Sander's 6.0 V12 745 project

[Sander]

Finally had time to work on it again. Subframe with diff is on the car now. Pleasant surprise of the day, all the mounting points for the various multilink components are on the chassis and threaded from the factory. They are just plugged up with some plastic plugs. No spacers needed anymore in the back now too, with the mk2 hubs in there. Had these wheels mounted before with 32mm spacers. Nothing needed now for them to fit.

This pic is just as a mockup. Cleaned and repainted everything now before bolting these on the car.



All the old bits that came off (will all be for sale soon):



All 3 types of fuel tank side by side, the 60L live axle one, 80L 960II (multilink mk2) and the 960I (multilink mk1) tank



The panhard support needs to go for it to fit, on both sides of the car. Driver's side will hit the subframe and on the passenger side the exhaust won't fit otherwise.













Had to cut out some parts of the spare wheel well. With the Volvo diff this is not necessary, but the E36 diff sticks out the back quite far with the mounting points.



Everything bolted on (minus the big trailing arms) just to see how it looks.









Bit of camber (can still be adjusted a bit):

[Harlard]

Hey that's cool

[Sander]

Small update: finished up the metalwork on the spare wheel well. Decided to just make a space for the diff mounts along the entire width of the spare wheel well. There is more than enough space now for the diff and the hand brake cables.

[Funkee]

Really nice work Sander! Curious to seeing and hearing everything work

[Sander]

Originally Posted by Funkee

Really nice work Sander! Curious to seeing and hearing everything work

Thanks! Me too Won't be anytime soon though, still a lot to do. Had no time at all to do anything the last few weeks. Finally had some time again today, so started on mounting the (80L) multilink fuel tank and see what's needed to fit it. The hard fuel line from the tank to the fuel pump/filter won't fit so that needs to be replaced by either one from a multilink car or just make something new from scratch. Also the lines from the filler tube to the tank are different. The tank straps themselves are the same, just the part that connects them together and to the car is different. Need to find one of those too... 1 small issue to fix next is the diff flange rubbing the fuel tank shield where the driveshaft goes through the fuel tank. This is because the BMW diff is much longer than the Volvo one and pushes the flange further forward about 5cm compared to the Volvo diff. Need to mod the shield thingy and reshape the tank a bit with a heat gun, shouldn't be a problem.

Here you see why you need the tank as well from the multilink car. It's a pretty tight fit.





Rear springs showed up too, I'm using a set of Eibach 5" outer diameter conventional rear springs. 450lbs/in, 11" long, should end up lowering the car by about 40mm I think. To be continued. 450 might seem a bit stiff, but the springs are mounted in front of the axle instead of behind it as with the live axle cars, so they need to be. The stock spring is very soft (so also rather long) as it was from a nivomat car.

[Råda]

This project is so awesome

[okoye]

Question can't the axles from a BMW e30 be used with the stock Volvo irs diff?

[FreeEMSFred]

Originally Posted by Sander

All 3 types of fuel tank side by side, the 60L live axle one, 80L 960II (multilink mk2) and the 960I (multilink mk1) tank

https://i.imgur.com/xZRgcXH.jpg

I object! There's at least one more type 70l live axle 940 tank - I have one, but haven't seen it out of the car. Thanks for the pic of the other two, though, I hadn't seen them before :-)

[Sander]

Originally Posted by okoye

Question can't the axles from a BMW e30 be used with the stock Volvo irs diff?

No that won't work. BMW uses 2 different flanges, only the large case diff cars like the M5 and V12 powered cars have the big flanges which are the same as the Volvo flange. The E30 uses the other smaller type of flange, so the E30 axles don´t bolt up to the Volvo diff. Also the wheel side of the axle is different. The Volvo axles have the splined part that goes through the wheel hub integrated in the axle, where the BMW uses another flange there that bolts the axle to the part with the splines/wheel hub. Why would you want to use E30 axles?

Originally Posted by Råda

This project is so awesome

Thanks!

Originally Posted by FreeEMSFred

I object! There's at least one more type 70l live axle 940 tank - I have one, but haven't seen it out of the car. Thanks for the pic of the other two, though, I hadn't seen them before :-)

Ah thanks, never saw one. What cars had those? I also vaguely remember there being an extra fuel tank option for the 760.

