now i love it...

[chemical-ali]

That all sounds great. And looks really good.

But how much and where do I sign?

[cit1991]

If that's by hand, you did a beautiful job.

Was the original surface sand-cast like the rest of it?

On the sketch, how deep was that step inside the bell?

[chemical-ali]

It actually sounds like a good old fashioned garage project. Get an old intake manifold, a high powered dremmel with appropiate bits, and get to work. And what a difference.

[pippyrips]

These results seem at face value speak for themselves. What I don’t understand Is why did Audi shape the inlet trumpets they way they did in the first place given the gains that have been found? Is there any long term risk to the engine? Or just sheer laziness on the part of Audi? I can’t believe manufacturing costs would come in to it?

p.s.

I don’t want to start the ‘Audi knows more than Joe Bloggs’ argument which comes up a lot when someone finds/does a mod. I say good on AntoRS4!

[jackWood2]

Those results look fantastic.

What did you actualy ue to produce the shape and finish? It looks very uniform to be done by hand.

[SR71]

Stunning results AntoRS4,

Like pippyrips says, I can't believe the whole inlet isn't polished from stock anyway....

Pay £55K and they don't even polish the intake for you....

Bar-stewards.

Once again, good work and do you want to do mine?

[PetrolDave]

Just goes to show that with an NA engine it's the old-fashioned methods (air flowing and polishing) that have the biggest gains - no electronic trickery can make an engine suck much more air through a restriction, but get rid of the restriction and good gains can be had.

Reading some of the tuning books from the 1960's gives exactly the same lesson - some things don't change...

[AntoRS4]

just say that 100mbar more in the rs4 intake produce apx. 40hp
now i can see 70/80 mbar over the atmospheric absolute pressure (at wot )
the porsche 997 gt3 rs stock intake manifold produces 150/160 mbar... it's like a low pressure turbo, great job!!
A plastic/carbon intake manifold is the best solution, on a £55K car should be a must !

[SR71]

Polish the whole RS4 inlet, and maybe you'd get the same delta....

So based on your sums, if you could engineer a RS4 inlet to optimize the fluid flow as well as the GT3 RS inlet, you'd be looking at ~450hp (385 + 30 + 30) - which should equate to ~107hp/litre, still a little short of the 115hp/litre of the GT3...

I can see where this is going...what we need is a price on a fully polished (and installed) inlet?



PS: I reckon all those Audi press cars probably had polished inlets then....

[sonny]

Interesting read, However as mentioned above, the RS4 engine "should" be Imperfection free, take the BMW e36 328 engine massive gains are had by Gas flowing and porting the manifolds, but the M3 you can’t do it as it has all ready been done and that the way the M division wanted it!...so the RS4 should be the same, if then I am truly gutted!

So have you got any before shots?

[AntoRS4]

about price, you need to contact an "old style" tuner, I'm here only to share my experience with this car.
It's about two years that i fight against the rs4 chronic power loss and now I'm a very happy user
just say that now i can accept also the drc issues....

about Audi press cars: you are right SR71, now my car runs 0 to 200 in about 15,5 sec

[pippyrips]

Interesting read, However as mentioned above, the RS4 engine "should" be Imperfection free, take the BMW e36 328 engine massive gains are had by Gas flowing and porting the manifolds, but the M3 you can’t do it as it has all ready been done and that the way the M division wanted it!...so the RS4 should be the same, if then I am truly gutted!

So have you got any before shots?

It does seem somewhat of a take

I've already asked about and been given the name and number of a few specialists capable of doing this so will giving them a call to get a ballpark price and their thoughts on it.

That said, a friend who knows a thing or to thinks it would be pretty costly? Either way I’ll let you know how I get on.

[Andyuk911]

I asked John Thorn of Thorny Motorsport(Milton Keynes) if they could do this and the answer is yes ...

I suppose if you are that keen, you can give them a call directly for a quote.

For personal reasons, I can't do this right now .. shame ...


Johm's reply


Yes of course, gas flowing (where you smooth out the internal sides and jins in the induction) is quite common, especially on NA cars. We do most of the race cars.



http://www.vxronline.co.uk/forum/image. ... 1225714659


http://www.thorneymotorsport.co.uk/

[WnelsonRS4]

way way beyond me

[silverRS4]

Trying to analyze this info. It looks like the stock horn inlets have the nice polished appearance from the factory, but Andyuk has blended the transition that leads from the horn into the untouched part of the casting - as well as reshaping the port. And the photo of the entire lower manifold shows a "before" port (the one on the lower left) next to a port that has been reshaped. The lighting is not quite enough to tell exactly. The closeup of the machined bell inlet is showing the "stock" inlet and the poor transition left by the Audi machining, correct? Was any work done to the upper manifold (plenum), or just the lower manifold, which is shown in the picture?