racing vs. freestyle carbs?
- Thread starter Pablo
- Start date
#ZERO
Beach Bum
- Location
- Florida - U.S.A.
All your questions should be answered if you read these Group-K technical documents.
http://www.groupk.com/tec-carbs99.htm
http://www.groupk.com/tec-carbs98.htm
http://www.groupk.com/tec-carbs97.htm
http://www.groupk.com/tec-carbs99.htm
http://www.groupk.com/tec-carbs98.htm
http://www.groupk.com/tec-carbs97.htm
WAB
salty nuts
- Location
- coastal GA
Some of the race carbs are not as great at fuel metering at lower RPMs....where we want it.
scottie mac
X-
The tuner, lol.
Scottie
Scottie
There is no difference between freestyle carbs and race carbs. The carbs job is to meter fuel to the demand. How it smoothly it does that is what makes the difference. Scottie Mac is right: Its the tuner that makes the big difference. There is no specific jetting, so asking (What jets do I need for my motor?) means you need a good tuner, and having the magic carbs will mean you spent a lot of money just to not have them tuned right.
#ZERO
Beach Bum
- Location
- Florida - U.S.A.
Are you sure about that............:scratchchin:
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
Ever had any luck with Buckshots and low end snap?
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
decent and spot on is far from the same. In race applications, I think the buckshots work well. Look at Novi and Full Spec, they both make carbs that either work well for Freestyle or Racing, but not really both. Purpose built.
Just my 2 cents.
Just my 2 cents.
Novi's or Full Spec's work well in both aplications. Both of those are used by the worlds top pro's. BS were just another carb in their time. There are others but it still comes down to the tuner. I personally know some of the best pro tuners and they can get almost anything to run good. The average guy would not be able to tell the difference between a well tuned not so good carb and an average good carb. Tuners make the diff.
Last edited:
Big Kahuna
Administrator
- Location
- Tuscaloosa, AL
I agree about the Tuner.
#ZERO
Beach Bum
- Location
- Florida - U.S.A.
Why would some of the A/M carb manufacturers offer freestyle & racing versions carbs if there isn't any difference???
I always thought freestyle specific carbs had reworked internal circuitry with modified inner booster venturi's that would actually improve the carb signal because carbs with stronger signal are lot easier to tune and offer more responsive & precise fuel metering.
Racing carbs are pretty much bored straight through were high cfm numbers and fuel atomization is more important then the actual carb signal. Also the larger cfm numbers have questionable value unless they are accompanied with improved carb signals.
Also it said the Group-K test data was gathered on a SuperFlow-600 flow-bench set at 20 inches of water for all tests. I'm sure he just lowered the water level to get more accurate test results.
Lol - freakin freestylers...... "freestyle carbs" that's a good one. Tuner makes the difference!
JAM
JAM
Freestyle carbs are carbs that don't flow enough at higher rpms but are more user friendly for inexperienced tuners or when the set up is not that great they are less likely to cause tuning problems. Most are just slightly taperbored and retain a similar booster venturi to a stock mikuni with the exception of boring the bottom to 48mm If you use them on really modified engines they can easily go rich when the engine comes on the pipe unless you lean it out enough. If you do this then you risk high rpm seizure. If you never run at high speeds then there is no need to worry.
You guys are nit picking the meaning of the words freestyle and racing. Here's the way I see it...
Given everything else the same... Yes a non bomb site carb will be better for upper rpms/WOT because there is less obstructing the flow into the engine. With a good tuner, yes a non bomb site carb can be made to perform the same or at least close to the same as a bomb site carb off idle. The key phrase there is, "with a good tuner". Since only a handful of people on this site have more than basic tuning knowledge, "with a good tuner" means tuned professionally by someone else $$$$.
Now with that being said, a freestyle rider will generally only use WOT for 0.5-1 second at a time and almost never hit the rev limiter in the water. A racer will spend the majority of his time in the upper rpms. So since a non bomb site carb is harder to get perfect, it would be logical that it is therefore harder to keep perfect from spring to summer to fall to winter. That in turn leaves the rider with that strange sensation of "my ski feels like it's lacking power but I don't know why". For the average rider with average tuning skills, a carb that is easier to tune will produce more power than a better carb that is harder to tune. The amount of difference may be noticeable but not as noticeable as a poorly tuned carb.
