Honda Grom banner

1 - 20 of 28 Posts

·
Registered
Joined
·
3,743 Posts
Discussion Starter #1
A good friend of mine who is a fabricator and i dreamed this up after looking at what was available out there. Not a big fan of low exhaust, and with no options for an aftermarket high-pipe, or of anything with a big I.D worth a shit, we made this . Inner diameter is 28mm at head-pipe and goes up from there. Using the tyga can for testing but getting another reverse cone unit from another source soon.


did initial test-rides last night, NOTICEABLE difference over the TYGA full system (which is a nice system but the head-pipe diameter was too small IMHO for a 4v head)


motor was also running about 10-12 degrees cooler when fully warmed up, and the initial checks of the fuel maps show it adding fuel in the mids and up high.

There will be a number of these available for sale soon. (with O2 fitting as standard) if there's any interest. as just a pipe or with muffler included.

all stainless, all tig welded. I am going to make one discreet support mount thats not on yet, and verify fitment on a stock bike. (no rearsets)













o2 sensor, located above cyl



slight undercut on the bung but hey, it was late.



backpurging



small bits being made on lathe (me)




welding slip fitting for muffler (me)





a comparison of stock headpipe and ours. flanges were laser cut to our specs




and testride. beer, wings, and pizza time.


beer-pizza-run.jpg
 

·
Registered
Joined
·
8,227 Posts
Very nice weld, no not nice weld excellent weld job, job well done.

I hope you guys sell a lot.

Coming from my Harley riding and Indian Scout riding I do not like any pipes that goes near any of my engine parts such as wires, cylinder and such.

I've been burnt so many times with pipes that sweep up next to my foot, calf and such.

I do like the size of the I/D of the pipe.

Hint on the WB 02 sensor mount the tip of the O2 should be just enough of it sticking inside the pipe but not in the flow of the exhaust to reduce exhaust gas exiting the pipe. I had a talk with Gromruckus about this and he has added a treaded spacer onto the bung unit until he had the tip of the 02 sensor barely sticking into the exhaust flow. Looking at you guys design my main concern would be the ease of taking off the 02 sensor unit for testing or replacing.

On a form fit and eye pleasing I like the lines that the stock pipe follows the Grom frame, but that is my own opinion and hopefully you guys won't take that as a negative on your project. In the world you can not please everyone and each person is given a choice to choose.

I was hoping someone would build a pipe with the I/D like you guys have made and it would follow the same lines as the stock OEM pipe follows but has a adapter pipe that will attach to the stock muffler, meaning you would have your welder cut the stock can connection point and add the pipe adapter welded to the stock can so you will have a flow of the bigger I/D to the stock can.

I just want a can that is quieter than my Finbro full exhaust can.

Good luck on your build and ride safe.
 

·
Registered
Joined
·
3,743 Posts
Discussion Starter #3 (Edited)
Thanks for the kind words.

The clearance of components isn't an issue when engineered correctly, leg burning, etc. you are nowhere NEAR this pipe with your leg or foot. Also, its is 1" more clearance than the tyga at the lowest point. . We liked this design and went with it especially since there was nothing else out there like it. Theres similar exhaust styles for my ducati by 'zard'.

There's a whole market of stock location exhaust, not interested in doing that, at all. Ity woudl have been a LOT easier to do that BTW. But easy is boring when it comes to design.

Thanks again, we like it. I am aware of the O2 sensor, note there's a spacer. Not too terrible for a 2 old farts in a shed. ;)

oh, and the 02 senor is super easy to get out, it was the last thing i put on before we ran it. I can take pics, but a 7/8 wrench fits right in and it slides right out the LH side of the bike. .
 

·
Registered
Joined
·
2,132 Posts
The real question... Will it burn my leg? (I see addressing above)

But yes. I call dibs on one.

Also, i thought you had switched over to some socket head caps screws for the exhaust flange on the head? I ended up getting some ones to fit the other day and im much happier with it. I forget the size, i want to say M8x1.25 - 30mm. I know i got ones that were too long and bottomed out, so i cut them down, (so 35mm initially)
 

·
Registered
Joined
·
2,370 Posts
The real question... Will it burn my leg? (I see addressing above)

But yes. I call dibs on one.

Also, i thought you had switched over to some socket head caps screws for the exhaust flange on the head? I ended up getting some ones to fit the other day and im much happier with it. I forget the size, i want to say M8x1.25 - 30mm. I know i got ones that were too long and bottomed out, so i cut them down, (so 35mm initially)

My problem with using something that you thread into the head for holding the header on... snapping it off in the head. You are more likely to snap the stud outside of the head where you can still grip on it to remove and replace the stud...
 