[FreeEMSFred]

Are you saying my 95 750i diff has Volvo 760 compatible flanges? If so, I might have to keep it for a rainy day

[okoye]

Originally Posted by Sander

No that won't work. BMW uses 2 different flanges, only the large case diff cars like the M5 and V12 powered cars have the big flanges which are the same as the Volvo flange. The E30 uses the other smaller type of flange, so the E30 axles don´t bolt up to the Volvo diff. Also the wheel side of the axle is different. The Volvo axles have the splined part that goes through the wheel hub integrated in the axle, where the BMW uses another flange there that bolts the axle to the part with the splines/wheel hub. Why would you want to use E30 axles?



Thanks!



Ah thanks, never saw one. What cars had those? I also vaguely remember there being an extra fuel tank option for the 760.

Someone mentioned the BMW axles and I wasn't sure what model

[Sander]

Originally Posted by FreeEMSFred

Are you saying my 95 750i diff has Volvo 760 compatible flanges? If so, I might have to keep it for a rainy day

It does indeed. The Volvo axles bolt right on and it has the exact same width as the Volvo diff. It is also bomb proof, can handle upwards of 1000Nm.

[Sander]

Been busy with small stuff that needed to be done before I can mount the rest of the suspension. Tank is finally in, had to buy a lot of parts that I didn’t have to mount it and the fuel lines etc as it’s all different. Fuel lines are still giving me a headache though. I'm using a hard line from a multilink car from the tank to the pump, but for the return line I'll probably use flexible one. Almost everything was still available at Volvo and quite reasonably priced too. One thing they didn’t have is the front bracket that holds the tank to the chassis. The lip bit on which the tank sits is longer on the multilink one, so I modded the stock one. Also modified the brake lines to fit with the brackets for the multilink axle as they are different too. The Eibach springs fit perfectly too, might need to shorten them a bit to get the right ride height though. Will have to see that once it’s back on its wheels again. I’m still looking for a set of broken nivomats so I can use the lower mounting point that bolts it to the trailing arm. I was planning on just pressing that in the Koni shocks and calling it a day. Anyone here has a set? This swap does involve a huge amount of tiny bits and pieces that are all different. If someone is planning on doing it, best would be to get a donor car. Anyway, pics:

[arsenix]

Amazing project! Not sure how I missed this so far. I am working on a turbo V8 swap into my 740SE and still debating what to do in the rear end to handle the power. I'm also thinking about swapping in the IRS with an alternate diff.

Why did you go with the Mk1 vs Mk2 IRS? The coil spring is a little easier to lower, but it looks a fair bit heavier?

[Sander]

O

Originally Posted by arsenix

Amazing project! Not sure how I missed this so far. I am working on a turbo V8 swap into my 740SE and still debating what to do in the rear end to handle the power. I'm also thinking about swapping in the IRS with an alternate diff.

Why did you go with the Mk1 vs Mk2 IRS? The coil spring is a little easier to lower, but it looks a fair bit heavier?

Thanks! I'm using the MK1 because it has a steel subframe which is much more mod friendly. I'm using a bmw diff because it comes in the weird ratio I needed to work properly with the mercedes trans gear ratios, has a factory LSD, can handle all the power I can throw at it and best of all, the Volvo axles bolt right on and it's the same width as the Volvo diff. The problem is that the mounting points are wildly different from the Volvo diff so the stock subframe needs to be modified like what I did. That is of course not impossible on the MK2 aluminium subframe, but it's much easier on the MK1. I think weight wise it doesn't matter much what you choose. The empty steel subframe is really not that heavy (maybe 10kg). By far the heaviest part is the diff. I think the MK1 setup would be maybe 10kg heavier (if not less. Taking the transverse leaf spring, mounting stuff for that and the big cast steel lower arms into account, it might not even be lighter at all), but it's all sprung weight. Also, as you mentioned, lowering is much easier. No transverse leaf spring or coilovers attached with a bolt/stud in single shear. Good luck with your build!

[adamdrives]

Impressive work, following this thread is like seeing a fantasy come to life, you make it look easy

[kampman]

Nice work!

[Groth]

This build i F**** cool! great job and looking forward for updates (check this every day)

[Sander]

Thanks for the kind words everyone!

Had some time to work on it again today. Still needed to make a lower mount for the Koni shocks. Unfortunately I didn't have the old nivomats anymore to take the lower mounting point from and press them in the Koni bushings, so I had to make them myself. First pressed the bushing out of the Koni's, then put the bushing over the new part and put them back in. I had to botch together a funnel kind of thing to get the rubbers back in the koni's again, but it worked (not fully pressed in in the picture, forgot to take a pic of the end result). Forgot to post this last time, the difference between the fuel line connecting the filler neck to the tank.

