GT186 - 4.6 or 4.89 final drive and which exhausts?

[Donnie]

OK chaps, at a point in the build where I can't decide on my gearing.

Basically it's already got a LI150 gearbox and 46 tooth rear sprocket.

Now, if I go 16 / 46 I end up with 4.89 final drive and I think i already have a stretched 80 link chain.

However if i go for the 17/46 I can get a 4.6 final drive and need to get a 81 link chain.

(I could go 4.8 ratio but then thats a 48 rear / 17 front and 82 link chain and not sure if its much advantage over the 4.89)

The big question is, which exhausts will suit which set up?

OK, I know some will ask what type of riding do you do, and basically im always one up, albeit 16.5 stone. I wan't it to be quick up through the gears to have a bit of a razz but not be running it's nuts off on dual carraigeway / motorway on the way to or from a rally. Mind you, with the lads I run with I won't be sitting anywhere over a genuine 70mph.

Oh and im running a 30phbh, wassell and mtech unit if that makes any difference.

[Donnie]

Forgot to say that the kits also had a boost port cut to match a third port in the casings behind the reeds.

[Lambretta Sash]

I've gt 200 kit on and tried 4.6 with Ron moss clubman it pulls well and can touch genuine 70 mph or 85mph gts speedo lol

I would of gone to 4.8 ratio but tried TT pipe 1st and tops out same mph, id go 4.8 to 5 with pipe

[eden]

so the TT pipe was no better than a clubman on top end?
interesting!

[Donnie]

Right google hasnt helped, whats a tt exhaust when its at home?

[a.j]

I've got two mates with Li150 boxes running gt186 kits. I'll find out tonight. I've got an iron 225 with a taffy exhaust and they fly past me no bother.

[Muttley McLadd]

I ran mine on 4.6. But it'd have gone better on a 4.8.
RS44 clubman on mine and a 30 mil carb.

[Donnie]

I've got two mates with Li150 boxes running gt186 kits. I'll find out tonight. I've got an iron 225 with a taffy exhaust and they fly past me no bother.

that would be great mate if you can

[storkfoot]

........Now, if I go 16 / 46 I end up with 4.89 final drive and I think i already have a stretched 80 link chain.

However if i go for the 17/46 I can get a 4.6 final drive and need to get a 81 link chain.

(I could go 4.8 ratio but then thats a 48 rear / 17 front and 82 link chain and not sure if its much advantage over the 4.89)

I have a standard GT186, albeit with a 115 conrod, 30 PHBH and MB Clubman.

I have the Li150 box and have tried 16/46 and 17/46. I found it struggled to pull 17 and that 16/46 is much the better of the two.

But, I do think that the ideal set up is somewhere between the two.

[Donnie]

I ran mine on 4.6. But it'd have gone better on a 4.8.
RS44 clubman on mine and a 30 mil carb.

I keep seeing good things about the rs clubmans i have to admit but who on earth stocks them? and what makes it a 44? stupid question i know, im assuming its just 2 mm bigger than a 42?