Exhaust Shoot Out Results

[muttsnuts]

Ok, first off, apologies for taking so long to get these posted up, but I've been very busy, secondly, I've written it all up into a document, so what I've put below is a precise of it.

If you want a copy of the full document, please PM me with your email address and I'll send it, its in PDF format and is 2.8MB's in size and contains lots of graphs and information etc.

Below is a summary of the results;



The next page is after I spent an hour on the dyno setting the bike up to run better with a set of TSA's on it



and the final page shows the improvement over the stock pipes compared to the TSA's - some difference !!

[steve h]

Nice work Mutts!

[1966baz]

Interesting results, very and prob similar characteristics to my bikes - {4lo with standard pipes, 31k Hybrid with Allspeeds and F2 YPVS with TSA'S. My Hybrid feels very quick to reach max power in each gear, but I think the F2 would win a race on a long straight with the TSA'S on it.Thanks for putting up the results Mate. Cheers Nick.

[midlifecrisisrd]

Good work there.

Must be a really good standard set up to get 41bhp out a standard set up when Yam claim 47 at the crank.

Credit to you

Steve

[copper99]

A very interesting read, thanks for taking the time to post the results and to all those involved for organising.

[Splodge]

At last some one has put all that 'pub talk' to rest and actually proven once and for all which pipes work best, TOP JOB FELLA

[steven]

Thanks very much for your time, very interesting reading.

[seahorse83]

Thankyou for the great report there Mutts,

Glad I bought my Kenny's a few years a go after I seen a report from Ian Booms bike, but at the end of the day they are all close. Would have been interesting to see a set of the claimed famous TRUSA and standard 31k pipes in the mix.
At any rate a big well done to Kenny TSA pipes, has anyone sent him a PM, he would be bloody happy.

Also Mutts is it possible to type what motor specs the test was on, for example ( 31 k pv motor, Vm 26ss Non Power Jet carbs, 25 pilots, mains 270 left 280 rights etc.) Or PWK specs if your running those carbs.
Kind regards Seahorse Perth Australia

[bare]

Yes V interesting info.
Notable to see that the venerable / noisy Microns are still 'up there'.
Not too shabby for 30 yr old efforts.
Actual HP numbers are erm.. always suspect, unless done on a decent Eddy dyno.
But the relative differences are the important bit Not necessarily the Number listed
(largely explaining the why of 41 hp in a Good Stock 350 LC, when 'in the day' testing only found 35/37 hp )

[jools]

An excellent investigation, hats off to all.

Whee the dyno tests carried out with a top gear roll on ?

Of interest to me was the actual time to reach peak power: 8.3 sec of the standard pipes to 11.2 sec for the TSA - that's a 5 second difference and shows how good the stock pipes are
for normal road use and the TSA's actually lose power in comparison to the stock pipes in that vital mid range area between 4500 - 6500rpm.
(If you don't think this is relevant check out your average cruising rev range next time you are out for a ride!)

I have heard that with some modifications the stock pipes are good. Looking at those graphs if the stock pipes could be modified to rev out as far as the TSA's they would be very good.

Having said that all the pipes in the list would probably give improved BHP and torque figures with time spent dialling the carbs in, as mentioned though this wasn't the object of the test.

Can I request that the second chapter does this LOL

[zedixe13]

You can share your PDF on :

www.sharepdfbooks.com/

It's free and there's no need to get a user account , just post the link .

[Deleted]

Great write up mutts
I was there at the dyno and the roll on tests were done in either third or fourth gear, third I think on a 4lo rd350lc with standard barrels, banshee racing coils, and kr1s carbs with standard air box. In fact it's the same set up as mine except mine has allspeeds pipes on. Now when dave had the allspeeds on I rode his bike and it felt the same as mine. At the two stroke meet at squires he had the kennys pipes on and he have me the honour of riding it. It was totally different and you do have to have your weight over the bars in first two gears, I did overtake a car in third and just on power the front wheel came up a couple of inches. I then did the ride out on my bike and to be honest my bike felt like a 250 in comparison. Needless to say my kenny pipes are on order and have asked for them just before Xmas which kenny was quite happy to do

[muttsnuts]

Hi Guys, all of the info requested is in the doc I mentioned, it details engine spec, how the test was done, what dyno was used, what calibration was used and a whole host of other info and it does indeed detail how the TSA pipes performed after an hour's set up on the dyno.

In respect of the point about losing mid-range, all pipes are a compromise, the mid-range dip has been smoothed out a lot after the setting up and with another hour or two on the dyno should be possible to eliminate it give or take, te point here is that if you just bolt a set of exhausts on then you can expect to have something like the above, if you spend sometime setting them up (on a dyno preferrably) then you will see gains and of course will come down to what you want.

