Great as a stock replacement, the BD 1045965 exhaust manifolds were designed with expansion joints and heavy webbing to prevent cracking. The exhaust runner design maintains exhaust velocity to drive the turbine wheel. Runner size does not go beyond the size of the exhaust ports on the head because when the runners are larger, the velocity to drive the turbo is lost due to the expansion and temperature in the exhaust manifold which reduces the turbine drive pressure needed for turbocharger response.
This 6.7L Cummins performance stock replacement manifold is for use with the Holset HE351 Turbo. It is cast of high silicon ductile iron to withstand extreme temperature cycling caused during DPF regeneration and in high performance applications. The larger porting design will handle any increase in power and the open throat outlet flange outperforms the stock manifold. The thick walled casting and integral slip joint also prevents cracking and exhaust leaks. Experience quick spool times and low drive pressures with an overall increase in performance.
On engines with enhanced fuel flow and larger turbochargers, the principal remains the same. Velocity and temperatures are needed to drive the turbine wheel which turns the larger compressor wheel that supplies the extra volume to attain proper air-to-fuel ratios. Optional manifold gaskets (part# 1045992) sold separately. This Product also comes with BD Diesel’s 3 Year / 75,000 Miles Parts Warranty.
