Subscribe Today

Boost Bottle/Shared Air

Boost Bottle/Shared Air

Postby RacinFan » April 29th, 2015, 12:14 pm

Hi There,

I was wondering if anyone could explain how the boost bottle/shared air concept works, in a nutshell.

I was also wondering if anyone could explain how this concept or idea, came to be a hot topic as of late.

I don't recall this concept being talked about much before, and I don't remember the ski-doo's being this dominant before. Is the ski-doo motor platform dominance of late, related to the boost bottle/shared are concept?

One more question, will it even be possible for the arctic cat and polaris motor guys to incorporate this concept?
Matt Maurer
RacinFan
Member
 
Posts: 170
Joined: December 4th, 2006, 3:48 am
Location: Tuscaloosa, AL

Re: Boost Bottle/Shared Air

Postby Mr.Pipe » April 29th, 2015, 5:39 pm

Boost bottles came about as a way to dampen out some intake pressure waves, and allow the carburetor to do a better job of providing a suitable mixture thru the entire RPM range. They often have a larger effect at part throttle, than at full throttle. The earlier Ski-Doo 440 reed valve engine used a boost bottle, then it was deleted in the last few years of production. Some people believe that the 440 Ski Doo has an advantage, by being able to use air from both 34 carbs by air passing thru the shared boost bottle.
The fact is that at the RPM's that the 440's race at, very little air has time to travel thru the convoluted passages of the boost bottle to be used by the opposing cylinder.
The new rule will (as I understand it) allow the Polaris and Arctic Cat to use their own boost bottle...adopted, or fabricated...we'll wait to see what gets put into print.
Will it even up the Polaris and Arctic Cat...they might see a small advantage from a proper designed boost bottle, but it will be a baby step fwd at best.
Mr.Pipe
Member
 
Posts: 50
Joined: December 17th, 2002, 8:45 am
Location: Winnipeg

Re: Boost Bottle/Shared Air

Postby RacinFan » April 29th, 2015, 8:13 pm

Thank you for the reply.

I appreciate the detail and straightforwardness.

Being a Polaris fan I can only hope that the Polaris guys can get it figured out again.
Matt Maurer
RacinFan
Member
 
Posts: 170
Joined: December 4th, 2006, 3:48 am
Location: Tuscaloosa, AL


Re: Boost Bottle/Shared Air

Postby FastCat87 » April 30th, 2015, 12:26 am

I know there aren't too many champs still running Cat power plants but of those left, were any of them currently using a boost bottle?
“If everything seems under control, you're not going fast enough.”
― Mario Andretti
FastCat87
 
Posts: 7
Joined: April 3rd, 2015, 2:01 pm
Location: Merrill,WI

Re: Boost Bottle/Shared Air

Postby motowrecker121 » April 30th, 2015, 1:18 pm

this isnt some new discovery. boost bottles have been around a long time. when I raced atv's back in 2000 I was running one on my yamaha banshee. I ran one on my 02 polaris trail sled. and I have an 06 champ motor that I ran one on.
motowrecker121
Member
 
Posts: 51
Joined: February 14th, 2008, 9:48 am
Location: CT

Re: Boost Bottle/Shared Air

Postby proton » April 30th, 2015, 5:16 pm

With all the effort to contain the cost and speed of champ 440 ,Im a little confused opening up the rules on the boost bottle, its going to cost racers more in the end to cover the cost of development, while at the same time speeds will more than likely increase..... it would have been better to ban them if they thought Rotax had an unfair advantage over Polaris.

I personally think its poor rule-making adopting rules to help one manufacture catch up with another, penalizing the hard work of some.

Maybe we should come up with an engine formula that allows champ 440 to assemble an engine from all the speedy parts from different brands and have one type of engine....EVERYONE would be required to start from same engine and have the engine builders go from there. that would make if fair and stop all the belly aching, then all the hard work of the engine builder/tuners would be rewarded respectfully where it belongs.

respectfully: D Dantuma
proton
Member
 
Posts: 97
Joined: January 18th, 2004, 2:28 pm
Location: USA

Re: Boost Bottle/Shared Air

Postby fast dad » April 30th, 2015, 5:23 pm

Let me just say this...If Boost Bottles worked that good why are they not on todays motors, any little gain would be used even 1/4 HP....I think this will be a mute point once people test them...

FYI it was voted on to allow same bottles as Ski-doo for all motors, voted down! NO boost bottles far anyone, Voted down, then was brought up how about open boost bottle, voted in....If anyone does not like how things get voted on I suggest going to the meetings...Rules LOCKED if for 5 years!!!

TJ
[b]fast dad[/b]
fast dad
Member
 
Posts: 105
Joined: April 21st, 2012, 12:05 am
Location: home

Re: Boost Bottle/Shared Air

Postby Flatout » April 30th, 2015, 6:51 pm

Boost bottles definitely affect a motors performance but only marginally at full throttle. I think they were dropped by the manufacturers in an attempt to cut down on warranty costs. An identical engine with versus without a boost bottle will require about 10 jet sizes bigger to stay together. Airflow increases with a boost bottle slightly but the signal to the jet is reduced. I personally would prefer no bottles since jetting is more consistent.
Flatout
Member
 
Posts: 191
Joined: November 20th, 2001, 5:05 am
Location: Ottawa Ont.

Re: Boost Bottle/Shared Air

Postby proton » May 1st, 2015, 12:49 am

TJ, correct me if Im wrong, Not every one is invited to the ISR meeting to voice their opinion, let alone vote
proton
Member
 
Posts: 97
Joined: January 18th, 2004, 2:28 pm
Location: USA

Re: Boost Bottle/Shared Air

Postby fast dad » May 1st, 2015, 5:57 am

No I believe if you are invited by a SMDG member or a affiliate you can attend. Most affiliates have 2-3 people attending. Can you have a personal vote no, but if you are a SMDG member you have a say in their vote.

TJ
[b]fast dad[/b]
fast dad
Member
 
Posts: 105
Joined: April 21st, 2012, 12:05 am
Location: home

Next

Return to Ovals & Enduros

Who is online

Users browsing this forum: No registered users and 2 guests