2.9 obd2 inlet manifold

[VR6Will 0]

from a mk3 syncro

has anyone fitted one of these to their 2.8 obd2? what gains if any are to be had?

[RIX 0]

all obd 2 are the same,so no gains unless u start port and polish.

[mk3anni 0]

all obd 2 are the same' date='so no gains unless u start port and polish.

[/quote']

WRONG

The 2.9 inlets have a bigger chamber, so are able to shift more air.

You might see a small gain.

[Eat this 2]

all obd 2 are the same' date='so no gains unless u start port and polish.

[/quote']

WRONG

The 2.9 inlets have a bigger chamber, so are able to shift more air.

You might see a small gain.

yes they open up pretty much straight after the tb whereas 2.8 r t shaped trn it over and ul see what we mean

i assume it flows more air better high up the rev range with a possible slight reduction in torque at low revs (countered by the extra cc on 2.9)

[gav_113 0]

ive opened up my std manifold, to c if it makes any difference, just need to weld it up now!

[VR6Will 0]

exactly what the sort of info im after gav_vr6 let me know how you've got on once its done,

affects on bhp, driveability etc etc

[gav_113 0]

ok i will post results, hopefully should have it done next week, if i can find time!

[RIX 0]

where not talking obd1 here but obd2 and they alle the same

obd1 theres a big diff. but thats another tread

[FishWick 21]

I've got the 2.8 OBD2 manifold and throttle on my 2.9 engine and it pulls a lot better than it does with the 2.9 manifold.

The CC difference between the 2.8 and 2.9 means nothing, purely a marketing excercise to seperate the Corrado from the Golf.....the differences in power and delivery are purely managment and intake governed. 2.9 lets more air in, but at the expense of bottom end. 2.9 has a higher rev limit, it was the fastest production VW at the time, so they didn't care about bottom end, just so long as it could pull 145mph.

OBD2 2.8s are by far the best daily usable VR6 engine.

[Eat this 2]

whats the rev limit on a 2.9?

[VR6Will 0]

where not talking obd1 here but obd2 and they alle the same

obd1 theres a big diff. but thats another tread

Wrong as someone has already pointed out to you! You can get a 2.9 obd2 manifold! they came on the mk3 vr6 syncro

[VR6Will 0]

I've got the 2.8 OBD2 manifold and throttle on my 2.9 engine and it pulls a lot better than it does with the 2.9 manifold.

The CC difference between the 2.8 and 2.9 means nothing' date=' purely a marketing excercise to seperate the Corrado from the Golf.....the differences in power and delivery are purely managment and intake governed. 2.9 lets more air in, but at the expense of bottom end. 2.9 has a higher rev limit, it was the fastest production VW at the time, so they didn't care about bottom end, just so long as it could pull 145mph.

OBD2 2.8s are by far the best daily usable VR6 engine.

[/quote']

so you have had at one point a 2.9 obd2 manifold on your car then went back to a 2.8 obd2 manifold?

[Eat this 2]

I've got the 2.8 OBD2 manifold and throttle on my 2.9 engine and it pulls a lot better than it does with the 2.9 manifold.

The CC difference between the 2.8 and 2.9 means nothing' date=' purely a marketing excercise to seperate the Corrado from the Golf.....the differences in power and delivery are purely managment and intake governed. 2.9 lets more air in, but at the expense of bottom end. 2.9 has a higher rev limit, it was the fastest production VW at the time, so they didn't care about bottom end, just so long as it could pull 145mph.

OBD2 2.8s are by far the best daily usable VR6 engine.

[/quote']

so you have had at one point a 2.9 obd2 manifold on your car then went back to a 2.8 obd2 manifold?

no iirc he converted from obd1 to obd2 that included the obd2 tb and inlet mani (which is 2.8)

[VR6Will 0]

right, so no actually experience of a 2.9 obd2 inlet?

i will be converting my 2.9 vr from obd1 to obd2 soon and thought about cutting my obd2 manifold open just like gav_vr6 is currently doing,

i was just curious to see if anyone had actually done this and what results they got with it.