·
Registered
Joined
·
3,743 Posts
Discussion Starter #8 (Edited)
The real question... Will it burn my leg? (I see addressing above)



Also, i thought you had switched over to some socket head caps screws for the exhaust flange on the head? I ended up getting some ones to fit the other day and im much happier with it. I forget the size, i want to say M8x1.25 - 30mm. I know i got ones that were too long and bottomed out, so i cut them down, (so 35mm initially)
Thanks Guys,

well I was going to. however after i modeled up the flange i checked to see if a 13mm hex M8 nut would fit.. and it does. barely but it clears. so, IF anyone were to use this aside from US, then new (stud) hardware not needed. nuts yes. but we'd throw that in.

the studs are stronger but the bolts into the head are fine as well. if you crack a pipe into curb shits going to break. id be more concerned with breaking the head casting.

nut-clearance-flange.jpg


I can assure you you wont burn your leg on this pipe unless you crash and it lands on you.

as far as i know there isnt one that is 28mm ID, i think the finbro one is 26 or so. dunno. also, 28mm is the SMALLEST is this pipe has, and thats only for the 1st 13mm of the id at the head, then it goes to 29.5 and doesnt neck down smaller than that any where else.

pipe thickness is .060: (1.5mm)


i can assure you the pipe wont be super cheap. I have some testing to do and want to get the silencer i want on it. But so far all day its been good. :)
 

·
Registered
Joined
·
2,132 Posts
Points for solidworks and not creo or inventor, or *shudders* solidedge.

Per franco,

(for the 2v exhaust)
Showing 28mm dia. Not sure what the flange area or the ID actually is, but meh.
The 4v is 35.5mm dia.

Glad you went with the ~16ga rather than going to a .040". Weight difference is minor, and nearly always, stronger = better.

On the studs vs bolts, yeah. Its steel into aluminum. Id be more concerned with stripping the threads/damaging the head. And i guess cross threading, which couldnt really happen with a stud (unless you removed it or came bad from the factory). As i think about Kohler's small engines, some were studs, some were cap screws. id say 70/30 (guessing), but the cap screws were always bigger, like M10 (again, guessing).

Seeing this makes me want to make my own again... Hmm...
 

·
Registered
Joined
·
3,743 Posts
Discussion Starter #11
How much for the header
not 100% sure but with a new can we were thinking 625.

update on fitment: looks like stock rearsets are a no-go w/out modification.

as far as the ID goes: its LITERALY as big as it can go with 16 gauge to fit without making a rigid flange (not a good idea IMHO). we put a smaller ring inside to give it a flange surface to have soemthing to seat against but might forego it on the next ones. just needed meat for the pipe to sit against the head w/out cutting into the gasket and/or head.

yeah SW. 'inventor' blows dog.
 

·
Registered
Joined
·
671 Posts
update on fitment: looks like stock rearsets are a no-go w/out modification.
lol! I thought ''dirty cheater'' when I first saw your rear sets! :witless:

Very nicely done, makes me want to be a bit more of an old fart in a shed... :encouragement:
 

·
Registered
Joined
·
3,743 Posts
Discussion Starter #13
im pretty sure you would only lose the rear brake light switch tabs. i'll mock it up in a day or 2 and see.
 

·
Registered
Joined
·
3,743 Posts
Discussion Starter #14
So, I spoke to david, guy who helped me build this. we could do lower stock location kits, in the same fashion. any interest? prob be in the 550 range pricewise. If no interest that's fine as well.
 

·
Registered
Joined
·
3,743 Posts
Discussion Starter #17
so far very good. silencer showed up so a bit of this and that and here it is. its much deeper tone, sounds pretty amazing. packing is steel wool so it wont blow out. will get vid clip in day or 2, have to move kid from apt to apt tomorrow (college).

note weld on #3, that was 1st weld on can.. packing asted as heat sink so looks a bit 'cold' there, will repair with torch tomorrow. Had to test-ride before tomorrows activities. :)

grom-muffler_1.JPG grom-muffler_2.JPG grom-muffler_3.JPG grom-muffler_4.JPG grom-muffler_5.JPG
 

·
Registered
Joined
·
5 Posts
A good friend of mine who is a fabricator and i dreamed this up after looking at what was available out there. Not a big fan of low exhaust, and with no options for an aftermarket high-pipe, or of anything with a big I.D worth a shit, we made this . Inner diameter is 28mm at head-pipe and goes up from there. Using the tyga can for testing but getting another reverse cone unit from another source soon.


did initial test-rides last night, NOTICEABLE difference over the TYGA full system (which is a nice system but the head-pipe diameter was too small IMHO for a 4v head)


motor was also running about 10-12 degrees cooler when fully warmed up, and the initial checks of the fuel maps show it adding fuel in the mids and up high.

There will be a number of these available for sale soon. (with O2 fitting as standard) if there's any interest. as just a pipe or with muffler included.

all stainless, all tig welded. I am going to make one discreet support mount thats not on yet, and verify fitment on a stock bike. (no rearsets)













o2 sensor, located above cyl



slight undercut on the bung but hey, it was late.



backpurging



small bits being made on lathe (me)




welding slip fitting for muffler (me)





a comparison of stock headpipe and ours. flanges were laser cut to our specs




and testride. beer, wings, and pizza time.


View attachment 27809
Hope you are still wanting to sell that beautiful pipe, or maybe the design. I would love to have it on 2017 honda grom.
 
1 - 20 of 28 Posts
Top