2.0 8v Turbo Inlet Manifold Improvement

[Rob Turbo 3]

I was intending on stopping at fitting the megasquirt to my 8v turbo, but, as you do, I've been getting ideas!

 

How would the standard manifold benefit from a plenum being added, I know there won't be much of the standard manifold left, but my idea is to cut the standard manifold down so there's just the flange, injector bosses and fuel rail mounting points left, then get an aluminium pipe, cut 4 holes in on one side for the runners, one on the other side for the throttle body, and block the ends off, obviously I'd need the fittings for the pipe to the servo, map sensor and fuel pressure regulator, then get it all welded up.

 

Basically, any good?

 

I already have a spare manifold that I could chop up and my mate has a TIG welder and would more than likely either weld it up for me or let me use it myself, but I'm not going to bother if it's a crap idea!!

[rapidcossie 0]

would only really see advantages over a certain power as there will prob be very little restiction in the manifold until you start to push way over 200 bhp

[Rob Turbo 3]

Well it was 199bhp before I upped the boost, fitted a new cam and put the megasquirt on, and the boost will getting turned up again now it's running a mappable ecu.

 

This idea won't loose me any power though will it? So given that all I need is a bit of aluminium and some time with a welder, this is going to be rather cheap if it will be removing a restriction, even if it's not quite a restriction yet, it could be later!

[welshpug 1,661]

something like this?

 

[sonofsam 5]

 

 

 

 

[weejimmy 1]

mmmmmmmmmmmmmmm

gota love custome inlets.

 

who cares if it helps if it looks like that.

 

but cant exactly be a bad thing,

ive got a gti6 inlet instead of the silly stock t16 one on my engine as advised by matt who has done this a few times.

 

its basicly the same going from no plenum to having one, but as rapidcossie says mayby more gain with higher powerd engines.

 

Edited November 12, 2008 by weejimmy

[Rob Turbo 3]

Basically like that yes, but shorter runners and have the throttle body in the middle so everything is in the same place as it is on the standard manifold. If I put the throttle body at the end it would mean a complete rework of my boost piping and possibly even have to change my intercooler or radiator (or both!) Thats more or less the setup on a cossie so I shouldn't think it's too bad an idea!

 

I might knock a quick drawing up to give a better idea.

[mr_exe 1]

I was just thinking it looked like an Mi16/Gti-6 manifold, therefore can one of those be adapted for use with?

[Rob Turbo 3]

Something like this is what I had in mind, excuse the crap drawing, paint using a touch pad on a laptop isn't that good!!

 

 

Possibly put the throttle body towards the drivers side but more than likely leave it in the middle

[Rob Turbo 3]

Any objections from people in the know? if not, I'll start butchering my spare manifold over the weekend.

[shalmaneser 26]

Would never describe myself as 'in the know', but you've got to be very careful with the airflow when you start doing things like this - car companies don't spend millions of CFD for no reason, you might find yourself with all sorts of weird harmonics and surge problems.

 

However, if you've got a spare manifold kicking about, may as well have a go with it!

[bensonmi 4 2 Cars]

what about usin the 205gti or bx gti(8v) inlet manifold looks like it would flow better and have heard you get gains from this. dont know bout fittin the throttle body tho. but where theres a will theres a way!

[M@tt 77]

Rob have a look at a cossie inlet plenum (2wd iirc), looks pretty much litke what you're thinking of. I bought one for my supercharger project. basically it has a removable back plate with trumpets on which my plan was to weld onto the cut down mi16 inlet manifold (assuming the ports matched up or if not make a new back plate and utilise the trumpts)

 

It has the inlet in the centre although it has a bolt on 90bend to the left iirc where the throttle body goes. Think i got mine for £30 off ebay

Edited November 25, 2008 by M@tt

[Rob Turbo 3]

I had a cossie inlet manifold when I started building my 16v turbo engine (that I should have kept and finished!!) that's why I thought it can't be that bad of an idea if a cossie has one like that!

 

I've got plenty of time to come up with something now that my engine's in bits again!!