I have a Two Bros slip-on exhaust without a PC3, and I have noticed a big loss of torque at low revs. It's especially apparent at red lights. When it turns green, I have to slip the clutch longer and give it more juice to get going. Before, the bike would get moving immediately without having to use much clutch. Once the revs get up to 4k or so the power is back. It's just at those low revs it really suffers. Will a PC3 remedy this (I'm guessing no). It almost makes me want to go back to my stock can.

 

is everything coshure with you oxygen sensor???.........

 

Yes, I have the mid-pipe with a sensor bung and the O2 sensor is in there securely.

 

Your clutch could be sticking a little and you wouldnt really know

 

You lost back presure that helps low end power. A pc I think would help but not sure it's going to get you all the way back. regearing would be a cheaper fix or a combo if you what to do it all. I would certainly double check everything first. most people don't have any real change without going to a full system

 

Have you changed you air filter? If you increase how fast you get the air out of the motor but do not increase how much you take in, the slip-on isnt doing any good, also make sure your valves are properly adjusted. sport bike valves are designed for higher rpm's so its gonna be a little slugish in lower range anyways.

 

I'm talking really sluggish. I live in california so at stoplights once everyone's stopped, I go between the cars all the way to the front. For my own safety it's crucial that I can make a quick getaway! But since I got a pipe on, there's very little pulling power at the low revs. I have to get the RPMs to 3-4K and slip the clutch just to make a getaway that I could have made at 2K RPMs before.

I think I'm just going to put the stock pipe back on. If I tracked the bike or did a lot of high-speed riding, I'd consider a PC3 and an air filter to sort things out. But most of my time is spent at lower speeds, on local roads around here. Having next to no torque from the get-go can be hazardous to my health. I'll take much improved low-speed response to the slight gain (if any) the slip-on provides at higher engine speeds.

 

Put the stock slip-on back on to verify that the new one was causing the problem. If you find out that the new slip-on is causing a loss of torque then keep the stock one on there.

 

From what i remember reading, the bikes run lean in the lower to mid range to help with emissions, but run a bit rich in the top end for cooling. When you add a pipe,it makes the leanness (is that a word?) more apparent in the lower to mid range, but makes the top end feel stronger becaues it leans it out a bit. Could be wrong, but its a guess.

 

This what I would do to start. It is the easiest way to make sure you know the source of the problem.It is easy to be fooled if you make a change to assume that is the problem when something else malfunctioned at the same time.
I have not seen gas mix numbers on a stock F4i, but my02 doesn't seam to suffer from being over lean in low rpm in fact I believe it's a little rich like my xx. I'm sure some one has had there's sniffed before on a stock setup. What did you find out? also at low rpm assuming you dont have a nest of rats in your air box, it should be getting ample air with the stock filter.
If you really like the new slip on and it is the problem dropping a tooth up front should solve it for cheap.