I have the same question. I put pod filters on and pulled the H-box off. I have about 1ft of exhaust pipe connecting the headers to my emgo shorty mufflers which are basically straight pipes with a small baffle in each, you can actually see straight through them. I have been seeing 90/120 come up a lot on this forum, but would I need to go a little bigger because of the exhaust? If so what would you guys recommend?
maybe a size or two bigger like 95/125 or more. everyone i've known to do this on other bikes or carbuerated projects has several different sizes at their disposal to be able to go higher if necessary. i know we're all on kinda tight budgets and having a stash of unused jets is a bit of a waste but i don't think there is a standard jet size for when you modify shit
i wasn't aware they came in different depths. i'll share some of my nightmarish experience regarding pods. i got a set of cheap ass emgo pods from the biker yard. put them on and they never wanted to fit right. on gl's the pods have to reside in a section where the frame has those large verticle sections that tie the side backbones to the lower frame. its a really tight fit so if you were to get them in there they are under stress from the frame internal structure. to the point where it doesnt want to stay on. i got them to stay on but every time i pulled the choke cable the wire would bind on the lip of the pod and knock it off. what i ended up doing was make my own "pods" the uni filters dont have a taper to them which may correct problem i was expericening but i wasn't gonna spend 30 bucks on a "may correct problem" i took 2 1/4 inch vacuum cleaner hose and cut to the legnth i wanted then took air filter screen material that i got free from work and wire tied it to the opening. i took the carb. end and glued it to the original carb boot from the emgo filter that got torn up. they sit on there and they kick ass now. plenty of clearance and cost me 10 bucks for the hose and freebie rubber cement and screen material.
i attached a blurry picture that will kinda show you what it looks liek.
i know pods are a cool idea but the correct mixtures are almost impossible to find by yourself and alot of the shops around wont do it for you, if your going with pods go with a different set of carbs too because our original carbs are set up for the 78/112 ive been in the head ache... save yourselves
stick original or plan on paying a lot for the compatible carbs and work to fit them to our bikes
There are many things to consider when changing your exhaust system. I recently read a set of awesome posts in here somewhere, and this was covered in great length. Besides the major tuning differences that are made when you start changing things from original design, I don't understand why pod filters wouldn't suck up water from rain or whatever. (Carwash?)
So why is exhaust velocity so important?
The faster an exhaust pulse moves, the better it can scavenge out all of the spent gasses during valve overlap. A fast moving pulse creates a low pressure area behind it. This low pressure area acts as a vacuum and draws along the air behind it. A similar example would be a vehicle traveling at a high rate of speed on a dusty road. There is a low pressure area immediately behind the moving vehicle - dust particles get sucked into this low pressure area causing it to collect on the back of the vehicle. This effect is most noticeable on vans and hatchbacks which tend to create large trailing low pressure areas - giving rise to the numerous "wash me please" messages written in the thickly collected dust on the rear door(s).
The H-Box plays an important role. And the air box keeps the carby from sucking in water droplets. Not sure how much a problem water is for a bike fitted with pods though. But I have enough problems