max power on standard engine

[Ryan_s3]

Hi,
Does anyone have a idea of what sort of maximum power the rs4 engine can safely run standard?
I know the standard turbos run out of puff at 500bhp which suggests they are slightly smaller k04's to the s3/tt ones.
If i were to get some new manifolds cast and replacement turbos with the aim of 650bhp,what would be the bottleneck?i see mtm port the cylinder head for 520bhp but still use the standard intercoolers.
What about valvetrain,intercoolers,engine internals,throttle body,cylinder head,pipework,maf,airbox,fueling pumps/injectors.
thanks for the help.

[dummi]

valve train only limits top end afaik. the use of bigger intercooler can't be a bad thing with high volume turbo's

cylinder heads,, fuel pump and injectors need to be higher volume over 500 if i am correct.

don't know what standard internals are good for though

what state of tune is the rs4 engine in at the mo?

[S2tuner]

The highest power I've seen out of a totally standard RS4 engine apart from compression ratio is around 600-ish crank HP and 600 lb/ft. This means no internal work, no head work, no pistons, rods or anything were touched whatsoever.

[Ryan_s3]

Thanks for the replies ,so 600bhp is possible with uprated turbos and standard internals etc.uprated fuel obviously.
Minhea ,what do you recommend as a stage 1/2 for a rs4 with scope for further improvement, i was thinking ,panel filter,3" exhaust system with twin 100 cell cats.

[S2tuner]

a 3" exhaust isn't bad but there's loads better available out there Like a dual 2.75" from the turbos back, with either no cats or 100 cell ones if you have to have cats. Then there's no power left on the table because of a somewhat restrictive exhaust system...

[Ryan_s3]

What about mot time?Why do you think a 2.75" system is better than 3"?worried about not enough backpressure to spool the turbo? Every tried different turbos on the rs4 minhea?

[S2tuner]

Ryan, are you talking about a dual 3" or a single 3"? In my experience, you can't get more than 3" downpipes and dual 2.75" under the rear diff, this is why we're using dual 2.75 all the way. Different turbos, yes, it all depends on which turbos

[Ryan_s3]

i have a few ideas of my own,but i would be interested to know what the specs are on the standard k04's,are they a similar size to the s3/tt k04's? Do you know if the stock exhaust manifolds are restrictive?

[dummi]

stock exhaust manifolds have awfully small ports, optimised for quick spooling i suppose...

[Ryan_s3]

sounds similar to the s3,they also have a tendancy to crack and have a maximum flow potential.
I'm really interested in knowing the specs for the rs4 and s3/tt k04's ,compressor/turbine etc. If they are similar then i have done alot of research into this size of turbo.

[dummi]

try buehnengineering theres nothing he doesn't know about the specs of our kkk's

[Ryan_s3]

Will he be along soon?

[ZeroK66]

He is not active on this forum. Find him over on audiworld.

The stock manifolds are not only restrictive, but simply terrible. A set of large tubular manifolds not only flow better, but spool up turbos quicker... go figure!

[davs4]

This is his website http://www.buehnengineering.com/forums/

[Ryan_s3]

oh yeah i remember this guy a few years ago selling k04 hybrids.