540i/6 dilemma

[dirtysd]

Hey everyone im thinking about ditching my 540/6 for a 525/5 and boosting it. Dont know if im crazy but just would like to see what you guys thought. It would be an M50TU car thanks

[BoldUlysses]

Not a crazy idea. I've owned both and while I loved the 540i's power, the 525i felt better balanced and was just a joy to drive. Boosting one would close the power gap and then you'd have the best of both worlds. Ultimate power potential is higher with a 525 than a 540 too.

A lot depends on whether you're up for the DIY work involved in boosting an E34, or prepared to pay someone to do it for you. There are no complete bolt-on kits for the 525.

And there's the "cachet" factor. Generally speaking, the 540i/6 is second only to the M5 as a desirable flavor of E34. A 525, even a turbo'd one, will always be "just" a 525. Different enthusiasts prioritize that kind of stuff differently, so YMMV.

[aalpine1]

Why don`t you buy the m50 and just put it in your car. You got a good platform to start with :)

[Leonator134]

I can haz Msport

[PorscheH6]

You'll probably put yourself in a place where you need a dead-reliable daily driver. You already have that with a stock 540/6.

[dirtysd]

I actually daily a Focus ST so this is kinda on the side. I just wish the 540i made more power.

[dirtysd]

I can haz Msport

You dont want mine yours is better!

[imae30driver]

540/6 are relatively hard to fine upon. Worth keeping.


525/5's are common and cheap enough you would be better off just buying one in addition.. And have a real world comparison on what it takes to surpass the 540

[BleedsBlue]

Coming from the E36 world before I bought this car, I know those M50s can support some srs boost with a proper set-up. If you want more powa and boost instead of NA torque, I say go for it.

The 6 speed wouldn't match up to an M50 so I wouldn't swap an M50 into your 540i if it's mostly original.

[atl530i]

I have both. The only reason I bought the 525i5 is for the reasons already pointed out. You can also swap in a low compression M52 and turbo it, S52, M52 with S52 cams, etc...

[ross1]

I actually daily a Focus ST so this is kinda on the side. I just wish the 540i made more power.

Agreed, the 540's power is underwhelming. Plenty of boosted M50s around that make impressive power. These cars were designed for straight sixes.
Depending on how much power is enough for you, how important balance is and if you are up for swapping LS motors have been done before.

[BleedsBlue]

I have both. The only reason I bought the 525i5 is for the reasons already pointed out. You can also swap in a low compression M52 and turbo it, S52, M52 with S52 cams, etc...

This is completely up for debate (and depends on boost levels), but sometimes the highest boost guys stick with M50 or M52 blocks due to thicker cylinder walls.

[V1990]

I'm going M30 boost next spring. I'd recomment boosting an M50.. But please keep the 540i/6!