Question 4 GearHeads

[yamaha_george]

Guys,
Take a look at an ebay item: Item number: 220344124435

OR

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0344124435

and tell me what you think .

seems a bit iffy to me but I do not walk on water so............................

[sweekster]

Modded R6 header? Sounds familiar....

[csofos]

That seller claims it fits on 400 and 600 as well. That sounds a bit of shit to me. 400's and 600's have different internal ddiameter headers. This header looks to have too big internal diameters, so i think it'll fit better on 600's. On 400's i don't think you'll have good or any back-pressure.

NOTE: According to Graham E. Bell's book "4-stroke performance tuning" on the exhaust chapter, he refers that 4 in 2 in 1 exhaust manifols (as this particular) gives better mid-range power.

[cad600]

Just sounds a little expensive for something hacked up and re-welded in someones garage. But then again, I don't know the going price for a R6 header over there. Stainless would be a nice touch though.

[zero9243]

huh? Isn't this the same thing TK does on the cheap?

[reelrazor]

Well, exhaust diameter is of less importance than the length (flow vs. sonics). It is the sonic wave action that provides the reversion pulse at the valve/port..NOT the downstream flow. It's hard to have TOO MUCH flow, not hard to have wave dynamics waaay outa synch.

A short, fat head pipe with a low reversion pulse is good for four stroke revs and top end (see drag car exhausts-single pipes)..long and skinny with abrupt collectors give ya torque (see jeep headers). Staggered collection (4-2-1) is a compromise to get a bit of each's benefit.

4-2-1 is using pulses from one cyl to help scavenge another in pairs, and then taking that pair's pulse to scavenge the other pair's and that is why they are good for midrange.

So, this short header designed for a very high revving 1-3-4-2 engine (R6) would probably work okay for our 1-3-4-2 12krpm mills. Most likely better than the stock squashed flat collector. The biggest issue I can see is if there was a big step at the head where port meets pipe which would effectively cancel any beneficial reversion.

I dunno, that is just what I am seeing in my head..no math behind it.

[yamaha_george]

Thank you all,
You have summed up my feeling that OK it is stainless but the price as stated is for a "chopped up pipe" to bear fair the seller does state that he would need "the" bike to make sure it fits since 400's 600's are different widths. Bell as quite rightly quoted says 4-2-1 gives better mids and is a"good" compromise.

The too fat a header may be ok IF they could have anti-reversal cones added ?????????

The sellers site 200mph.com <?> is a bit inflated although there is serious work going on to get a normally aspirated bike to 200mph and every so often you will see that some bod has dropped a wad of cash on a project to be the first at 200mph.

[95FZR600]

Same thing TK is doing and he's cheaper. He also does not mention anything about the fitment either. I thought using the R6 header you have to cut some of the fairing for it to fit right? .

[the_finch]

The item in question:


When I look at it, the first thing I think is, "That looks just like the 1999 YZF600R (non-R6) stock exhaust manifold I have at the house, only with shiny paint instead of rust."

Examples:



The one in question doesn't look cobbled together to me, but like it was manufactured in the shape it is in (minus the finish). He might be misinformed and just have a stock YZF600 header that has been coated in a stainless or "stainless finish ceramic" coating.

A stock YZF600 header is supposed to match up to a FZR600 Genesis motor (thus why I own one) and comes in the 4-2-1 configuration, which should provide more mid-range. It is made of the same mild steel tubing and stamped sheet metal that the FZR header is made out of.

As everyone else before me said, I don't think it's worth it. Spend the money on a Micron or D&D instead.

Mystery of the mysterious part: solved.

Score: Finch - 1 Internet - 0

[sweekster]

Same thing TK is doing and he's cheaper. He also does not mention anything about the fitment either. I thought using the R6 header you have to cut some of the fairing for it to fit right? .

Yep...
Clicky Clicky

[yamaha_george]

A stock YZF600 header is supposed to match up to a FZR600 Genesis motor (thus why I own one) and comes in the 4-2-1 configuration, which should provide more mid-range.

Finch,
you say supposed have you not tried it out? or is garage art ?

[the_finch]

Finch,
you say supposed have you not tried it out? or is garage art ?

Lol, just been busy lately. And I'm still debating between the YZF600 header (4-2-1) from eBay and the FZR400 Yoshimura full exhaust (4-1) I got from Rage a little while back.

It also recently got cold enough that you couldn't go riding (without really, really bundling up), so now I can justify ripping the bike apart to install some more of the small mound of parts I have in the shop. Doesn't make a ton a sense to take it apart when it's in the 70's F on Christmas day (really warm for Christmas, even by Alabama standards).

Now it's in the 40's and 50's during the day, so after night class I'll probably be locking myself away in the shop for a few hours at a time, starting with sorting out the suspension and then moving to the more fun "go faster" parts.

[match417]

personally i would advise against it unless you only want it because its shiny. stainless exhaust pipes dissipate too much heat, and when the heat is released through the walls of the header, the exhaust temp goes down quicker than it normally would, then the exhaust gasses are harder to push out of the header. This is why people use titanium exhaust kits on bikes, and why drag racers get ceramic headers on their cars. Holding as much heat in as possible so that you can get that exhaust out of there as smoothly as possible. Having an exhaust pipe that releases too much heat has the same effect on hp as having a slightly smaller exhaust diameter. A little trick for a little more hp is buying some heat wrap and wrapping the header from end to end, it looks ugly if you really look at it, but it's more efficient. and more efficient equals more hp!

on second thought though, the stock header probably doesn't hold in much heat anyway..my exhaust isn't hot at all...so it might not hurt performance

[yamaha_george]

Header wrap is OK but must not be allowed to get wet as It will kill your pipes quick, ceramic (if you have a thick wad) is better.
as for looks with the lowers in place they are hardly seen.