There is so much power you can make without increasing the compression ratio, you can still do a lot of breathing mods but you can only benefit from it to a certain point. People are just a bit bat crazy over bolt on VR mods tbh...
Anybody seen these?
AFI VR6 24V INTAKE MANIFOLD Tuner Headquarters
Certainly look like sturdy and quality-built pieces of "art" but at $1300 USD you'd want to make sure there were decent gains.
Its easy to find proof that the 12v VR6 heads had terrible flow design (and then they talk of increasing valve size and cam lift duration) but there isn't a lot of info on the 24v.
As far as I can determine the 24v head was designed by Cosworth. I am taking that to mean that they redesigned the 12v head and that the two heads are relatively similar aside from the obvious number of valves.
MY02 Bora V6 4Mo|Matte Black plastidip|VTDA|R32 Exhaust|R32 dampers and springs|TT pedals|R32 steering wheel|17" 8L S3 rims|R32 sways|Blue Haldex|EBC reds
There is so much power you can make without increasing the compression ratio, you can still do a lot of breathing mods but you can only benefit from it to a certain point. People are just a bit bat crazy over bolt on VR mods tbh...
80,000km 1997 MK3 VR6 manual for sale - www.vwwatercooled.org.au/forums/f23/80-000km-1997-manual-vr6-nsw-sydney-67658.html
MY02 Bora V6 4Mo|Matte Black plastidip|VTDA|R32 Exhaust|R32 dampers and springs|TT pedals|R32 steering wheel|17" 8L S3 rims|R32 sways|Blue Haldex|EBC reds
That is a truly beautiful manifold. I wonder if it still incorporates the variable intake runners? Or propably just for max gain I suppose.
Id say that intake manifold is designed with turbo conversions in mind given its identical runner length and the ditching of variable geometry. I dont think it would be a great option for an NA car.
Thats a pity, would look top notch.
the 2.8L has a lot of room for improvement in the head (as proven by the R32), and the intake manifold isnt ideal if your doing big mods to the motor.
That one looks to be for F/I usage, and note that equal length on the outside, but the intake ports are different on 3 of the cylinders so not really equal length from the valve.
The dual runner intake is proven to make a very big difference to low end torque
Current: '04 Astra SRI Turbo - EDS IPF Flash, 3" TBE, Quaife LSD
Previously: Bora 4mo, cams, coilovers, tune, exhaust, brembo's etc
Nothing to see here...
I think he was saying there's only so much power you can make before going FI, and if that's the case, he's right - in the end, without FI, you can only fill the cylinder with a single atmosphere's air pressure, and it's the O2 content that limits how much power you can make in the end.
That CNC page I linked to says the intake is pretty decent but the exhaust is terrible - doesn't surprise me given that between the 12v and 24v VR6s VW introduced the variable flow intake (you can get an after-market option to replicate it on 12v VR6s from Schrick) to optimise airflow for lower and then higher RPM...
Nothing to see here...
Use a R32 head....already a better design!
To use the 2.8 24v head and to even match the performance of the R head is goin to cost u $$$$s......
And yes the head of the 2.8 24v head has room for more improvement
Last edited by JVLR32; 19-06-2010 at 08:44 PM.
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