Hey guys, I got a manual boost controller. I get more boost now, but the power doesnt kick in as linear as without it. Ive got a to4 hybrid on my streetported s5 engine.

At first I had my car decently tuned without the mbc, power was pretty linear, with little peel out in first gear.

After I installed the mbc, the boost spikes up pretty quick, and my car spins out in first gear when it hits boost around 3.5-4K rpm.

I had 7-9psi without mbc, then I added the mbc up to 12psi on 91 octane. It knocked a little, so my buddy helping me tune it, set the ignition timing back a degree of 2 and richened it out in high rpm. I really need a tune, as for now its jsut rich up top.

 

if you want really linear power get a stock FD

 

The boost is probably coming on harder because the wastegate isn't gradually opening at the lower pressures. The MBC is keep the gate fully closed longer so that gas helps spool the turbo.

Most people want quick spool on t04's not slower. Drop the PSI down to say 10 and you may find a sweet spot where your making less power(psi related) but spooling quicker because of the extra time the turbo has to spool before the wastegate opens.

 

Thanks, at first I was just trying to go max boost for my turbo and 91 octane. Makes sense, a little more but not too much more. Cool