Turbo options on a B engine

[RadioFlyer]

My turbo works fine, but just thinking about future upgrades. Anyone tried a different turbo on their B-engine? Would you have to swap in a different exhaust manifold to delete the giant external wastegate? And if so, would an exhaust mani from an H-engine fit? Or would you have to get something custom made?

[Cark]

I think Tial makes an external WG that fits the B motors.
http://www.tialsport.com/index.php/tial ... tes/40-f38

So then you've got a good selection of Garrett's to choose from, you just may need to plumb water to it depending what you go with.

[RadioFlyer]

Aha! I found this pic online. This is more like what I'm thinking - it looks like the owner just removed the wastegate (or is that big metal arm a BOV?), blocked off it's port on the exhaust mani, and stuck in a newer turbo with elbow and later downpipe. Anyone ever done this?



Here is what mine looks like now (minus the OmniCool intercooler):

[Crazyswede]

You can put the H motor turbo exhaust manifold on which will eliminate the B motor blow off valve. You will want to swap in a newer turbo with external wastegate. When looking for an H turbo manifold be sure to look at them closely as most of them are cracked. The crack may not be an issue but its something to look out for. Or talk to someone about getting a good SS unit made up.

[RadioFlyer]

Would the newer turbo still fit if I just used the stock B-motor exhaust mani? Or is the turbo port a different size on the H-motor?

[Geoff]

I've seen more B engine turbo manifolds cracked than H engine manifolds. I think I have 3 cracked manifolds at home. I think I may have only ever seen one H manifold crack. Might just be a small sample size.

I could measure the B motor exhaust manifold and H motor manifold if you want, but I think they flanges are all the same since they're the same type of turbocharger, just different wastegates.

John W was running an H manifold and turbo on his 99T B engine (Frankensaab) before the 16V swap.

If you're interested I have an external wastegate turbocharger at home that was rebuilt with a hardened valve seat for the wastegate and the center housing was upgraded to a water cooled unit. It has the correct 4-bolt flange for an '80 900T. I've been thinking of selling it. Either that or installing it...

[RadioFlyer]

Ooo... I'm listening. Would I then just block off the BOV port? How much of an improvement in boost do you think that is? Would a B-engine be capable of water cooled? I would just need the lower rad hose and what else?

[TurboBudapest]

This discussion breaks my heart - so few B engine turbos out there, why ruin the originality? The large external waste gate is such a wild design.

I have a 99 Turbo with the same basic engine, and the large external wastegate gives the engine/turbo such a unique sound. Like a high speed tornado ripping through the engine bay. Your car is such a treasure. Not that I am such a purist, but I would hate to see this car loose some of its originality/character!

In any event, intersting discussion!

[RadioFlyer]

True... but the large mechanism blocks the ability to add the uber-rare and ultra period-correct (though probably blatantly unnecessary) OmniCool intercooler. Plus I keep melting batteries. Might as well do a serious upgrade. And I'll keep all the stock stuff to go back on if ever necessary.

Not to mention, if I were to be in competition for the concours d'elegance, there would already be a lot to switch back to stock... like the Swedish Dynamics springs and exhaust, Koni shocks, 9Sport panhard, modified and relocated rear axle, Epsilon racing rims, '90 SPG swaybars, '86 SPG front hubs and vented/slotted/drilled brakes, '79 hatch grille and corners, H4 headlights, Alpine sound system, 99 turbo rally stripes (yes I did) and wagonback vent covers just to name a few. Might as well keep going on this track.

[Geoff]

The turbo I have uses the large external wastegate so it looks almost stock (it almost is). It uses the same B engine exhaust manifold. The only real difference is the watercooled center section. Water is supplied from the head from an unused fitting in the warm-up regulator/thermostat housing. There is a -6AN adapter in the housing and then a hose between the AN fitting and the turbo. The coolant outlet could drain into a later 900T lower radiator hose.

Since it's a newer turbo (watercooled) I imagine it might be lighter than the stock one, but I don't know.

It wouldn't help with your intercooler fitment or your battery warmth though.

[Crazyswede]

A b turbo with some 9:1 pistons and a mitsubishi turbo would probably be a hoot to drive.

[99Super]

I did very much what you are talking about.
The manifold was from a B201 "H" engine, the turbo was (and still is) from an 87 9000. No water ports, but a big improvement over the 900 unit. The elbow out of the turbo was also from a 9000. Intercooler and plumbing from 900s.
Like the picture you show, it's entirely possible to just build a plate to blank off the wastegate if you want to keep the manifold original.
I had to move the battery to the trunk, although you don't have to. On one 99T project, I wedged in a 16VT, keeping the original battery box in place.
You will need the intercooler sooner than later.

Left.JPG (50.02 KiB) Viewed 5559 times

[Saabguy70]

I have an H manifold on my 99 turbo! I am currently running a t3 turbo as well(now rebuilt), Viggen Intercool...

[SalemSaab]

In for later .. would love to turbo my 99 with a donar 81 turbo I have avail if possible

[99Super]

In for later .. would love to turbo my 99 with a donar 81 turbo I have avail if possible

Easy to do. Just get the 81> turbo (you have), manifold (you could re-purpose yours.) and about 18" of downpipe from any 900.
Rotate downpipe so it points down towards the 99 exhaust opening and run new pipe from there.
Manifold and plumbing bits mount directly to the 99 points.
You will have to clock the compressor outlet more upright for adequate clearance.

John