Page 5 of 28
Re: Pops' 1997 S6 2.5L Stroker build - chasing boost
Posted: Fri Jun 10, 2011 1:29 pm
by Hank
The chain wears too. 100k miles chains will never line up perfectly in my experience. You slap a new 19 dollar chain in there, and they tend to be perfectly matched up.
Cool on the spool. I can't wait to see what kind of power it makes.
Hank
Re: Pops' 1997 S6 2.5L Stroker build - chasing boost
Posted: Mon Jun 13, 2011 5:35 pm
by chaloux
Quickspool results are in. Text only for now: 50kpa gain at 4krpm. 78kpa gain at 5krpm. Small turbo hits maximum boost at 5k, big turbo builds linearly with RPM.
Only boosting to 22psi right now, so can't comment on the 29-30 tune we're shooting for. The QS actuator is pooched - leaking boost. We disconnected it and the turbo is running in "big" mode for now while we chase our low boost issue. We think we have a leak, still, and are going to do another pressure test and include the compressor housing.
Re: Pops' 1997 S6 2.5L Stroker build - chasing boost
Posted: Fri Jun 17, 2011 12:11 pm
by my2000apb
will you guys have boost maps with and w/o quickspool valve
so as this valve is for a divided turbo and open mani, yes? how do you think spool would be on a fully divided setup vs the half divided withthe valve?
Re: Pops' 1997 S6 2.5L Stroker build - chasing boost
Posted: Fri Jun 17, 2011 4:26 pm
by Hank
It wouldn't work at all. This blocks off one side(would be 3 runners in your case) till boost is achieved, and then opens up the other vane for more flow. If they were true divided, you wouldn't get anything.
Re: Pops' 1997 S6 2.5L Stroker build - chasing boost
Posted: Wed Jun 22, 2011 9:42 am
by my2000apb
ShavedQuattro wrote:It wouldn't work at all. This blocks off one side(would be 3 runners in your case) till boost is achieved, and then opens up the other vane for more flow. If they were true divided, you wouldn't get anything.
hahah yea der me, the question sounded better in my head hah
ok i was attempting to compare a full on divided setup, ( proper and w/o valve) vs a half divided setup with a valve( open mani and divided turbo)
will the full divided spin its turbo faster still? or is the valve that badass?
Re: Pops' 1997 S6 2.5L Stroker build - chasing boost
Posted: Wed Jun 22, 2011 3:05 pm
by chaloux
Can't say for sure. But I know that the difference between open and closed is quite significant.
BUT - we *have* to get this boost leak nailed down before anything definitive can be said about its results. That's why there's text only for now, and why I said they aren't final.
Don't know when boost leak/QSV actuator will be fixed. Running short on time lately

Re: Pops' 1997 S6 2.5L Stroker build - chasing boost
Posted: Wed Jul 06, 2011 7:10 pm
by chaloux
Oh gosh.
Fixed boost leak. The Samco coming off the turbo was looseygoosey (how did we not notice?).
~28-29psi is heavenly. The car just puuuuuuuuuuuuuuuuulllllls forever until you shift. QSV is currently wide open. Full boost at 5700rpm, starts building nicely at 3500rpm. Would have been full boost at 5k or under with QSV closed and at least 15psi by 4krpm.
The car has finally gotten to the point where I thought it should be (minus the QSV). Love it.
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Thu Jul 07, 2011 2:35 am
by loxxrider
congrats, I knew there was some boost stupidness going on!
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Fri Jul 22, 2011 1:36 pm
by chaloux
Small update...
Past 22psi (our old peak), the motor was running extremely lean, scary lean. So, we stopped going above 22psi while we investigated. The two possibilities seemed to be ignition issues or fuel pump lameness.
Today we installed a fuel pressure gauge, and lo and behold, once we hit 22psi the fuel pressure takes a dive... pump can't keep up. So I got in the trunk and pulled the pump. Same physical size as a stocker, but it's got a weird PN and has a black top. PN is either 0372 085 03 27226 _OR_ 03/2 085 03 27226
Ordered whole 044 kit and caboodle from Marc. In the meantime, she waits thirsty in the shop... Hopefully this is the last issue to sort out on the car for a while. Then it's track and dyno time!
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Tue Jul 26, 2011 1:27 pm
by my2000apb
mmm 044 pump goodness
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Fri Jul 29, 2011 10:02 am
by Mushasho!
Is it in and on yet?... did it fix the above 22psi issue...
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Fri Jul 29, 2011 12:21 pm
by Ronald G Wainwright+
This car going to make it to //sfest?
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Mon Aug 08, 2011 5:33 pm
by chaloux
The car will most definitely be at //Sfest
Here's a QS/tuning update, copied from QW
This is still preliminary as we're not 100% tuned yet. Close, but not quite perfect.
We also don't have the QS valve entirely tuned. The following picture shows it opening too slowly using our controller (vs. all the way closed, or "fast spool" mode). We have to find the sweet spot between closed and where we are now. Takes a bit of time doing a log and then checking/changing, repeat.
Regardless, with the turbo in half and half big/small mode and 100% small mode, we see an 80kpa (12psi) gain at 5000rpm. We're only boosting to 25psi right now, so at 29/30psi the difference should be even more pronounced. I would recommend the Q.S. valve to owners of 30R sized turbos and larger. Thanks for bringing it up Nick (germantoy)!
Here ya go:

Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Mon Aug 08, 2011 6:16 pm
by loxxrider
very impressive! I'll be doing this for sure on the big beast
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Mon Aug 08, 2011 7:46 pm
by chaloux
Here is a better graph that Marc made.

Doing some more testing, we realized that the reason why the car wouldn't build full boost is because the QSV was opening too soon... the turbine must be huge. We set it once so that it opened at 6500rpm - boost dropped by 30kpa (5psi) before building back up again. It's like the engine just can't flow enough. Might have to make a small adjustment here...
I mentioned it on QW - makes me think that we might have to adjust the timing another tooth. I wonder if we didn't bother checking moving two teeth because we were so blown away by the change 1 tooth made. Something to consider, I guess...
Re: Pops' 1997 S6 2.5L Stroker build - :D
Posted: Tue Aug 09, 2011 5:14 am
by chaloux
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Tue Aug 16, 2011 9:07 am
by chaloux
Ooooooooookay, bit of an update.
We're working with Marc and Comp to possibly switch turbine housings to a .82 instead of a 1.0. IMO, when the QSV opens and the exhaust housing is at 1.0, there is a massive hit in boost. I think the 1.0 is just tooooo big. The difference is just too big and the motor can't push enough air through.
But before we get ahead of ourselves, we're going to check the cams again, and set it one more tooth forward. We'll see what happens with that first.
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Tue Aug 16, 2011 9:40 am
by chaloux
As this log/graph indicates...

Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Tue Aug 16, 2011 11:02 am
by audifreakjim
I bet it is just the boost control. Can you leave it open then tweak the boost control to hit higher boost? It looks like it in the charts a few posts up. I have found closed loop boost control to be anything but. It's still very picky and has a hard time going outside of a certain range it if you will. I bet it's just unable to compensate quick enough resulting in the drop off.
to me it looks like you are not really gaining anything by opening it. I would be curious to see a dyno with it open then closed to see if you actually lose power with it closed. You may need cams or a much larger turbine to really take advantage of it being open.
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Thu Aug 25, 2011 3:56 pm
by chaloux
Wow, going catless made a large impact on spool - or at least it feels like it. I'll have to verify with VEMS. Also, no noticeable change in sound. At all. So that's nice. Now onto idle tuning (and a bit of QSV tuning) before //Sfest!
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Tue Aug 30, 2011 4:31 pm
by chaloux
Well, //Sfest was a blast.
Car made 407whp/390wtq @28psi. Not sure about timing. We were expecting a bit more, but maybe adding water/meth injection is the solution for more boost and timing.
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Tue Aug 30, 2011 5:36 pm
by loxxrider
probably just needs more timing
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Tue Aug 30, 2011 7:41 pm
by chaloux
We were hoping Marc was going to tune timing more on the dyno w/ the headphones and crap. Or is it just because water/meth is a good safety measure when advancing? iuno
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Tue Aug 30, 2011 9:53 pm
by ice rckt
This car is just SICK! I can't thank you enough for the opportunity to put her to the test! Hearing that QS valve crack open is really neat... the sound of the exhaust rushing through the turbo completely changes. Thanks for the company on the ride home fellas; I'm not soon going to forget our leisurely drive through the mountains

-E
Re: Pops' 1997 S6 2.5L Stroker build - vids
Posted: Wed Aug 31, 2011 4:22 am
by Marc
chaloux wrote:We were hoping Marc was going to tune timing more on the dyno w/ the headphones and crap. Or is it just because water/meth is a good safety measure when advancing? iuno
mostly an issue of time. As you saw, I already ran out of time to tune all of the cars that wanted to be put on the rollers (at 5 am!). Your car probably could have used more advance in a few spots, I pushed the timing in the key areas to make sure I wasn't going to see giant leaps in power without any knock (which it didn't) so I left it alone. Given another hour or so, I would have pushed the load cells using steady state tuning at full boost while dialing the advance and listening for knock. Only so much that can be done in an hour unfortunately.