Dear Motorhead:
I am interested in an aftermarket dual exhaust system for my 2011 Polaris RZR 800.
Will it do engine damage to my machine if I run the system without using a fuel controller?
The whole machine would be left stock except for this exhaust system and I would probably be using quiet cores as well.
I love your show and never miss an episode, keep up the good work!
Thanks,
Kyle
Kyle:
Thanks for your email!
Your question is impossible to answer with a 100% for sure response, but I can tell you about our experience with the RZR 800 mill and both single and dual exit exhausts.
Thus far we have not used any modified ECU’s with any aftermarket RZR systems – however, that doesn’t mean we shouldn’t have used one!
4-stroke EFI engines are much more tolerant to air flow changes from intake and exhaust mods than 2-stroke engines. Having said that – the benefit of an aftermarket exhaust should be improved performance and its pretty hard to get all a free flowing aftermarket system delivers without changing the fuel map.
Most of the time, the free flowing nature of an aftermarket exhaust simply “fools” the engine’s stock ECU – it doesn’t know anything has changed so the engine becomes leaner by virtue of the new unrestricted exhaust system allowing more air to flow and thus leaning out the air/fuel ratio in the combustion chamber.
If you take the lid off the airbox – if that’s practical given deep water forays can flood the mill without the cover on – you’ll often experience even more performance from the combination of less restriction at the intake and exhaust ends of the mill. FYI – Lean = more power.
So…what does the exhaust maker recommend? If they believe the system needs an ECU change and they’re saying you’ll hurt the engine without it – you better get it when you do the exhaust.
Hope this helps!
Thanks,
Motorhead Mark
