Subframe spacers?

[BimmerScreamer]

Is anyone using them? Would it be a safety concern?

[bmwmech1]

front or rear?

[BimmerScreamer]

front

[bmwmech1]

I machined a set for my M3 project... the car's not finished yet, but I can't see where there would be any safety concerns. I milled mine from 20mm T6061 aluminum and turned the locating pins from steel. Longer metric hardware and it all bolts together as if they were not even there...

Garey

[BruceBe]

I machined a set for my M3 project... the car's not finished yet, but I can't see where there would be any safety concerns. I milled mine from 20mm T6061 aluminum and turned the locating pins from steel. Longer metric hardware and it all bolts together as if they were not even there...

Garey

I agree with Garey - not a significant safety concern, as long as the spacers are made of sufficiently hard material, have a generous surface area, and the fasteners are correctly sized.

For the track, I didn't want to raise the relative height of the body with spacers, and then have to chase the resulting changes in roll axis, rake, CGH, etc. However, there is no free lunch, since I am now in the process of solving steering shaft clearance issues with the X5 exhaust manifold. If the manifold was about 20mm higher, everything would be OK. My hood clearance is also tighter, as a result of not using a subframe spacer.

-Bruce

[BimmerScreamer]

i assembled my car yesturday with the spacers and the motor is so far down and back I think I will leave them in.

[BruceBe]

i assembled my car yesturday with the spacers and the motor is so far down and back I think I will leave them in.

Because the body of the car was raised by the spacer thickness.

[bmwmech1]

Because the body of the car was raised by the spacer thickness.

When I mocked everything up last fall, I hadn't made the spacers yet, so I curious to see how they affect everything...

Garey

[E30SPDFRK]

They arent needed, the motor fits fine without them.

[bmwmech1]

They arent needed, the motor fits fine without them.

True, it does, but it helps lessen the pinion angle and the added space doesn't hurt under hood. I've already mocked up everything last fall when I made the engine mounts. I made the spacers a few months ago, but have not put the motor back in the car yet to see what difference the spacers make. We'll see...

Garey

[E30SPDFRK]

It also decreases ground clearance in comparison to the body, increases bumpsteer, and makes the steering rack harder to connect. The pinion angle doesn't matter, the driveshaft and guibo still work fine even with the increased angle. Pretty much the only benifit is being able to use the e34 coolant bottle on the firewall.

[bmwmech1]

It also decreases ground clearance in comparison to the body, increases bumpsteer, and makes the steering rack harder to connect. The pinion angle doesn't matter, the driveshaft and guibo still work fine even with the increased angle. Pretty much the only benifit is being able to use the e34 coolant bottle on the firewall.

I don't know how thick of a spacer you're imagining, but the ones I milled are only 20mm thick... bump steer is minimally affected, pinion angle does matter if you like doing things the right way and ground clearance is minimally affected, unless you're already in the weeds. The benefits are better exhaust/firewall/tunnel clearance on the passenger side manifold, better hood clearance, more strut tower to top of engine clearance for a straight tower bar and the ability to use the correct coolant reservoir in the designed location. So there are a few more benefits than just the coolant reservoir. Plus it's his car... if he wants to run the spacers, who are we to say no, right?

Garey

[Paukert11]

I put my m60 in with out spacers. i didnt have a problem...... but then i took the motor out because i wanted to do some more work on the motor. hehehehe

[bmwmech1]

I put my m60 in with out spacers. i didnt have a problem...... but then i took the motor out because i wanted to do some more work on the motor. hehehehe

I agree with spdfrk, that it can most definitely be done without them. Since my build is basically from the ground up and I have the resources to make them, I milled some and I'll use them, unless I come up with a reason not to. Like I said previously, we'll see...

What kind of "more work on the motor. hehehehe"?

Garey

[E30SPDFRK]

I'm not telling him to not use spacers, I'm just making the point that if you don't need them, why add them? The exhaust is a pain in the ass either way, there is only one strut tower brace that fits with the spacers, but you can make your own that fits without them (you have to make half the swap anyways, why not). And you say bumpsteer is minimally affected, but you think that 20mm down 4' in front of the pinion is important? It comes out to like 1 or 2 degrees, which you can almost make up by mounting the transmission as high as it will go. 20mm down suspension-wise is almost the same as a 1" drop, which is quite a bit if you already have a reasonable sized drop and WILL increase bumpsteer.

Once again, I'm not saying DO THIS ONLY, I'm just stating facts about the other way to do it. I'm of the "if its not broke, dont fix it" mindset, and while the spacers may be the best way to do it, there is nothing wrong with not using them.

The one problem I have had is it wears the guibo slightly quicker. But, I have 20,000 miles on my swap and it's just starting to crack, so I can deal with it. That's 20k of abuse too.