Cams! Bigger injectors to be on the safe side?

[GodSpeed]

Before putting the cams in RStuner records 100% Injection Duty Cycle if I pull the car over 7100rpm... Some argue that that figure may not be correct! But I have also used some methods of calculating the IDC and they have all shown that ~200hp would be on the edge for the stock injectors. However I’m really feeling bad about it. Don’t want the car to ever have the chance of running lean. As stock injectors are rated by MM at a max IDC of 90% and I’d rather not exceed that.

Since I’m mounting cams in the car and it will be remapped by Henk would it be any good upgrading to the 283cc IWP042 injectors to the bigger IWP043 injectors at the same time?

I shall say that the car goes 7000km (4000+ miles) on track each year so it’s got a pretty hard life. And I do some ice racing with the car during the wintertime, it may be as cold as -30 degrees so I need propper headroom for the injectors. So I’d like to keep within those 90% IDC to be on the safe side. The cost of new injectors does not really matter; just want reliability to be as high as possible.

Happy for some response!

 

[Jonny1*2]

not sure if you have to change them Marten, but I believe GDI used the megane 225 injectors in there Throttle bodied kit.

 

[GodSpeed]

not sure if you have to change them Marten, but I believe GDI used the megane 225 injectors in there Throttle bodied kit.

They are to big tbh as they are rated at 491cc. At least according to the different calculations Ive made 330-350cc would be well within the 90%.

EDIT: By the way what is the fuelpressure on a Clio Sport? 3,5bar as on 1,6 16v?

 

[brutal]

We saw %108 duty cycle with rstuner on a stock engine :dead: it seems it is not correct. If you still want to change the injector there is some helpfull information below:

0280160575 it is a bosch 4bar fuel pressure regulator.
8200211099 this is the 225 meggy injector part number. 390cc(std 250cc)

You will use both solutions for your car. I have a C&B'ed 172 and now running about 15 afr with henks base map, i will connect a piggy back unit to adjust the AFR, if piggyback doesnt works, so we need to change the injectors or regulator.

 

[Fastchip]

We saw %108 duty cycle with rstuner on a stock engine it seems it is not correct.

It is correct.

 

[Fastchip]

You do not have to change the injectors with any road cam solution

 

[GodSpeed]

We saw %108 duty cycle with rstuner on a stock engine :dead: it seems it is not correct. If you still want to change the injector there is some helpfull information below:

0280160575 it is a bosch 4bar fuel pressure regulator.
8200211099 this is the 225 meggy injector part number. 390cc(std 250cc)

You will use both solutions for your car. I have a C&B'ed 172 and now running about 15 afr with henks base map, i will connect a piggy back unit to adjust the AFR, if piggyback doesnt works, so we need to change the injectors or regulator.

Okay :dead:

But about 15 is rather ok isnt it? You are supposed to aim for 14,7 to 1 right?! Or do you want it to be 13-14 to be on the safe side?

But there is no need to change both the flow regulator and the injectors right? Since using the bigger injector will cause them to flow more at stock fuel pressure?!

 

[GodSpeed]

It is correct.

You do not have to change the injectors with any road cam solution

How do these two statements match up with the MM max duty cycle of 90%, I dont understand?!

 

[brutal]

14,7 for crusing or idle, 13,5 to 12,5 will be safe and fine for performance use

Henk can you explain how can we go over %100 of the duty cycle?
is %100 duty means all the time open injectors or what?

 

[Fastchip]

How do these two statements match up with the MM max duty cycle of 90%

Its a myth spread by people who 'think' they know.

 

[Fastchip]

is %100 duty means all the time open injectors or what?

Yes off course

 

[GodSpeed]

Its a myth spread by people who 'think' they know.

Well Im certanly not one of them who think I know, but I like to understand things. So just saying its a myth dont make anything clearer for me to be honest.

The main thing I cant understand how the car can run at 100% cycle today (at peak power) with low power and then be perfectly okay to run with a lot higher power and still at 100% cycle. In my world logics tell me that there is more power to find, giving the engine more fuel?

108% cycle and AFR 15 doesnt seem like the engine would like more fuel, but as I said I dont understand these things. Wish some one would explain.

Would it be any problems making a custom map for the larger injectors?

 

[sideways danny]

standard injectors are fine for ITBs, let alone cams on their own

 

[franx]

Godspeed , mine has been going strong for 2 years now with the nasty C&B's , and i'm not easy on the throttle either :evil: I do'nt think you have to worry about the injectors.

I have to say i do'nt have the Fastchip tuner Kit, so i do'nt ever get to see all these numbers and values. Maybe if i did i would also be worried haha !