So I put a new intake and exhaust (Arlen Ness Big sucker stage 1, and Samson Big Guns 3) on the Low Rider. However, I did not do an upgrade to the computer. I talked to the dealer today and it will take him over 4 weeks to receive the screaming eagle computer upgrade thing (I live in Italy). He recommended I take the intake off, as it will cause more damage to the engine than the exhaust will. Does anyone know what kinda of damage we are talking about? I know the stock engines run really lean, but will it cause that much damage and how soon? I am shipping the bike soon and don't have the 4 weeks it will take for him to get the part in. I won't be near a dealer when I move. Should I go back to stock, or buy a fuel management program myself and go that route. Any feedback would be great.

 

If you run an intake which lets in more air without adjusting the fuel mixture to match the increase, your lean condition will get much worse. And yes, it could damage the engine through overheating/detonation/all kinds of bad things.

Since the motor is an air pump, the amount in is the biggest concern. After all, the most open exhaust can only output the amount of air taken in. If it's too open you get into no back pressure which robs the engine of power, but that's not the case here.

I'm with the shop on this one. Put the stock intake on until the SERT comes in and is installed/tuned.

You could also consider XIEDs which send false signals from the O2 sensors to the ECM to enrichen the mixture (about $100) or get a different fuel management device.

Another option would be to use the "self adjusting" nature of the closed loop EFI to your advantage and put the stock intake on. Run the bike for a while (50 miles or so) with the new exhaust only to let the EFI adjust. Then put on the intake and repeat the procedure. Supposedly it can't handle two or more changes at once and since it is only allowed to adjust within a certain range (I don't know those numbers) it will fail. Doing one at a time helps.

 

You should indeed put the stock intake back on, but leave the pipes. A quicker route is definatly a aftermarket tuner. Might look into the auto adjusting tuners so you dont have to worry about getting the right map, and since you will be without a dealer when you move, having something that can adjust to modifications like that would be ideal. Good luck!