If you put a regular 670 pipe on a snowmobile with the 670HO engine, how much horsepower do you loose? I am in the same predicament.

 

You’d never notice if there was. The problem lies with fitting it. Even if the exhaust is full and complete(with can),the exit location through the body of the machine might be in a different location. Some fabrication might be in order. Just so you know, the cans are not interchangeable. I put a full HO exhaust on my mod 97 MXZ, and I had to make it fit and had to modify the can. The hole exit location through the body is slight further back to towards the rear of the machine. If you’re really worried about the loss of a couple hp, you could shorten the y-pipe. The HO pipe is about a 1/2 inch shorter. I’ve had them side by side and measured both. They are tuned to 8k instead of 7700.

 

Perhaps a parts sled might interest you? It’s surprising how many parts a person robs off them. Lol.

 

For what it's worth, Jaws will make you a pipe for the MXZ 670 HO - and I think it's the same pipe as the summit (I think Y pipe is different but not pipe). They used my old Haikonen sled to measure and mock it up and it was a very high quality part, definitely noticed some added power. I'd strongly recommend giving them a call to get one.

 

Thanks for the feedback!! Yes.. It looks like I will have to go that route. I also have a 1999 SkiDoo Summit with the 670HO engine and I tried putting its muffler on the MXZ but it seems like the MXZ engine sits lower in the front so the muffler touchs the plastic moulding.