Cutting my exhaust off and adding pods???

G

GeeterB

New Member
I want to cut my exhaust down to where it is straight and wrap it with the heat tape. Then I want to get rid of the air box and put some pods or velocity stacks. That I can definitely do pretty easily but from what I have read on here it sounds like I am going to have to do some re-jetting. Does anyone know a magic jet number to get me close or a post on here where I can find the info?

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There are tons of resources out there for rejetting carbs. Since you only have a single carb, it is a much easier task. First, find out what your stock jet sizes are. A little googling will tell you that. Find out as much as you can about your carb. Then I'd suggest going to a forum specifically for you make and model bike and finding out how many sizes you should go up on your jets. For me, I chopped my exhaust down to right below my feet and replaced my air box with a pod filter. I increased my main jet from 110 to 135 and my slow jet from 35 to 42. I also shimmed my needle. The thing runs like a champion.

I do have to warn you about pod filters. For smaller engines, if you live in a cooler climate you are going to have some trouble. A filter in an air box pulls in idle air, while a pod filter pulls in moving air. If it is cold out, air moving at 50mph is going to be even colder. Your engine can't run off of freezing air, so it will stall. I'm not sure if larger engines have the same problem, but I know smaller ones do. So keep that in mind.

Also, higher airflow also means higher heat. With shorter exhaust and pod filter, your pistons and such will wear faster. If you want to ride the bike for the next 20 years, keep that in mind also.

Lastly, it's your bike, do what you want. If you want to run it with long mufflers, open pipes or even open headers, go for it.
 
I have no idea how the bike would perform, but I think that would definitely look sweet with short pipes and an open body.
 
Does MAC make a 2-1 exhaust for the little 400? I know they make it for the GS450.

Suzuki CV carbs can be really, really picky about their intake setup. They aren't easy to work on, and you will be working on them a LOT if you put pods or stacks on. My personal opinion (which is worthless if you so choose) is keep the stock airbox for as long as you feel possible. The filter element can probably be modified with Uni filter foam (sold in bulk sheets BTW) for a little bump in air intake.
 
yes, mac does... I understand where he's coming from, he wants to "clean" up the bike a bit... Thats cool.. Just expect it to run a tad weaker... With out doing some internal tuning( cam, compression,increased valve size etc), it cant really use the advantages of free flowing filter and free flowing exhaust... Trust me.. for whats there, Suzuki put some thought into making it run well with what they had to work with. You'll be choosing form over function... My advice is hold off until you can get your hands on a diff exhaust that you like. And a nice intake set up inst really all that hard to come up with (just a little clever-ness), But most people take your route, the $10 looks fast, so it must be approach...
 
Baffle said:
I do have to warn you about pod filters. For smaller engines, if you live in a cooler climate you are going to have some trouble. A filter in an air box pulls in idle air, while a pod filter pulls in moving air. If it is cold out, air moving at 50mph is going to be even colder. Your engine can't run off of freezing air, so it will stall. I'm not sure if larger engines have the same problem, but I know smaller ones do. So keep that in mind.

Also, higher airflow also means higher heat. With shorter exhaust and pod filter, your pistons and such will wear faster. If you want to ride the bike for the next 20 years, keep that in mind also.
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Sorry, but none of that is really correct.

Moving air is not cooler, is just feels cooler to we humans because it pulls heat away from us more efficiently than standing air. Furthermore, colder air is denser and contains more oxygen per cc than hot air. Gasoline engines LOVE cold air which is why so many in the auto world go through great lengths to ensure their engine compartments are cold and that the engine isn't sucking air from inside the compartment.

The main issue with pods is that they reduce the intake length and the air entering the carbs is more turbulent than it would be otherwise. Some makes and types of carbs are sensitive to this change and require a lot of tinkering before they can accomodate it.

Also, higher airflow does not necessarily mean higher heat. The heat generated by an engine is mostly determined by the compression ratio, timing, and fuel/air ratios. So, yes, while adding more air to the mix without adding more fuel will cause things to run hotter, it's not the air that really does it; it's the lack of fuel to accompany it. The goal of any efficient engine is to increase air flows and it's a bit disingenuous to pass that off as a "bad thing".

Finally, increased heat will not cause increased wear in the engine components. It would have to be a hell of a lot of heat for this to occur and even then some fairly simple maintenance takes care of 99% of those problems. Higher weight oils and more frequent oil changes help, but to be honest, your wet clutch is doing more "damage" to the integrity of the oil than an increased heat in the combustion chamber will.
 
yes, pods reduce their vaccum abilities. Which is what your jets operate on. Thats why stock air boxes are usually huge... So they draw air from a controlled envirnment. Ditching the whole idea is senseless unless your running all out all the time, at maximum vaccum.
 
Sort of... maximum vacuum will always be at idle when the slides/butterflies are closed and the engine is trying to pull in more air than the throttle allows. As air velocity increases (such as with WOT and high RPMs) it does create lower pressure zones within the venturi that pulls in more fuel, but a vacuum gauge attached to the carbs will (or at least should be) reading less than an inch of mercury at this point.
 