I'll have a look at the pdf share and if it looks ok I'll post it up there for all to access

[tsa]

Thats fantastic work you've done there mutts most interesting. Id like to send you a set of my new LC pipes at some time and you can put them back to back if you are willing. These lower the peak rpm and add valuable midrange just for the LC.

[muttsnuts]

Sept 26, 2013 10:31:54 GMT 1 tsa said:

Thats fantastic work you've done there mutts most interesting. Id like to send you a set of my new LC pipes at some time and you can put them back to back if you are willing. These lower the peak rpm and add valuable midrange just for the LC.

Hi Kenny, no problem, just let me know when and I'll see about booking some time on the dyno, I am hoping to finish off my setting up of the current pipes on my LC in the next week or two, but I need to get my van sorted first and get a few peoples jobs out of the doors as well.

Glad you enjoyed the read, you did get my email I presume?

[muttsnuts]

Sept 26, 2013 11:02:49 GMT 1 headcoats said:

Great results and like you say stock motor etc but just look at the gains with just going a little further with a tune on the barrels,V force for a start

hoping to do something with that next year, but its expensive all of this, so far this year I've spent in the region of £2k on the dyno and buying parts etc, money I doubt I'll ever make back in reality, although it does help me advise my customers and sort their bikes out etc.

Its great and really appreciated by me that all of you guys are so positive about what I have done, not just on this test but also the mid-range postings etc I did earlier this year, I have a good number of things I want to try and I also want to do a very similar thing with the A/C RD's, although the 250's are different animals to the 400's, so its 2 bikes worth of testing etc.

For me to take the 350LC further I need to sort out some barrels so that I can do small tweaks to the ports etc, but finding a set of barrels with standard porting isn't easy or cheap (anyone got some they want to donate?), my next test is to sort the squish on the head out and see what difference that makes, I have 2 heads to go at, I'll start by taking one down from the 1.7mm to 1.2mm and the other down to 1mm and then trying them, of course this is expensive as well since I will be using genuine Yamaha head gaskets !

I know some poeple suggest a squish of 0.9mm or even 0.8mm but I think that is probably pushing it for the crank, although I am building a new crank at the moment with TZ big ends, so if I do decide to push the envelope it will hang together all being well.

You see, there's another couple of hunderd quid just in the crank, let alone the cost of stripping and rebuilding the engine, it all adds up !!

Maybe I should set up a donation scheme..........

[jollyjoiner]

Great work, and thanks for putting in the effort and sharing it with us all

[carioca656]

Sept 26, 2013 13:03:23 GMT 1 muttsnuts said:

Sept 26, 2013 11:02:49 GMT 1 headcoats said:

Great results and like you say stock motor etc but just look at the gains with just going a little further with a tune on the barrels,V force for a start

hoping to do something with that next year, but its expensive all of this, so far this year I've spent in the region of £2k on the dyno and buying parts etc, money I doubt I'll ever make back in reality, although it does help me advise my customers and sort their bikes out etc.

Its great and really appreciated by me that all of you guys are so positive about what I have done, not just on this test but also the mid-range postings etc I did earlier this year, I have a good number of things I want to try and I also want to do a very similar thing with the A/C RD's, although the 250's are different animals to the 400's, so its 2 bikes worth of testing etc.

For me to take the 350LC further I need to sort out some barrels so that I can do small tweaks to the ports etc, but finding a set of barrels with standard porting isn't easy or cheap (anyone got some they want to donate?), my next test is to sort the squish on the head out and see what difference that makes, I have 2 heads to go at, I'll start by taking one down from the 1.7mm to 1.2mm and the other down to 1mm and then trying them, of course this is expensive as well since I will be using genuine Yamaha head gaskets !

I know some poeple suggest a squish of 0.9mm or even 0.8mm but I think that is probably pushing it for the crank, although I am building a new crank at the moment with TZ big ends, so if I do decide to push the envelope it will hang together all being well.

You see, there's another couple of hunderd quid just in the crank, let alone the cost of stripping and rebuilding the engine, it all adds up !!

Maybe I should set up a donation scheme..........

hi maybe something could be done like they have on the aircooled rd forum have a project x bike I don't know how it would work though just a idea

[arrow]

Sept 26, 2013 13:09:35 GMT 1 jollyjoiner said:

Great work, and thanks for putting in the effort and sharing it with us all

+1.

[tsa]

Squish doesnt strain the crank as much as comp ratio. Its fine to have 0.9mm squish as long as you keep comp down. 6.6:1-7:1 is ok on the road but much more will put lots of extra pressure on the weak link THE CRANK. Going to 0.9mm is ok as long as if you have to change the pistons, gaskets etc these are all the same as the ones you took out in dimensions. Id say 1.1mm squish will give you a far better margin for error.

