Downpipe design

[Sheep]

All advice,thoughts etc welcome....

I am in the process of rebuilding my EFE's engine (1230cc) and I want to fabricate a new downpipe as the one I made last year was pointed out to me to be of incorrect bore size.When I had the chance to measure another downpipe it showed I was slightly smaller on the i/d...

Anyway,fast forward to the present and I am thinking of doing something slightly different...along the lines of a V&H/Muzzy sidewinder,I will put an image up at the bottom of this post

Ok,my questions are,will it effect performance a little/a lot/not at all in your opinions,in other words,will it be detrimental?..I am thinking of routing the pipe from the headers along the frame rail tucked under the right side under the pick-up cover rather than lower like the V&H system,I still want to be able to go around corners without scraping anything.

I think they look really good,especially on an old Suzuki....

Cheers peeps.

Edited February 6, 2017 by Sheep
Speling!

[Gixer1460]

As V&H and others were active in ProStock, these systems were / are designed to work at high rpm's - 12/13,000+ rpm due to short and fat primaries - 20 odd" x 1 and 7/8th" and to me, adding 'silencing' just eats hp through back pressure!

[Sheep]

If i were to use standard bore tubing as Suzuki intended but still mimic the curvy design would this still have this effect?..(.I could simply route the manifold like every other but i fancy doing something different.)

Doing some rough measurements shows my collector being not much closer to the exhaust ports than a regular 'under sump' manifold.

[teltwosheds]

So long as you work out the tuned width and length to the collector, you will have no detrimental effects. plenty of free to use calculators online 

[dixiethedog]

I love the design of the pro pipe's.  They do look extremely good on an EFE too.

Ive had a bit of a bash at doing pipe's myself. Im no expert, and would not pretend to be one. But I do think that as long as you can make each pipe the same length you should be able to create an exhaust that will work.

I dont know what experience you have with pipe work,but I find that starting with pre-made bend's make's thing's easier. I dont know the cost's today, but I used to pay about £5.00 a bend for my stuff. 316L Stainless steel by the way.

The bend's are available from the like's of here;

http://www.pipecenter.co.uk/

 

[dixiethedog]

Im not on my workshop PC at the minute, so dont have many pic's, but amongst other stuff I had a try at making some Mr Turbo style headers for a project.

This look's like it was part way thru the build, but it gives an idea of how bend's can fit together.

 

[dixiethedog]

Now, Im the first to admit my welding skill's are not tidy. lol

Luckily I discovered a disc system from this company;

 

[dixiethedog]

The grinding discs look like the "shite" you can buy anywhere for your grinder, but honestly they are not. They just seem to remove the weld and do NO damage to your pipework.

I was absolutely amazed when I tried one. They cost about £15.00 a disc but if you are doing pipe work and want a no weld finish are the best thing since sliced bread.

[dixiethedog]

Good luck.

[dixiethedog]

If you get stuck, I have (in the loft) a nearly new Star Racing Pro Pipe. I was keeping it for my own EFE but could be tempted to sell it. Possibly.

[Sheep]

Cheers guys....yeh I'm pretty proficient with a welder (its my day job lol) but any advice is always appreciated.I have a few pre-formed elbows in he shed but I am using metric pipe as opposed to dairy as its closer to the true/original size.Metric tends to cost a little more mind you.I also plan to use segmented sections to deal with any unusual shapes,plus I think they look cool,just a lot of work though.

I've fitted the flanges and stubs to the head ready to start fabricating.The only real problem i have is fitting it in between the frame and wheel.Most drag bikes tend to be raked further away leaving more room to play.

 

 

Edited February 7, 2017 by Sheep
Removal of non OSS picture.

[Gixer1460]

I managed to use a modified Star Racing Pro Spyder in a Kat frame using GSXR 400 USD's without a rake. It wasn't modified for fit just cos I used a GSXR head on an EFE bottom end.

[dixiethedog]

I used to run an EFE with a Star Racing pipe, with a Kwak ZXR400 USD front end. I dont recall any problem's at the front. 

It was the back end that caused me problem's. 

I used my EFE as my ONLY transport, 365 days a year. Rain,shine,snow, everything...

One day sitting looking at the bike, I figured I could get it a touch lower. So out came the grinder,and I cut the lock up strut's down and then rewelded them back together.

"That look's mega cool now" I thought. Helmet on, and off I rode. The first roundabout I came too,turning right,crunch noises from the megaphone end can thing. Oop's.

So, rather than lift the back end up, I used to (seriously!) plan my journey's locally so that I could avoid sharp right hand corner's.  If I planned it right, I could travel in a "square" type of route. Left,left,left..home.

What a tit. 

A piccy of the said bike. Partly stripped (no back brake)and wearing an odd set of panel's.

The pink paint stem's from getting sponsored from a sex shop. I havent a clue now how that came about.

[dixiethedog]

You can see the end of the megaphone is no longer round. lol. That pipe went off to a bloke called Alan who was building a race bike. I think?

[Sheep]

It looks like it still tucks up snug under the engine mind you....I'm planning to use a small can I already have in the shed with a tilt upwards to clear the tarmac lol.

[dixiethedog]

I'm sure a small can will be fine. I dont know what height you'll set the ride height on your bike, but hopefully higher than the height mine was. I think I had less than 3 inches clearance (ground to bottom of frame).

By the way, I had a dynojet kit fitted which allowed the bike to run very very quickly. I ran K & N style filter's too.

[Reinhoud]

On 2/6/2017 at 1:14 PM, Gixer1460 said:

As V&H and others were active in ProStock, these systems were / are designed to work at high rpm's - 12/13,000+ rpm due to short and fat primaries - 20 odd" x 1 and 7/8th" and to me, adding 'silencing' just eats hp through back pressure!

The silencer doesn't has to cause any back pressure per se.

If you take a perforated pipe the same diameter as the pipe what takes the four incoming pipes, and you take the outer pipe for the muffler about 3 to 4 centimeters bigger then the perforated pipe, that makes it quite a bit less loud... to a more "acceptable" level..

I made my exhaust like that, and it isn't that loud.

I must say, in Tasmania the police doesn't give a f#ck if your vehicle is loud, they just look at you and smile.  (as long as you're not going to fast, you get away with a lot!)

[clairetoo]

home-made drag pipe , used to ride it on the road but not too much due to a slight lack of ground clearance !

[Sheep]

Funny you should bring this topic back up because tonight I have mostly been cutting pipes about,again, after a slight altercation with the tarmac and pipe lol....I am now routing it tucked under some more...plus the can is fooking loud so the Yoshi is going to be bastardised!!

[Reinhoud]

I hardly read anything, best thing to do, is the thing you don't want to do.... Experiment!!

Almost every exhaust you buy is compromised, what do you want, low down power or power in the higher revs?

Runner diameter too big is also no good, gas speed goes slower, best thing is to make an exhaust from SS, SS doesn't conduct heat that well so the gasses get hotter, this is what you want, the hotter the gasses, the faster they flow..

Also, an exhaust shouldn't be too long, the longer the higher in revs the power gets available, no more or less power, just in a different rev range.

 

No 2 engines are the same unfortunately..

[Sheep]

Makes sense Reinhoud.....I just wanted something different really.Its all out of st st..runner length is not much shorter than my under-sump manifold and I tried my best to get them equal length as each other...i originally mated it to a 2.5" link pipe to a short fat can but this grounded out on sharp corners and the can was getting tiresome due to how loud it was.Today I have reverted back to a sensible 2" link pipe and Yoshi tri oval can.Sounds better,corners better.