Large Bore Exhaust System for Saloon and XJS         LARGE BORE SYSTEM - Saloons & XJS   Our LARGE BORE EXHAUST SYSTEM with all straight-through silencers removes virtually all the restriction from the system but in reality only gives about 5-10 b.h.p. more than the Silencer Substitute Pipes so is only really worth thinking about if the complete system is in need of renewal. TT Extractor System Our TT EXTRACTOR system is a tuned front section designed specifically to boost mid-range torque (which is what most people find useful). The original Y pipes below the standard manifolds (headers) are replaced by pairs of pipes of tuned length and diameter which merge just behind the transmission then feed through short adapters onto a pair of Silencer Substitute Pipes. From that point on the original system can be retained, renewed as a complete TT EXTRACTOR system, or replaced by a Large Bore Rear system for extra top end power but this option does tend to be noisier than some people would like for road use. The TT system significantly outperforms a Large Bore system so much so that fueling changes (included in the kit) are essential for it to work properly. The adapter pipes can be supplied with lambda sensor tappings but heated sensors must be used because of the distance from the engine. A wiring extension kit is included and we can supply heated lambda sensors as an extra.   TT HIGH TORQUE EXTRACTOR PIPES + Sil Sub Pipes + ECU mod. TT SYSTEM - Complete - Std rear section TT SYSTEM - Complete - Large bore rear section TT SYSTEM - Complete - V12 6L Saloon (XJ40 type)