Expansion pipes

[Monty]

I asked this on the other site and did not relay get an answer.
Will an expansion pipe increase the revs on most standard lambrettas?

My Ancilotti improved the revs by around 500 over a cloverleaf will something like a Sterling or RS do the same?
I can not quite get my head around how these expansion pipes work, but understand that some have to have a high revving tune to keep then at peak output. Is it chicken and egg, got to get the revs with the kit or will it give more revs by itself?
I have the dreaded Casa 185 kit that has been designed for low down grunt and touring. Understood.

It just seems to hit a brick wall for revs that from the gearbox ratios is around 6000RPM, if I change the front end sprocket down its still does 6000 RPM but 4 or 5 MPH slower.
Dont mind changing the jetex 22mm but would like to keep it through the airbox

Casa 185 out of the box
Ancilotti 42mm
Jetex with 150 inlet, (the stud spacing is 150)
Li 125 gearbox 46x19 yes very tall but it pulls it fine, ran it on 17 for a while no more revs just slower
I dont want to be the Guinea pig and take a file to what was not a cheap kit
Any advice appreciated
Monty

[J1MS]

I asked this on the other site and did not relay get an answer.
Will an expansion pipe increase the revs on most standard lambrettas?

My Ancilotti improved the revs by around 500 over a cloverleaf will something like a Sterling or RS do the same?
I can not quite get my head around how these expansion pipes work, but understand that some have to have a high revving tune to keep then at peak output. Is it chicken and egg, got to get the revs with the kit or will it give more revs by itself?

The standard looking exhaust Clubmans etc... These dont give power in the same way as a true expansion chamber..... An expansion chamber setup to suit a perticular kit will usually allow that engine to pull higher revs on power than a clubman type exhaust.... The Ancilloti copy now available, would not be my first choice of Clubman type exhaust.....
If your setup suits a high torque low reving expansion chamber you might be throwing good money away. by buying an expansion chamber aimed at power at higher revs...... As your setup might not allow you to get into this powerband..... I would suggest a JL3 or somthing of that sort of charachteristic might be better suited.. as I would expect a good clubman exhaust to achive around 6500 to possibly 7000 rpm in top gear in the right conditions thats if the rest of the engine is set up properly... The Sterling is a bit of a copy of a PM pipe, aimed more towards mid power engines and would probably allow more revs but would, I think need a down gear on your setup...There are some with alot more experience of your setup than me and they will better advise, I just thought as you had little feed back I would give my thoughts....All the best

[corrado]

Will an expansion pipe increase the revs on most standard lambrettas?

Short answer is no.

The expansion pipe only allows your engine to reach the potential that the rest of the kit has. It won't in itself give you another 1000 revs unless the kit is tuned to rev high enough. If you fit a scootrs / sterling exhaust with your current set up you'll just end up with 3 gears plus overdrive for downhill / downwind situations. The fact is that it's NOT a performance kit, that's not what it was designed for. It's designed to be a straight swop for a std 150 / TV175 with all the benefits of alloy/nicasil.
I'd have the barrel tuned to run with a TM24 Mikuni or Dellorto PHBH26 to run through the airbox and with the clubman it should work with 17 x 46. I'm not sure if anything will pull 4.45 that 19 x 46 gives. LI 125 was designed with 5.65 final drive.
I know feck all about port timings etc but I showed a Casa kit to someone who does .... he took a quick look at it and said "that's no good, it needs tuning, a Mugello will p*** all over it."

[Mel K]

I don't know, but it will certainly be louder :bald:

[Monty]

Thanks corrado
At least thats a strait answer.
The problem is everyone gives you a bit of info based on this kit or that kit and no one seems to know the Casa kit. Yes its a grunty kit and I can cruse at 50 all day in 4th, yes a hill knocks it down to 3rd.
Everyone says I should put a 28mm carb and an expansion pipe on and I look at the buck per MPH increase as not been worth it. Getting 500 revs more but having to go down to a 17 front sprocket equals no improvement in speed.
At the end of the day I bought the Casa coz I didn't want to live on the edge of blowing up all the time.
PS just done yourself out of a sale, but a genuine comment that I appreciate
Monty

[corrado]

Thanks corrado
At least thats a strait answer.
The problem is everyone gives you a bit of info based on this kit or that kit and no one seems to know the Casa kit. Yes its a grunty kit and I can cruse at 50 all day in 4th, yes a hill knocks it down to 3rd.
Everyone says I should put a 28mm carb and an expansion pipe on and I look at the buck per MPH increase as not been worth it. Getting 500 revs more but having to go down to a 17 front sprocket equals no improvement in speed.
At the end of the day I bought the Casa coz I didn't want to live on the edge of blowing up all the time.
PS just done yourself out of a sale, but a genuine comment that I appreciate
Monty

I've talked more people out of buying scootrs / sterling pipes than I've ever sold.

