Low boost after porting
 

I had my s5 turbo waste gate ported and did all the removal and reinstal of he turbo myself. I was only able to get 2 out of 3 bolts on the down pipe to th turbo because I cross threaded one of the studs. I have an exhauslt leak now. I hooked every thing else up right. Except for the fact that I severed the o2 sensor wire on accident.

On my short test drive I gunned it and found that my boost guage only went up yo 5. It used to get up to 10 since the exhaust is opened up a bit. That's on a blown rear rotor too. What's wrong? Did I mess something up or did the guy I had port my waste gate go too large? You can fit a quarter through the bigger whole. Help please!

unless you have a boost controller on it which is turning up the boost, it sounds like he did a good job porting it and brought the boost back down to the stock level that it should be at.

all you need to get it back up now is a way of raising the boost manually, ie a boost controller.

I have a manual boost controler in the car already. I'm not sure how to hook it up though. I think it's a blitz one but I'm not sure. Any ideas on how a manual controler?

one problem is you got a blown rear rotor. Why bother playin with the turbo when your motor is half shit?

This is true. I want to make sure everything else is working right before I get my new engine in there though.

That sounds a little backwards to me, but oh well. Installing a manual boost controller is easy, you've got two nipples on it. One goes to the nipple on the turbocharger, the other to the wastegate actuator.

3 including the atmospheric vent, to be sure just look it up on their website or do a google search for your model of boost controller(should have some sort of part # on it or series #).

generally it works like this though. the single line goes into the boost controller from a good pressure source off the compressor housing or intake manifold somewhere. the teed line, one has a restrictor pill in it and one doesn't, the restrictor pill line goes to the wastegate actuator and the open line goes to the turbo intake duct piping or put a filter on it and strap it somewhere in the engine bay(preferable to plumb it back in if you still are running the stock AFM).

some MBCs just have 2 lines though and bleed air through the valve itself, so i have no idea which yours is. some extremely cheap MBCs have no atmospheric vent at all.