Carburetor diameter inserts
 

What do you guys use ? And if running without the carburetor restricted will waste more I assume but will it cause poor performance ?

Faster and more fuel used. Plus it's not legal for sanctioned racing.

Ok thanks and not legal info is good know. Didn't know if running without would cause tuning issues or performance problems, I know more air can produce more power but sometimes more air can cause other issues from what I hear.

The .21 carburator is legal without the insert because the hole is still 9mm. No problem running w/o the insert but indeed a bit consuming compared with the normal 8.5mm insert.

Good info thanks Roelof.

Smaller diameter -increase torque, reduce top end ,less fuel consumption
Bigger diameter -reduce torque, increase top end ,more fuel consumption

Thanks Kysosho

Having trouble making 5mins with my Nova 2660 pipe. I'm running a newly rebuilt Plus 12-3SCT that's just been run in. Does anyone have any recommendations for a good efficient pipe?

u really feel that I don't know when I run the bigger insert I just have more power all around and faster laps times even on a smaller track where u would say u need more bottom end but the small restrictor just slowed the car overall..?

You shouldnt have an issue making 5 minutes with a novarossi engine. The 2660 pipe is very efficient and actually many use the pipe on OS engines to make time. We need to look elsewhere to get time....

Firstly how short of fuel time are you? Is your tank full size (many are undersize out of the kit - Serpent is a particular tank thats about 5cc too small out the box). Clutch setup properly - not slipping? Is the engine lean enough - if the engine has just come off break-in then the engine will get better as it fully breaks in and you can go leaner.

Honestly you should make 5 minutes easy on that pipe and engine. I can get around 5:30 from most Novarossi .12 engines on the 2660 pipe with both the 5 ring and 6 ring manifolds.

To be honest onroad we rarely change the restrictors these days. 8.5mm .21 engines and 5.4mm in the .12's. Offroad engines is where you tend to change the restrictor from track to track.

Yes I can see that off road would be better suited for the smaller restrictor, I use a 9.5 and I love it!!

Don't ya mean 8.5?? 9.5 would be illegal ;)

[QUOTE=dan_vector;14976671]Don't ya mean 8.5?? 9.5 would be illegal ;)[/

have u ever seen anyones restrictor checked ??? lol

[QUOTE=ralphierace13;14976674]YES! Here the engines are tech inspected. Especially in 1/10 IC .12 engines... Also in 1/8 GT the engines are randomly inspected to ensure 5 ports and 7mm restrictors. By the way in Novarossi engines even if you remove the restrictor completely the smallest section of carb throat is 9mm anyway... So even if you drilled out a restrictor to 9.5mm you are still only at 9mm because the carb throat is 9mm.