Difference between aftermarket exhausts

[SDB]

Looking at 1986 16k all original one owner bike. I do Not want to go down the long dirty road of mod after mod with this bike (have 4 other Yamahas that are mild to full custom modded). I want this to remain 100% original or near to it (period correct mods). I know exhausts can be a tricky thing with some not gaining any real power over stock. All I would be interested in doing would be air box/filter mod, jetting carbs, and full exhaust... Not really anything else. This bike would be for Vintage bike nights/shows and occasional romps around town (peobably less than 1k miles a year realistically). I don't want to throw $ at it for no reason.

I have heard a gen 1 with full Kerker 4-2-1 system and liked that sound for sure. I hated the $1200 new price and can't find any used. I'm Assuming that the full kerker will be about the best for actual performance (to me performance is measured on how fast it gets down the quarter and not dyno graphs alone)... And I like the look. I also like the dual exhaust look.

For keeping bike NEARLY 100% stock other than jetting/airbox/exhaust.... What is the "BEST" vs the "BEST BANG FOR THE BUCK" for exhaust on a gen 1?

Also stock vs jetted carbs/airbox/full exhaust what can be expected in terms of 1/4 mile performance as well and dyno improvements.... From what I've seen it seems to be 110rwhp stock to 120 rwhp with above mentioned mods... Is that about right? About a 10% increase?

Lastly... Any modifications to the stock exhaust that gives actual performance gain not just improved sound?

Thanks

 

[[email protected]]

No slip on or stock exhaust mods will increase power. None.

All the major brand full exhaust systems perform close enough to one another to say there is no best.

Buy your exhaust based on what looks and sounds best to you.

If you install a full exhaust, you can get away with decreasing the main jets, shimming the needles, and some AF screw tweaking.

Dyno Jet stage 7 and Morley Muscle jet kit are the 2 jet kit options. Both have similar top end results. The muscle jet kit will give you better mid range power.

If buying all new parts, its an expensive upgrade for 10-15hp.

Putting a full exhaust on the max is worth the cost just to hear the motor sing IMO.

I'm not a Kerker fan since the centerstand tabs need cut off the frame. I kept the stand in the garage for maintenance.

 

[Fire-medic]

The UFO Dragstar 4/1 doesn't require amputation of the centerstand tabs, and you can re-fit the centerstand for maintenance should you want it. However, it can't be left mounted to ride the bike.

I sold a Kerker 4/1 to a member on-here awhile-ago. They're out there. Sean Morley and CaptainKyle get them.

 

[Montana vmax]

There is a half price full voodoo exhaust on here posted last week.

 

[Parminio]

No slip on or stock exhaust mods will increase power. None.

Dale Walker would like to have a word with you.

 

[[email protected]]

Dale Walker would like to have a word with you.

Dale Walker would like to have a word with you.

I'm sure Dale knows his stuff.
I'm sure a slip on can make power on other bikes.
On the Gen 1 vmax, I've not seen any slip on that does anything more than add noise.

 

[one2dmax]

As noted above. Slip-ons for sound and a little less weight. Full systems for 5-7% more power and a jet kit to get the last 2-3% out of it. I do sell a few systems including the kerker (though it sounds like for your requirements that would not be an ideal option). Email me at [email protected] and I can break it down for you.

 

[Parminio]

Walker's slip-ons, according to him, net 10% horsepower gain.

His bike was a 2005 stock Vmax with 2500 miles on it. He got 99 HP out of it on his dyno stock and 109 HP out of it with the new slip-on system.

Or he's lying. But I don't think he's lying.

 

[VMAXXIMUM]

That’s a great advertisement. Where is the explanation for how his slip on’s make more power with the restrictive stock headers that are the cause of the power restriction?

 

[Parminio]

Well, all I can tell you is my friends 85 Vmax with Dale Walker's on it pulled away from my stock 07 with surprising ease.

 

[SDB]

Well, all I can tell you is my friends 85 Vmax with Dale Walker's on it pulled away from my stock 07 with surprising ease.

Too many variables....

If an independent shop tested a stock gen 1 and then on the SAME DAY ON SAME BIKE tested just that slip-on being different.... Then that's accurate. He said in his video they were different bikes and different days and different states etc. That is NOT an accurate representation of improvement. It's a sales gimmick and nothing else. I'm Not saying his slip-on doesn't work or add power... Just sawing there is no real data that it does.

I'd just about guarantee that if he makes a slip on that made +10 rwhp lb/ft and +10 rwhp with no loss in low end or midrange and backed it up with improved 1/4 mile ET/MPH for a gen 1 and it was less than $750 he would sell a TON of them....... and everyone who has worked on exhaust for these bikes for the past 35 years would be feeling pretty stupid right about now...

 

[Craig Huckeby]

Too many variables....

If an independent shop tested a stock gen 1 and then on the SAME DAY ON SAME BIKE tested just that slip-on being different.... Then that's accurate. He said in his video they were different bikes and different days and different states etc. That is NOT an accurate representation of improvement. It's a sales gimmick and nothing else. I'm Not saying his slip-on doesn't work or add power... Just sawing there is no real data that it does.

I'd just about guarantee that if he makes a slip on that made +10 rwhp lb/ft and +10 rwhp with no loss in low end or midrange and backed it up with improved 1/4 mile ET/MPH for a gen 1 and it was less than $750 he would sell a TON of them....... and everyone who has worked on exhaust for these bikes for the past 35 years would be feeling pretty stupid right about now...

