GS 1085 Wes Cooley replica

[Ade]

I was asked to modify the exhaust on a Wes Cooley replica because the end can it had was too modern and at the wrong angle. I got it looking similar to the stove pipe Yoshi on the original.

[mkoppeser]

Noice! 

Gotta love the bands on that Yosh header though.

[mkoppeser]

Shit.  Love the "bends"....stupid auto correct

[CockneyRick]

Very similar to mine, although my one has a shorter length.

[Fazz711]

They remind me of the old Alfa and piper 4-1

[Ade]

Mk1 pipe is too restrictive. Mk 2 is being worked out with 63mm tube and proper baffling.

 

[fab]

it would be a very loud pipe wouldn't it?

[HUM]

Very loud ?!   it is like very much cheese  or very much beer  = nearly not  possible in principle , or rather a formula that is not logical    

[Ade]

16 hours ago, fab said:

it would be a very loud pipe wouldn't it?

It's not so much noise that is the problem, although the owner does classic track days so needs it around 108dB to pass scrutineering. At the moment the 2" pipe is restricting the power of the 1085 tuned motor even with no dB killer fitted. As soon as we fit a dB killer it chokes up even more. The 63mm pipe has 60mm bore where the 2" pipe only has 48mm bore. I have some 2" perforated baffle tube. The plan is to make a freer flowing semi quiet pipe that lets all the power of the motor out. 

[Ade]

On 3/17/2020 at 1:30 PM, CockneyRick said:

Very similar to mine, although my one has a shorter length.

What diameter is the end pipe on yours? And what is the baffle like?

 

[CockneyRick]

I actually chopped the baffle in half cos it felt a bit strangled. As for size, no idea but i'd guess at 52mm?

[R1guy]

I saw a Yoshi pipe to this recently, external diameter was advertised as 70mm

[Ade]

Mk2 pipe is being made Monday, I'll update with new pics then.

 

[Ade]

Mk2 pipe is done. 63mm tube with 2" proper baffle tube the full length of the straight part at the end.

[Ade]

I made baffle support rings from sections of tube welded together, it was cheaper than buying a billet of stainless and turning some.

[Ade]

I used a 63mm 45degree bend but it wasn't quite right.

I cut one leg off to weld on the other end to make the length right to the reducer. The reducer is actually used as an expander 2 " ID to fit the original header/link pipe, 60mm OD to fit inside the 63mm tube. I cut the 60mm section down a bit just leaving enough to line it up square in the tube. I drilled the 2" bit for the slots but didn't cut the slots until it was welded.

When I had welded the bend to the extender and reducer I worked out the right angle to fit the straight end tube. The lower baffle support was used as a slug to brace the two sections together so it's all welded solid. The 2" baffle tube fits from the end to where the support is at the bracket.

[Ade]

The angle of the pipe isn't quite right yet, it was just test fitted. The pipe is being painted black and will be adjusted to the correct angle when refitted. It works and has a deeper sound than the Mk1 2" pipe. It lets the motor make full power all through the revs. The first pipe was great low revs but choked up at high revs, now it revs out. It is way too loud with no baffle wadding but at least a little wadding can be added to tone it down now. It can have a regular db killer fitted to tone it down a bit more without choking the motor.

 

Edited May 22, 2020 by Ade

[fab]

you do some nice work, should look great

[Ade]

Mk 2 pipe is painted and fitted at the right angle, looks good to me.