Sprinter 4WD Conversion Idea, GMT-800 IFS.

[Len.Barron]

getting the bushings out of the later stamped steel design(when they need replacement) is always a treat...you have to make an insert to keep from crushing it and usually a fair amount of heat(and the burning rubber smoke that comes with it..
cognito also sells some nice UCAs

 

[luthj]

Made a fox 2.5x6" coilover model (got half of it from some random one on the web).



As mentioned the UCA does not even come close.


I can shift the upper mount forwards a bit, which will help slightly, but a new UCA will be needed. I am hopeful I can find a solution that doesn't cost 600$+ for a pair of UCAs. Anyone with a 2011-2018 GM 2500 out there? I could use the dimensions of the UCA mounts, and the UCA overall length.

With a 1.4" lifted coil plate the axle shaft clears. There is still room for a 14" spring too. Though getting the shock compressed to mount will require a coil compressor I think.

 

[b dkw1]

The newer arms do not have replaceable BJ's. The main reason aftermarket arms are so popular. I believe the taper is the same though.

 

[luthj]

For the first time in many months I was able to set up my desktop. After working on my tiny (though heroic) laptop for so long, it was nearly orgasmic loading the model up. From 30 seconds to 3... Too bad it won't fit in the van. Though I doubt I could power it for long periods!

A bit of trimming and the factory Arm fits. Cutout is about 0.9" of the arm width with a light radius. There is room for a bit more meat on the upper side if needed. So if I can't find a decent high clearance one I can modify the stock unit with a doubler bracket welded to the top.








Anyone have thoughts on machining the spring plate/nut to accept a 70mm (2.75") spring? It nets me 1/8" more clearance, thought I am not sure if I would get spring/body rubbing?

 

[luthj]

It is always nice to look back and see the progress on a project.

Here's where I started in January.



Here where I am today. I am a bit excited. The van is going to ride great when I am finished. I just need to resist the urge for big lift, big tires, and an expensive rear axle (none of which I need).

 

[Riptide]

Been following with keen interest, as a fellow T1N Sprinter owner myself. But the elephant in the room is the electronics. How are you going to get all this to play together?

(I apologize if you've already answered this over on Sprinter Source. I haven't visited your thread over there in a few weeks...)

 

[luthj]

Been following with keen interest, as a fellow T1N Sprinter owner myself. But the elephant in the room is the electronics. How are you going to get all this to play together?

(I apologize if you've already answered this over on Sprinter Source. I haven't visited your thread over there in a few weeks...)

With custom tone rings attached to the diff output flanges, the van will behave normally without any changes to the software in 2WD high. I also believe it will perform just fine in 4WD high. Obviously I can't be certain, as the parameters of the ESP program are not known to me. If all five gears are desired in low range, a custom programmed arduino will need to be inserted between the TCM and the rest of the CANbus.

I have been in contact with an electrical/computer engineer to write the software. We worked out which frames need modified, and narrowed down the specific bytes. At this point we need to decide on which hardware to use, and he will write me a test sketch to confirm the bridge works. Testing the ratio compensation will require a van with low range Tcase, which is a ways down the road.

Essentially the Arduino serves as a CAN bridge. It passes all frames normally between the TCM and the van (transparently). When in low range it will modify the wheel speed frames. The modification will consist of the dividing the speed by the low range ratio. So the traction and stability control will behave normally, and the TCM won't freak out because it thinks the holding clutches are slipping (ratio plausibility error).

This same arduino/software could be used to compensate for axle ratio changes as well.

 

[Buddha.]

getting the bushings out of the later stamped steel design(when they need replacement) is always a treat...you have to make an insert to keep from crushing it and usually a fair amount of heat(and the burning rubber smoke that comes with it..
cognito also sells some nice UCAs

Ive had some success drilling out the rubber of the bushing with a small bit. It's still not easy though.

