than 2 bills in price, if you are shopping for injectors this needs discussion.

 

[Hal]

Upgrading the pump DOES NOT raise the pressure unless the fuel pressure regulator is unable to cope.

If you're going to do this... why not just keep 450's and crank up the fuel pressure to increase the flow?

 

[jrotten]

If you do the math based on RC's website, this would not produce any thing near 550 cc even at that pressure if you used 450's right? Plus I am not sure how they would react at that pressure when they are rated at 43 psi. I'm thinking they would act kinda flakey. I jacked mine up to 50 psi base pressure just to see after I got the Spoolinup reg some months ago, the car did not like it at all.

 

[jrotten]

thedodgegarage.com

 

[jrotten]

another Mopar 550 cc injector link If nothing else, read about the 13 second Mini Van. Its low tech and its a hoot.

 

[CraigB]

I ordered 4 of them today. I can get them for alot less than 175. I will let you guys know how they work out.

 

[jrotten]

and thanks for having the balls to try something that doesnt just "drop in". If this works, we can all hopefully thumb our noses at RC forever, or at least until Dodge realizes they are selling 10 times as many injector sets as they have in the past.

 

[CraigB]

The injectors came in today overall the look good. About the same as the Holley injectors. The install should be the same as the Holleys. I will install the next week and update you guys.

CraigB

 

[9d1awd]

i am also very intrested in how these turn out too

 

[pneumo]

It almost sounds like you have to run 55 psi anyway. Even though our injectors are rated at 43 psi, our base FP is 36 to 38. From the math I did if you crank up the base pressure to 55 psi on stock 450cc injectors it comes out to 545cc. Maybe the advatage is that the Mopar injectors can handle the high pressure and still flow accurately?

 

[mrfloppy]

hey how did it go??? with the injectors craig?? wanting to know.

 

[CraigB]

Well I put them in 2 days ago. You will need 2 stock o rings to seal them into the fuel rail. You also need longer bolts for the fuel rail and washers to shim it. The mopar injectors are a little longer. Also I changed the seals that go into the cylinder head

 

[jrotten]

Sounds even more simple than I have heard. Do you have an adjustable fuel pressure regulator and/or SAFC to tune with? Or are you running stand alone? Still wondering about pressure curves and the limts of tunability of these injectors to achieve good idle. Sounds like you had a sucessful install though. Guess I will go ahead and order some unless you have some negative feed back to add against them. The fact that you didnt have to cut them like I have read makes them easy to resell also. Thanks for the response Craig. Screww RC! Ah'm going home!

 

[CraigB]

I have a adjustable regulator and a e-manage. The injectors are working just fine. Just change all of the seals and triple check for any leaks. It was a pain to get everything to line up but I don't have any leaks.

 

[nigma]

tell us more about this injectors... are they flowing better has your injetor duty cickle become shorter ?
as for hier fuel preasure i can say some thing
our fuel pump can pump up maximum ~85 psi preasure
thats system preasure now.. base preasure is a difference between manifold and fuel rail. if we have let say 36 psi base preasure
and 20 psi boost (manifold preasure) this meens that actual fuel system preasure will be 56 psi and now if we have to have 56 base preasure that will make 76 psi actual fuel system preasure with 20 psi boost level that is close to maximum our fuel pump can make and it actual could be that fuel pump will not be able to hold that preasure at hi fuel flow
so it will dye sooner tahts for sure and you'll have to upgrade it to be able to hold requered fuel preasure. thats why dsm turbo engines have prety low bse fuel prease and one of the bigest stock injectors in import car industry

 

[D@nno]

I just stumbled across this thread. Just wondering how the injectors are working and if you ever developed any leaks?

 

[kpt4321]

Guys, this is silly.

These Mopar injectors only flow 8.1% more fuel than stock 450's do, at stock base fuel pressure. For an extra 50 bucks or so, I would much rather get a set of RC 550's that are 22% bigger than stock.

Hell, you can find 550's for around, if you shop the trader.

8.1% more fuel isn't too exciting.

You can get like 13% more fuel flow by just grabbing the FPR off a non-turbo car.

So, there you have it. Spend like $150 to get an almost insignificant 8% more fuel, or spend like $10 to get 13% more, almost twice as much.

Doesn't sound so good anymore, does it?

 

[D@nno]

If you could tell me where to get new rc 550's for 200 bucks new then i would definately go for it.

I would also use them at a base of 55 psi, which should be more than enough for my big 16g. i also work at a Chrysler dealership so I can get them even cheaper.

Just wanted to know if they are still sealing OK

Thanks, Dan

 

[kpt4321]

If you run the Mopar 550's at 55 psi, then you will indeed get 550 cc/min of flow out of them. However, if you just keep the 450's and run that same 55 psi, then the 450's will actually be flowing at 509 cc/min. So, basicially, we're talking about spending over a hundred dollars, plus doing some custom fabrication, for 41 cc/min of fuel flow. It's so not worth it.

Do it once, do it right.

 

[D@nno]

The injectors on the car are 13 years old. I don't think they are flowing that great anymore, as i get mid teen knock counts at 12 psi on the big 16g. i think that these injectors would be a great upgrade for me. Also I don't think having to shim the fuel rail is all that much work.