850 Turbo MBC valve help
 

Ok guys, i may be beating a dead horse here, but bare withme.....i only have a phone, no computer, and searching through a ton of posts is exhausting. Recently bought my first Volvo, a 96 850T with 157k. Love it, great car, good condition. Today i did the stage zero (vacuum lines, oil, F/F, etc., as well as the N/A intake/TB swap. No issues. I also got a manual boost controller. Installation instructions say a high flow air filter and exhaust is required. Im not about to spend a ton of money on an exhaust. Im cheap. My questions are, do I really need the exhaust? And what is a tolerabe amount of boost for astock engine? Im not trying to take this thjng to the track, just looking for a few more ponies. I dont want to blow this thing up as it is my daily driver........Im an ASE certified tech, and if you give me a small block Chev i can pull 800hp out of it no problem, but this is my first real venture into the world of forced induction. Any insight would my VERY greatly appreciated.

Like i said, bear with me on this one, spent the.last hour searching this site on my phone and didnt quite find what i was looking for. Just wanting to hear others input on what a 150k mile stock motor can handle. After some thought i think im going to eliminate my Cat tomorrow, as i dont need to pass emissions, that should help my exhaust flow a bit. Again, im a tech, i can hamdle hard specs, just need to know what my stock lower end and head gasket can handle. Thanks...........and in case anyone cares/is wondering, the N/A manifold and TB swap showed a definite improvement in low/mid range torque, certainly noticeable over stock.

Opening up the exhaust on these engines is #1 for performance. If you throw that MBC on it there is a built in limiter at around 15psi, the ECU will cut the fuel. To get around this you would need a tune. As for the bottom end and what it can handle, again its all based on the tune. I have seen 27psi successfully on a stock bottom end. The head gasket will hold but being the mileage on the car it is approaching its brittle phase. I ran at 18psi on a stock block for years without issue.

Here is a good read for you:
Modifying Fwd Turbo Volvos (Read, Don't Comment) - Performance Modifications - Volvospeed Forums

Thank you very much for your input Boxpin. Not really looking for an ecm tune or even thinking of going over 15psi. From what i understand stock is 7-9, so id like to run 12-13, just want to make sure im not going to grenade anything. Like i said just want a few extra horses, and would like the boost to kick in a bit quicker. Going to look into modifying my exhaust today. Thanks again for the input

Tighten the wastegate rod 1 turn and add the MBC, done.

Tighten the rod as in shorten it, or extend it? Also am i correct that the stock turbo control solenoid opens at a specified pressure to apply pressure to the wastegate actuator? I put a hand vacuum pump on the actuator yesterday and it began to move at about 2-3lbs of pressure.....

Oh good, you have a pump...set it to 4psi

Thanks.holding off on everything for.now. Awaiting a boost gauge thats in the mail. Been having a runability problem since my manifod swap......idles very rough when cold. The 960 throttle plate i ordered from Snabb didnt fit very well and i think thats the problem, so getting this thi.g idling right and opening up the exhaust is priority rightnow. Still not entirely sure how to adjust the wastegate, but continui my research. Thanks again

Faster, faster...