s4-rs4 heads?

[scow]

Does anyone know if there is any benefit to fitting rs4 heads to s4(b5) . If i can source some early next year i hope to get them ported and polished and inlet matched. I'm also saving to get full stage three package for car .Has anyone done this before(heads ). Also what price should i expect to pay for set of heads. Thanks in advance.....

[Imolavirus]

Well, if you do the RS4 heads, then there are some other items you'll have to do. First, will be the intake manifold...which means you'll have to do the RS4 fuel rails, RS4 injectors, RS4 throttle body, RS4 up-pipes from the intercoolers and i'd imagine the RS4 intercoolers as well. With the RS4 heads, i'd imagine you'd do the RS4 intake cams too.

Once you add the larger intake components, the throttle body and cams mainly, then you'll have to get tuning to suit, as it's not going to run well at all with the larger throttle body and cams.

Good luck though....with all of those upgrades it will sure be a monster

[Morpheous]

Better off getting the whole engine ASJ or ASR, bottom end has been modified to cope with the higher revving engine.
Reinforced conrod bolts. Now M9.
Crankshaft bearing caps made from cast steel.
Extended thread sections in block for cyl head.
Reinforced crankshaft. 10% higher load capability
Gudeon pin diameter increased and longer.
Conrod small end diameter increased.
Pistons have a raised ring land, are PVD coated and have hard anodised ring grooves,
they also have adapted recesses.
Oil pump output increased to provide incresed supply even when idling.
Oil return to sump is via channels in cylinder block and a baffle plate to below the oil level.(Prevents frothing of oil at high rpm).
Larger oil return duct diameters.

Cant see why you would want to overstress a standard bottom end when you could go for a ready modified one, lets face it an RS4 engine would go POP less quickly when tuned.
Hope you dont screw up things by porting the already optimised heads.

Good Luck what ever you decide to do.

[scow]

Just a quick reply to everyone especially morpheus(f**k me you know these cars inside out any more advise/tuning very welcome-PLEASE contact me by pm thanks).
I already have APR S4 Intercooler Kit , APR Engine Snub Mount ,APR 2.7T BiPipe Kit ,APR ECU Upgrade(but getting custom remap to enhance all other products),Milltek catback dual system,full samco 12 hose kit ,forge dv's and full Nology ignition pack (was told first set to be imported for uk s4)+ silverstone plugs........ in the procecss of getting 200 cell race cats + downpipes + lightweight crank pully.

None of above fitted apart from chip hope to get everything done first week of Feb work permitting .
Will let everyone know of progress/ dyno results.
Want flat torqe curve max power from minimum boost MAX reliability/driveability.

[Morpheous]

Sounds Great, only know a bit about standard stuff, U need the advice from ones that have gone wrong And the tuning experts for a reliable engine with all these goodies.

[BlackShadow]

So just out of interest, and with an eye on future upgrades, how much is an RS4 engine?

I take it the engine would slot in an S4 B5?

Also, would the freeflow cats & exhaust, fitted to mine at the moment, still work with an RS4 engine - i.e. chipping with this, would yield some 460 bhp?

[S4RS4]

So just out of interest, and with an eye on future upgrades, how much is an RS4 engine?

I take it the engine would slot in an S4 B5?

Also, would the freeflow cats & exhaust, fitted to mine at the moment, still work with an RS4 engine - i.e. chipping with this, would yield some 460 bhp?

The RS4 engine will just slot into the S4. S4 free flow DP's, CAT's and exhaust will fit fine. Just make sure your S4 is a facelift model and the RS4 ECU will plug in too.

[Verruckt]

I'd stay with the S4 stuff. You'll lose torque with the RS4 heads.

Go with a valve job and 2.8 liter cams.

[tartan_rob]

Verruckt - are you saying that the 2.8 cams have a better profile than the std turbo ones on the 2.7 engine..?

Or have I missed something?

[BlackShadow]

Ja, das klingt nicht genau richtig, dass die 2.8 cams besser als die 2.7 turbo cams sind.

However, anybody know what an RS4 engine actually costs? If it's just a couple of grand, then I'll have one slotted in my facelife S4.

[S2tuner]

The RS4 engine DOES fit any S4. On pre-face lift models with the 551C ECU, the RS4 ECU doesn't fit straight (I know from experience), however, the stock S4 ECU can be tuned for the same performance as with an RS4 ECU. I have BTDT last week with a 98 S4 and a complete ASJ engine, gutted precats, no main cats and Milltek dual exhaust and the car is a real screamer.

On face-lift models, there's the advantage of being able to fit a straight RS4 ECU, but RS4 code can also be run in most face-lift ECU's too.

The RS4 heads/intake cams flow lots more than the S4 ones, they make a huge difference at the same boost levels.


HTH,

Mihnea

[KayGee]

Do you mean the RS4 ECU doesn't physically fit or is wired differently?

Since no one seems to have K04 or RS4 map for the earlier ECU (551c) I was planning on doing an RS4 ECU swap myself.

Any help greatly appreciated!!

[S2tuner]

I have to investigate more here. The factory repair manual (ELSAWin) says that a '99 AGB (551C ECU) is wired identically with a '01 ASJ (551F ECU), but it's BS, because the ASJ has 4 lambda sensors vs. only 2 for the AGB.


When my buddy with the '98 S4 and ASJ engine came over, we plugged the RS4 ECU in, and the engine runs with the RS4 ECU but we had a permanent fault code about the cam timing controller on Bank 1, electrical malfunction it said, so the ECU couldn't adjust the intake cam on bank 1. We didn't have much time to figure all this out, so I decided to stick the 551C ECU in there and to tune the 551C completely from scratch for the ASJ engine. The result is really a scary fast car, I'd estimate power around 470-480HP, while running very reasonable boost levels (max boost is 1.45 Bar).

Tuning a 551C ECU for K04 upgrades or an RS4 engine is no big deal, it took me 3 hours to do it from scratch. Top speed reached 6 times was in excess of 185 mph and we could have done much more, but we weren't sure about speed cameras, and none of us wanted to go to jail for doing this sort of speeds on the belgian motorways where the limit is 75mph.

HTH,


Mihnea

Do you mean the RS4 ECU doesn't physically fit or is wired differently?

Since no one seems to have K04 or RS4 map for the earlier ECU (551c) I was planning on doing an RS4 ECU swap myself.

Any help greatly appreciated!!

[KayGee]

Where did the guy source his RS4 engine from, I've never even seen one advertised.....I always assumed the cost would be astronomical......

[S2tuner]

Well, he got it from a burnt RS4, apparently the going prices in Germany/France are around 2.5-3.5k Euros for a complete RS4 engine with all anciliaries. I don't know about harness+ECU but these can be had separately.

Fitting the engine is pretty much straightforward as it's relatively "plug 'n play" with the AGB engine. Only the secondary air injection pump has to be removed and that's it. For the variable cam electrical malfunction problem with an RS4 ECU, it could just be because it's wired the other way around, I'll have to check that out and find out if the RS4 ECU cannot be used at all or if it can, provided some mods are done... I just don't want to have to rip every customer's wiring harness apart, just to get an RS4 ECU to run in the car, it's easier then to remap the 551C ECU to run the RS4 engine


HTH,

Mihnea