A 2008 Ultra Classic I recently bought came with Rhinehart true duals. The bike has the stock air cleaner and ECM. The dealer who installed the pipes for the previous owner said the bike will run fine with this set up.

I realize that a high flow air cleaner and ECM map will increase performance and lower engine temps with better throttle reponse. On the other hand, my bike runs okay. The only thing I noticed is since the weather turned cold, I get occasional popping on deceleration. I asked a number of sources if the motor will be okay long term with the current set up. Here's what they said:

- Rhinehart Racing: Not changing air filter and ECM can be a problem
- Fuel Moto: Will not harm the bike by using Rhinehart with stock air cleaner and ECM
- Local Dealer A: Motor will run lean
- Local Dealer B: Bike will be okay

I'm confused. Has anyone installed true duals and retained the stock air cleaner and ECM map? How does your bike run? If there's any chance of damaging to the motor, I'll reinstall the stock exhaust.

 

Your bike came from the factory running lean for EPA purposes. It's probably running leaner now. You are probably getting excellent gas mileage too. It's a bad thing over time to run that lean. Get an air cleaner and at least a download at the dealer if not a real fuel management system.

 

I'm a bit puzzled, you say the stock air cleaner, but then mention a high flow air cleaner.

If the bike has the stock air cleaner, it can't pull in any additional air to further lean the mixture.

If only the pipes are changed, they can't make the engine pull in any additional air to make the bike run lean.

You should be fine.

 

My bike has the stock air cleaner.

An email I received from Rhinehart stated "Not changing the air filter can be a problem. Your engine is going to be getting rid of the exhaust much easier and will need to be replaced with more air flow. The stock air filter will not provide the sufficient amount of air needed to run the bike at certain speeds."

 

If you want the full benefit of your Rinehart pipes, you need to do a stage1 Air filter.
If you don't plan to do anymore engine mods than that, you can get by with the Dealer DL. Or buy a set of XIED'S. You don't have the Catalytic converter in the header. I had an 08 UC with jackpots and SE a/f and a set of XIED'S, the bike ran fine. Check them out at Tuneyourharley.com.

 

I'd follow Rinehart's advice - they designed and thoroughly tested the pipes. The bike will not perform as it should with the setup you currently have. Is it going to hurt anything, probably not...it just won't run as it should. True duals pipes (having no crossovers) like the Rinehart's were designed to be used with higher flowing air filters and a richer fuel mixture (controlled by the ECM) associated with the higher volume of air moving through the engine.

 

When I got my 09 SG I thought of just doing slip-ons. That summer I went to Sturgis and sat in traffic a few times around Chicago and almost burned the back of my legs off from the heat. I ended up getting Rinehart slip-ons and a Fuel Moto A/C and pre mapped PCV. My bike runs cooler for sure. If it wasn't for the heat I would have only done the slip-ons. I wouldn't waste any money on a dealer down load, it will still run hot.

 

I recommend a freer flowing intake and re-map with your Rinehart TD's. Your bike will run better and cooler.

 

An 08 ( no cats ) shouldn't run so hot as to make it ping but a PCV should fix your curious mind the minute you ride it for the first time.