[arsenix]

Originally Posted by Sander

O
Thanks! I'm using the MK1 because it has a steel subframe which is much more mod friendly. I'm using a bmw diff because it comes in the weird ratio I needed to work properly with the mercedes trans gear ratios, has a factory LSD, can handle all the power I can throw at it and best of all, the Volvo axles bolt right on and it's the same width as the Volvo diff. The problem is that the mounting points are wildly different from the Volvo diff so the stock subframe needs to be modified like what I did. That is of course not impossible on the MK2 aluminium subframe, but it's much easier on the MK1. I think weight wise it doesn't matter much what you choose. The empty steel subframe is really not that heavy (maybe 10kg). By far the heaviest part is the diff. I think the MK1 setup would be maybe 10kg heavier (if not less. Taking the transverse leaf spring, mounting stuff for that and the big cast steel lower arms into account, it might not even be lighter at all), but it's all sprung weight. Also, as you mentioned, lowering is much easier. No transverse leaf spring or coilovers attached with a bolt/stud in single shear. Good luck with your build!

Ah! Nice to hear that the weight isn't that different. Good point about the easier modding. My aluminum welding isn't the greatest too I didn't realize the lower arm on the mk2 was steel. That does look quite heavy.

I am looking at using the aluminum 8.8 explorer diff, although the bolt in axles makes the BMW diff attractive. From my internet research I think the aluminum 8.8 diff is about 70lbs vs about 110 lbs for the BMW diff, which is a pretty sizable difference.

PS: Maybe I will go to the J/Y and do a weight breakdown on all the piece parts.

[Sander]

Finished up the other side shock mount and put everything together. Next up, figuring out the handbrake setup. The S60R brake rotors have a bigger diameter drum part for the handbrake, so I'm modifying a pair of S60 brake shoes by welding in part of the multilink brake shoes. To not burn up the brake lining I had to weld a part, cool it again, weld, cool etc. Also keeping the brake lining wet. Worked great. It fits too, still need to make a spacer kind of thing that pushes them further outwards, as the S60R rotors have the drum part further out. Before I can finish that and a new brake shield, I need to design the adapters for the S60R calipers. I could finally lower it onto it's wheels again to check the ride height with the Eibach universal springs, it's pretty much spot on. Maybe 1cm higher than I'd like, but it still has a completely empty fuel tank, no drive shafts, exhaust system and 100A heavy ass battery in the back, so I'll leave it for now. No idea how much the springs will settle in either after driving it for a bit, if it settles at all. The springs I'm using are Eibach Conventional Rear springs, 1100.500.0450 (11" open lenght, 5" outer diameter like the stock springs and 450 lbs/in). Anyway, pictures:

Originally Posted by arsenix

Ah! Nice to hear that the weight isn't that different. Good point about the easier modding. My aluminum welding isn't the greatest too I didn't realize the lower arm on the mk2 was steel. That does look quite heavy.

I am looking at using the aluminum 8.8 explorer diff, although the bolt in axles makes the BMW diff attractive. From my internet research I think the aluminum 8.8 diff is about 70lbs vs about 110 lbs for the BMW diff, which is a pretty sizable difference.

PS: Maybe I will go to the J/Y and do a weight breakdown on all the piece parts.

Should be interesting to see the weight difference between the 2 versions. I doubt it'll be much though. Both multilink versions will add some weight compared to the live axle, but unsprung weight is greatly reduced.

[Sander]

Finishing up the design for the rear brake adapters and finished the front now too so I can have it all laser cut in 1 go. The adapters mount on the inside on the face where the stock caliper mounts too. The rings are just for spacing to measure how thick the spacer needs to be that goes there. Front 350mm rotor on a 960II hub (will be using 960II wishbones and hubs with 850 coilovers in the front):

[FreeEMSFred]

Consider getting it cut out of a single thicker piece and machined down to suit in a step-wise fashion so it's stronger.

[Sander]

Originally Posted by FreeEMSFred

Consider getting it cut out of a single thicker piece and machined down to suit in a step-wise fashion so it's stronger.

That'll be the next one, machined out of a single piece of aluminium. This one I'll be welding together, should be plenty strong though.

[Funkee]

Nice progress, love the ingenuity with the rear drum pads.
It'll prolly come down a little more than just 1 cm with fluids, battery and some break in of the springs and shocks.