Boost on RS6 turbos

[pauloM]

Hello
I have RS6 turbos form Vast Performance and I would like to know how much boost can be used before destroy the original rods

I´m using 1.5 bar and don´t know how much power my car has, as the nearest 4x4 dino is 450 km away from my home.

The car has RS4 intercoolers , Siemens 630cc and Unichip

Anyone has this config or knows the power generated ?
Vast says the limit to rod is 550 hp. Is it BHP or WHP
Thanks !

[Blue_Thunder]

You can't measure a car's power by boost alone. There are many other factors which can alter the power, ie: fuel quality, fuelling, timing, volume of air being used (MAF reading), etc.

I would contact Vast and see what they recommend that the boost is limited at.

Would also recommend you upgrade your intercoolers to get the most out of those turbos.

[dazzer]

I think torque should be your first concern!

[JonnyX]

Indeed. You should be OK on standard rods to around 500ft/lb (~670NM)

[pauloM]

Ok JonnyX
That´s what I wanted
But you mean 670 NM at whell or motor ?

Blue, I think upgrade over rs4 intercoolers a complicated issue. All new routes for so many tubes. After new rods this should be a must

I had that RS6 RS4 hybrids, and they start loosing performance, and some oil in the cold side.
Change for the RS6 from Vast and mapped to 1.5 bar.
As I don´t intend to open motor to change rods this year, I´m looking for this limits and try to leave it all working.

When mapped to 1.2 bar I got 540 NM - motor - with .77 A/F.
Then I changed to 1.5 bar and the A/F touch .94 .
New injectors coming in 3 days

Thanks for help !

[pauloM]

sorry for the whell

[S4]

Are you using a MBC manual boost controller? or an electronic one. .77.........thats not good.

Darren

[pauloM]

I use Unichip. Very easy to make all work.
That´s 0,77 lambda , not mV ( too rich )
The story is simple...I changed turbos and adjusted boost 450 km away from my home and 850m alt without changing injectors. So I decided to use less boost just to go home. At local dyno, got that 0,77 1.2 bar.
After getting home, I used a trackday to get a better AF ratio and do some tests. Finally I decided to use 1.5 bar and buy new injectors, as with the actual injectors, I got 0,94 AF ratio lambda ( too poor )

[Mikse]

PauloM, Interresting setup you have. Do you have any intake mods like manifold or heads/cams? When those rs6 turbos start to make boost/power? I´m thinking of same kind of setup but I`m worried about the lag.

[pauloM]

Hello Mikse. Sorry I haven´t seen that.

I there´s nothing extra, except all tubes from RS4 APR kit.

Today I´m running the car with siemens deka injectors @ 4 bar ( some like 70 lbs )
It´s running like the old RS4/RS6 turbos, almost no lag. But as I didn´t change rods, I decided to make a remap that should never go over 1.5 bar.
Boost gets 1.5 at 4000 rpm and stays there until 7000 rpm.
There´s a good sensation of never ending power when we don´t use overboost

Some day I´ll put at youtube the rpm and boost.

Today I´m having trouble with boost as went to trackday and changed the air filter to K&N and a almost complet free flow exhaust. It´s getting 1.8 bar.
So I´m thinkin of a MBC to permit a fast control of the boost without remap everytime I change exhaust.

And I think I´ll have to make holes at the air box as the tubo after MAF gets "sucked" sometimes !

[Blue_Thunder]

And I think I´ll have to make holes at the air box as the tubo after MAF gets "sucked" sometimes !

Some people are replacing their accordian hose with silicon tubing to prevent this collapse.

[pauloM]

I´d to solve this using 3M tape and hose clamps. Ugly
Did not find any silicone tube that could fit.

[Mikse]

It´s running like the old RS4/RS6 turbos, almost no lag. But as I didn´t change rods, I decided to make a remap that should never go over 1.5 bar.
Boost gets 1.5 at 4000 rpm and stays there until 7000 rpm.

Full boost at 4000rpm, that seems quite a late or is it tuned that way to spare the rods? At what rpm it start to pull? Just for comparison my K04 starts to make useable power @ 1800-2000rpm and full boost 1,4bar comes ~3000rpm.

[pauloM]

Yes, it´s working this way as I mapped to do so.
When I wrote the car was getting > 1.8 bar ( 4 posts up ) it happened @ 3000 rpm. I did´t try harder to see how much I could get

Yesterday I mounted the APR full exhaust and 1.5bar @ 4000 returned.
But the start point I´ll have to answer later...

This is a video with the ex RS4/RS6 turbos
----------
Have to be at home to put the link


Reading old posts, I decided to drill some holes on the air box! Maybe this is the problem with the MAF hose.

Thanks for all help !

[pauloM]

http://www.youtube.com/watch?v=aRFHcOU6Gko