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whats the maximum power(reliable)you can get out of a standard s4 block and heads? the old fellas just bought a c32AMG and it feels alot quicker than my standard s4 and i cant have can i ???

450bhp ish, not cheap though.

Paulm wrote:450bhp ish, not cheap though.

Minhea's running 511bhp on s4 head and block

I added it all up as im getting ready for a conversion soon enough, and to do it properly,

youre looking at a decent flowing exhaust system, hybrid k04's rs4 intercoolers or front mount, ceramic coated tubular manifolds, uprated clutch and flywheel, and compression dropping gaskets.

That should give over 450 odd.

Will cost approximately 10K if done properly.

If you want to be faster than a c32 amg all you need to do is get an exhaust upgrade, miltek, decat the car to give extra 20 hp, gut precats, and get car remapped. MRC will custom map it, and you should see around 350 hp.

Mines 350hp and it is significantly faster than a c32 amg. The remap makes the car into a different maching. It being a stage 2 + as well will be cheap. Costs are 500 for a custom remap from MRC. 700 for exhaust, 300 for pre cat gutting, and another 300 for the decat.

So for £1800 you will have your self a completely different machine. And it will out run an M3 too as i have done a few times. Ive also out paced the new S6 5.2 V10 from standing start. By the time I was in third gear, I was at least 8 car lengths in front of him.

I believe the C32 AMG is around 350 hp and has about 450 nm of torque.

Your car standard is 265 hp and about 340nm. With a remap and exhaust and precats gutted you will see about 330 - 340 bhp on a custom remap. but 520nm torque which is considerably more than the c32 amg. the torque giving you the advantage.

With a decat, you should see 350 - 360 hp and anout 540 nm torque.


Either way youll out run him each time, especially from a standting start.

Sorry Moh, a stock S4 has about 400Nm in standard trim, not 340.

Agreed with everything else. My car runs 511.5 BHP (with 97 RON and crap cooling on the rollers) and most importantly: 505ft/lbs of torque, i.e. 684Nm.

HTH,

Mihnea

Sorry mate.

Youre right. I got confused with nm figures from my friends bmw 320 diesel we were discussing earlier.

by the way, what does HTH stand for?

And as were talking about maximum power, i guess this is relevant too. Your exhaust system . How did you get 2 pipes at 2.75 to fit. Was it a lot of trouble getting them made that size and not knock?

If you did change your heads, would that exhaust be sufficient for about 600 brake?

you have a PM Mihnea

Moh,

HTH means Hope This Helps

Exhaust: it's custom made and jigged to fit, it fits great and is an awesome piece of kit. We're now selling it too.

As for changing heads: I don't think this is what's preventing me from making more power. I'll try soon to run more boost and see if it will make more power...

price of the exhaust kit please.

Im thinking of trying a few different exhausts. I might try this vortex exhaust that, ive seen before and after plots of running on a 120 d bmw. This made about 20hp more. (yes, seriously). and about 30 to 40lbs of torque.

the vortex boxt acts like a turbo and pulls the gases out. Makes a lovely sound as well.

Some guys say thatthe S4 engine block is too weak to run more power and rods istons engine might go bang. I dont know who else to ask with more experience on these engineg than you. As oyu know the mapping side, i guess youd be the best person to ask.

On a standard block what do you think is preventing you from making more power? Is it maybe the bottom blok?

I think the compression dropping gaskets sort out the heads and allow more gas to go through. What thickness are the gaskets that you are using?

Id be scared of blowing up he engine if running more boost.

The other this is you have 0.7 bar actuators What are they?

Wastegate actuators are set to 0.7 bar. The block is not normally limiting factor in any cars ability to make horse power. Cranks, rods, pistons, rings or shells will usually let go well before a block does.

Engines are pretty simple in basic terms, to get more power you need more air and fuel getting in the engine, to set fire to it at the right point and the ability to get it out after it expodes. All the time keeping the components from getting too hot.

Fast, cheap and safe is the tricky bit. Any two of three is pretty easy. Three out of three is much harder.

Where is the limit of the S4 block and stock internals, to be honest no one knows yet.

There are lots of 400+ bhp cars around the world all running strong.

MTM has produced 600 Bhp RS4 blocked engines. Interestingly RS4 blocks seem very robust, all the engine issues I've seen have been holed pistons. Not block related issues indicating there is definetly some room for more power before we need to start looking at engine internals. RS4 block has additional cooling, larger crank bolts and larger shells than the S4 block.

VTG boys in Poland run S4 blocked dragster with around 800bhp at last count, although they do run uprated rods.

Until there are enough people running 500, 600 or 700 bhp we'll never know where the real limits are. 500s certainly looks doable and can still be driven every day.

Thanks for the very informative reply as always by yourself kayGee.

Easy to understand too.

What does setting the wastegate actuators to 0.7 bar do?

IF upgrading engine. Are their any after market parts to upgrade the cranks rods pistons rings and shells?

Ig uess rings and shells can be upgraded by running an rs4 block for a start. Seen that 034 motorsport do the forged rods for the 2.7T. have youheard any reviews on them? Have you got that new clutch yet Kaygee?

Actually my WG actuators are 0.6 bar, i.e. stock.

ok. you said that they were 0.7 in your other post when you listed mods of our car, so i thought they were special. lol

Still dont know what actuators do. Im guessing it means that when boost drops to 0.6 bar, the air is dumped (re circulated) at that point?

A C32 is fast, I doubt at any more of a weight disadvantage than a B5 and they are automatic so of course a perfect change every time. I'm not confident a S4 with like for like power even with more torque would be quicker. Feel quicker perhaps.

saf wrote:ok. you said that they were 0.7 in your other post when you listed mods of our car, so i thought they were special. lol

Still dont know what actuators do. Im guessing it means that when boost drops to 0.6 bar, the air is dumped (re circulated) at that point?

I wrote an explanation of the charge-pressure and wastegate actuator feedback loop. You can find it Here

0.6/0.7 Bar may be stock for Mihnea's turbos, but the original S4 stock turbos have actuators set to ~0.4 Bar.

I am having a similar setup to Mihneas...

Hotside Ported, clearanced K04's
Lowered CR - 8.2:1
FMIC + custom large steel intake piping
Coated Tubular Manifolds
Injectors & Pump
A little MRC Magic

I hope to get 470+ - I am not at this stage upgrading the inlet system (Y-Pipe & MAF) & the exhaust. These for now will be my limiting factor... so I may not get over the 450 mark for now. once these are done my engine shouldnt be any different to Mihneas. Not sure I would be happy with 500+ on a daily driver.

Watch this space.

Cheers,