questions about turboing a 4.6L X5
 

Ok guys, if there's a chance this can be done, maybe it has already so I'm looking to the forum to see if it's doable.

First off, does the exhaust manifold from a 4.4L fit a 4.6L. If it does, it widens the search to 540 sedans and since my buddy has both X5 in a 4.4L and a 540 sedan and he's well versed in working on them, this is going to become easier then I had originally thought. Please give me your feedback.

Thanks

Never seen it, but I'm also new to X5s. Check with Active Atuowerke in FL. If it can be done they can tell you how.

Bentley Arnage - Wikipedia, the free encyclopedia

For whatever it's worth, the Arnage 5HP30 couldn't handle the torque.

10.5:1 compression will limit the CFM from the turbos with 93 fuel. Probably keeping them out of their efficiency range unless they are really small.

Still, good luck!

For the money.... The 50i is really the answer.

And you'd get a pretty rad 8-speed.

If your buddy is so versed in E53 and E39, why do you ask about some simple things like manifold compatibility in froums? My suggestion would be to ask your buddy first...

I also don't get what can be inpossible in turbocharging any engine?

The other question is the price and durability.

So what's your exact question?

OP: Are you asking about the M62 4.4, the N62 4.4, or the N63 4.4? Different engines. While BMW offered the N63 with turbochargers, the engine is completely different, with the exhaust manifold between the valley of the heads.

Jeff, I think he's going on about a M62 as spec'd for a 4.6

I thought so at first, but couldn't understand why he thought it was a good idea to add turbochargers to a high compression engine.

Agree. Would be quite a challenge.

Edit: even moreso to put the torque down through the 5HP24, considering what the Arnage did to its 5HP30

I considered turbochargers. Both one and twins. One TC wasn't that much less than two and would reduce lag so I got quotes on twins. I got two quotes. The estimates were $6,000 to $8,000. Both were custom systems so the estimates were open ended. One was a system positioned conventionally and done locally, the other was from STS, a system under the X--somewhere. For STS system X had to go to STS headquarters for install. Both would result in similar gain in horsepower and torque. Don't remember torque but HP gain was 125-150 with capability for more but risk went up exponentially. I didn't go either direction largely because they both needed the X at least three or more weeks. The more weeks had no estimated end as they didn't know what they would be getting into, especially for the tuning. I decided that was too many weeks, too much money and no other systems to reference into the decision tree.

There are are supercharged 4.6s out there that produce around 450HP and 404 ft/lb with a Dinan system that dealers installed when the owner took delivery. One can conclude the reprogrammed tranny is capable to handle the extra torque. One would also conclude the tranny would last a shorter period of time, though I don't know if that is reality.