Lancia Delta - Holzer Style Exhaust Manifolds
The Speedshop.ch Lancia Delta Holzer Style Exhaust Manifolds are made exclusively & revisited by and for us. These are designed for different applications up to custom fittings, such as our exclusive Maranello Manifold. All are always designed to use less welded joints as possible thanks to the mandrel bend tubing’s. This setup allows to achieve the best cost to performance ratio.
Main and first noticeable difference from the “Base” to “High” level manifolds are the material used within. The Base-Level starts with a thick wall 304 steel tubing, with mild steel flanges, to give the best reliability possible and still being cost effective, but with no downsides in terms of performance. Our High-Level options are always bespoke solutions with Material used such as Inconel to be considerably low weight with thinner walls and reliable in different driving and racing conditions.
Headers will provide the biggest gains to all Lancia Delta’s equipped with cast-iron log-type exhaust manifolds. A log-type manifold is just a big tube bolted to the exhaust ports to collect the exhaust gas. It doesn't take up a lot of space in the engine bay and does the job of getting the exhaust gas back to the exhaust pipes, but it doesn't do much for performance because all the exhaust pulses dump into the same space and especially in the 4th cylinder area even against the downward exhaust gas stream. Lancia Delta's equipped with the cast steel manifold, suffer especially in the mentioned area from higher EGT & CHT.
An exhaust header has individual tubes for each exhaust port, allowing each exhaust pulse to flow unobstructed from the cylinder head. Lancia Delta’s with our individual runner Holzer Style manifolds will benefit in turbo response on the road and in terms of dyno numbers allowing to improve torque and hp figures.
These have been also tested against standard design 4-1 manifolds and always get the better power and torque figures.
Our manifolds as sole modification, where tested to improve the Lancia Delta Turbo 16V low RPM turbo response in the 4-500rpm range, producing far more low-mid-end torque, especially noticeable in conjunction with larger turbos. Tests have shown an average power gain in the 13-16 hp range, always manifold alone with no mapping. Tubes on the header are larger in diameter compared to other exhaust manifolds, plus header tubes are mandrel bent to ensure the opening of the pipe stays the same radius at points where it curves. Once again, the goal is to reduce restriction and increase flow, thus lower back pressure and better turbo response as an added value.
Our manifolds are designed with a 38mm inner diameter, to cope best with the 45mm exhaust ports of the Lancia Delta 16V head. Different to other 4-1 headers, these headers follow the firing order, clockwise in a downward motion, producing a "scavenging" effect. When an exhaust gas pulse exits a header tube into the collector, a negative pressure wave is created that travels back up the header tube to the exhaust port during valve overlap. This negative pressure helps pull any remaining exhaust gas from the cylinder and also helps draw the incoming intake charge into the cylinder.
At your disposal are many flange option, an highlight is V-Band feature with a Stainless Steel CNC machined Exhaust Merger. This will reduce the fatigue in the Merger section which is generally prone to cracks. A major plus we noticed with this type of install, it will give the option to clear the gearbox housing with larger Turbo Compressor housings, which on standard installs won't always clear the gearbox, making it necessary to take of some material from that area.
Optional it is also possible to Coat the manifold, with standard Ceracote for aesthetics or also with a functional Heat Barrier by Zircotec coatings, pls. enquire directly via eMail for further coating informations: info@speedshop.ch
Due to space restrictions, we highly recommend fitting a low profile SPAL Radiator Fan. With all manifold options we sell. Further to gain more space between manifold and Radiator/Fan, we recommend installing spacers on the top Radiator brackets, giving so more clearance. This operation on A/C equipped cars, needs to be carried out carefully, as space is further limited up front by the A/C heat exchanger.
Check our manifold page for an overview: Exhaust Manifold