I am running 9lbs boost on my procharged f150 and while shifting gears I lose so much power. It takes about 3 or 4 seconds for it to start making boost again while it sort of sputters and feels like there isnt enough fuel getting to the motor fast enough? or maybe it is pumping too much fuel while im shifting? The wideband reads about 12.6 with 9lbs boost



Ford F150 4x4 4.6l 5 speed 3 core intercooled-procharged, true dual flowmasters

 

12.6 is lean. Needs to be in the 11's. But other than that can you give us more details? When did this start? How long have you been boosted? Fuel system mods? Tuning?

 

Are you running a FMU or are you using larger injectors and a MAF with enough resolution to read your air flow? Are you running a stock fuel pump or an upgrade? If you have fuel upgrades, do you have a suitable tune? Have you ever data logged your truck?

 

The procharger was finished yesterday. The kit came with an alternate fuel pump that jacks up the fuel pressure. And procharger says it doesnt need to be tuned if it is stock maf and injectors. I have a lightning 90mm maf, 42lb injectors, and a 255 fuel pump(not installed yet). I figured I would see how it runs before I put those parts on and have to get it tuned.

Thanks for the help!

 

I have a 90mm maf, 42lb injectors, and 255 fuel pump. That I havent installed yet. I am running stock fuel pump along with the one that comes in the kit. Stock calibration so it doesnt need to be tuned? I did install an sct tuner but I put it back to stock when I put the procharger on.

Thanks!

 

It is normal to loose a few pounds between shifts because of the rpm change between gears. But it should not sputter. That is a leak. Go over your install and check all the connections to be sure there are no leaks and the clamps are tight. It took me a week to get them all tight enough to not blow off and stop leaking.

 

You do know that the injectors and MAF and not plug and play? You have to have a tune that has the correct transfer function for that specific MAF and the correct injector settings (slope, offset, etc.) need to also be updated, before you can install them. You would need to get someone to write you a tune that has the updated parameters in order to install those components. Likewise, you would remove the FMU, which would be a device they had you install between your fuel pressure regulator and the return line to the tank.

 

get a tune...

 

If you correctly installed a complete kit from Procharger it should not sputter. While it is not the ideal way to use a Procharger, it will work.

 

are you running the stock procharger bypass valve??? if so it's probably leaking as well as the drop in RPM causing the loss in boost...

 

It does sound like the bypass needs to be tightened up, but iirc the one provided with the Procharger is the Bosch, black one, which is not adjustable. I would think that with a manual trans, it would help a lot to limit the bypass action, either by using one with an adjustable diaphragm or modifying the Bosch.
Discussed here beginning at post # 50:

https://www.f150online.com/forums/su...stalled-4.html

 

This is what came in my kit.



It is adjustable in that you can set how much it opens the valve but even fully closed it leaks. In the past I contacted Procharger about this and they said it was designed that way and that the leaking was normal and it would not change things if it didn't. I chalked that up to Procharger standard response #75 and left it at that. I had a replacement butterfly fabricated and it leaks less but it still leaks. One of these days I will get around to getting one that doesn't leak.

What I have done to reduce pressure loss during shifting.

1- Better bypass valve. Get a bosh/ piston bypass valve or fix the Procharger system.
2- Shift faster: I have a Hurst short throw. My clutch is fully disengaged when the pedal is pushed in 1½ inches.