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Discussion Starter · #1 ·
Hi Guys,
It's been a busy time these last two weeks. A Honda Grom cylinder is out to the production machineshop to time how long it takes to install the 61mm sleeve. The Grom SLS head gasket & a CMM dimension sheet went out to the gasket manufacturer. I thought I would post a few photo's of the prototype exhaust system, that I just finished. I got to ride it for the first time today. I finished my billet air box inlet, and mounted the O2 sensor. I was very courious how the ECM would react to the changes, and the decrease in back pressure. I also removed the gas tank vent system. So there were a few major changes. The ECU seemed to handle the changes in normal fashion. It ran most of the time at 14.0/1, 12.8/1 under hard accel, 14.7/1 backed off throttle @ 50 mph. What's interesting is that the exhaust gas temp never got over 780'F. I would have thought closer to 1100'F or 1200'F for a cat. engine program
Brian





 

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That looks awesome ! :D
 

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Discussion Starter · #11 ·
More Work!

Lets see, what questions need to be amswered:
The base stainless muffler is from Cone with my welded bracket & spring mounts. It is too loud, nice tone, but too loud. I added a stainless washer to the end of the core, but it needs more. To be honest, the engine feels like it needs a little more back pressure on the bottom, Revised muffler this week. Please remember the main use for this exhaust is for the 170cc kit. I showed the dyno guy the Grom today, just to make sure it would fit on his dyno, it's so small. It will, with a little work, figure early Nov. I attached a air horn that I machined today to replace the extra rubber tubes in the air box. If you remove the 4" extension, without replacing the inllet, it will flow LESS air. There is a ledge inside the tube that needs to be filled in. I started to receive the components that I will need to re-engineer the swing arm pivots. By the end of the week, I'll have all the bearings & seals. It's a bit of a project, but I think it's worth doing. Anything can be made, but at what price point.
Brian





Guys, what I'm doing with all these parts is trying to see what parts make sense to manufacture, the parts that really do improve the engine & bike.
 

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....I attached a air horn that I machined today to replace the extra rubber tubes in the air box. If you remove the 4" extension, without replacing the inllet, it will flow LESS air. There is a ledge inside the tube that needs to be filled in.



Hey Brian, loving your work.
I did the air box mod and was also worried about that lip left after removing the extention pipe.
Great solution there with the inlet horn.

Dog
 

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just awesome. what else are you planning in terms of GROM parts?
 
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