nothing to see here. move along please.

**JRL** · 03-15-2011, 05:54 PM

ECU flash

**smp375** · 03-15-2011, 09:00 PM

I'm not at all familiar with the specific turbochargers used on these cars. Would you mind explaining why a manual boost controller can't be used?

**dave941** · 03-16-2011, 05:40 PM

Originally Posted by smp375

I'm not at all familiar with the specific turbochargers used on these cars. Would you mind explaining why a manual boost controller can't be used?

JRL said that you can only use a MBC on 1998 and earlier. you can ask him for more specific details

**dave941** · 03-16-2011, 05:54 PM

Originally Posted by JRL

ECU flash

ok so i did what you said with the connecting rod and i really couldn't notice any difference at all. so i put 2 full turns on it and i see a very little difference in the performance but after all, it could be my imagination. i haven't blown a head gasket yet so im not too worried. i watched the rod when it was being revved in the stock position and i can see how it bypasses the exhaust. after i shortened it, it wasn't moving, so that tells me that its not bypassing the exhaust and building pressure but i don't see why its not showing any change in the performance. what's going to happen if i keep it at 2 full turns?

**JRL** · 03-16-2011, 06:25 PM

You turned just the rod, not the nut and entire assy, I hope?
If you did it properly you really should notice something and you DID tighten it right?
(shorten the rod)

**dave941** · 03-16-2011, 06:26 PM

Originally Posted by knucklebuster

Volvo turbos have exhaust bypass, not waste gate.

i.e. exhaust gasses can bypass the turbo impeller, lowering boost.

instead of excess boost pressure being "wasted" through a pressure relief valve . . .

So changing the length of the connecting rod between the intake pressure membrane thingie and the bypass valve (on the top of the turbo) will change your boost. Forgotten which way but I think shortening it increases boost. Don't quote me. You must be careful not to rotate the end in the rubber membrane thingie - it will tear.

I'm not encouraging you to increase your boost pressure. Higher boost engines like the 2.3L usually have lower compression ratios and retarded timing, niether of which your engine has. The XC is meant to be a light pressure turbo.

There has been lots of discussion on this site about not increasing boost.

is the turbo being bypassed at idle?

**JRL** · 03-16-2011, 06:28 PM

Here, read:
http://forums.swedespeed.com/showthr...alve-Adjusting

You have no boost at idle in any turbo car, you need the exhaust pressure to move the turbo

**dave941** · 03-16-2011, 06:31 PM

can anyone post a picture of one of these turbos disassembled so i can see exactly how these volvo turbos work?

**dave941** · 03-16-2011, 06:37 PM

Originally Posted by JRL

You turned just the rod, not the nut and entire assy, I hope?
If you did it properly you really should notice something and you DID tighten it right?
(shorten the rod)

i didn't turn the rod because i had to use PB Blaster to break it, and i did tighten it. i think the exhaust is bypassing the turbo until maximum throttle is applied.