 

[Riptide]

I have been in contact with an electrical/computer engineer to write the software. We worked out which frames need modified, and narrowed down the specific bytes. At this point we need to decide on which hardware to use, and he will write me a test sketch to confirm the bridge works. Testing the ratio compensation will require a van with low range Tcase, which is a ways down the road.

Essentially the Arduino serves as a CAN bridge. It passes all frames normally between the TCM and the van (transparently). When in low range it will modify the wheel speed frames. The modification will consist of the dividing the speed by the low range ratio. So the traction and stability control will behave normally, and the TCM won't freak out because it thinks the holding clutches are slipping (ratio plausibility error).

You make it sound easy. What about ABS?

 

[luthj]

The ABS subroutine (part of the ESP/stability software) shouldn't care one bit about low range. All it cares about are wheel speeds (read directly by the ESP/ABS module). These are totally unchanged with the arduino. The ASR should work without issue as well. The ASR does command engine power reduction, it may be a bit more aggressive with power reductions in low range, as the TCM might play a roll with torque converter clutch activation.

Factory 4x4 T1Ns have ASR/ABS, and it works fine. Even if the transfer case switch sticks, and the van thinks its in 4WD high (and is actually stuck in low). The majority of the ABS/ASR programming is shared with the manual transmission variants, so they would have written the code to work on either model with minimal changes. On a manual van the ABS/ESP module has no idea what gear your in, and really doesn't care, it just knows if the clutch is in or out, and how much power the engine is making.

For reference, Allrad? in germany did aftermarket T1N 4x4 conversions. On the auto trans van, the had a black box, which connected between the TCM and the rest of the van. This black box corrected any gear ratio issues, and allowed normal operation in low range. No other changes were made to the vans electronics. So I am inclined to believe they found the ABS/ESP/ASR performance acceptable with just the TCM CANbus fix.

PS: I may make it sound easy, but the information required to develop this approach took me a couple years to gather. Changing 7 bytes in a tiny Canbus frame? Pretty easy. Knowing which bytes to change? Hard.

 

[Riptide]

PS: I may make it sound easy, but the information required to develop this approach took me a couple years to gather. Changing 7 bytes in a tiny Canbus frame? Pretty easy. Knowing which bytes to change? Hard.

You couldn't see me being facetious. I know it must be hard; I've watched the Sprinter forum for years as T1N 4x4 dreams have come and gone. I am rooting for you as hard as anyone...

 

[mgmetalworks]

The ABS subroutine (part of the ESP/stability software) shouldn't care one bit about low range. All it cares about are wheel speeds (read directly by the ESP/ABS module). These are totally unchanged with the arduino. The ASR should work without issue as well. The ASR does command engine power reduction, it may be a bit more aggressive with power reductions in low range, as the TCM might play a roll with torque converter clutch activation.

Factory 4x4 T1Ns have ASR/ABS, and it works fine. Even if the transfer case switch sticks, and the van thinks its in 4WD high (and is actually stuck in low). The majority of the ABS/ASR programming is shared with the manual transmission variants, so they would have written the code to work on either model with minimal changes. On a manual van the ABS/ESP module has no idea what gear your in, and really doesn't care, it just knows if the clutch is in or out, and how much power the engine is making.

For reference, Allrad? in germany did aftermarket T1N 4x4 conversions. On the auto trans van, the had a black box, which connected between the TCM and the rest of the van. This black box corrected any gear ratio issues, and allowed normal operation in low range. No other changes were made to the vans electronics. So I am inclined to believe they found the ABS/ESP/ASR performance acceptable with just the TCM CANbus fix.

PS: I may make it sound easy, but the information required to develop this approach took me a couple years to gather. Changing 7 bytes in a tiny Canbus frame? Pretty easy. Knowing which bytes to change? Hard.

