RS2 . Boosting, seems to be only under full throttle?

[weta.worker]

hiya, hoping I can get some feedback from other owners of turbos

I've had the car back for a while now and its great to not have it in the garage

One thing I've noticed is that I don't really ever feel the turbo kick in unless I've got the foot flat. If I plant it, the car pulls and feels great. But if I let it creep up the rev range I don't feel it at all.

Also, if I sit on 3 > 3500 RPM where I'd expect the turbo to be spooling then kick it, it takes a few more rpms until it kicks in (say 4500). If I plant from 1000'ish , then it kicks in about 3 > 3500.

In the RS4 I can pretty much sit on the edge of boost and feather the throttle and get a solid response from it. On the RS2 I can't do this at all.

Is this normal? and if not, what do you think is causing the prob?

Thanks so much!

John

[veneto rs2]

You havve to live with that.... It's called turbolag
RS4 has two turbos and smaller (hence faster to spool up) plus one piston plus 500cc....
It's a whole different story

Stefano

[weta.worker]

You havve to live with that.... It's called turbolag
RS4 has two turbos and smaller (hence faster to spool up) plus one piston plus 500cc....
It's a whole different story

Stefano

thanks! well at least I know it's normal

[A80Avant]

if your car is stock and acts that way, im not sure id call that normal. Even the old KKK turbo could spool fast enough to give full boost of 1.5bar before 4000rpm when you put your foot down on around 3000rpm. Of course it also depends on which gear you are referring to. So id say on 3d gear and above, if you dont see full boost before 4000rpm, it needs to be looked at. Things tend to get tired after a while and need replacing.

[weta.worker]

if your car is stock and acts that way, im not sure id call that normal. Even the old KKK turbo could spool fast enough to give full boost of 1.5bar before 4000rpm when you put your foot down on around 3000rpm. Of course it also depends on which gear you are referring to. So id say on 3d gear and above, if you dont see full boost before 4000rpm, it needs to be looked at. Things tend to get tired after a while and need replacing.

thanks, i'll have a 'play' and note what it's doing

[twoqu]

Sounds similiar to this and we are stil working on that one!

http://www.s2forum.com/forum/showthread.php?t=66662

[weta.worker]

if your car is stock and acts that way, im not sure id call that normal. Even the old KKK turbo could spool fast enough to give full boost of 1.5bar before 4000rpm when you put your foot down on around 3000rpm. Of course it also depends on which gear you are referring to. So id say on 3d gear and above, if you dont see full boost before 4000rpm, it needs to be looked at. Things tend to get tired after a while and need replacing.

I've just been out and noted when the boost kicks in and in what gear. From what I can tell it fits the above.

I thought it was strange that nothing would really happen (boost wise) unless I planted my foot) , if I had 3/4 throttle all the way through the rev range I wouldn't feel 3/4 boost.

I'll try more testing just to make sure I'm not lying (to myself!)

[Rusty]

That's certainly how the S2 is mapped so I'd expect RS2 to be similar. Get a decent map in there and you'll be laughing.

For many reasons, don't compare RS2 and RS4, they're very different.

[weta.worker]

just had more time behind the wheel and started to experiment a bit

if I put my foot down about 80% on the throttle the car never really gives me any indication that it's boosting at any point of the rev range. if I let it get to say 5000 (using 80% of the pedal), then plant it (to get that little extra bit of travel), it hesitates (it almost feels like it looses power - but maybe thats just the hesitation?) then I can feel the boost kick in as it starts to spool up.

so foot flat from low range, it spools up at 3'ish which is what I'd expect

I always thought that the boost was dependent on the rev range not the position of the throttle? the exhaust gasses spinning the turbo so you if you were at 3000 then it's got boost? so when you give it more throttle , you dump more gas into the engine and with that boost you're away and laughing?

or is there something that lets the boost escape (DV) until you foot flat and then it closes that off and bumps it into the engine? sorry for the noob question...

Also, I notice quite a bit of smoke come out the back at full boost as well....so I'm thinking thats not a great sign. Any ideas?

And the brake light (and beep) has been coming on more and more lately. In the past its gone away after a few minutes but now it's hanging around more and for longer. Reading up it's possibly fluid levels or the brake bomb (will test how many brake pumps it takes for the pedal to go hard when off)

thanks for listening!

john

[dkw_dude]

Black smoke at WOT = running too rich, could be caused by boost leak. Sluggish response can also be caused by boost leak. My experience from standard and chipped S2. PCV system leak can also cause poor running. Pressure test hoses, check for broken clamps.
Good luck, you'll get it running good again

[simon20vq]

Reading what you have put it don't sound right although there is a big difference between a standard RS2 and a chipped one. As dkw dude said boost leak check.

[UrS4boy]

N75 WGFV and By-pass Valve (BPV) info

...or is there something that lets the boost escape (DV) until you foot flat and then it closes that off and bumps it into the engine? sorry for the noob question... thanks for listening! john

Some reading for you:

N75 Wastegate Frequency Valve (the device the ECU controls to set boost levels):

http://forums.quattroworld.com/s4s6/msgs/20987.phtml

The By-pass (cut-off) valve that is used to keep the turbo from stalling during shifts:

http://forums.quattroworld.com/s4s6/msgs/20994.phtml

[Christophski]

I can't help with the smoke and boosting but the warning symbol is probably a sticky sensor on the cap for the power steering fluid. Take it off and soak it in brake cleaner and gently with a soft brush, give it a rub to clean it up. Be careful not to bend the nipple as this will cause it to stick on. Hth's

[weta.worker]

thanks all!

will see how it all goes. i'm due back in at Audi to do some other stuff so will make sure they check the hoses \ pressure etc

and I'll check the sensor on the power steering fluid

[minim]

isn't it normal that it's not boosting max before you got WOT with a stock map? I think I read a post by PRJ(?) where he explained that the boost map was like that. IMO it's the best way also that turbo pressure is controlled that way because then you don't put more stress to the turbo than needed. If it's for racing then I guess it's best to have it ready at all times but it makes little sense for a road car if you want the turbo to last longer.