[335dsleeper]

Originally Posted by 335dM

Lol

Slick! Can't wait to get a snowmobile, or to live where it snows often. Ha

[335dsleeper]

Originally Posted by QUIKDZL

Yeah, I get a lot of rubbernecking with the enclosed trailer attached.

I bet. I get similar stares and lots of comments questions during fuel stops. So many people assume you need trucks to tow a trailer. I love using my x5 as a tow vehicles and really love the way the 35d pulls. My old 4.8is towed amazing too.

[335dM]

Originally Posted by QUIKDZL

Yeah, I got the bimmerretrofit camera system. They now have it with active back-up lines, which would be nice.

Tongue weight is not supposed to exceed 200 pounds (European towing spec), and this rig occasionally does, so I added the air bags. Mounted the little compressor high up on the left side of my trunk by riveting it to the carpeted panel just behind the wheel arch. This puts it just above and forward of my water/meth tank.

I can't remember the actual air bags I used, but I can probably figure it out next weekend. I bought everything from airliftcompany.com. The bags are 3" diameter x 9" long, and they could stand to be longer. There is not a system for our cars, but similar ones for Hondas and Mustangs. I wound up with the 3x9 springs with some large flat rings to support the bottoms and allow the air line access to the bags. You also need a couple of their top spacers, which look like large test tube plugs--about 2" tapering to 3" and about 2.5" tall. I didn't want to remove the springs to install the bags, so I tossed them, but now regret it. They're needed to fill the tapered top of the coil spring. One day I'll reorder them and remove the spring and stuff them above the bags.

If these were in place, I could actually lift the back end. As it is, I can only increase the spring rate.

Pulling this enclosed trailer is easy, but it is a parachute. Because of this, I use the manual transmission mode when pulling the large trailer (it wants to downshift too easily). I always start in first and briskly accelerate, shift through second quickly to get torque converter lockup, and then upshift with speed. Once underway, I have never needed to downshift on the highway, and usually use cruise control. Cuts economy to about 18 mpg at 70 mph, and it is pulling going downhill to maintain the speed. Exhaust gas temps will hit 1000-1100 on long uphill interstate sections, but quickly drop to about 800 when the road levels out. I pulled a much smaller two-place PWC trailer with two Wetbikes on it from SC to OK and back last summer with the cruise set on 75 and got 32 mpg. Hard to tell it was back there.

You used Airlift system
I have the same on my Ecodiesel Ram

[Puerto Rican 335d]

Bam!!

[VIABONO]

Originally Posted by charlie fairmont

[IMG][/IMG]
Ha! I was just gonna post on the "what did you do to your d today" thread that I hooked the 'ol girl up for the first day on the water this season. Had a truck for a few months and couldn't stand it either. Traded it on the d.

So you have an air suspension? I was thinking about those...

Is that a 17ft Whaler? Do you know its total weight including trailer, engine, fuel etc? Does your 335d have the sport suspension? I'm interested in towing the same model boat short distances, but am concerned about my sport suspension and transmission handling the load. I assume with all the torque pulling it up a boat ramp is easy.

[ptpending]

if you install european bmw genuine towing hitch with tow module your car will know when additional load is attached, disable rear PDC when needed and adapt transmission for towing

[BB_cuda]

PDC=? Is this the sensors on rear bumper? I need to learn how to turn those off when I have bike rack installed into my receiver hitch. It screams at me when in reverse

[rulonger]

Originally Posted by ptpending

... adapt transmission for towing

I am preparing to install a receiver soon and thought that the car could handle pulling a light trailer. What, if anything, needs to be adapted in the transmission?

[charlie fairmont]

Originally Posted by VIABONO

Is that a 17ft Whaler? Do you know its total weight including trailer, engine, fuel etc? Does your 335d have the sport suspension? I'm interested in towing the same model boat short distances, but am concerned about my sport suspension and transmission handling the load. I assume with all the torque pulling it up a boat ramp is easy.

