If something else doesn't eat up the time I have set aside to work on my car.....


I have an 89 740T, the turbo bolts are slightly loose, from what I have read in the FAQ's I have to R&R the ex. mani. etc. to get to them. (But I'm still trying to figure a way to get a modified wrench up in there). So I'm prepared and set to go. I have read somewhere- i wish I could find it again- that newer model exhaust manifold, I think they are referred to as round runners, and I have a square runner on my car, will give a mild hp. gain. I recall a caveat that the newer ex. manifolds crack easier.



Is the Hp increase story true? Anyone know how much?
Reliability wise- is going to a newer ex. manifold advisable?
If an upgrade is a go, does anyone have one F/S?

And one other thing- do I need to replace the turbo oil inlet pipe, or can I clean it out and reuse it?

Thanks in advance

R

Hi R,

The 90+ manifold is supposed to be a 10 hp gain. Volvo didn't reflect this in their specs though. I'd say it's a good swap. Mine had a crack in it 2 years and ~30K km (~20K mi) ago when the engine was rebuilt. I haven't had a problem (knock on wood). It doesn't seem to be much of an issue. As Jim said, you'll probably need to do a little modifying to bolt up your turbo. Those manifolds aren't exactly easy to get though. My mechanic has one, but it's for the B230F+T he's putting in his '78 242 GT restoration/project car (I can't wait until that's done!!!)

CW :)
--
Chris. Halifax N.S. '91 745Ti, 290K km and '91 745 NA, 381K km.

First, what turbo does your car have?
The manifold to turbo bolts should have lock plates which will keep any kind of wrench from working, so you will have to remove the manifold.
The '90+ manifold is not a straight bolt-up unless you use a '90+ turbo, usually a Mitsubishi TD04-13.
I have '90+ manifold and a TD05-12B on my '87; welding and grinding was required for the turbo to manifold fit, but everything else was straight forward.
Mounting a Garrett is more work, but it's been done.
Yes, all the later manifolds are cracked, but it's inconsequential.
I wouldn't say the HP increas is much, but I haven't dynoed the car since I changed stuff.
Unless the oil line is really cruddy, I'd clean it and reuse it.
--
Jim McDonald