What are roller barrel throttle bodies?
Discussion
Normal throttles use butterfly valves to control how much air gets into the engine so when fully open there is still a slightly blockage of the throttle body from the side-on butterfly valve. Roller barrels use a rotating cylinder (barrel) to regulate the air intake which provides a completely clear airflow when the throttle is fully open.
). Throttle is still pretty analogue as the barrel gradually opens.They are more expensive to make as you have to have the barrel turning in the body. They are more prone to dirt getting in. They probably don't have as long a life as normal butterflies and they are harder to recondition.
The air path is not very straight at part throttle, so can lead to poor control at the lower end. Not always though.
The benefit over butterflies is there, but it's quite marginal. So not that great in terms of cost/benefit over standard butterflies.
I think though that they are the only TBs that caterham have fitted as standard. So they are in fact on all Caterhams (that have got TBs on as standard).
Bert
The air path is not very straight at part throttle, so can lead to poor control at the lower end. Not always though.
The benefit over butterflies is there, but it's quite marginal. So not that great in terms of cost/benefit over standard butterflies.
I think though that they are the only TBs that caterham have fitted as standard. So they are in fact on all Caterhams (that have got TBs on as standard).
Bert
Roller Barrells offer the least restriction to the air flow as it enters the cylinder head from the air inlet.
A typical butterfly like a jenvey has a shaft and a blade that restrict this flow creating a turbulent flow into the head.
AT Power produce shaftless bodies which offer 7-10% greater air flow than the Jenveys along with the leading and trailing edge of the blade being chamfered to increase the air velocity. They also see a good improvement over the Jenvey design on back to back flow and power tests.
The Roller Barrell throttle is a rotating cylinder effectively that offers no restriction to the air at WOT. Roller Barrells however are very expensive and harder to map at low speeds and idle conditions.
Caterham use roller barrells on the race engines and road cars as they offer the greatest overall performance gain.
A typical butterfly like a jenvey has a shaft and a blade that restrict this flow creating a turbulent flow into the head.
AT Power produce shaftless bodies which offer 7-10% greater air flow than the Jenveys along with the leading and trailing edge of the blade being chamfered to increase the air velocity. They also see a good improvement over the Jenvey design on back to back flow and power tests.
The Roller Barrell throttle is a rotating cylinder effectively that offers no restriction to the air at WOT. Roller Barrells however are very expensive and harder to map at low speeds and idle conditions.
Caterham use roller barrells on the race engines and road cars as they offer the greatest overall performance gain.
Finchy172 said:
...
Caterham use roller barrells on the race engines and road cars as they offer the greatest overall performance gain.
I'm sure I recall reading some tests somewhere that demonstrated the difference really wasn't that great over a good set of normal TBs in 99.9% of circumstances...Caterham use roller barrells on the race engines and road cars as they offer the greatest overall performance gain.
Murph7355 said:
Finchy172 said:
...
Caterham use roller barrells on the race engines and road cars as they offer the greatest overall performance gain.
I'm sure I recall reading some tests somewhere that demonstrated the difference really wasn't that great over a good set of normal TBs in 99.9% of circumstances...Caterham use roller barrells on the race engines and road cars as they offer the greatest overall performance gain.
Titan Roller Barrells were top with power and torque, the AT Power were 2 bhp less, and the jenveys were 9 bhp less.
Personally if i was building an engine for my caterham and it currently didnt have TB's i would look no further than AT Power. With them being almost half the cost of roller barrells and offering virtually the same power, adjustable trumpet lengths, and the fact i can customise the colours of the anodising etc would be ideal.
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