I recently bought a 91 740 turbo and was just wondering about the amount of boost it puts out. I put a boost gauge on it and after running in the wastegate actuator arm i'm only making 5 pounds of boost. My last 740 was an 86 turbo wagon (also with the b230ft) and I was making around 10 pounds.

I know that the 82-88 run could be boosted to 14.6 or so before the computer would shut off fuel supply, so i was just wondering if there is a limitation of the same type put on the 91-93 range.

 

There is. But unless you change the turbo, you don't need to worry about it.
The 13c turbo you have will be reaching the end of its efficiency range by then.
Most I would run on that turbo is 14psi. If you still want more, go to a 19t or similar.

 

thanks, still wondering about why i can only get it up to 5 though.

 

the spec is 7-8 PSI on a B230FT. if you're only seeing 5, then your turbo is tired, or you have air leaks or something

 

hopefully it isn't too tired. my wagon had 130k more miles on it. i'll have to get in under the hood and see if i cant track anything air leaks out.

 

Got under the hood today and didn't really find anything. One of the nuts on the downpipe flange was loose but I tightened that down with no change. Vacuum at idle is around 9" Hg which I thought was a bit low. I haven't been having any symptoms of a vacuum leak, though.

On a side note, I have a fairly significant oil leak where the turbo oil drain pipe meets the block and was wondering if anybody had any experience with that.

 

I had that exact leak. covered the whole underside of my car in oil... I had to remove the drain pipe, clean out the hole on the block, and replace the washer, which was volvo PN 1306264 on my 1992 740T

 

got the seal and installed it today, sealed perfectly.

no more dumping smoke at stop lights (hooray).