Best exhaust and carb for torque on a Casa 185 kit?

[Pompeydave]

Hi all, just bought a Casa 185 kit for another engine I'm building. I'm trying to maximise low down grunt, so does anyone have any recommendations as to the best exhaust I could fit? Carb advice would be welcome too please. I don't want to pour fuel in for the sake of it, so a reasonably fuel efficient performance increase is my aim if poss....

[Mr G in NYC]

Running a 185 Casa on this with a 42 mm big bore and
a 25mm Dellorto through the air box. Very happy with
it ....my best scoot for zipping about the city on G.

[Toddy]

Built a couple both tourqey little motors both with 42mm Clubman and Jettex Ran well , will sit at 55 all day and economical , a Mate ran one with a 25mm PHBH and Anvillotti big bore again pulled him well and he was @ 16+ stone

[CHRIS in MARGATE]

Pal of mine who does the short and long haul runs with our lot runs 42 mm Clubman and 22mm Jetex on a TV 175 gearbox and he is just as fast as the rest of us. Ticks over, pulls away cleanly, restarts easily and returns 65mpg.

[Pompeydave]

Ok, cheers for the advice guys- the 42mm Clubman seems popular- would there be anything to be gained by going for an expansion chamber?

[CHRIS in MARGATE]

Depends on your gearing. You can't have everything. With the exception of the more expensive pipes, most give an increase in revs and mid-top end power at the expense of low down power meaning you have to keep the engine revs up to feel the power band which may not come in until well over 4500 rpm. Not necessarily a bad thing but if you haven't got the power low down then you will probably be changing down to 3rd a lot if your gearing is too tall.
My expansion pipe feels "dead" below 4200 rpm and the engine is unresponsive so I change down and rev it hard into the power band to get enough inertia to change up to 4th.
For the last rally knowing we had a lot of hills to negotiate, I put my Clubman on; felt like a new engine.

But .... Every engine is different.

[Pompeydave]

Ok, so I think that the statement: "With the exception of the more expensive pipes, most give an increase in revs and mid-top end power at the expense of low down power" it seems that a plain old 42mm big bore is the way to go. With this in mind, are any big bores better than others?

It's a shame really, as I fancied a noisy pipe on this one, but I won't get one if it's not going to aid overall performance. I'm getting the impression that with the Casa kit a 'less is more' approach seems to pay the best dividends

[CHRIS in MARGATE]

My Clubman is much noisier than my expansion pipe.

[Mark ULC]

Had a 48mm clubman which gave nice low down grunt. Changed to an Ancellotti and equal low down grunt but higher revs top end, beautiful sound. Now run a NK rally/road and better than the clubmans. Pulls well from 4500, great round town and on the main roads. It sounds great and not too loud.

[corrado]

ADS3 is a great expansion for low down grunt, I've seen some dyno graphs where it out Taffy's the Taffy.
As loud as Brian Blessed with a megaphone and your hearing aid turned to full volume.

[Pompeydave]

Would I get more low down out of a ADS3 than a 48 clubman or an Ancillotti then?

[speedy]

Why not try the AF 42mm vw reverse cone clubman if you want loud? Clubman but mega LOUD!!!

[Pompeydave]

Did a bit more research into this last night and I found a 2011 copy of Scootering that had a 15 pipe Lammie test. Admittedly, it was based on a TS1 cylindered engine breathed upon by Taffspeed to 'road' tune spec, and fitted with Varitronic ignition and a 30mm PHBH Dellorto, but the comparison is still valid between the pipes.

What it showed was that the ADS-3 was the 'Torque king', developing most of it way down the rev range from about 4500 upwards, but tailing off rapidly above 7000. However, the AF Rayspeed NK 'Road' pipe has a wider spread of power, but the torque doesn't start coming in until about 5000, hence it's not quite as relaxed and grunty low down. However, it holds onto the power for longer than the ADS-3, with a gentle drop off all the way through to 8500.

The final figures for the above engine were:

ADS-3: PEAK POWER: 22.3HP (11th out of 15 in a range of 24.8 to 19.4hp) PEAK TORQUE: 21ft lbs @5474rpm (1st out of 15 in a range of 21ft lbs to 15ft lbs), PRICE: £250 +P&P

AF Rayspeed NK Road: PEAK POWER: 24.7hp (2nd out of 15 in the same range as above) PEAK TORQUE: 20ft lbs @6284rpm (2nd out 15 in the same range as above), PRICE: £217 +P&P

This has left me with a dilemma- do I go for the out and out torque king, the ADS-3, or the pipe that won the group test overall but has slightly less torque lower down, the NK Road?

[Toddy]

I think the decision is what are you going to use the scooter for Round town shoret distance or long range touring those factors may help you decide

[Pompeydave]

Well, us Pompey lot usually meet up at McDonalds in Cosham on a Wednesday, have a liesurely ride out to a pub somewhere 10-20 miles away, and then usually thrash the pants off the bikes back to a burger van in Hilsea.

It's a bit of a mix really, but mainly around town I suppose. Maybe the ADS-3 is the way to go...

[foremanbob]

do I go for the out and out torque king, the ADS-3, or the pipe that won the group test overall but has slightly less torque lower down, the NK Road?

I had a ADS-3 pipe on my Suzuki 190, and it pulled really well; the kit was also setup by Harry Barlow to be a torquey motor.

However the ADS-3 pipe needed a 4.4 final drive to work the pipe, and the cliff wall was nearer 6000 RPM rather than 7000.

Great pipe but IMHO it only does low end torque and in the end for me the other compromises were too great.....

[corrado]

Yes gearing is critical with pipes. I'm running the ADS3 with a Mugello225 with reed valve and Mikuni TMX27., it was running with 5.0 final drive but recently lowered that to 4.7 and no drop in performance. I may try and see how low I can go before I have to start changing down to 3rd.

[Pompeydave]

4.4 is mighty high though- TV200 territory. I wonder if a 190 would pull gearing that high? In the article I mention above it suggests using a 4.4 final drive for an ADS-3, but that's with a TS1 engine which throws out a lot more power than a 190. Most of the pipes in the test were tied to an engine with a 4.8 final drive (TV175/SX200 box + 15/46 sprockets), so maybe your gearing was too high?

[speedy]

The NK is a fantastic pipe, but it is gonna work totally different on a 225 TS1 with an 80's tune, chucking out 24 horse, compared to a small block 185 kit chucking out 10 horses less. Speak to Ben or Ray at AF's to see what they would suggest regarding their pipe on the kit, versus a clubman or other. If it's any comparison, a friend runs a Casa 210 with a 22mm phbl through the airbox and a bgm big box clubman. It's not a fast bike compared to TS1's etc, but it really pulls and had no issues going to Davos and running with TS1's and other tuned and kitted scoots. Gives him about 60mpg too which is a bonus.cheers,Speedy.

[foremanbob]

Pulled it OK, and would pull well up hills etc, but I found when riding with a group the pipe wasn't where it wanted to be.... If you follow me. So I'd be hunting between 3rd & 4th and everyone else was happily tootling in 4th.

More power may have helped punch a higher gear, but moved to 4.4 when I found that I couldnt get above 60.