3.0 Power Adder Options

[nick325xit 5spd]

Originally Posted by e39_touring

I'll throw my two cents in here since I've kind of been thinking of doing the same thing as you are. I've concluded that the M54 engine will be fine with boost provided you don't become addicted to it and overdo it and also provided that your tune is good (never lean). The N54 has basically the same bottom end and runs 8 psi of boost for ~300 chp from the factory. An M54 with 8 psi of boost properly tuned will do just fine under the rigors of towing.

A small-ish turbo or positive displacement supercharger will be a better match for a heavy SUV like the E53 compared to a centrifugal blower like others have already mentioned. The centrifugal blower won't 'feel stronger everywhere' but will rather come on stronger and stronger as RPM's build with little difference being felt coming off a stop and at lower RPM's. Not really ideal for towing.

Upgrading the cooling and drivetrain is not a necessity, but making sure it they are in tip top shape is. IIRC, the auto 3.0 is rated to 5 or 5.5k lbs while the manual is 6k. Keep your loads within those limits, and don't do extended full throttle pulls at max load, and you'll be fine.

However, if your trans is already heating, it's already slipping, and adding power will make its failure that much quicker. The E53 GM trans is electronically controlled and has a series of clutches and solenoids to actuate gear changes. Once a gear is locked, there should be no slippage, and the heat generated should be minimal (i.e. towing or not, your ATF should roughly maintain engine coolant temps since it is cooled & heated by the engine radiator). If it's heating, it means that you trans is slipping excessively during gear changes, which can be more frequent with towing.

I've also decided that if I go the V8 route, it won't be in a BMW but something domestic with a more robust drive train like a Trailblazer SS or Jeep Grand Cherokee SRT or the like. A little less refined than the bimmer, but they sure can take a beating in the drivetrain dept.

Keep us posted on what you decide to do!

It seems like OP's real issue is that his transmission can't handle the load already. I really don't see how adding more power fixes that.

The GM transmission is configured for extreme sloppiness. BMW uses that torque converter to give the X5 way more oomph than it rightfully should seem like it has. The result is that of *course* it's going to struggle under load.

Edit: That and if you're going to tow with an automatic E53, it's kind of nuts to engineer your own FI kit vs. just pick up an N62 with the ZF6 that will have the power, torque, and transmission to handle it.

[X5chemist]

How does Sport mode on a 3.0i work with towing? When I need to accelerate aggressively, I throw it in Sport mode.

[nick325xit 5spd]

Originally Posted by X5chemist

How does Sport mode on a 3.0i work with towing? When I need to accelerate aggressively, I throw it in Sport mode.

It doesn't get rid of the torque converter slip - that would make the X5 feel and accelerate a lot slower. That sloppy torque converter is why the E53 3.0i feels so much faster than the E70 3.0si, even though the (only slightly heavier) E70 has a good bit more power.

[e39_touring]

Originally Posted by nick325xit 5spd

It seems like OP's real issue is that his transmission can't handle the load already. I really don't see how adding more power fixes that.

The GM transmission is configured for extreme sloppiness. BMW uses that torque converter to give the X5 way more oomph than it rightfully should seem like it has. The result is that of *course* it's going to struggle under load.

Edit: That and if you're going to tow with an automatic E53, it's kind of nuts to engineer your own FI kit vs. just pick up an N62 with the ZF6 that will have the power, torque, and transmission to handle it.

Adding power won't fix a bad transmission, and I noted that in my post where I said the transmission and cooling need to be in top shape before considering boost.

However, I think you misunderstand how auto transmissions and torque converters work. By 'extreme sloppiness', I assume you mean that the torque converter is loose/high stall speed. Yes, this slippage allows the engine to get into its RPM power range before transmitting power to the transmission, but that is VERY different than a transmission that's slipping due to bad clutches, seals, or solenoids. Once at highway speed, with the torque converter locked and the transmission in gear, there should be no slippage and minimal heat.

In the OP's case, there isn't enough information to tell exactly what's going on since I don't know how and what he's measuring with his temps. It could be the engine is heating from load and since the ATF shares the engine radiator, the ATF will heat, too. The temp gauge will still stay in the center with quite a wide range of coolant temperature change. My point is, you can look at your gauge and see that it's centered but monitor engine or trans temps with an OBD reader and see something different than you expect.

No need to engineer a power adder for the M54 as there are a couple of positive-displacement blowers out there that will do the trick. A V8 will certainly work as well, but the OP sounds like he's experienced the typical unreliability and high cost of maintenance associated with the BMW V8 (and probably the reason the resale value of them is so low). Oh yeah, and everything that we've both said about towing and the driveline applies to the 4.4/4.6/4.8 as well. It's not like those don't eat their share of transmissions, too, towing or not.

