[Project] 205 Dimma S16 Turbo Converting To 4X4

[lybker 26 2 Cars]

As I am struggeling to ensure sufficient grip for my 205 S16 turbo, my devious plan is to convert it to 4x4 using PSA components only. So in short the details are:

 

reinforced 4x4 drivedrain: strnger rivets and splines in the center gearbox and stronger flanges for the centershaft.

 

I will modify a BE3/6 gearbox and add the centerdiff to this housing - enabling 6 speed and higher rear ratio.

 

should be fun :-)

 

anyway please find a couple of Pictures to get it all started :-)

Edited February 14, 2016 by lybker

[lybker 26 2 Cars]

The plan is to modify a 306 rear axle (to ensure correct Width of track)

 

To make it Work, I will modify the rear arms to house the rear hub. this will be done by merging the citroen bx rear arms with the 306 ones (cut & weld)

Hope to embed camber and toe adjustability while I am at it.

 

naturally the rear frame will be reinforced to take the extra load of the rear diff housing & all the forces added from the rear drivetrain.

 

[allye 530 3 Cars]

Very interesting and what seems to be a good solution. Fuel tank in the car?

[lybker 26 2 Cars]

After a torough clean, I took the center gearbox apart for reinforcement. I plan to remove the mechanical diff lock as it likely will explode if I would ever use it :-)

 

the 2 splined axles will be reinforced,. Not sure yet what would be the best way to go, so I will have to give it some thought. Even it might be the perfect solution, i cannot affort to Shell the 2500€uro for a reinforced set from adt.....

 

Also the spotwelded studs will be removed and replaced by stronger grooved ones fully welded.

 

Then the flanges for the driveshaft needs to be upgrade, cant belive how small they are as standard (from the citroen bx 1,9)

 

The rear differential does not seem to have the option of differential lock - I will not miss it, just strikes me as odd - was thinking all bx/405´s was equipped with this feature?

 

Finally the be3/6 housing needs some modification to make it bolt onto the center gearbox. will drill and cut threading for the missing bolts & machine the bearing sleeve in the housing bigger to match the larger center bearing supporting the splined axle.

I will stick to the original gti 6 gearing for the final drive.

Edited February 14, 2016 by lybker

[lybker 26 2 Cars]

Hybrid rear axle & drivetrain:

Started to evaluate how to modify the rear axle. Basicly merging a 306 beam with a bx 4x4 drivetrain and mounts. Finally moving in the mounting points from the 306 axle to fit onto my 205 chassis.

 

choice might seam odd, but as I have no spare 309 or even 205 rear axle - thats how it is going to be :-)

 

I will be cutting the mounting points on the axle for the main brackets to move them inwards by 2x 30mm allways strengthening the weld afterwards. Then the fork connection from the bx rear beam will be cut and modded to fit these 2 main brackets ensuring a good bolt on solution for the rear drivetrain. main tube will be cut and flattened where the drivetrainpasses underneath and i will add a fastening bracketdirectly to the tube

 

Finally i will cut off the driveshaft hub on the bx suspension arm and join it onto the 306 supension arm for the rear hub to bolt onto

 

 

gearbox trial fit:

having a spare engine block and sump from a gti6 i did a trial test finding out mainly thesump needs modification to ensure sufficient clearance for the center gearbox - seems pretty straight forward luckily....

Edited February 16, 2016 by lybker

[opticaltrigger 52]

Great project. I love it.

Please keep the updates coming.

 

All the best

O.T.

[lybker 26 2 Cars]

slowly started to modify the rear beam:

 

first shortned the main tube from the 306 so its mounting points will fit the 205 and made the offset to allow clearance for the rear diff. the shortneded rear axle will now fit torsion and arb from a Peugeot parner - sowill fit the 22,5mm bar´s I found new at ebay for only 60£ a set :-)

 

Also the first trailing arm is now welded and ready for trial fitment before refurbishment can start. benefit is the hub Mount will allow for camber and toe adjustment. so in case I dont get the alignment done 100% I will be able to compensate when the car is tracked in

 

[Putte205 4]

Looks like s solid weld, but is it safe to cut and weld the cast suspension arm like that?

[lybker 26 2 Cars]

both arms done. Will manufacture a bracket to keep the rear arms in place. When welding the arms, i preheated the cast iron. and as carbon content is ok - it is possible to weld them just fine. Will think about adding sheetmetal on top for safety though.

 

I did a welding fixture to ensure angles and dimensions are as original 306 arms.

Edited February 18, 2016 by lybker

[lybker 26 2 Cars]

rear beam is nearing point before shotblasting and painting - I am happy how it turns out :-)

 

 

remaing to do the 2x2 front mounting points - but really either needto take my current 205 beam of to meassure it up or hope some friendly soul would post me the dimensions in the other thread i posted on this subject....

 

[lemmingzappa 75 1 Cars]

[lybker 26 2 Cars]

Finalized the frontmounts of the rear beam, allowing for the first trial mount to asses how much i need to modify the fueltank to ensure clearance.

 

As I am on a budget i need to perform some shortcuts to keep cost reasonable. Hence my plan is to mark the contact points between rear diff and the fuel tank. Remove the tank, emty it (clearly :-) heat it up till the plastic gets soft and then push it inwards, creating a driveshaft tunnel.