So in my mind, the carb that is easier to tune on the low end would be ideal for freestyle and the carb that makes more power in the upper rpms would be ideal for racing. Hence racing vs freestyle carbs. I don't want to thread jack but lets not forget that keihin carbs are excellent carbs but because they are harder to tune, have practically disappeared because no one likes them.
Given everything else the same... Yes a non bomb site carb will be better for upper rpms/WOT because there is less obstructing the flow into the engine. With a good tuner, yes a non bomb site carb can be made to perform the same or at least close to the same as a bomb site carb off idle. The key phrase there is, "with a good tuner". Since only a handful of people on this site have more than basic tuning knowledge, "with a good tuner" means tuned professionally by someone else $$$$.
Now with that being said, a freestyle rider will generally only use WOT for 0.5-1 second at a time and almost never hit the rev limiter in the water. A racer will spend the majority of his time in the upper rpms. So since a non bomb site carb is harder to get perfect, it would be logical that it is therefore harder to keep perfect from spring to summer to fall to winter. That in turn leaves the rider with that strange sensation of "my ski feels like it's lacking power but I don't know why". For the average rider with average tuning skills, a carb that is easier to tune will produce more power than a better carb that is harder to tune. The amount of difference may be noticeable but not as noticeable as a poorly tuned carb.
So in my mind, the carb that is easier to tune on the low end would be ideal for freestyle and the carb that makes more power in the upper rpms would be ideal for racing. Hence racing vs freestyle carbs. I don't want to thread jack but lets not forget that keihin carbs are excellent carbs but because they are harder to tune, have practically disappeared because no one likes them.
scottie mac
X-
Waternut,
I am diggin the flat deck, looks cool.
My take, I have pretty much run every carb on the market at one point or another - Green racing, Black Jack, Red Top, stock mikuni 44s and 46s, Full Specs from 44 to 49, and Novi 46s, 48s and the new style Novitecs. In my opinion, the full specs and Novis were just better than the others. They seemed to 'hit' better on the bottom and pulled good enough on top not to worry about searching for more rpm.
I sometimes think that the freestyle fellows think race skis have no bottom end. I can tell you now, I would put my 8mil TJ/Joe McKenna built 'race' motor up against anything on this site in terms of bottom end hit. And that is with a dry pipe and small 140mm pump. In my class, holeshot is VERY important because of the Blaster's hull limitations once the water gets rough. And, there is no chance I would use anything but a Novi or full spec. From looking at this site, it looks like most serious riders on here - freeriders or racers - use either Full Specs or Novis.
Even still, a good tuner will be able to get more out of a 'race' carb on a freestyle ski than a bad tuner will get power out of a 'freestyle' carb on a freestyle ski.
I am a perfect example of this scenario, lol, cause I suck at tuning.
Scottie
I am diggin the flat deck, looks cool.
My take, I have pretty much run every carb on the market at one point or another - Green racing, Black Jack, Red Top, stock mikuni 44s and 46s, Full Specs from 44 to 49, and Novi 46s, 48s and the new style Novitecs. In my opinion, the full specs and Novis were just better than the others. They seemed to 'hit' better on the bottom and pulled good enough on top not to worry about searching for more rpm.
I sometimes think that the freestyle fellows think race skis have no bottom end. I can tell you now, I would put my 8mil TJ/Joe McKenna built 'race' motor up against anything on this site in terms of bottom end hit. And that is with a dry pipe and small 140mm pump. In my class, holeshot is VERY important because of the Blaster's hull limitations once the water gets rough. And, there is no chance I would use anything but a Novi or full spec. From looking at this site, it looks like most serious riders on here - freeriders or racers - use either Full Specs or Novis.
Even still, a good tuner will be able to get more out of a 'race' carb on a freestyle ski than a bad tuner will get power out of a 'freestyle' carb on a freestyle ski.
I am a perfect example of this scenario, lol, cause I suck at tuning.
Scottie