Boost on K03's?

[RogueStatus]

Bought an MBC and TCD from vast,trying to figure out what to run for boost on my k03's and to run it in parallel with the n75 or not.

01.5,only stage 2,brand new k03's (>4k miles),GIAC X software

TCD in parallel with N75 or standalone?

What should i spike and hold at for boost with the MBC? Want safe but aggressive...

Thanks.

[mholme]

Don't know..but how did you end up with brand new K03's?

[RogueStatus]

good ol' certified pre-owned 100k mile warranty! haha blew the originals and got new ones for free

[Matt@JHM]

good ol' certified pre-owned 100k mile warranty! haha blew the originals and got new ones for free

Thats the exact reason why Audi isnt going for turbos anymore. They are still buying k03s!

[RogueStatus]

hahaha,not like i blew em on purpose! just happens when you put GIAC software to them...anyways back on topic! WHAT BOOST can i run?!

[Matt@JHM]

hahaha,not like i blew em on purpose! just happens when you put GIAC software to them...anyways back on topic! WHAT BOOST can i run?!

Yeah, didn't mean it as your fault - just saying they don't have a great track record.

So yeah on topic: 16-18PSI will be fine.

[YBLEGL]

If you have GIAC software and its the newer version just use the MBC no N75 valve and you wont need a TCD with that software. As far as boost I have mine spike at 19 to 19.5 lbs depends on the day it fluctuates a little. Do a few pulls in 3rd and watch block 115 with vag com

[The_Jerbel]

What elevation are you at?

[RogueStatus]

elevation....hmm...i duno? in MA.

yeah i thought i could run the MBC standalone,but a friend told me i have to keep the n75 or something would happen,i forget what he said.

[1997gtx]

You can run it in stand alone.

You can run just the MBC with a TCD and you'll be fine. With a good tune, you can work the K03's pretty well.
--Adam

[RogueStatus]

haha nope,they knew i was chipped. i didnt tell them,but when they called they said "we found a flashloader in your car,do you by chance have a chip?" i said "yeah,and?" and they didnt say anything about it so...i think they were trying to get something out of me. plus i had piggies with test pipes too...

[YBLEGL]

If you need help let me know I live in MA also you are at sea level btw, but I would just run the MBC standalone get rid of the n75 valve. Also you dont need a TCD depending on what version of GIAC software you have, I run standalone with no TCD and have zero problems, car pulls real hard.

[crosenhahn]

Question: can I run a MBC with the APR 91/93 program...?

[RogueStatus]

i think the install is pretty easy and self explanatory,TCD is the 2 wires on the MAP sensor on TB,and MBC is just as easy.

i live right next to Wachusett mountain so i dont live at sea level,but i commute to providence everyday so thats sea level...

not sure what GIAC i have,got it from Marc (10secs4) before he was banned.

I'll run the TCD anyway,what harm can come from it ya know..

[Blue AWD]

You can not run MBC with APR software. It goes into limp mode.

[crosenhahn]

Well that sucks...but thanks!!!

[RogueStatus]

is spiking at 20psi too much? one of you said 18,other said 19.5...why not go for 20? then maybe taper down to 18 or so...that ok?

waiting for my god damn AWE vent gauge too. ordered it like a week ago with 3 day shipping and it hasnt gotten here nor have i heard from them with a tracking #

[YBLEGL]

20 psi spike will be ok try not to push it more then that. As far as running apr software you can use it with a MBC but leave the N75 valve plugged in and you then need a TCD with apr also

[RogueStatus]

cool,thats what i'll do then with the MBC alone and the TCD in place.

What happens when i switch programs with the flashloader?

[YBLEGL]

the boost wont spike at 20 psi it will spike at whatever program you set it too, you wont need to touch the boost controller at all.

[Sniper512]

I have GIAC as well. I was running standalone(and TCD) but found that the boost was very unstable at part throttle. The car was spiking at 19 and sometimes holding other times it would taper to 15 by redline at full throttle. I hook my N75 back up to say the least. I left my N75 valve plugged in along with the passenger side vac line hooked up when in standalone would this have anything to do with it? Would completely removing the N75 have been better? Did I need to plug the open ends of the N75?

[YBLEGL]

Remove the n75 completey and plug the pcv recirculation line with a bolt and a clamp

[Sniper512]

Does that mean I had a bad boost/vacuum leak then?

[YBLEGL]

it should taper to around 15psi at redline it wont hold at 19psi so I wouldny say you have a boost leak that is normal

[Sniper512]

Ok thanks. I set it up the right way and lowered the boost so it was hitting 17ish and holding 15 and the car feels much stronger than when it was hitting 19psi.

[The_Jerbel]

19 psi is slightly outside of the efficiency range of K03's IMO, at the very upper limits at least.

The N75 SHOULD be left plugged into the ambient air pressure line (pass side line) with the electrical connector plugged in.

[Sniper512]

Do I need to cap the 2 open ends on the N75? With it out I have noticed part throttle is much better?

[The_Jerbel]

Nope, don't cap it off at all. If you are having problems, then you probably have some other issue that you are masking by capping off the ambient line and disconnecting the electrical connector.

What were you boosting at before with the N75 in place? I would put the N75 back in (just the ambient line and electrical connector), and leave the MBC set to 17-18 psi. See how it runs.

[Shomegrown]

This thread is full of stupid. Running an MBC only on K03's is just about the WORST thing you can do with them.

Have fun with your next turbo swap.

[Sniper512]

With just the N75 I was hitting 13-15psi(GIAC on Pump). I have the MBC set to 17psi right now by itself with no N75 in place. I think I am just going to run the N75 and thats all and let the GIAC software do its thing. Also Question if the S2 O2 sensors are not plugded in at all meaning at the firewall will this have an effect on the cars performance? I know if your just getting the old warm-up code its fine but I am getting open circut on both as well?

[The_Jerbel]

It won't affect performance. It'll just give you a fault code.

If it were my car, I'd run the MBC in parallel with the N75 to cap boost spikes but run the boost that the chip was designed for.

[1997gtx]

^ x2

[YBLEGL]

All I can say is iv'e run a MBC for months with no n75 plugged in completely deleted and I have zero issues, as far as a boost spike if the boost controller will only let in 17psi then thats all its going to do. I dont know why so many of you have so many problems, but I have had zero and the car pulls real well.

[YBLEGL]

Oh and some of the fastest low 12 second k03 s4's run MBC only

[The_Jerbel]

"MBC only" usually refers to MBC in standalone, which includes the ambient line on the N75 left plugged in as well as the electrical.

[Sniper512]

Jordan I'll plug her back in for ya tomorrow. I am seeing a fair bit of oil from the driveside Forge Splitter. I think my turbo is on the way out and could be causing the inconsistant boost. I may be calling you for some advice on turbo options.

[The_Jerbel]

Sounds good Ryan. That sucks, but at the same time it's frickin awesome, trust me

[Sniper512]

Haha ya I will need a clutch and turbos, fueling for now can wait.