FRPP M39 or LU60 for 4.6L 3V?

I have a N/A 07 Mustang GT, and plan to go with a supercharger in the near future. But I want to run the new injectors beforehand to make sure the fueling is smooth/even so I'm not trying to diagnose any possible issues in the future with a new DW300 pump, supercharger, and injectors all at the same time.

Do you recommend the FRPP M39 (39# blue Cobra) or the FRPP LU60 (60# Siemens) injectors? With the 60s, I could run full E85 later on with the blowers I am considering. But how would either injector run w/ the N/A engine? I know people say it is "overkill" but I am interested in driveability in N/A - knowing I will add a blower in the future. American Muscle's page for the LU47 said those are not recommended for forced induction on the 05-10 4.6L 3V V8s for some reason. I think it might have to do with the tiny O-rings for the intake manifold side of the injectors... But those style (including the LU34A) are very different and my 4.6 3V never ran right with the LU34A (Boss takeoffs) no matter what I did.

It seems fairly easy to tune for the M39s as Edelbrock's tune only changed the 4 scalar settings for the injectors. The LU60s would have more headroom but I am hesitant to spend the money only to find that the FRPP settings don't work well with the 4.6 3V in either N/A or FI configurations.

Deka 60. Have tuned the 80s on 93 octane without issues and the 60s have even better low pulse width control it seems like.

So the LU60 would be fine for my N/A 3V V8 even without the blower?

I would say so. I've tuned them on turbo 3v cars that wouldn't have been moving more air than stock at low pulse widths

Did you use the FRPP calibration sheet settings or did you have to tweak some/all of them to make them work?

I use the Ford data but suspect the low slope needs lowered. I usually just mess with MAF a little to get it close.

HPXe MAF and Deka 60 was literally within one percent or so WOT on a turbo 3v I tuned recently. Was running around 18 psi.

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Originally Posted by metroplex

American Muscle's page for the LU47 said those are not recommended for forced induction on the 05-10 4.6L 3V V8s for some reason. I think it might have to do with the tiny O-rings for the intake manifold side of the injectors... But those style (including the LU34A) are very different and my 4.6 3V never ran right with the LU34A (Boss takeoffs) no matter what I did.

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If I remember correctly, I think it has to do with injector height and a PD blower manifold on the 3 valves.

I've used the LU60s with a procharger without a problem in the past.

Have you tried LU60s with a N/A 3V? Do you have any tune files that you could share with the LU60 settings?

Not injector related but if your planing a supercharger for that motor check out department of boost. They make a manifold to put a stock gt500 blower on the 3v 4.6.

I looked at PD blowers, but I'm thinking more along the lines of a centri. Still looking at injector options.

Someone said LU47s allowed for vacuum leaks on the 3V 4.6, and I just want to make sure the nozzle pattern and fit is right for the 3V. The stock 24 lb injectors look like Siemens Deka IV's, like the LU60 and LU80 but the M39s are what they include in almost all the basic blower kits.

Would I have to tweak the LU60 settings a lot to make them work with the 3V?

I made a set of LU80's purr like a kitten in a stock 4.6. As long as your data is good, they'll do what you need them to do in 60s for sure

I've done 2 supercharged 3v's with the stock 07-09 47LB GT500 injectors and they are a pain in the ass to get the transient fueling right with them or at least they were with me.

Aren't the G302 GT500 47lb's shorter than the stock 3V injectors? Any experience with the FRPP 60lb (Siemens Deka IV) for the 3V? I'm hoping to use the FRPP settings without having to mess with transient settings.