Okay thanks you guys for all the good insight and opinions. I have now learned that pods and a hacked exhaust can severely effect my performance. And I now understand that you can choose between max performance or that mean cafe look. The only thing that I am stuck on and correct me if I am wrong is that. Most of the Best looking bikes on this site look like they have pods and chopped pipes and they have been re-jetted. I can only speak for how they look (and they look bad ass) but most who have these mods claim their bikes run great and a lot of the bikes I have drooled over on this site have been built by bike wizards who I would say that they definitely know their stuff from all the detailed builds. So just to be clear: Can you modify your pipes and pods and jets and end up with the same or better performance than stock? I have decided to stick to working on the seat, electrical, suspension and ride for summer and save the major tinkering for the snow days.
 
Sonreir, Max vacuum or pressure drop is while decelerating isn't it?

As velocity increases, pressure drops - Bernouli and all that. Higher gas velocity = greater pressure drop . BUt with CV carbs, the slides rise to keep velocity almost constant....

Geeter, Please show me a bike with pods, short pipes and better performance than stock. A simple side by side roll on or dyno test to confirm will suffice. Most bikes perform worse than stock with those changes. Sure they sound louder and we might mistake that for more power but it rarely is. The simple fact is that as they are usually less powerful at low to mid revs and not so much of a loss further up the rev range, the step out of the deep hole makes them feel more powerful but they are not.

That's not to say that performance cannot be improved, but chopping pipes and fitting pods doesn't look cool to anyone that knows anything about bikes.

Checkout the well developed bikes on here and ignore the bling and noise.

Get your bike on a dyno and then chop it around a do a back to back test and see for yourself what happens. You never know. Maybe your bike is one that responds well to simple changes. It's possible.
 
teazer said:
Sonreir, Max vacuum or pressure drop is while decelerating isn't it?

As velocity increases, pressure drops - Bernouli and all that. Higher gas velocity = greater pressure drop . BUt with CV carbs, the slides rise to keep velocity almost constant....

Geeter, Please show me a bike with pods, short pipes and better performance than stock. A simple side by side roll on or dyno test to confirm will suffice. Most bikes perform worse than stock with those changes. Sure they sound louder and we might mistake that for more power but it rarely is. The simple fact is that as they are usually less powerful at low to mid revs and not so much of a loss further up the rev range, the step out of the deep hole makes them feel more powerful but they are not.

That's not to say that performance cannot be improved, but chopping pipes and fitting pods doesn't look cool to anyone that knows anything about bikes.

Checkout the well developed bikes on here and ignore the bling and noise.

Get your bike on a dyno and then chop it around a do a back to back test and see for yourself what happens. You never know. Maybe your bike is one that responds well to simple changes. It's possible.
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+1 cant ever argue with dude. Just talk about it.....
 
That was all very great advise. I have realized that the general consensus by pretty much everyone who on here so far is that pods and chopped pipes are garbage. The strange part about that is that I went back to the "Bike of the month" picks again for the thousandth time and every single bike on there is running pods or stacks ( I had to make sure that I wasn't going crazy). And I know that the Best thing about cafe's or customizing any bike for that matter is that you can do anything you want to "your" own bike. Can most people on here agree that when it comes to pods, nobody recommends them but almost everybody has them.
 
There are reasons for chopped pipes and pods though. Most bikes here are pretty old - so factory replacement parts aren't usually accessible (or easily affordable) .

If I'm not mistaken, most shortened systems produce the most power at extreme rpm's. Not where most street machines run.
 
Big Rich said:
If I'm not mistaken, most shortened systems produce the most power at extreme rpm's. Not where most street machines run.
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True to a point. But quite often I see guys just running headers and there's no way their engines are capable of turning fast enough to make use of pipes that short. I'd never go shorter than foot pegs and even then I'd only go that short if I had some sort of issue that required it. I think it's one of those things that's more for looks than for functionality.
 
If you want a short straight pipe with the correct length to match peak torque or peak power revs, it will still be much longer than sawn off pipes. Do the numbers and work it out. Better off with good, efficient, not too noisy mufflers or a good 2 into 1 with a nice looking cafe style muffler.

Back in the day we all used megaphones or Goldies and they were muffled (up to a point) if we just hacked them off the bike would be confiscated or we'd get a ticket for making too much noise (nuisance). no one did it though because we all knew it wouldn't help performance and that's what this is all about - stylish performance. Not noise or following the crowd who know no better.

Do you want a bike that's slower than stock and runs like crap so you can look like the other lemmings, or do you want a bike that looks good and works as well as you can make it?

Forget that "make it your own" BS. That's hipster talk for I screwed up by I can't admit it to myself or others.:)

Bottom line is that a motorcycle is not a toy though it is often a fashion statement. It should be fun and safe and not annoy the crap out of neighbors and fellow road users.

That's just my opinion. Your mileage may vary.:)
 
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