How quiet can an EFI 450 become?

[Mikec265]

Just wondering if anyone knows how quiet you can make a 450. I'm sure there'd be a drop in power, but would the EFI adjust itself to a majorly corked silencer. I remember those old Supertraps that a lot of quad guys ran years ago. They were pretty damn quiet.

Anyhow, I was just pondering ideas to ride in stealth mode if my MXR is disabled.

 

[Rix]

Just wondering if anyone knows how quiet you can make a 450. I'm sure there'd be a drop in power, but would the EFI adjust itself to a majorly corked silencer. I remember those old Supertraps that a lot of quad guys ran years ago. They were pretty damn quiet.

Anyhow, I was just pondering ideas to ride in stealth mode if my MXR is disabled.

When it comes to making gassers quiet, the bigger the exhaust muffler, and smaller the exhaust pipe is key. of course this usually comes at the price of output power loss. In my experience, nothing beats the stock set up for being quiet on offroad approved Motorcycles. That being said, take any closed course MX bike, put a FMFq4 on it, it will probably be quieter.

 

[Philip]

You'd have to re-map that EFI for the bike to run normally. The dirt bike EFIs are pretty dumb. They do not measure the airflow (right??), they do not have Lambda sensors or knock sensors. They assume the bike remains the same way it came from the factory. If you drastically constrict the exhaust, it will run crazy rich.

 

[Mikec265]

If the EFI is that bad, maybe I should custom fab a longer can for my RM250 or my other RM with a KX500 stuffed in it. Then re-jet.
I don't want to go back to changing oil and filters all the time. This MXR has me spoiled with the lack of maintenance and cheap mix of 110/240 octane race gas. Everytime it's dusty I just think how nice it's going to be not changing any filters. Maybe I just have a severe phobia of my all-time favorite bike being a paper weight.

 

[Philip]

Buy a second Alta. You will have more fun and will sleep better at night.

 

[Mikec265]

I've thought about it but I'm too cheap to spend the money yet. I'm hoping this thing lasts until something comparable is available. Worst case I'll just ride gas bikes before 5pm for a while.