Hey man,

it's a 15ft. whaler. I have not taken it to any scales but here are my calcs, most of them from the manufacturers of the given components:

Hull 500 lbs; motor 200 lbs; gas 100 lbs; battery 62 lbs; misc gear 100 lbs; trailer 400 lbs (I think it is probably more like 3-350), for a total of 1362. For my next calcs, I round that to 1400 lbs.

my "home" ramp is roughly 15 degrees. To factor in Isaac Newton's work, I take the 1400lbs x sin(15) to get 362 lbs. next, the car itself is roughly 3800 lbs. 3800 x sin(15) = 984 lbs. That means gravity on the ramp is adding 1362 to my 1400 lbs calc'd above for a total of 2746 lbs the engine is moving up the ramp. The car has no problem whatsoever pulling it up the ramp. I am uncertain how I would go about calculating the drag on the trailer from the water but like I mentioned, the car is not bothered one bit by the load.

Like Jet Wrench mentioned, I definitely get stares at the ramp but have never had any issues pulling it up, even at low tide. on a flat surface, the car will move the rig at idle just as if it weren't even back there.

I do have the sport suspension (and even the RFTs) on my car and the tongue weight is roughly 100 lbs. It does drop the rear end a bit but there is still plenty of travel and I have never bottomed out. I tow in manual mode because I was thinking manual mode allows for less clutch slip and less heat. If any of you smart guys think I have this (or anything else I posted) wrong, I would love to know so I do not mess anything up with my misinformation.

I do want to get the Euro wiring harness either from westfalia or bmw (but not the ball itself b/c euro ball is a millimeter or two smaller than our 2" balls). I am using the one supplied with the invisihitch simply because I am still under CPO warranty and the westafalia harness (which apparently talks to the tow module) needed to be spliced-in rather than being plug-n-play. it would have been just my luck that I splice into the canbus and then get some fault a few days later that would get denied under warranty because of my electrical work. CPO expires in November at which point i'll get the new harness and shed some unneeded alphabetic parts from my new favorite tow pig

[GaryE30]

Originally Posted by BB_cuda

PDC=? Is this the sensors on rear bumper? I need to learn how to turn those off when I have bike rack installed into my receiver hitch. It screams at me when in reverse

Yes, Park Distance Control

[JayNC335d]

Originally Posted by charlie fairmont

Hey man,

it's a 15ft. whaler. I have not taken it to any scales but here are my calcs, most of them from the manufacturers of the given components:

Hull 500 lbs; motor 200 lbs; gas 100 lbs; battery 62 lbs; misc gear 100 lbs; trailer 400 lbs (I think it is probably more like 3-350), for a total of 1362. For my next calcs, I round that to 1400 lbs.

my "home" ramp is roughly 15 degrees. To factor in Isaac Newton's work, I take the 1400lbs x sin(15) to get 362 lbs. next, the car itself is roughly 3800 lbs. 3800 x sin(15) = 984 lbs. That means gravity on the ramp is adding 1362 to my 1400 lbs calc'd above for a total of 2746 lbs the engine is moving up the ramp. The car has no problem whatsoever pulling it up the ramp. I am uncertain how I would go about calculating the drag on the trailer from the water but like I mentioned, the car is not bothered one bit by the load.

Like Jet Wrench mentioned, I definitely get stares at the ramp but have never had any issues pulling it up, even at low tide. on a flat surface, the car will move the rig at idle just as if it weren't even back there.

I do have the sport suspension (and even the RFTs) on my car and the tongue weight is roughly 100 lbs. It does drop the rear end a bit but there is still plenty of travel and I have never bottomed out. I tow in manual mode because I was thinking manual mode allows for less clutch slip and less heat. If any of you smart guys think I have this (or anything else I posted) wrong, I would love to know so I do not mess anything up with my misinformation.

I do want to get the Euro wiring harness either from westfalia or bmw (but not the ball itself b/c euro ball is a millimeter or two smaller than our 2" balls). I am using the one supplied with the invisihitch simply because I am still under CPO warranty and the westafalia harness (which apparently talks to the tow module) needed to be spliced-in rather than being plug-n-play. it would have been just my luck that I splice into the canbus and then get some fault a few days later that would get denied under warranty because of my electrical work. CPO expires in November at which point i'll get the new harness and shed some unneeded alphabetic parts from my new favorite tow pig

I would have very little concern with power, we are good on that. Traction could be an issue depending on the ramp grade and condition. I live on the coast, and some ramps at low tide, if I stand up, I slide down ha!

