Spec 2 Chambers

[giron]

you said best about Gary. He is about performance. Willows springs 1975 Gary set up an R5 and people could not believe it
The R5 was blowing the doors off the 900 Kawasaki. I would give Gary credit for opening my eyes to the two stroke world.
Gary was a big help with my 1977 RD400 and later with my RD400F

[Questo vecchio rz]

Garys RDs 350s & 400s best many a Honda 750 @ Ontario and Riverside. He's forgotten more than most know.
Sure I like stainless pipes & carbon silencers, but as the owner posted 40 lbs lighter and a mid range hit, that is substantially noticable...you don't hear other pipe owners saying that about the RZ 500. I think the owner would smile as his bike powers off the line & out of corners ahead of a "pretty pipe" equipped 500. I know Lomas are awesome pipes I own 2 sets, but I know for a fact they font deliver a big improvement on the 500.

[Smoker]

I don't care if those are the fastest pipes in the world - they look absolutely ridiculous.

MK - very nice work on those pipes! Takes a lot of skill to do that.

[giron]

Smoker

I have to say that Gary's pipes are not the best looking. I will agree with you on that. Gary doesn't care how ugly they look. Gary cares only on the performance. Even Brian has mention to me more than once. Building pipes to be routed the same way for the rear cylinders (RZ500) is not that advantageous. I will say again that the pipe builders have a tough job building pipes for the RZ500 motor. They are limited with body work and attaching it to the frame. This reminds me what Ken Smith a long time member of this forum said one time. You want to do it right look at a RG500. Rick Lance always liked the Tommy Crawford pipes. The rear pipes came out straight on the rear cylinders.

[wolfgangh]

It can be done. My straight pipes (custom made by JL) deliver 96.5 RWHP.
Sure I don tknow how much more would be possible with longer upper pipes, but for me in that case function followed form as it is a replica.

[giron]

Yes wolfgang. What about the subframe? What does it look like?

[giron]

wolfgang. What kind of frame are you using? a 3MA?

[wolfgangh]

Thats a Costin frame. No subframe, just a self-supporting carbon seat.

[Questo vecchio rz]

Yes the YZR replica is not a RZ500, It's Basiclly a completely diffrent motorcycle. Can't really compare the two.
Its true, what many say about the RZ, isn't easy to make pipes for, From what Ive always viewed on 2 strokes, the straighter the pipe the better. for most people who want the best performing exhuast, on a Basiclly (stock) RZ there going to end up with a pipe extending out a handful of inches more than others jus lIke Toomeys did. As the original poster stated, there is a BIG substantially noticable improvement in acceleration and midrange, on a 100% stock RZ500. You just don't see that with too many other designs. Gary isn't just a builder, he's a engineer and a racer, his only goal is to do everything he can do to make the fastest, his work has surfaced on land speed record bikes, drag race bikes and probably 1000s of RD,RZ club race wins. He must be in his early 70s now, still doing his thing that's good to see.
And really ? , such excitability shown over silencers, is kind of silly, when you consider the goal was optimum..performance. Credit is due where deserved.
Garys silencers have always been long , look at almost all rz500 upper silencers they use very short stubby ones for the top. In my experience diffrent length silencers can and do affect performance on a 2 stroke even minor changes can drastically alter the perfornance, that could be another reason he's left them. And knowing Gary, he will tell your straight to your face, if you want shorter pipes..get outta my shop & go somewhere else...lol He's always been a character.

[silverstrom]

As I said earlier, unless the stinger runs deep inside the silencer I don't think the silencer length makes any difference. Sound yes, performance no. If you have an internal stinger then the length of the silencer matters, but only so much as it accommodates the internal stinger. Past the end of the stinger it's just sound quality.

[2smoke]

As I said earlier, unless the stinger runs deep inside the silencer I don't think the silencer length makes any difference. Sound yes, performance no. If you have an internal stinger then the length of the silencer matters, but only so much as it accommodates the internal stinger. Past the end of the stinger it's just sound quality.

+1

[Questo vecchio rz]

Like many here I suspect, I've been around 2 stroke dirt bikes since I was old enough to hold on. Silencer length can and does affect power ...period.
For me this is not even open to debate. Shorter,longer, amount of packing etc.. there is no "magic" formula. Each and every pipe/silencer combo works quite diffrent. Take any 2 stroke dirt bike say a YZ250 or a Banshee twin there are probably a dozen pipes available, each one of them is basiclly only slightly diffrent than the next, however the characteristics are changed substantially ,additionally when trying the phethora various avail aftermarket silencers shortys to forest service quiet versions there are similar changes. The tuned system is very sensitive to even minor changes. Short works on some while long may on others. Just the smallest of changes can and will affect a powerband through scavenging/back pressure etc..
Anyone who's ridden with worn out packing, or packing removed vs a freshly packed pipe can confirm this sometimes the results are very noticable. If I were to shorten the above silencers a little, I probably would, as I'm a flawed visual guy...lol, I wouldn't be surprised at all if the performance on that pipe design would suffer.
If I had a nickel for everything I've scaricifed to try to " look good" I'd have some heavy pockets..lol. But a nice compromise seems to often work okay.

[giron]

You said it best. I posted earlier on the GP two stroke bikes. I saw in the back of the trucks in the pits. Different set of pipes. This probably had to do something with the track the race was on. I may be wrong, but it seems that by changing the pipes out. You can make your two stroke motor run differently. Again the pipe builders have a hard task ahead of them. They have to accommodate stock body work and mounting since most folks do not want to alter the body work. Then the looks and last the tuning with an equal compromise for the type of environment you will be riding.

[silverstrom]

To keep this simple, silencers do not add power. Period. Tuned pipe matters. Silencers are not part of the tuned pipe.

If silencers affected power as you believe we'd all be swapping silencers looking for cheap power gains.

This is where I leave this conversation. I'm just wasting key strokes.

[begbie]

^ what he said.