A friend of mine told me if I can install a single carb with a acceleration pump like a 400EX carb, I could gain power everywhere. But I will have to change my whole intake. I know I can buy a full kit with carb / intake and any other mod I need to do. But I would like to try to build it myself.

If anyone can give me good information or any link that can help me, I will appreciate [img]i/expressions/face-icon-small-smile.gif[/img]


thx

 

Edelbrock Quicksilver carb is made for a single carb setup on a Raptor, the kit is about 600 bucks,not owning a Raptor, I really can't tell you the pros and cons of single carb set up. It would simplify the tuning, but you have to balance the low end response and the high end fuel needs to see an all around power gain, one of the reasons for the 2 carb set up.

 

If you go with a single carb setup you will gain bottom end but lose some top end ( at least thats what edlebrock told me ). If you talk to WARD660R he runs a single lectron carb with a homemade intake, he could give you some pointers i guess.

 

I run Edelbrock single on my raptor and will never go back this nonsense dual set up. I don't feel any problem on top, but I feel instant throtle response. Adj. difference is like day and night.
rnuts

 

Does it get rid of the stumbling and hesitation in rough terrain, like on a MX track?

 

I personally have no complaints about the dual carbs. I have dyno tested them and there is nothing wrong with them. The problem with these carbs is the people working on them. They have no clue how to set them up and then they blame the carbs.

For the life of me I cannot understand why a single will do any better. The only time it will do better than a duel setup, is if one of the carbs is out of tune. Also, all the DS owners are ripping the single carbs out and replacing them with bigger carbs. Why? Simple, the single does not flow the air required for top end power on a 660cc motor. You need more air than a 42mm carb will flow to produce high end power on the 660cc.

Constructing a home made adaptor is going to mess up air flow even further. The duel carbs have a direct path to the valves, no messy corners and airflow trying to bend around and splitting up. Each time you split the air up from a single to a dual, you mess with air flow and the way it enters the cylinder.

Everyone is saying the single is better, yet I have not seen any dyno reports confirming their statements. Are Sparks, Craycraft, and all the other raptor tuners using a single carb??? Do you know something they don't? I don't think so.

 

The single setups normally flow less overall CFM's...dropping top end performance.

But, A single carb could easily give the top end flow of two smaller carbs. Physics says that if you double the size of a round pipe it willl flow 4 times the amount as before.

Most race motor setups will not idle well below 3000 rpm's.

In a thumper single the problem is only amplified because in order to use a single carb the max total air flow of the single must be lower then the total air flow of the two carbs you are replacing in order to keep the air speed up in the low rpm's.

It is just not possible to replace the flow of the dual carbs with a single and keep the low rpm air speed high enough. Therefore the single must balance the max airflow potential (top end) with the loss of the low end air speed.

A good example of this is a V8 where a four barrel carb will produce more low end power then a two barrel....even when both have the same flow rating. In this case the first two barrels are normally much smaller the the second two barrels...in order to keep the idle and drivability needed. Normally this is solved by having some way to only using the second two barrels when needed.

I think that the best setup for a raptor would be duel carbs with some kind of progressive linkage. This linkage would open the two carbs one at a time....giving both good low speed response and wide open power.

Of course tuning this setup would be even more problematic. Just don't expect to replace the dual carbs with a single and get both low and top end gains.

 

Everyone is saying the single is better, yet I have not seen any dyno reports confirming their statements. Are Sparks, Craycraft, and all the other raptor tuners using a single carb??? Do you know something they don't? I don't think so.[/quote]

Some of them are. Just read about Duncan Raptor.
rnuts



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We'll hopefully have some dyno #s by the end of the month.

 

Sixsixt, is that 1bads quad? I have not heard much about his new set up. How is it going? I have my carbs set up good now and can't wait for dune season.