I think where we should watch is tongue weight, rear suspension, rpm when driving, and I would be most concerned with braking. I don't claim to have any SAE calculations for this, but I always see the average joe forget about what it takes to stop all that extra weight when at speed. I mean aren't our stock disk pretty crap? I mean there is good stopping force, but high speed braking and all that traction control crap has rear disk failing way to early.

Don't get me wrong, I love this and would have no issue driving the load you have at ramps I know. If I was going to do a lot of towing with possibility for questionable roads I would get an adjustable rear suspension and better brakes though. We are good on power and with smart driving in manual mode I think the transmission is fine, short of the fact it's an autobox

[VIABONO]

Originally Posted by charlie fairmont

[IMG][/IMG]
Ha! I was just gonna post on the "what did you do to your d today" thread that I hooked the 'ol girl up for the first day on the water this season. Had a truck for a few months and couldn't stand it either. Traded it on the d.

So you have an air suspension? I was thinking about those...

Originally Posted by charlie fairmont

Hey man,

it's a 15ft. whaler. I have not taken it to any scales but here are my calcs, most of them from the manufacturers of the given components:



Hull 500 lbs; motor 200 lbs; gas 100 lbs; battery 62 lbs; misc gear 100 lbs; trailer 400 lbs (I think it is probably more like 3-350), for a total of 1362. For my next calcs, I round that to 1400 lbs.

my "home" ramp is roughly 15 degrees. To factor in Isaac Newton's work, I take the 1400lbs x sin(15) to get 362 lbs. next, the car itself is roughly 3800 lbs. 3800 x sin(15) = 984 lbs. That means gravity on the ramp is adding 1362 to my 1400 lbs calc'd above for a total of 2746 lbs the engine is moving up the ramp. The car has no problem whatsoever pulling it up the ramp. I am uncertain how I would go about calculating the drag on the trailer from the water but like I mentioned, the car is not bothered one bit by the load.

Like Jet Wrench mentioned, I definitely get stares at the ramp but have never had any issues pulling it up, even at low tide. on a flat surface, the car will move the rig at idle just as if it weren't even back there.

I do have the sport suspension (and even the RFTs) on my car and the tongue weight is roughly 100 lbs. It does drop the rear end a bit but there is still plenty of travel and I have never bottomed out. I tow in manual mode because I was thinking manual mode allows for less clutch slip and less heat. If any of you smart guys think I have this (or anything else I posted) wrong, I would love to know so I do not mess anything up with my misinformation.

I do want to get the Euro wiring harness either from westfalia or bmw (but not the ball itself b/c euro ball is a millimeter or two smaller than our 2" balls). I am using the one supplied with the invisihitch simply because I am still under CPO warranty and the westafalia harness (which apparently talks to the tow module) needed to be spliced-in rather than being plug-n-play. it would have been just my luck that I splice into the canbus and then get some fault a few days later that would get denied under warranty because of my electrical work. CPO expires in November at which point i'll get the new harness and shed some unneeded alphabetic parts from my new favorite tow pig

Thank you very much for the excellent details. I will also be using Invisihitch. Now I've got to go get the boat!

[ptpending]

Originally Posted by rulonger

I am preparing to install a receiver soon and thought that the car could handle pulling a light trailer. What, if anything, needs to be adapted in the transmission?

out cars equipped with 6hp gearboxes
to get more fuel efficiency these gearboxes have multidisc clutch with variable lock-up in torque converter which lock very early
old style gearboxes have simple lock-up clutch which is locked on 3 or 4 gear, this is ok when you start with additional load because on oil torque transfer

so, for our gearboxes, when we have additional load it is better to start lock on higher gear and more smoothly
you can see when gearbox locks when you press accelerator, car speed goes up but engine revs stick on some number

[335dsleeper]

^ I tow my 335d on a 16ft open trailer. The combo weighs right around 5k total. I pull this with my 35d x5, which has the same transmission found in the 335d. Tows great and transmission shifts perfectly. The X5 has 161k miles too.

That said, I'm confident you guys will be perfectly fine towing your lighter trailers with the 335d.

[TLO03]

Respect!

[motoseb97]

Very interested in doing this to my 2016 435i. However, the ID of the F32 rear springs is ~2.5 inch (62mm to be exact)
What is the ID of the OP's car? Did the E90 have 3 inch ID rear springs?

