How to balance throttle bodies
Probably one of the most significant power upgrades you can make to your engine involves fitting throttle bodies. Most modern engines use a single throttle body which feeds into a common plenum. This set up is easy to produce and install and also removes the need to accurately balance individual bodies at manufacture but has some significant draw backs. Firstly to give really good low speed engine control and good torque the throttle plate size has to be restricted which restricts air flow at high engine speeds. Also due to the common plenum the air flow into each cylinder is disrupted by the pressure pulses from adjacent cylinders.
By fitting multiple throttle bodies one throttle plate feeds each cylinder individually, massively improving airflow into the cylinder and therefore enhancing performance. By utilising different shapes and single or twin bodies almost any engine configuration can be catered for.
Northampton motorsport supply and fit throttle body systems from 3 respected manufacturers Webcon, Titan Motorsport and Jenvey Dynamics.
Webcon have been instrumental in bringing modern engine management systems within reach of the enthusiast and clubman competitor, they were the first company to offer a range of fully developed turnkey kits for a wide range of popular engine. The Webcon throttle bodies are superb quality and offer fantastic reliability and performance. These bodies are available in 40 and 45mm diameters and have air ports that allow for easy connection of an air bypass valve for idle speed control and also for servo and breather connection. Each barrel can be finely balanced to give super smooth idle quality. Easy to fit poly propylene air horns also support the air filter back plate and both top and bottom mount linkages are available making the installation process really easy.
For a road car installation where precise control and reliability are key the webcon system is second to none.
Titan was founded in 1971. At that time, the company's business was the design and manufacture of single seater racing cars and engine preparation. As the company developed, the design, manufacturing and assembly facilities expanded to meet the worldwide demand for motorsport products and services. Titan now has a range of top quality precision machined components from limited slip differentials to their Roller barrel throttle bodies. Conventional throttle bodies use a central
shaft and circular butterfly plate to regulate air flow into the engine. This works well at part throttle but when fully open the shaft and plate represent a small restriction to the airflow. For this reason very high performance applications have always used slide throttle arrangements where a sliding plate is used to regulate airflow. At full throttle the plate withdraws completely leaving no restriction to the air flow whatsoever. At part throttle however the plate would result in heavily disturbed airflow into the engine which made this system unsuitable for road car applications. The titan roller barrel uses a barrel with a hole machined through the middle, when fully open there is no restriction just like the slide throttle, but at part throttle the barrel restricts airflow without the disruption. This gives the best of both worlds with good part throttle operation and fantastic flow capability.
These roller barrels are available in 40 and 45mm sizes with dcoe flange patterns and also as a 45 mm taper direct to head throttle body for the Ford Duratec engine
Roller barrels are Ј892 plus vat per pair excluding trumpets. trumpets are available from 35 to 100mm long and start at Ј 23.50 plus vat eac
Jenvey Dynamics are probably the best known manufacturer of intake systems in the UK if not worldwide. Their range of products includes the popular dcoe flange pattern twin bodies to individual bodies in all shapes and sizes. This versatility coupled with a massive range of air horns, linkages, fuel rails injectors and other accessories means that Jenvey have a solution for just about any application. In fact Jenvey are sole supplier of intake systems for the BTCC and have been involved with manufacturer projects ranging from world superbikes to designing a bespoke intake system for the Nissan 350Z.
Jenvey also manufactures a range of inlet manifolds and air boxes to compliment the range of throttle bodies. As the range is so big it would not be practical to list all the prices here. But we have used Jenvey's engine price guide as an example of the cost of installing the SF type of body,
Price for typical major parts required; Manifold, Throttle bodies, (SF body configuration), Fuel rails, Air horns.
All prices are shown without VAT.Source: www.northamptonmotorsport.com