 

judging by the first trial fitment, i would like to lift up the center diff by roughly 30mm to improve ground clearance and straighten up the driveshafts when the car is at the correct rideheight.

 

Does anyone have a Picture of the rear diffs correct angle (from the side) for me to evaluate how much I need to modify?

 

 

[lybker 26 2 Cars]

current angle of the rear diff, noting the front section will come up by another 10-20mm once it does not hit the fueltank anymore:

Edited February 24, 2016 by lybker

[lybker 26 2 Cars]

Fueltank was interfering with the main shaft, so after removal I could get a better idea of how much would need to be changed. After a torough clean, i used a torch to heat up the polyethylene plastic untill it turned soft, and carefully reshaped the tank. Took a bit of trials to get right, but basicly I did not have to push it up further than standard - just widen the existing tunnel for the exhaust.

trial fitted it all, and found a small lump needed to be pushed in, but else it seems fine.

 

 

[lybker 26 2 Cars]

Now the rear beam is located correctly i still need to evaluate if the diff needs relocation upwards.

[Anthony 1,002]

Looks like you're making excellent progress on this!

 

Out of interest, where is the exhaust going to go now that the propshaft is running along the route the exhaust used to take?

 

The car looks to be sitting quite low in the pictures and doesn't look like there's going to be enough ground clearance to run it underneath the fuel tank and diff hangers?

[lybker 26 2 Cars]

True - seems the rear diff sits rather low, so will have to elevate the ca maybe 15-20 mm. The exhaust will have to keep to the left of the tunnel even it currently sits to the right. Also the gearlinkage needs to be lifted upwards to it clears the center chaft.

 

Mainly doing trial fitment and brackets ect.....will dismantle, shotblast and paint all parts, however that is still a long way out. Biggest hurdle cirrently it the very good and very expensive adtperformance upgrade parts for the center differential :-(

[imaS 0]

 

The rear differential does not seem to have the option of differential lock - I will not miss it, just strikes me as odd - was thinking all bx/405´s was equipped with this feature?

405 Mi16x4, 405 T16 and BX 4x4 do not have a 100% lockable rear differential. These models utilize torsen rear differential as standard. Push button lockable differentials were only in 405 GRx4 and probably in SRx4 too.

So did you break a 405 or a BX? I might be interested in some of the parts if the shell is still lying around.

[lybker 26 2 Cars]

Bx, and all that is worth a bit is the rear brake calibers, as i cut the rear beam and axles for parts. I worry this does however not hold torsion diff at the rear, so might be looking to upgrade the rear diff at some point

[lybker 26 2 Cars]

small update - no Pictures. raised the rear diff by 60mm for much better ground clearance and improved driveshafts angles. Drawback is the diff is now tilted at 10 degrees - hence i need a propshaft with CV joint at the rear, instead of the original U joints to ensure it does not take itself apart.

I solved this by sourcing a complete propshaft from a BMW e39 - including the flexdisc and flanges - hence all the weakpoints on this part is removed :-)

 

will take some Pictures there of when i recieve it in 2 weeks

[lybker 26 2 Cars]

Finalized welding the rear frame, and fairly happy with the result. Lifted the rear differential up by 60 mm resulting in a much improved ground clearance, and with some luck I can keep my diffuser.

 

I redid the front Mount for the differential - by increasing the cut out in the rear crossbeam and removing the original alu mounting bracket from the diff, meant I could move the front part up. Thereby realigning the input flange to the propshaft horizontally, meaning oil-level in the diff will be ok and strain on the joints in the propshaft will be reduced.

 

Next up is shotblasting and painting. Brake caliber mounts and fitting.

 

This project does include alot of trial and error, but hey - it is the endresult that counts, right?! :-)

[lybker 26 2 Cars]

small Progress update:

 

Re-threaded the ARB to M12, as the plan is it will ensuring the rear arms are fastened to the main beam sufficiently, given the new forces the rear understructure will have to absorb from the AWD.

 

shotblasted and painted the rear beam and accessories, hoping for final assembly this week. Still a lot of to-do´s like propshaft, center diff, modification of the be3/6 gearbox to modify it to 4x4....and choose to cut the fueltank in ½ - to fit the rearmufflerin its oldlocation, so i can keep the diffusor.

[welshpug 1,655]

how are you going to stop the trailing arms moving side to side?

 

arb will not do this, merely stop them falling off.

[B1ack_Mi16 67]

Will they not be held by the torsion bars anyway?

[lybker 26 2 Cars]

Basic build up of the rear frame is loosely based on the Dangel 4x4 309 rear frame layout. In principle the 405 T16 rear beam is not much different: the trailing arms is rotating around 2 main bearings - and the distance between the 2, determines the ability to absorb energy in all other directions than the intended rotation - forces moving the arms linear out / inwards as you describe are rather small, but none the less the trailing arms needs to be forced tight towards the main beam using a flat bearing as contact surface between the 3. This the new M12 bolts in the ARB will do just fine - they will ensure the sufficient torque is there, and will be kept this way using locktite. of course the arb is a bit shorter and will not hit the bottom of the end plates, else this would not work :-)