It transformed my Imola thought, but that was still producing more power than a std 200 at 9,000 rpm, but as I found out they can easily go wrong at those revs.

[chris2470]

I always have wondered about the overall performance of the ScootRs/Sterling pipes as I have never seen a review of either pipe. However when I see other scoots nearly every other one is fitted with a stainless Sterling so are they that bad?? You will always get comments about the fact they are crap compared the a JL, Taffy, Devtour or the original PM pipe but they also cost up to a third of these and probably fitted to a TS or RB.
I pruchased mine from Corrado 2 years ago and 3000 miles later its still in perfect nick, only have a couple of muffler repacks so for this reason its got to be great value for money.
When I ride with other guys with a similar spec machine (std 200cc Indian Stg 4) such a mugello 186/200 fitted with a JL3 I would not say they have a performance advantage, if at all.

So I'm curious to know if anybody has some dyno results or real world experience of both pips.

[Monty]

I always have wondered about the overall performance of the ScootRs/Sterling pipes as I have never seen a review of either pipe. However when I see other scoots nearly every other one is fitted with a stainless Sterling so are they that bad?? You will always get comments about the fact they are crap compared the a JL, Taffy, Devtour or the original PM pipe but they also cost up to a third of these and probably fitted to a TS or RB.
I pruchased mine from Corrado 2 years ago and 3000 miles later its still in perfect nick, only have a couple of muffler repacks so for this reason its got to be great value for money.
When I ride with other guys with a similar spec machine (std 200cc Indian Stg 4) such a mugello 186/200 fitted with a JL3 I would not say they have a performance advantage, if at all.

So I'm curious to know if anybody has some dyno results or real world experience of both pips.

I think Thats the point I am getting at. The guys at the club range from the out and out boy racer with Imoloa ans TS but we have more of the cheaper Indian barrels that get a good slagging off, all with a sterling or Rs pipe, is it all show, like the noise, or are they giving a better output.

[corrado]

You have to match the exhaust to the gearing. I ran my Imola with 5.3 final drive with a scootrs / sterling exhaust (forget which one but I think they're exactly the same anyway) and with a TMX 27 mm Mikuni it was fantastic, it would keep up with modern GT200 Vespas and clocked with none Lambretta speedos at over 80mph, so I reckon it was a genuine 75 mph. When I did Lands End to John O'Groats with it I decided that as it was 80% motorways that I put taller gearing on it and change the exhaust to match. Forget the combo of sprockets (with Pacemaker gearbox) but the final drive was 4.99 and I fitted a Devtour exhaust. It absolutely killed it's performance, it no longer had the zip it had before and would struggle to pull 4th gear into headwinds and up inclines that it easily flew up previously. On paper it should have worked but for one reason or another it didn't. A mate with a lot more experience of tuned engines warned me that it wouldn't work and I wish that I'd of taken his advice but we live and learn. My thoughts were that if an SX200 with 10 bhp could pull 4.8 then my Imola with approx 17 bhp should pull 4.99 without a problem (I can hear Adam Winstone chuckling now). I ran it like this for a few more thousand miles until I blew it up on the M1. It still got to 75 but took much longer to get there and still had more pace than a TS1 200 and a Malossi 210 that I rode with. It was OK just not the fun it used to be. Would love to have had dyno plots of the 2 set ups but something I never got around to. It would be foolish (and incorrect) for me to now turn round and say that Devtours are no good as there's so many variables that effect the whole package. Fact is that a Devtour is still probably the best all round pipe out there IMO.
The fact that Monty's Casa kit can actually pull 4.45 gearing speaks volumes for the kit and how it produces it's power and torque though. I'd love to see how it would go with GP200 gearing, 5.2.

[Monty]

The fact that Monty's Casa kit can actually pull 4.45 gearing speaks volumes for the kit and how it produces it's power and torque though. I'd love to see how it would go with GP200 gearing, 5.2.

This is where I start to get confused, If I can not break the brick wall 6000RPM, GP200 gearing at 5.2 gives me 58mph but with the 4.45 I get closer to 68 on paper. The 125 box gives great torque for moving off at lights so I don't have to rev its nuts off like some at the club with 150 or pacemaker boxes.
I only want 500 more revs. It doesn't sound a lot.