2 into 1 intake discussion

[firebanshee]

When's the last time you saw a 6-pack in action on the strip? Most high HP drag cars are running a single dominator carb with a low rise manifold on a V-8.

This topic is about the motors running a 2 into 1. I own a 472 Cheetah and I wouldn't run a 2 into 1 on that motor. But for a 392 or smaller the GRAYDON is a strong option that doesn't loose HP like you think it does. Read the entire post. I own one and it's a runner. I removed the twin 28's that were on it. Do you think I did that to loose HP? It's easy to bash stuff that you don't agree with. This post is asking how to make it work. Your signature tells me that you motor and your fuel are well beyond providing a helpfull input here. Plenty of people have posted saying that they have run them for years and like them. If you think they are throwing away power....fine. You just feel safe knowing you'll be out front with your twin 39's on alky.

I have had many different banshee's and still have a 3 of them,i have built alot of different banshee motors(i am by no means a pro motor builder)i do it as hobbie.I have tried alot of different setups and ridden ALOT of diferent setups between my bikes and my buddies bikes and my kids bikes.I also have 4 stroke quads and a rhino.I am also building a 558 cheetah drag big. My point being is my drag bike in my sig is not my only bike.You should not make assumptions that i know nothing about 2 into 1 set ups.I have played with them didn't like them.I also have never been beaten by 2 into 1 on my dune bike yet alone on my drag bikes.I would rather keep dual carbs.What is the benifit of running a 2 into 1?It wont make me faster, and i don't care if i have to change jets in 2 carbs.If i want a bottem end or trail bike i will buid a dual carb motor to accomplish that.Too each there own though.

Sorry i forgot that it said at the start of the post that if you did not like the 2 into 1 you were not allowed to post.

[AKheathen]

it's funny you should bring up a six-pack....... the point of that was mainly circuit racing in the trans-am and circle track "course" racing, but the 6 barrels obviously out flowed a spreadbore, or square bore, so it saw the drag, too. point being, that 2barrel carbs can be tuned allot more precise and responsive than a primary/secondary, but that's a whole other story to go on about........i think a more appropriate would be tunnel ram vs. low profile single plane, or something of that nature. the problem with the trinity 2-1 is the angles, and constant change in flow direction in such a confined space, more so than just the natural recipication. on a dual carb setup, the return puls id allowed to spit out of the carb, reducing interference at higher throttle range, and doesn't simply go to the other carb on the 2-1, because of delay, so the total air mass gets a little congested. think of it as 2 separate highways, vs. a 3-way intersection. i don't know how the greydon plays into this, since i have never even seen pics of it.

[SLORYDER]

This is a great thread. The banshee I just bought has two 35mm keihins and I think they are why it has no bottom end. I ride 95% mx so I need bottom end. Can I just put one of my carbs on the shelf, buy a 2 into 1 boot and single throttle cable ad run that set up? Does anyone know where I could get a throttle cable for one of those carbs? Im guessing there is no way to use the cable I have now. Also, would I need an air filter with a larger surface area? If I can find all the stuff I need to set up my shee for the single carb I will have a extra 35mm keihin that I will sell.

 

I think you should fine tune your jetting before you do anything else. I am under the impression that those big carbs come set up for a cylinder much larger than 175cc, as far as the low to mid circuits. It appears they work well for topend.

Not saying the 2:1 won't help, because it seems like most people notice an increase in performance in the bottom end after going 2:1, but I really think that on a cylinder smaller than 250cc or so the stock jeting on those carbs is way off on the pilot and needle circuits..

[WINDYCITYJOHN400]

This is a great thread. The banshee I just bought has two 35mm keihins and I think they are why it has no bottom end. I ride 95% mx so I need bottom end. Can I just put one of my carbs on the shelf, buy a 2 into 1 boot and single throttle cable ad run that set up? Does anyone know where I could get a throttle cable for one of those carbs? Im guessing there is no way to use the cable I have now. Also, would I need an air filter with a larger surface area? If I can find all the stuff I need to set up my shee for the single carb I will have a extra 35mm keihin that I will sell.

 

 

This is the other end of the discution....a motor (that I assume) is close to 350cc's = a couple of overbores and it's got twin 35's! Talk about overkill. I'm running twin 35's on my 100+HP 472 cheetah!

 

For MX ,you would like a 2into1. Like I've said time and time again....I'm a fan of the GRAYDON. The Trinity model works...but I feel it's sharp direction changes do hinder performance. You will see an improvement in performance as your carbs are more than likely too big. (Yes I know some people run 35's on a stock type motor, but your loosing MASSIVE amounts of bottom end doing it)

 

Twin 28's would work well for you too, but since you just bought this quad...I'd keep stearing you toward the 2into1 because you will have an easyer time jetting with the strong intake signal. Plus it's less work.