Suzuki 2 Strokes

Has anyone ever had any experience with these?

http://omarsdtr.com/Ex750suz.html

The price is right, but is it good for the money, or just cheap?

They boast low and midrange power which is more what I'm after than a peaky high rpm machine.


Thoughts? Opinions? Warnings?

Hi,

If you searc the forum you will find many treads about exhausts, alo this particular model from Omar. Also other 3 in 1pipes are to find.

Like here:

viewtopic.php?f=2&t=8228" onclick="window.open(this.href);return false;

viewtopic.php?f=21&t=6606&p=122901&hili ... er#p122901" onclick="window.open(this.href);return false;

viewtopic.php?f=21&t=9552&hilit=gt+750+chambers" onclick="window.open(this.href);return false;

viewtopic.php?f=5&t=548" onclick="window.open(this.href);return false;

Copy those into your browser and you will probably find wht you search

Good luck

It all depends on what you want your bike to do in the end. There has been plenty of discussion on this pipe on H1's and H2's and I actually tried one on a H2 but without actual dyno numbers, there's no hard "proof" of how it performs. My perception was it completely eliminated the ability of the engine to reach resonance or come "on the pipe".

Since expansion chambers work by resonance waves, it stands to reason that each cylinder will need it's own pipe to scavenge/stuff the full charge of fuel/air. By using a 3-1 it may APPEAR to have more low & mid range because the top end is removed altogether leaving it feeling like there is more in the middle and down low. If I were building a bike for show & sound and didn't care about performance, I might think about a 3-1 but I don't build bikes that way.

All depends on what you want.

jeff

I think Jemco makes these so contact them directly if you want one.

I have a friend in Norway that is doing some reed testing for me on his H2's. He has his own dyno, and is testing all sorts of different expansion chambers including a 3 into 1. He got some very interesting results with the 3 into 1. The motor is a hot Stage II (with 34 mm carbs) which is pretty top heavy with the hp in the upper rpm range.

The physics behind expansion chambers is pretty clear, the return soundwave needs to arrive at the correct time to push the fresh mixture in the pipe back in the cylinder for the supercharging effect. You can't have it all, (the effect can't be made to work at all rpms) so through pipe shape and length, the return wave is manipulated to work at the best rpm range where the different circuits of the engine all sync up. (hitting the powerband) This is usually at the the upper rev range where the most hp can be produced.

The reason the 3 into 1's fall on their face right when the power should come on, is that there are now 3 weak return waves coming back to each cylinder, mostly negating any effect of supercharging. BUT, The same 3 pulses are returning at all rpm, so at lower rpms, when the pipe is out of sync, the other pulses actually come "close" to the correct timing actually adding some supercharging effect, so that's why the 3 into 1 actually help power down in the rpm range.

Which is "interesting" in a different direction than most take for more power. When testing the 3 into 1 with his Stage II reed converted motor he found with the larger ports and more port timing, actually made for a massively torque monster of a motor. It did fall flat at higher rpm's, but down low it was ridiculous.

So maybe it might be something to look into for a low rpm power monster, which you can gear up to go fast also.

I also have a customer that has a ported motor and my reed conversion that has gone from the stock H2 gearing of 15/47 to 16/43 and can still do easy first gear wheelies and dropped the rpm to 3700, from 4300 at 70 mph.

So i would say, it would have to be the full package of porting pipes and reed conversion, which may just make a great motor that lasts longer.

Here in the states I'd reach out to Jon Easton at Jemco. He has a good all around template for your bike that he will build to or can build to your specs. His number is 713-461-3834.

I've either bought or sent a dozen or more orders his way and everyone has been impressed with his work.

jeff

Pipes are all about timing and with a 3 into 1, if it were designed to resonate at peak RPM, as JA mentions, the return wave travels up all 3 pipes, but one of the others has just opened the exhaust just as that return wave arrives, so that royally screws up the peak. On sleds where 2 into 1 and 3 into 1 pipes have been common for years, they can make those pipes work well even at peak RPM, but the pipe volume is enormous.

They typically have an extremely short header design, presumably to minimize that loss of returning wave energy. You can design a 3 into 1 pipe so that the natural pipe resonance is different than port resonance and force a broader power band. Big ports typically make that worse, but if port timing is sufficiently outrageous and pipe volume is large enough, it should be possible to get the results that JA described, but it's easier to get power out of 3 pipes.

Pipe design is fascinating. I have access to a set of J&R, Bassani and Jemco pipes and on a stock or mild motor J&R appears to make most HP but at low revs and with a ridiculous peak. Changing the header length can change that situation and with the right port combo that pipe can make more power with a better power band than the other 2. Now I need to work out the optimum porting for the other two pipes.

When I run a certain porting combo with the three pipes what's best changes from one pipe to another as you might expect.

With 3 into 1 pipes Jemco and JollyMoto use long headers. Jemco has parallel headers and JM use fully tapered headers. Strader, piper, Roca, Reimo etc all used parallel headers as did TCE. In fact TCE appear to have a shorter center pipe that the outers, and that may be packaging or maybe it spread the powerband.

Without a lot of testing on a dyno, there's no way to really know.

To clarify, I was not even aware that Jon @ Jemco even made a 3 into 1 pipe. I was only referring to his sets of 3 individual chambers. His GT pipes will work well with porting so I'd be interested to see what your testing shows TZ


jeff

Jeff,
I am referring to the pipe sold by OMAR which I am led to believe is manufactured by Jon Easton for OMAR.

@Richard - what is it about the J&Rs that means they peak at lowish rpm and stop dead, right at that peak?

Is it header length? They also seem to have a smaller diameter centre 'belly' section, and relatively shallow cone angles compared with other designs.

You can change a few factors in a pipe to shape the curve, so it's usually just not one thing.

Thanks guys for all the replies. I always wanted to do 3:3's but they're so expensive. I'll have to peruse all these links and tips and see what's out there. At this point I have no plans to change the porting nor am I gonna put pod filters on it. I'm just building a bike to ride, I'd put the stock pipes back on if they'd fit with the TL swingarm. But that ain't happening! Haha. I just want reliability first and formost. That being said I wouldn't mind a little Brraaap when I get on it! Haha. I used to be a Yamaha guy. Worked on a metric shitload of Banshees. I wish toomey racing made chambers for GT's I'd buy those in a second. By far the best all around 2stroke pipes I've dealt with. Made great power, strong, durable and they sound so good!

My Norwegian friend tested a figaroli 3 into 1

I hate to be the negative voice on this, but I tried to buy a 3 into 1 from Omar last summer (2013) after waiting 8 weeks and getting countless excuses, I finally got my money back. Not to be put off, I contacted Jon at Jemco directly, verified that they did indeed produce a 3 into one for my 1974 GT750, and sent him a money order on March the 30th. On May the 22nd I called for an update and was told the pipe had not even been started on, and would I like my money back. Folks, I have learned my lesson. I am saving my pennies until I can afford a beautiful set of Higgspeeds from David in England. What the heck, the old girl seems to like revving her rear off, why not let her sing while she is doing it?

As always, my thanks for the exceptional info I get from this site.

Really sorry to hear what you went through Mighty and it surprises me because I've dealt with Jon for so long and have always had nothing but the best from him. It really sounds like there is a missing component to this whole thing, that maybe Jon has been having the 3-1 built for him by someone else, then reselling them to Omar. I say this based on the countless conversations I've had with him about his work, his methods and never ever did he ever bring up that he also build a 3-1 so I'm wondering if maybe it's because he doesn't, he subs that work out to another local builder who none of us know?

Regardless, it still stinks for you but I'm glad that you have a path going forward.

jeff