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Hi guys, Just a quick one to clear something up for me.

I've currently got a Volvo 850R which is running 280BHP

I've been thinking about going a bit bananas and heading for big power with this 850R, but an Audi S4 has come up which I've fallen in love with (turbos upgraded / lots of RS4 parts) and the car is running 350BHP.

So my question is regarding the Quattro 4WD transmission losses and how this translates to speed.

850R - 280BHP through front 2 wheels
Audi S4 - 350BHP through 4 wheels

Now the Audi will always be quicker off the line, but what about everything else. From what I have worked out about the transmission losses on the 4WD, it looks like the Volvo is faster (BHP on the road wise) but this doesn't seem right. I'm 100% certain the Audi will be much faster so can someone help with my figures please!

Cheers

FWD will have much less losses for sure, but with a BHP gap like that, I think the S4 is always going to be quicker. The power at the wheels of the S4 is not going to be far off the power of the engine in the Volvo as it stands at the moment.

AFAIK The nominal figure for transmission loss on the S4 quattro system is around 60 - 70 bhp, so like Graham says, it'll be 280 at the wheels ish....

Whilst the Volvo (Is it manual or automatic) will be around 230 - 240 at the wheels.

That said the other thing to look at is torque - that modified S4 is probably pulling 400ft/lb's of torque, what's the Volvo making - 300ft/lb's?

Dunno about you but give me torque any day of the week over hp. I'm certain my new S4 feels dog slow compared to my old one because it's making 90ft/lb's less torque rather than it being down 45hp

turbo,s upgraded but with only 350bhp..is that rite..

Thanks for the replies guys.

The Volvo was dyno'd recently and was bang on 245WHP so I think perhaps 280-285bhp.

It's a manual (more powerful than the 850R auto)

I'm not sure how to convert to ft/lbs, but the torque on my Volvo is 410Nm

s4woody - Good point. The turbos are actually "hybrids" from Turbo Developments. The seller tells me they are S4 turbos (so K03) but reworked and strengthened. He definitely said they are hybrids so maybe TD have mated the K03 with something else.

The only two things that concerned me are

1) The new turbos haven't had the new oil lines swapped. Still running on the old pre-facelift lines then........
2)Exhaust manifolds not been changed. Owner said no rattles though

hi carpy ive just replied to your post on the t5 forum .......

Please can you find out more about these turbos and the supplier and share with us?

It sounds like you have a pretty rare configuration there and there are a lot of people here that would like to know more.

T5 forum seems to be down at the moment!

Graham - I've only had a 10 minute chat with the owner over the phone so not exactly sure of the turbo details. The company that worked on them is http://turbodevelopments.co.uk/

The guy sounds really nice, and said that one of his turbos developed a whistle so he took it to TD and went for the reworked S4 turbos as it was cheaper than the K04 route.

This is the car up on the trader
http://atsearch.autotrader.co.uk/www/ca ... locale=STF

I've decided not to buy this car, but if you want to find out more he's called Steve & he's got the paperwork from TD so he can tell you what was done.

I really want one with the K04 already done or even RS6 hybrids, oh and in Imola or Noggy too. Might be waiting a while eh!

craigs4 wrote:hi carpy ive just replied to your post on the t5 forum .......

LOL mate just read your post on the T5 forum. You'll have those Volvo owners up in arms if you keep telling them their cars handle like a bus!

410nm = 302 lbft so that's a little lower than a remapped S4.

My one size fits all remap made 470 nm and most if not all MRC cars make 500nm (368lbft)

TBH My two S4's had well over 100K miles on them with stock manifolds and pre facelift oil lines and still on first set of turbo's, I wouldn't worry too much about these items on an S4. If he got to 90K miles on the stock manifolds then IMHO they ain't likely to break.

What turned you off that autotrader car out of curiosity? Apart from the nogaro alcantara and blue door inserts - yuk!

Before you all start flaming me, my car is Nogaro blue, I just don't have the nogaro interior - can't stand it! Do have the carbon trim though - v nice.

nickb834 I have PM'ed you.