reversed intake manifold

larSTI8

Active member
ISDC Club Member
How's it goin. Looking for info, has anybody reversed a intake manifold without modding the manifold itself. I have done my own . I going to custom make the intercooler pipes. But thinking now the way the throttle angles up . the pipes may hit the bonnet. Anybody any ideas??? or have done it
 
Yep doing the same myself... no bother spinning manifold round but throttle body needs alloy wedge fitted between it and plenium to point it towards front rather than up at the bonnet... !

Damian at Street performance has done one of these... see traders section to contact him! :thumbsup:
 
Heya,

You need to either fabricate it yourself or get someone to fabricate it for you. An engineering fabricator should be able to do this for you, but you will need to find an alloy welder afterwards to attach it. What version Impreza do you own... make, model? As the V3/4 inlet manifold can be spun round and has the same stud spacings as most classics and doesn't need a wedge just a 45 degree 70mm Samco pipe... see the below post from Zen Performance on the best Manifold to use as found on Scoobynet.....

Just incase your not fimiliar.... abbreviations are....

ISCV - Idle Speed Control Valve

PS - Throttle Positioning Sensor

TB - Throttle Body

TGV - Tumble Generator Valve (useless butterfly valves that lower emissions only on cold starts for like 20 seconds and restrict your intake for the remaining 99.9% of the time you drive your car)


Early phase 1 manifold from v1-2 car will fit on your car, will make the best peak power of the manifolds that will fit on your car, but a little less torque. It will not easily accomodate the inlet pipe, will need spacers to raise it. To reverse it, it will need a new plate for the throttle welding on the front. It carries the ISCV that is compatible with your car, and your throttle body will fit meaning no connector changes for the TPS. Fuel rails will not be transferable, although you can put your injectors into the rails that come with these manifold as standard.

Phase 1.5 (or late phase 1 as some people say (V3 & V4) is easily reversable, just fit it backwards and get a 45º 70mm samco on the TB to get the pipe down away from the bonnet. Without spacers, all you need is to twist the top of the ISCV to get bonnet clearance. It requires no welding, just some mods to the engine loom due to the different position of the ISCV and TPS relative to the loom. It has humps on BOTH SIDES and can be made to accomodate your inlet pipe with ease (just remove some lumps underneath). It will give better low down torque, and IMHO is probably the more suitable manifold over the V1/2 unit. It's free, and to be found on your car right now.

Phase 2 manifold will not fit on your car, not simply reversed due to the ISCV which isn't compaitble with your version of PFC. It is not symettrical, doesn't equal branches and is only humped only on one side which precludes you from reversing it as is.

New age manifold with TGVs will not fit on your engine, like the phase 2 the stud pattern is different at the ports are 15mm further apart. It is however easily reversed as the TB sits nice and low, it is also humped on both sides, although there is nowhere immediate to locate the coil. The ISCV isn't compatible, but may I think be adapted with some electronic work. It uses Top feed injectors with different fuel rails, but new injectors are relatively easy to come by for you power level, not cheap though.

New Age manifold without TGV (JDM STI) is same shape overall as TGV version, but with a straight transition onto the head, much like the previous inlet manifold.

You can also get some others, but I don't think you will be interested.


Hope this helps you...

Jamie. :thumbsup:
 
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