£ vs. hp/torque = dilemma!

[snbS4]

Having had a rattle from the o/s of my engine for some months now, I was fairly convinced/hopeful it would be the heatshield issue. Having removed the heatshield and run the car up on ramps, the rattle was still there!

On Saturday, I went up to AMD who have carried out much/most of the work on this and my other cars for a second opinion. It seems the manifolds themselves have a collar which separates and rattles ultimately resulting in bits breaking off to be ingested by the turbo and then the engine. Horrible.

So, the dilemma is:

1. Just change the manifolds. Engine out £1,200 plus 2 manifolds at £300 each.
2. Add Milltek downpipes at £1,500 plus 1. above.
3. Replace K03's with K04's plus 1. and 2. above at £4,935 = 400 bhp and 465 lb/ft.

The car is 1999 and presently 'reprogrammed' to 326 bhp then a Milltek cat-back system and Forge DV's/Samco hoses etc. and has 50,000 fairly gentle/careful miles on it and synthetic oil every 5K miles.

Would also be a good time to change the cambelt at £220 rather than £800 in December so a bit of a saving there.

I really want to keep the car so it's worth the reliability of the K04's but until I have had a ride in their equivalent of no.3 above car it's difficult to decide. The car is booked in for the end of the month but I need to decide whther to K04 or not asap so that they can order them.

I know that I do not want it to be like the standard RS4 in terms of delivery which apparently as i would be retaining the standard cams etc and not having the fuelling extras it should keep its high-torque driveability.

Help!!

Simon

[JonnyX]

Shame. There were some RS4 K04's on ebay recently for just under a grand. Sorely tempted
myself. If you have to have the manifolds done then it I think it makes sense to do the turbo's
as well, especially if you are planning to do this at some stage anyway. As an aside, autospeed
in the states do manifolds and downpipes. Might be a chance to take advantage of the
exchange rate?

[Dippy]

Simon,

Don't forget that the standard RS4 is still constrained by the OEM map which gives it more lag than the S4.

I have seen a few torque graphs of AmD K04's S4s and can assure you that you would not experience any lag compared to your current map, just increased torque over the whole range.

But beware, without the extra fuelling parts, you will not get a reliable 400 bhp.

If you really do want to keep the car for a few more years then you should be prepared to replace the turbos at some point. Therefore it makes sense to do so whilst the engine is out. If your turbos are sound then you might be able to sell them to TD for reconditioning. There is no point replacing with K03s unless you have to. So your only issue is whether or not to do the complete upgrade or not. My recommendation is to get the RS4 fuelling and intake parts fitted as well. That will give you a RELIABLE 400 bhp and possibly more.

There are other things to consider such as intercoolers and clutch/flywheel. The gains here become more marginal for the cost. If you do not track the car you will get away with the standard intercoolers. A lightened flywheel would give you increased torque response but it surely has a downside (I can't comment as I don't know what it is). Unless your clutch is fairly new it makes sense to replace it and it would be foolish not to upgrade it because there will be a lot more torque going through it.

And my final comment is exactly about that: With a K04 upgrade there will be a lot more stress on the transmission...

If it helps, I also intend to keep my car for a while. If I have any problems with it which will require engine removal, then I will be getting K04s and as many associated RS4 (or equivalent) parts fitted as my 'mental' bank balance can stand!

[grizz]

GO ON , IN FOR A PENNY, IN FOR A POUND (OR 5 K)

[S4RS4]

Having had a rattle from the o/s of my engine for some months now, I was fairly convinced/hopeful it would be the heatshield issue. Having removed the heatshield and run the car up on ramps, the rattle was still there!

On Saturday, I went up to AMD who have carried out much/most of the work on this and my other cars for a second opinion. It seems the manifolds themselves have a collar which separates and rattles ultimately resulting in bits breaking off to be ingested by the turbo and then the engine. Horrible.

So, the dilemma is:

1. Just change the manifolds. Engine out £1,200 plus 2 manifolds at £300 each.
2. Add Milltek downpipes at £1,500 plus 1. above.
3. Replace K03's with K04's plus 1. and 2. above at £4,935 = 400 bhp and 465 lb/ft.

The car is 1999 and presently 'reprogrammed' to 326 bhp then a Milltek cat-back system and Forge DV's/Samco hoses etc. and has 50,000 fairly gentle/careful miles on it and synthetic oil every 5K miles.

