I need to upgrade to larger injectors and need some advice. Do I only need to make adjustments in the injector correction menu to compensate for larger injectors? I'm trying to hold off on spending money on a retune until I get cams.

 

It depends on the size of the injectors. What size are you upgrading to?

 

I actually found that if I changed to 720cc injectors with cams and Magnus intake manifold (plus the usual goodies) I didn't touch the injector sizing. I had to take out quite a bit of fuel on the top end but the part throttle wasn't that bad at all. YOu have to enter the ms time delay for the new injectors divided by the stock units to make the injector correction work properly.

 

720s were recommended to me so that's probably what I'll do. With the stock injectors I'm at 100% at WOT sometimes and the car is running rich. I don't need anything crazy since I'm not going for 500 HP. At the most I'll add cams, but not a larger turbo.

 

That's interesting. I wonder why you didn't need to readjust sizing.

I was reading the instructions in the Power FC manual and it seemed pretty easy to adjust for larger injectors. Just enter the new injector time correction and lag time correction values for each cylinder and that's it.

Would you recommend changing the fuel map, the injector settings, both, or something else? BTW, I have a Walboro fuel pump.

 

You should change the settings to your particular setup. I would recommend taking it to an authorized Power Excel shop to have it professionally tuned. We go through training and a screening process to become an Excel dealer so I would trust them more than trying to do it yourself.

 

That's very true I can always pay somebody to work on my car for me. Or, I can learn how to do the simple stuff myself and save $$$.

Since this was already professionaly tuned I'm only making a minor adjustment for larger injectors.

 

If you change injectors you have to retune the whole map. IT isn't as easy as just punching in correction numbers.

 

Thanks. That's what I wanted to know.

 

evotino, what 720cc injectors are you planning to go with....have you installed them yet? I will need to get larger injectors when I install cams so I'm very curious.

 

I haven't installed (or even purchased) them yet because I don't want to have the car retuned now and then a second time when I get cams. I was hoping the injector correction would compensate for larger injectors but Guru said it would not. Injector correction I can do; a full retune I can't.

What about you? Who has the best deal on injectors right now?

 

I'll probably go with the Nippon Denso 720cc Injectors. MZM has them in stock, but I'm not sure on the price. Maybe $400 for the set.

 

Those are the same ones I got avngr, very nice injectors!

 

Karash, a couple questions...

Do you recommend a larger fuel rail at this power level (cams, PFC, TBE, stock turbo)? When does a fuel rail become necessary?

Is there anything wrong with buying 1000cc injectors if you only need 720cc? Will they meter fuel less precisely since you use a smaller range of the injectors capacity?

I was only considering it because they are the same price. I won't ever need that much injector but when I eventually sell the car it may be a good selling point...if the buyer wants a 500 HP Evo.

 

evotino, Robert Russell was running 1000cc injectors on the stock turbo, and now the "El Diablo" 10.5 custom MZM turbo. It's probably overkill, but he ran a 11.9 and its his daily driver. He doesn't seem to have any issues.