I will reiterate a previous post of mine... Make sure you're not counting on the Arduino hardware to handle anything super important because they aren't so stable with high bus loads....at least not in a 'count on it every day, all day' sort of way like most automotive electronics these days. The off-the-shelf Arduino hardware isn't really designed for automotive environments either, you'll have to deal with that too. I was only trying to run a tach, water temp, battery voltage and oil pressure gauges with my setup in the Cummins swap van and it was temperamental to say the least.

You don't necessarily need custom tone rings either. You could make an inline device (inline with the ABS sensor...and for all intents and purposes it could be a ruggedized Arudion based piece of hardware...) that reads in X number of pulses and outputs Y pulses. There are far more examples of pulse dividers or pulse multipliers out there than there are 'usable' CAN bridges or gateways. The hardware and firmware are much simpler too. The point is, don't overcomplicate what has to be done here. The ABS module doesn't give a hoot if you have 44" boggers or tiny stock tires as long as the input to the module is within its programmed range of values.

 

[luthj]

You couldn't see me being facetious. I know it must be hard; I've watched the Sprinter forum for years as T1N 4x4 dreams have come and gone. I am rooting for you as hard as anyone...

Yeah, no worries. Its good to inform the less experienced who may come along and read this, that messing with CAN stuff is not for beginners.

I will reiterate a previous post of mine... Make sure you're not counting on the Arduino hardware to handle anything super important because they aren't so stable with high bus loads....at least not in a 'count on it every day, all day' sort of way like most automotive electronics these days. The off-the-shelf Arduino hardware isn't really designed for automotive environments either, you'll have to deal with that too. I was only trying to run a tach, water temp, battery voltage and oil pressure gauges with my setup in the Cummins swap van and it was temperamental to say the least.

You don't necessarily need custom tone rings either. You could make an inline device (inline with the ABS sensor...and for all intents and purposes it could be a ruggedized Arudion based piece of hardware...) that reads in X number of pulses and outputs Y pulses. There are far more examples of pulse dividers or pulse multipliers out there than there are 'usable' CAN bridges or gateways. The hardware and firmware are much simpler too. The point is, don't overcomplicate what has to be done here. The ABS module doesn't give a hoot if you have 44" boggers or tiny stock tires as long as the input to the module is within its programmed range of values.

I am with you 100%. Worst case I bypass the unit. The sprinters CAN is far from saturated, so I am hoping... I can also tell the arduino to ignore frames from modules I know the TCM doesn't monitor. Such as the climate control, or immobilizer. Do you know what CAN rate the ford system you were working on was? The sprinter is 500kbit I believe.

I was considering a pulse (AC signal) modification approach. I would need to modify all 4 wheel channels, which adds a bit of hardware needs. The main issue is that the ESP/stability is watching the accelerometers and wheel speeds. I just can't predict what it would do if the actual speed was 1.7x lower than the reported speed. The last thing I need is it freaking out and intervening because it thinks I am spinning out at 60mph, when I am just turning sharply at 35mph...

Although, I could use the GM tone rings, and modify there signal from 55 to 44 pulses per rev. Hmm, it may be worth it, just to avoid tone rings etc. I will ask my guy what he thinks.

 

[mgmetalworks]

All of the pertinent stuff is on the high speed bus for Ford. The Cummins ECM has only a 500k "CANC" for the vehicle interface and three J1939 for emissions and VGT. Data is coming hot and fast on a vehicle with 20+ modules. You'r lucky that early Sprinter is "less complex" than say a Raptor or even a Transit.

 

[luthj]

Going through the motions to decide on wheel sizes, max steering angle etc. With 3" of rack movement a 245/75R16 tire with 4.7" backspacing just kisses the UCA at full droop. With that offset the track width is about. 68" Turning radius (curb to curb) is about 25ft. Not bad for a vehicle with a 12ft wheelbase.



Left Lock looks pretty good.



Looks like it will accomodate up to an 8-9" wide wheel (with the same offset).

I wouldn't go as far as to call this view erotic. Maybe just stimulating in a dirt covered, windswept mounting kinda way?