[ChrisP 0]

where not talking obd1 here but obd2 and they alle the same

obd1 theres a big diff. but thats another tread

Most people that know about VR's know that there is a difference between 2.9 and 2.8 inlet manifolds on OBD1' date=' the reason being that corrado 2.9's were OBD1, [b']BUT when the Golf VR Syncro changed to OBD2 along with the 2WD Golf VR in 1996 they gave the 2.9 (that was always installed with the syncro) a bigger manifold. So there is a 2.9 or bigger OBD2 manifold. I know this for a fact because I have one!

See the pics below

[FishWick 21]

right' date=' so no actually experience of a 2.9 obd2 inlet?

[/quote']

No, what's the point when it has the same plenum area as the OBD1 2.9 manifold and I've already said the engine is better on the 2.8 OBD2 manifold?

Why don't you just plug weld the throttle holes on a 2.9 manifold and redrill and tap them for an OBD2 throttle.......it's been done loads of times before....

[gav_113 0]

so im i going to benefit by opening up my OBD1 manifold the same as a 2.9 manifold plus fitting a XXL TB?

[VR6Will 0]

No' date=' what's the point when it has the same plenum area as the OBD1 2.9 manifold and I've already said the engine is better on the 2.8 OBD2 manifold?

[/quote']

because your comparing obd1 against obd2, how can you say the engine is better on the 2.8 obd2 manifold when you have never tried the 2.9 obd2 manifold?

Why don't you just plug weld the throttle holes on a 2.9 manifold and redrill and tap them for an OBD2 throttle.......it's been done loads of times before....

that is another way of doing it...

[RIX 0]

if you have an obd 1 engine,you will gain something by changing from a 2.8 too a 2.9 manifold,but not on the obd 2 a they all have the big manifold period.

compered too my obd 1 2.9 syncro the obd 2 only has a bigger tb,all obd 2 have 72mm tb.

[VR6Will 0]

if you have an obd 1 engine' date='you will gain something by changing from a 2.8 too a 2.9 manifold,but not on the obd 2 a they all have the big manifold period.

compered too my obd 1 2.9 syncro the obd 2 only has a bigger tb,all obd 2 have 72mm tb.

[/quote']

obd2 inlets are not all the same, chrisp has even shown you a pic of an obd2 2.9 inlet - compare that to gav_vr6's 2.8 obd2 manifold, and you will see the difference!

[gav_113 0]

if you have an obd 1 engine' date='you will gain something by changing from a 2.8 too a 2.9 manifold,but not on the obd 2 a they all have the big manifold period.

compered too my obd 1 2.9 syncro the obd 2 only has a bigger tb,all obd 2 have 72mm tb.

[/quote']

obd2 inlets are not all the same, chrisp has even shown you a pic of an obd2 2.9 inlet - compare that to gav_vr6's 2.8 obd2 manifold, and you will see the difference!

mine is a OBD1 isnt it?? it better be? im getting confused now!

wot are we talking about?? ahhhhhhh

[VR6Will 0]

it might be gav but the 2.8 obd2 looks the same as yours from underneath

[gav_113 0]

someone correct me if im wrong, but my understanding is that the 2.8 2wd obd1 and obd2 inlet manifolds have both small chambers, but they have different throttle bodys and different fitting holes so the TB are not interchangeable? mine is def obd1 because the TB is obd1, and it would not fit on a obd2 manifold?

[RIX 0]

i have a mate in dk,that drives an 97/98 vr with 75tkm on the clock,thats an obd2 car it has the same big intake as a 2.9 engine.

you guys iven have and old tread where it also stats all obd 2 have the big manifold,it´s only on the obd1 cars that theres a diff.

[VR6Will 0]

someone correct me if im wrong' date=' but my understanding is that the 2.8 2wd obd1 and obd2 inlet manifolds have both small chambers, but they have different throttle bodys and different fitting holes so the TB are not interchangeable?

[/quote']

in the uk yes! correct!

i have a mate in dk' date='that drives an 97/98 vr with 75tkm on the clock,thats an obd2 car it has the same big intake as a 2.9 engine.

you guys iven have and old tread where it also stats all obd 2 have the big manifold,it´s only on the obd1 cars that theres a diff.

[/quote']

Ok i didnt realise you werent from the UK. In the UK 2.8 obd2 inlets are the same size as 2.8 obd1 inlets, sounds like from what you are saying in europe the 2.8 obd2 inlets are the same size as the 2.9 obd1 inlet.