[JOHN-DYNOSTAR]

Sept 26, 2013 10:31:54 GMT 1 tsa said:

Thats fantastic work you've done there mutts most interesting. Id like to send you a set of my new LC pipes at some time and you can put them back to back if you are willing. These lower the peak rpm and add valuable midrange just for the LC.

tsa; This would be interesting to see.



most of the the results have been rather suprising and I have gone from slightly interested to ,wow ! what if, and how, and could you
it was a good test day

[muttsnuts]

Sept 26, 2013 14:34:05 GMT 1 JOHN-DYNOSTAR said:

Sept 26, 2013 10:31:54 GMT 1 tsa said:

Thats fantastic work you've done there mutts most interesting. Id like to send you a set of my new LC pipes at some time and you can put them back to back if you are willing. These lower the peak rpm and add valuable midrange just for the LC.

tsa; This would be interesting to see.



most of the the results have been rather suprising and I have gone from slightly interested to ,wow ! what if, and how, and could you
it was a good test day

Hi John, good to see you on here, credit to you for being so patient with the old strokers and me of course !!

Will be popping round later today to see if I can crack that bloody NAS issue which is bugging me !!

I'll have to drop the doc round for your to read etc, no doubt I'll have some more dyno work for you very soon......

[Deleted]

Certainly will john. When my tsa pipes come I will want my bike setting up on your dyno again

[muttsnuts]

Sept 26, 2013 14:07:34 GMT 1 tsa said:

Squish doesnt strain the crank as much as comp ratio. Its fine to have 0.9mm squish as long as you keep comp down. 6.6:1-7:1 is ok on the road but much more will put lots of extra pressure on the weak link THE CRANK. Going to 0.9mm is ok as long as if you have to change the pistons, gaskets etc these are all the same as the ones you took out in dimensions. Id say 1.1mm squish will give you a far better margin for error.

Totally agree Kenny, I am making a re-profiling tool at the moment so that if I do take the squish down I can adjust the comp ratio's accordingly, I want to keep reliability as well and too high a compression will knock the bottom end out, I've not worked out what I think a good setting would be, too high might give good gains, but will shorten the engine life and reliability, but upping it by a small margin should yield some results if done carefully without compromising reliability and engine life

as usual its all about one change at a time and then checking/testing it

[rich]

Very interesting stuff, many thanks for taking the time to do the tests and compile the results

[foxyjohn]

Thanks for taking the time to do the dyno tests & posts the results muttsnuts I think we all owe you a few pints of Guinness

[seahorse83]

Sept 26, 2013 10:31:54 GMT 1 tsa said:

Thats fantastic work you've done there mutts most interesting. Id like to send you a set of my new LC pipes at some time and you can put them back to back if you are willing. These lower the peak rpm and add valuable midrange just for the LC.

Very Interesting Kenny, I just happen to be building a 4lO hybrid, can they be black, do return customers get another beanie ?

[seahorse83]

Sept 26, 2013 8:34:26 GMT 1 muttsnuts said:

Hi Guys, all of the info requested is in the doc I mentioned, it details engine spec, how the test was done, what dyno was used, what calibration was used and a whole host of other info and it does indeed detail how the TSA pipes performed after an hour's set up on the dyno.

In respect of the point about losing mid-range, all pipes are a compromise, the mid-range dip has been smoothed out a lot after the setting up and with another hour or two on the dyno should be possible to eliminate it give or take, te point here is that if you just bolt a set of exhausts on then you can expect to have something like the above, if you spend sometime setting them up (on a dyno preferrably) then you will see gains and of course will come down to what you want.

I'll have a look at the pdf share and if it looks ok I'll post it up there for all to access

That would be awesome Mutts, will be interested in seeing what carbs you used, and what needle, pilots and mains. 

Thanks again for the write up, love your work.

Kind regards

Seahorse

[Deleted]

Foxy's bike has kennys new midrange pipes and it had a go on that at squires too ( maybe I am the only one to test both types of kennys pipes ). On foxy's bike power does indeed come in earlier from about 3k you can feel it but seems to run out off steam at top end, a bit like allspeeds do. I liked both pipes but for different reasons. If I was just going to ride sensibly on the road, then I would go for the midrange pipes. As it is I ride fast on the road and go on track too so it is kennys old type pipes I have ordered. But that's just me and as I say kenny can now supply you with a choice of pipe to appeal to most

[foxyjohn]

Mick I am sure you are the only one to try both sets of Kennys pipes the midrange pipes Kenny made for me pull cleanly from 2k @ 3k they start to make good power @ 5k they pull really hard all the way to 9k this is what I asked Kenny for when he designed the pipes so i am well happy with these pipes they perform brilliantly on the road with out high revs but it depends how you want your power the choice is yours with Kennys pipes