Would also be a good time to change the cambelt at £220 rather than £800 in December so a bit of a saving there.

I really want to keep the car so it's worth the reliability of the K04's but until I have had a ride in their equivalent of no.3 above car it's difficult to decide. The car is booked in for the end of the month but I need to decide whther to K04 or not asap so that they can order them.

I know that I do not want it to be like the standard RS4 in terms of delivery which apparently as i would be retaining the standard cams etc and not having the fuelling extras it should keep its high-torque driveability.

Help!!

Simon

If it helps, I may be selling genuine 17K mile KO4 turbo's and new RS4 intercoolers. May also upgrade to MTM exhaust manifolds so the RS4 manifolds may be available. Going to upgrade to hybrid turbo's and front mounted intercooler if I can sell my OE stuff. You can try all the above in the car.

[snbS4]

Thanks Guys

Well I think I am now convinced that K04's are the way to go. At the same time, part of the kit seems to be new pipes etc on the lower part of the engine which are RS4 items plus new downpipes etc.

A clutch also makes a lot of sense at the same time.

TBH, I would be really quite chuffed with a reliable/genuine 400bhp but that would be a very nice by-product as I was quite happy with 326bhp before!!
Too much is just enough as they say.

Think I would prefer more reliability (even if it means a bit less than 400bhp) as I would like to keep the car's flexibility, as it's my daily driver, rather than all out bhp - if there is a choice/sacrifice to be made?

An expensive rattle huh?

More phone calls to be made I think!

Will post back with more news if of interest.

Rgds

Simon

[jeffw]

Having run my S4 with the AmD K04 conversion (395BHP) for 25,000 miles without a hitch (apart from F pipe & TBB splitting) on a standard clutch and standard injectors/inlet I'm not convinced that the change to the RS4 inlet parts are necessary. The change maybe 'nice to have' but it's not necessary.

[sitas3]

I considered doing all this recently but have now decided against it. If you are having the K04's done then you may as well spend the extra and get the downpipes/cats done at the same time and ultimately save on the labour for extra bhp.

Along with my new turbos, I have an RS4 clutch fitted to my S4 and would definitely recommend replacing the clutch at the same time.

Good luck with whatever you decide and let us know how you get on..

BTW, Kim Collins/QST recommend you also fit the RS4 injectors/induction for reliability (according to MTM) but this pushes the cost up more!

[excursion]

S4RS4 - PM sent. I'm interested in the parts you are selling

[Dippy]

Having run my S4 with the AmD K04 conversion (395BHP) for 25,000 miles without a hitch (apart from F pipe & TBB splitting) on a standard clutch and standard injectors/inlet I'm not convinced that the change to the RS4 inlet parts are necessary. The change maybe 'nice to have' but it's not necessary.

Jeff, it's a bit more than a 'nice to have' because it would increase the peak power. However I agree with your point, especially considering the extra cost.

Of course if you drive like a granny there's no point either...

[JonnyX]

How do AMD port match the RS4 intake mani to the S4 heads?

[Dippy]

I didn't think the intake manifold was included - although it should be for the price!

[JonnyX]

Really, how do they mate up the throttle body then? I assumed it was airbox + MAF + Y-pipe + RS4
hard pipes in TB (like APR bi-pipe) + TB + RS4 manifold. Anyone who has had the full conversion
care to explain?

I believe RS4 intake ports are 20-30% larger than S4 ports so putting this together without some
sort of port matching would probably be a bad idea. I think most tuners in the States end up using
2.8 heads as there is a bit more material to remove.

[jeffw]

Of course if you drive like a granny there's no point either...

Ummmm....the boys are in their way round

[Dippy]

Really, how do they mate up the throttle body then? I assumed it was airbox + MAF + Y-pipe + RS4
hard pipes in TB (like APR bi-pipe) + TB + RS4 manifold. Anyone who has had the full conversion
care to explain?

I believe RS4 intake ports are 20-30% larger than S4 ports so putting this together without some
sort of port matching would probably be a bad idea. I think most tuners in the States end up using
2.8 heads as there is a bit more material to remove.

The point is that although AmD charge an extra 2K for the work which seems a lot, the parts and labour for just the air intake up to the TB, and the fuel pump and injectors take up a lot of that. I can't see them also changing the TB and intake manifold, including porting, for that price.