[QUIKDZL]

Yes, the E90 springs have a 3" ID. The customer support at airliftcompany should be able to find the right bag for you. It just might be the same bag, as a 3" bag would fit inside a 2.5" spring, I think.

[motoseb97]

Originally Posted by QUIKDZL

Yes, the E90 springs have a 3" ID. The customer support at airliftcompany should be able to find the right bag for you. It just might be the same bag, as a 3" bag would fit inside a 2.5" spring, I think.

I asked them about it a while ago and they highly recommended against it. The issue with putting an oversized bag is it can very easily kink and tear.

I wish they published their sizes on their site. I see they have a bag available for the 2013 Mustang which also (I believe) uses 2.5 inch ID springs. I wonder if that would work.

How has your kit held up over time? I've been towing this for about 3 years now, working very well. Would just like to have it a bit more level.

[QUIKDZL]

That Mustang spring should work very well. It's important to constrain the ends with their plugs and donuts, in my opinion, as the bag will squish through the coils a little. Constraining the ends will give you lift.

I notice your car is about an inch low in the back and about a half-inch high in the front. Mine sat the same way with my 6x12 box trailer. With the trailer brakes, this posed no problems at all. Note that if you get some rear lift with the airbags (springs), your front end will raise too. You're not changing the weight distribution, just clearance.

My airlift system has held up very well over time. It was cool that the air compressor would occasionally top up the air pressure on its own--like when suddenly hitting rain causing the bags to cool down. I have recently removed it because of the following sequence of events.

• Busted all four shocks while towing a PWC trailer at 70 mph cross-country. Idiot bridge construction in Dallas.
• Bought the Ohlins suspension system I always wanted (love it).
• Sold the trailer and golf cart.

I still do the lighter towing (PWC trailer) on my new suspension without airbags. The spring rates are stiffer and I don't need to adjust anything for an 800 pound trailer with 80 pounds tongue weight. I now have a big diesel box truck for serious loads. Your car and trailer look very nice!

[motoseb97]

Originally Posted by QUIKDZL

That Mustang spring should work very well. It's important to constrain the ends with their plugs and donuts, in my opinion, as the bag will squish through the coils a little. Constraining the ends will give you lift.

I notice your car is about an inch low in the back and about a half-inch high in the front. Mine sat the same way with my 6x12 box trailer. With the trailer brakes, this posed no problems at all. Note that if you get some rear lift with the airbags (springs), your front end will raise too. You're not changing the weight distribution, just clearance.

My airlift system has held up very well over time. It was cool that the air compressor would occasionally top up the air pressure on its own--like when suddenly hitting rain causing the bags to cool down. I have recently removed it because of the following sequence of events.

• Busted all four shocks while towing a PWC trailer at 70 mph cross-country. Idiot bridge construction in Dallas.
• Bought the Ohlins suspension system I always wanted (love it).
• Sold the trailer and golf cart.

I still do the lighter towing (PWC trailer) on my new suspension without airbags. The spring rates are stiffer and I don't need to adjust anything for an 800 pound trailer with 80 pounds tongue weight. I now have a big diesel box truck for serious loads. Your car and trailer look very nice!

Thanks for the info! Would you by chance sell your airbags? I contacted airlift and they mentioned the mustang springs are STILL for 3 inch inner diameter. They told me they highly recommend against installing it in my car as it will kink/tear due to the bag not being able to properly expand (It'll likely have a fold in it even when expanded).

[QUIKDZL]

I would happily give them to you if they had not been thrown away. Sorry!

[Flight335d]

I mounted a U-haul hitch and towed an 8 x 12 utility trailer with my mortorcycle on it over 2,000 miles from Stuart Florida to Ohio and back.

I was worried about heat levels so I used a blue driver OBD2 reader Live Data to monitor engine temps and fuel consumption. Average temp was 175F. While passing trucks in the West Virgina mountains in 80F temps it peaked at 208F. I hardly knew the trailer was behind me. Cruised at 80 mph in 6 gear at 2,100 rpm with no issues.

Fuel consumption on open flat road whas about 3.5 g/h When behind a truck it dropped to 2.5 g/h. I average 24 mpg driving at +80 mph