So comforting to know someone that knows everything....

 

[SDB]

So comforting to know someone that knows everything....

I don't know much of Anything about Vmax bikes.. But I know a bit about race cars and bikes in general. My statement was absolutely factually correct and I'll wager ANY mechanically inclined person who has raced or been involved with product develop will agree with my above statement 100%. What exactly do you think was wrong about my statement or my logic? You feel a part should be tested on different bikes in different states on different days maybe on different dynos to show a percentage increase in power? That's just asinine, anti-scientific, and downright stupid. Especially if you chase the almighty dynonsheet like the Vast majority of people with "fast" cars or bikes who never go to the track do... The same people who brag about their dyno and won't ever race someone on the street from a dig.

I don't know everything but I sure as hell know testing a product the way it was... and reporting the results as" proof" a product works well is complete and utter bullshit, deceptive, and actually unethical in terms of a business practice.

 

[Parminio]

So comforting to know someone that knows everything....

I emailed Dale about it. Here's a snipet of his response to me:

That specialist does not have a clue, and you cannot manipulate dyno numbers on a Dynojet 250.

I have designed and made two full system through the years, and also 3 different style slip-on systems.

A good full system will always beat a set of slip-ons, but the mid pipe and collectors I have now beat any other slip-on I produced in the past big time.

Proper jetting is also important, way to many kits are way Rich and kill the top end power.

Cheers Dale

And after all that he comes back with this:

I don't know much of Anything about Vmax bikes..

So, yeah. He's full of crap.

 

[SDB]

So... Has anyone other than the "creator" of this slip-on

I emailed Dale about it. Here's a snipet of his response to me:



And after all that he comes back with this:



So, yeah. He's full of crap.

Done testing and seen a gain of 10 rwhp over a stock bike? Any track times before and after? Anyone figure out how he made the ONLY slip-on that made this much power over stock after countless others have tried for 35 years?

I wait for the deafening roar of the crickets to stop when some validation is offered from someone NOT trying to sell their own product

 

[Parminio]

Wow man. Get some professional help.

Dale Walker has been building exhaust systems for bikes since 1995. I don't know who the hell you are, or who you THINK you are, but you obviously have far too high an opinion of yourself.

You're on ignore now. Life's too short to deal with know-it-alls.

 

[Montana vmax]

I am thinking at 739 each they better add some ponies, holy crap! Thats more than half the cost of my bike.

 

[one2dmax]

Something was wrong with his baseline bike. We've tested MANY vmax's with MANY combinations including the same bikes with different combinations on the same day and also through the years of the same bike with different configurations as they added mileage and changes. I noticed that his video does not show any of the A/F ratio measurements for the before or even the after. Possibly the video may be misleading if the before was not given the proper A/F ratio, but the after did (which would explain the large gain for a slip-on system). The biggest gain we ever saw was 27 hp from a stock to Kerker change (on the same day a few hours apart) which was also not accurate when the data was all compared (he was WAY off the A/F on the baseline).

When we tried to compare systems vs systems we did our best to try and "tune" to match the systems.

Dale is absolutely correct in that most (probably 95%) of people tune on the overly rich side and thus give up HP (in exchange for some torque).

I will say I may likely have dyno'd a larger variety of Vmax's when compared to Dale as well as likely more brands (including his). That even includes the variations of the headers he sold over the years (Starting with his rebadged Hindles up through is own proprietary stuff, even his rebadged hindle 4-1 with his modified dual outlet conversion which was interesting to say the least). We have not found any slip-on that gives a significant power gain over stock (though we found the cobra's gave a horrible loss that was about the 99 hp he measured).

Added some pictures since you seem to be a "need proof" guy.

 

[one2dmax]

On another note. Typical power numbers:
110-112 RWHP for STOCK configurations (years do not matter though the 85's are more consistently at the upper end of that range). Occasionally you will find one with more power (any year) which is hard to explain exactly what that is.
Very similar power for Slip-on systems regardless of brand (except Cobra's)
Around 100 HP (10% loss) when going with the Cobra 4-4's. This is mostly due to the lack in scavenging as the mufflers themselves are not overly restrictive.
115-125 RWHP for Full System bikes. The variation in that range is more mileage based then brand based. There is no single brand that consistently out powers other brands. Buy your full system based on cost, sound, availability, and cosmetic preference. The full system (and slip on's for that matter) will perform better typically if you jet down one or two jet sizes on the main from stock.

As I mentioned mileage plays a huge part in overall power creation. The more mileages these bikes get the more power they make. We've seen 50-60k miles bikes make into 130's rwhp. I have seen a 1300 conversion (venture block/pistons with vmax heads/cams) with 90+k miles make over 130 RWHP with a STOCK exhaust and airbox.

The primary pipes are the restriction and not the mufflers. This is why I say that slip-ons in general will not give a power gain. This has been dyno measured on many bikes we've had over the years. Here's more pictures of various exhaust related stuff for your enjoyment.

So, please resend an email to Dale (noting my comments as Sean Morley) as I would love to see what he would want to say. I DO consider myself to be a "Vmax Specialist" and base my data on years of testing as I mentioned below. While I didn't get started on these until 1988 that is still a lot of years of dedication to nearly one model of bike (I occasionally work on Ventures and Fazers).

 

[one2dmax]

Too many pics so had to do another reply. Here's more including many mufflers we've experimented with (mostly sound changes is all that happens).