Anyway, different strokes for different folks - do what makes you happy

[nick325xit 5spd]

Originally Posted by e39_touring

Adding power won't fix a bad transmission, and I noted that in my post where I said the transmission and cooling need to be in top shape before considering boost.

However, I think you misunderstand how auto transmissions and torque converters work. By 'extreme sloppiness', I assume you mean that the torque converter is loose/high stall speed. Yes, this slippage allows the engine to get into its RPM power range before transmitting power to the transmission, but that is VERY different than a transmission that's slipping due to bad clutches, seals, or solenoids. Once at highway speed, with the torque converter locked and the transmission in gear, there should be no slippage and minimal heat.

In the OP's case, there isn't enough information to tell exactly what's going on since I don't know how and what he's measuring with his temps. It could be the engine is heating from load and since the ATF shares the engine radiator, the ATF will heat, too. The temp gauge will still stay in the center with quite a wide range of coolant temperature change. My point is, you can look at your gauge and see that it's centered but monitor engine or trans temps with an OBD reader and see something different than you expect.

No need to engineer a power adder for the M54 as there are a couple of positive-displacement blowers out there that will do the trick. A V8 will certainly work as well, but the OP sounds like he's experienced the typical unreliability and high cost of maintenance associated with the BMW V8 (and probably the reason the resale value of them is so low). Oh yeah, and everything that we've both said about towing and the driveline applies to the 4.4/4.6/4.8 as well. It's not like those don't eat their share of transmissions, too, towing or not.

Anyway, different strokes for different folks - do what makes you happy

A high stall speed torque converter runs a lot hotter than a locked up torque converter. That's why tow mode locks up the converter as early as possible in a truck. Given that the Aisin / GM transmission is *already* sufficiently marginal that BMW saw fit to reduce the tow rating, I don't see how adding extra stress is a benefit. And my experience with with an auto 3.0i is that it unlocks the torque converter basically any time you're below the stall speed.

As for transmission reliability, well, the ZF6 is by FAR the best and toughest and most reliable auto transmission that you can get in an E53. It is only in the N62 X5s in the US. The N62 has quirks that can be managed. It's the M62, and especially the Alpina variant of the M62 that are awful.

Also, you say that there positive displacement blower kits out there, but are there any actually still in production? Because I did check that and none of the ones that I recall are still available.

[PropellerHead]

Originally Posted by nick325xit 5spd

As for transmission reliability, well, the ZF6 is by FAR the best and toughest and most reliable auto transmission that you can get in an E53. It is only in the N62 X5s in the US. The N62 has quirks that can be managed.

And I've replaced mine. Twice.

[EODguy]

I've replaced mine once, but I live on the surface of the sun and drive like I'm heading to a pool party...

Sent from my SM-A528B using Tapatalk

[e39_touring]

Originally Posted by nick325xit 5spd

Also, you say that there positive displacement blower kits out there, but are there any actually still in production? Because I did check that and none of the ones that I recall are still available.

No, I think only centrifugal blowers can still be bought new for the m54 - now or of production for what, 17 years? You'd have find a pd blower used. But, no way I'd spend $5-7k on a blower for an e53 x5 3.0 these days when the truck is only worth $3-4k at best.

P.s. - ironically, I've never had a problem with the gm transmission in our old x5 3.0 even with a bit of towing (waaay over max rating, but only around town), but the zf auto in our old e46 3 series took a dump at 40k miles. However, the zf6 manual in my old corvette IS a brute!

[Happy]

Originally Posted by EODguy

I'm heading to a pool party...

Dang EOD, How come no invite.!? LoL.. I am trying to get wet.. 🤣🤣


E53 RiPPeR
XOuTPoST jUNkiE
ReVELaTiON 22:21

[nick325xit 5spd]

Originally Posted by e39_touring

No, I think only centrifugal blowers can still be bought new for the m54 - now or of production for what, 17 years? You'd have find a pd blower used. But, no way I'd spend $5-7k on a blower for an e53 x5 3.0 these days when the truck is only worth $3-4k at best.

P.s. - ironically, I've never had a problem with the gm transmission in our old x5 3.0 even with a bit of towing (waaay over max rating, but only around town), but the zf auto in our old e46 3 series took a dump at 40k miles. However, the zf6 manual in my old corvette IS a brute!

It's worth noting that they barely sold any PD blowers when the M54 was new. People who wanted blowers mostly wanted the bigger peak numbers of the centrifugal kits, or were turned off by the TS/PD blower price premium.

I mean, if I stumbled across an M54 PD blower kit for cheap, I'd absolutely pick it up. But I can't say that I expect to.