Arguably, the hardest part of boosting the CVH is the turbo manifold. Simply put, no one makes a good manifold. In this post, I'll break down the different manifolds for all of the new people, so that they can get an idea of what can be run with what, and how.
Stock Escort EXP Manifold
These manifolds are found stock on turbo EXP's from the late 80's and can be difficult to locate. The flange is a standard IHI flange, and allows a VJ-11 to be bolted to this manifold A hybrid, fast spooling, high flow turbo can be built form the hot side of a VJ-11 and the cold side and centersection of a Thunderbird IHI turbo. The port spacing is dead on and the correct "D" shape for the CVH head. The problem with using this manifold is the turbo comes into contact with the clutch slave on the second generation and up cars, requiring the slave to be modified or moved. Below is a picture of the manifold on a first gen car.
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Escort RS turbo manifold
This is the stock manifold on the MK3 Escort RS turbo from the UK. The engine is factory turbocharged, and is a CVH, but the port shape is round, instead of D shaped. This manifold is forward facing, and uses a standard T3 flange, enabling any T3 flanged turbo, even a hybrid T3/T4 to be used on the manifold. Most likely, this manifold will need to be imported from the UK unless you happen to be lucky enough to find one in the states. The RS turbo gaskets can be made from a set of gaskets for a 4.0L SOHC V6 engine.
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Fiesta RS Turbo manifold
To my knowledge, no one has attempted to use this manifold on a USDM escort, but, it has the same port spacing as an RS turbo manifold, with one significant difference. The flange is for a T2 class of turbochargers. Pictures and information on this manifold is difficult to find.
JGS log manifold
JGS tools www.jgstools.com sells a log manifold, or manifold kit for the CVH engines. The kit comes with a pre ported flange, and schedule 40 weld LS and Tees. It can either be assembled by the buyer, or by JGS for an extra cost. The manifold is very robust, and properly welded, should not crack. Since it is a log, it does have the characteristic lack of good flow, but the compactness and ability to mount any turbo at any angle are major draw points. Below is a 3d modeling of the manifold.
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DSM manifolds
The port spacing on the 4G63 turbo engine is spot on for the escort, with the problem of the stud pattern being different. A stock 4G63 manifold can be redrilled for the escort pattern and then bolted on the head, but there is a significant difference between the escort port and the DSM oval port. The draw of the manifold is the cheap price, abundance, and no need to move the clutch cylinder. Aftermarket tubular headers for the Mitsubishi can also be used, with the advantage that the flange can be cut from the tubes, and a new one, from JGS tools welded on in its place, making the manifold bolt on to the escort. Because of the wide variety of aftermarket options for the DSM, the headers can be found for MHI turbos, as well as Garrett and other varieties. The stock manifold supports T25/14b/16G/20G and equivalent MHI flanges. Below is a picture of a stock second gen DSM manifold. The second gen eclipse manifold is the preferred manifold over the first gen, due to a different metal composition, leading to reduced tendency to crack.
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Miata turbo manifold
The miata turbo manifold is much like the eclipse manifold. It has the same port spacing as the escort, but has an oval port like the DSM, requiring a header to be reflanged, or a manifold to be ported. Both will need a new stud pattern drilled. In my experience, it is better to sell the manifold and buy something more appropriate, since cast manifolds for a miata are worth significant money. If you happen to have a cheap Ebay turbo manifold, reflange it, and run it! Below is a picture OF a Bell Engineering Group cast manifold. I have since sold this manifold, and used the profits to pay for the following manifold.
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Custom
There is no end to what can be done custom. The best, however would be stainless steel, or heavy mild steel. Below is the start of my custom schedule 40 header. It will end up being utra compact, with a forward extrusion of 2.5", and a downward extrusion of 3.5" making it more compact then an RS turbo manifold from an escort. Being made of schedule 40, it will resist cracking and should run from quite some time.
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Stock Escort EXP Manifold
These manifolds are found stock on turbo EXP's from the late 80's and can be difficult to locate. The flange is a standard IHI flange, and allows a VJ-11 to be bolted to this manifold A hybrid, fast spooling, high flow turbo can be built form the hot side of a VJ-11 and the cold side and centersection of a Thunderbird IHI turbo. The port spacing is dead on and the correct "D" shape for the CVH head. The problem with using this manifold is the turbo comes into contact with the clutch slave on the second generation and up cars, requiring the slave to be modified or moved. Below is a picture of the manifold on a first gen car.
Escort RS turbo manifold
This is the stock manifold on the MK3 Escort RS turbo from the UK. The engine is factory turbocharged, and is a CVH, but the port shape is round, instead of D shaped. This manifold is forward facing, and uses a standard T3 flange, enabling any T3 flanged turbo, even a hybrid T3/T4 to be used on the manifold. Most likely, this manifold will need to be imported from the UK unless you happen to be lucky enough to find one in the states. The RS turbo gaskets can be made from a set of gaskets for a 4.0L SOHC V6 engine.
Fiesta RS Turbo manifold
To my knowledge, no one has attempted to use this manifold on a USDM escort, but, it has the same port spacing as an RS turbo manifold, with one significant difference. The flange is for a T2 class of turbochargers. Pictures and information on this manifold is difficult to find.
JGS log manifold
JGS tools www.jgstools.com sells a log manifold, or manifold kit for the CVH engines. The kit comes with a pre ported flange, and schedule 40 weld LS and Tees. It can either be assembled by the buyer, or by JGS for an extra cost. The manifold is very robust, and properly welded, should not crack. Since it is a log, it does have the characteristic lack of good flow, but the compactness and ability to mount any turbo at any angle are major draw points. Below is a 3d modeling of the manifold.
DSM manifolds
The port spacing on the 4G63 turbo engine is spot on for the escort, with the problem of the stud pattern being different. A stock 4G63 manifold can be redrilled for the escort pattern and then bolted on the head, but there is a significant difference between the escort port and the DSM oval port. The draw of the manifold is the cheap price, abundance, and no need to move the clutch cylinder. Aftermarket tubular headers for the Mitsubishi can also be used, with the advantage that the flange can be cut from the tubes, and a new one, from JGS tools welded on in its place, making the manifold bolt on to the escort. Because of the wide variety of aftermarket options for the DSM, the headers can be found for MHI turbos, as well as Garrett and other varieties. The stock manifold supports T25/14b/16G/20G and equivalent MHI flanges. Below is a picture of a stock second gen DSM manifold. The second gen eclipse manifold is the preferred manifold over the first gen, due to a different metal composition, leading to reduced tendency to crack.
Miata turbo manifold
The miata turbo manifold is much like the eclipse manifold. It has the same port spacing as the escort, but has an oval port like the DSM, requiring a header to be reflanged, or a manifold to be ported. Both will need a new stud pattern drilled. In my experience, it is better to sell the manifold and buy something more appropriate, since cast manifolds for a miata are worth significant money. If you happen to have a cheap Ebay turbo manifold, reflange it, and run it! Below is a picture OF a Bell Engineering Group cast manifold. I have since sold this manifold, and used the profits to pay for the following manifold.
Custom
There is no end to what can be done custom. The best, however would be stainless steel, or heavy mild steel. Below is the start of my custom schedule 40 header. It will end up being utra compact, with a forward extrusion of 2.5", and a downward extrusion of 3.5" making it more compact then an RS turbo manifold from an escort. Being made of schedule 40, it will resist cracking and should run from quite some time.
