Mounting the engine without subframe spacers, and without tilt.

[E30SPDFRK]

FYI, it's not going to be cheap to get the pan modified. I used to work at a welding shop so mine isn't a good example, but theres a lot of stuff inside the pan that needs to be adapted to fit. It's not as easy as cutting it off and welding on a new piece. Expect it to be a couple hundered dollars at least.

[noid]

What inside the pan needs to be adapted to fit?

[E30SPDFRK]

There's the 2 stringers (for lack or a better word) running lengthwise and then the 4 mounting tower things for the windage tray. Also you need to rebuild the wall that runs widthwise and has a bend at each side.

I didn't take any really good pictures of the process, but you can kind of see what I'm talking about in this pic

[Jonsku]

I say it once again; you don't need to cut your oilpan. The engine fits fine in there without cutting..

Btw, dropping your steering rack e.g. by 2mm is piece of cake - just grind a bit away from the bottom of attaching points and put spacer to the top - voilâ! :)

[The Dark Side of Will]

I say it once again; you don't need to cut your oilpan. The engine fits fine in there without cutting..

Btw, dropping your steering rack e.g. by 2mm is piece of cake - just grind a bit away from the bottom of attaching points and put spacer to the top - voilâ! :)

This changes the bumpsteer curve of the suspension.
Have you measured your bumpsteer curve before AND after to see how you're changing it?

[noid]

I say it once again; you don't need to cut your oilpan. The engine fits fine in there without cutting..

Btw, dropping your steering rack e.g. by 2mm is piece of cake - just grind a bit away from the bottom of attaching points and put spacer to the top - voilâ! :)

In my mind a factory-esque swap doesn't play with suspension geometry, any modifications should be made to the engine instead (ie. oilpan), to attain the perfect angle. The reason we are trying to avoid using spacers isnt because of the cost, it is because we dont want to mess with the geometry. Without using spacers we get the problem of having unwanted drive train angle. Thus to fix this we notch the oil pan.

Unless you mean there are is a way to avoid spacers, and angle without notching the oil pan?

[The Dark Side of Will]

Without using spacers we get the problem of having unwanted drive train angle.

Exactly what problem is this?

[Jonsku]

Unless you mean there are is a way to avoid spacers, and angle without notching the oil pan?

This is exactly what I'm saying. With manual gearbox, you can get to an driveline angle which is very near to being zero (it does not have to be exactly zero, that's why there are all kind of "bearings" in between and actually driveline angle which is exactly zero is not good in durability point of view - there has to be some tilt. Not too much, of course).

Maybe you misunderstood my point with the steering rack. Nothing e.g. 2mm away from it has virtually no effect on the bump-steer (which you all are surprisingly afraid with, has any of you actually driven a car with e.g. 80mm drop and 20mm subframe spacers? I can tell you that in a daily driver, you don't even notice the difference).
Bump-steer is affected much more by dropping the car, 2mm drop in the rack is negligible...

[The Dark Side of Will]

Is there a thread somewhere that summarizes driveline alignment "problems" with the M60 E30?

Here's how I see things:
-There wasn't a problem with the stock driveline alignment (right?)

- The M60/310Z combo can use the SAME transmission crossmember and mounts as the Getrag 260. (This locates the trans output vertically in the same location as stock.)

- Making the driveline angle the SAME AS STOCK makes the driveline alignment the same as stock.

From eyeballing my mom's '88 325, the angle of the M20 was NOT zero. That engine definitely appears lower at the rear than the front.

In fact I've never heard of a car with a level driveline. The reason that drivelines are lower in the rear is the same reason that hypoid bevels are used instead of spiral bevels: The design keeps the driveshaft as low as practical under the floor pan.

Can we have an actual discussion of driveline alignment requirements before anyone wastes any more time trying to achieve something that is possibly counterproductive?

[E30SPDFRK]

Without spacers you can visually see that the engine is angled back farther than stock



With my 6 speed pushed as far up into the tunnel as possible with a custom mount, you can see the guibo deforming slightly from the angle. Theres no doubt at all that not spacing the subframe messes with the angle. However, even with this angle I still got 15,000 miles of extremely hard driving out of my guibo. I haven't had any drivetrain issues besides for that.

[The Dark Side of Will]

Have you or anyone else taken any measurements?

It shouldn't be hard at all to measure to the center of the crank pulley and the center of the trans output flange from fixed points on the body or crossmember to come up with an actual number for the angle difference...

Or just put a level on top of the engine...

[The Dark Side of Will]

Maybe you misunderstood my point with the steering rack. Nothing e.g. 2mm away from it has virtually no effect on the bump-steer (which you all are surprisingly afraid with, has any of you actually driven a car with e.g. 80mm drop and 20mm subframe spacers? I can tell you that in a daily driver, you don't even notice the difference).
Bump-steer is affected much more by dropping the car, 2mm drop in the rack is negligible...

I'm not "afraid" of bump steer.
Every suspension has a bump steer curve. Lowering a car doesn't change the shape of that curve, it just makes the suspension operate at a different location on it.
Moving the rack relative to the control arms changes the curve. Before I'd be willing to change the curve, I'd have to see the measurements and analysis showing that the change I'd be making would have beneficial results.
Bumpsteer adjustment is built into every racecar fielded by a professional team. However, race teams don't mess with those adjustments without measuring the bumpsteer curve.

[The Dark Side of Will]

This is exactly what I'm saying. With manual gearbox, you can get to an driveline angle which is very near to being zero (it does not have to be exactly zero, that's why there are all kind of "bearings" in between and actually driveline angle which is exactly zero is not good in durability point of view - there has to be some tilt. Not too much, of course).

Zero angle across a Guibo = good
Zero angle across U-joints = BAD.

[bmwmech1]

I think that some of you guys have been over-thinking the subframe spacer affects... Bumpsteer is changed by changing the mounted height of the rack relative to where the tie rod ends are connected to the steering knuckle, correct?
If that is correct, then the reason Jonsku is saying that there is no discernible difference in a car running spacers to one that doesn't, is because there is no difference in bumpsteer! There is a difference in roll center height, but not bumpsteer... the reason? You have not made any changes in the geometry between the mounted height of the rack and the attachment points of the tie rod ends to the knuckle. The whole assembly is being moved, or more accurately, the body is being raised, relative to the whole assembly. All of the components that could affect bumpsteer by moving them independently of each other, are all being moved together. The wishbones and the rack are both mounted to the subframe in the same relationship to each other, whether the subframe is bolted against the frame rail or bolted to a spacer which is 20mm thick. Nothing in the geometry of the rack height, to the tie rod ends, to the mounting of the wishbones, to the location of the knuckle changes, no matter where you locate the height of the subframe, relative to the frame rail... within reason. A large change in space between the frame rail and subframe will result in a change in geometry of the rear of the wishbone mount and the inner wishbone ball mount, I'll concede that.
For a track car, the roll center change, by using the spacers on the subframe is not a good thing... on a street car, not so much of a bad thing. Think about it and you'll reach the same conclusion... all things being equal, raising the body 20mm, relative to stock, by using a spacer between the subframe and the frame rail, will not change any geometry of the rack to the knuckle. It can't, they're mounted in the same plane, you've just raised the body, relative to that plane...

Garey

[E30SPDFRK]

I agree with what you're saying Garey, but you're also forgetting that the top of the strut stays with the body. So in reality, it is the same as a 20mm drop as far as the subframe is concerned. The vehicle and bottom of the struts will stay the same height while the subframe drops down.

And when people talk of bumpsteer on here, I believe they're speaking of the extra force you get acting on the tie rod after it passes horizontal rather than changing its plane relative to the control arm.