24V AWD Swap Knowledge Base

[Nisse Järnet]

I think X5 outer wont fit E30 or E34 hub. Maybe you can pair X5 axle with E30 or E34 outer cv?
And for rack clearence im not sure X5 stuff helps cause the diff is bigger than E34 :S I have to get a X5 pan to test with!

[nando]

my point for posting this one is that the difference between the center section of the e30 axle and e46 is a whopping 3". this means that the axles are probably about 1.5" too long on each side. even with modified center section of the e34 axle, they are going to sit outboard more and will certainly need to be shortened.


i really don't understand why the oil level sensor is so important to you? e30 m3's don't even have one of those. i always check my oil every time i fill up the gas tank.

personally, i have doubts that there will be any better fit between the steering rack and front diff. we have determined that the hole goes through the pan in pretty much the same place i believe. if anything, since the diff sits further out toward the driver's side of the car, i would assume the interference to be worse, no? don't get me wrong, i would really like to see" domestic" parts that could make this happen. as you know, its a pain to get this stuff on this side of the ocean. so far, i'm not able to see the feasibility of it.

as far as ratio is concerned, what would you consider as the ideal for this project? i know we've talked about this before, but there have been a lot of revisions since then. (transmission choice for example)

s5x rwd swapped cars with a g260 generally run 3.23 as the ideal ratio. with the extra driveline drag associated with awd, 3.38 seems like a good ratio to run on the street. s54's are close to 290hp at the wheels. with the tune you are working on, probably a good deal more than that.

people commonly use 3.23 with the ZF320, not a G260. 3.38 gearing with a G260 is way too long IMO. I'd rather a 3.64 or 3.73. I don't want to go to jail for having fun in 2nd gear. It has nothing to do with power, I think the car will be fast no matter what. The S54 isn't a truck motor, it's built to rev!

As for the oil level sensor, on the E46 it also monitors temperature and on the M3 it runs the oil temp gauge. so yes, I require it to function. And I don't have an E30 M3. :p

anyway, I agree it still looks pretty difficult. The thing is I already have all of the E34 parts so I'll probably continue down that path. An alternative for me would to get a modified E46 or E53 ring and pinion to work in the E34 diff case. then I could run a 3.64 or whatever I wanted.

I'm still concerned about being able to move the engine forward enough for the trans mounts to work, clear the firewall, and be able to fit the rack in there somewhere. I can always have the oil pan modified for a level sensor hole. but everything else is basically a slam dunk..

[Nisse Järnet]

people commonly use 3.23 with the ZF320, not a G260. 3.38 gearing with a G260 is way too long IMO. I'd rather a 3.64 or 3.73. I don't want to go to jail for having fun in 2nd gear. It has nothing to do with power, I think the car will be fast no matter what. The S54 isn't a truck motor, it's built to rev!

As for the oil level sensor, on the E46 it also monitors temperature and on the M3 it runs the oil temp gauge. so yes, I require it to function. And I don't have an E30 M3. :p

anyway, I agree it still looks pretty difficult. The thing is I already have all of the E34 parts so I'll probably continue down that path. An alternative for me would to get a modified E46 or E53 ring and pinion to work in the E34 diff case. then I could run a 3.64 or whatever I wanted.

I'm still concerned about being able to move the engine forward enough for the trans mounts to work, clear the firewall, and be able to fit the rack in there somewhere. I can always have the oil pan modified for a level sensor hole. but everything else is basically a slam dunk..

From the mockup i did (not very accurate) i think this is doable with delrin mounts (or similar)

[nando]

What do you mean? There's just a bushing, not really a set of mounts. Are you using the ix mount bracket or something else?

[Nisse Järnet]

What do you mean? There's just a bushing, not really a set of mounts. Are you using the ix mount bracket or something else?

Sorry i meant the motor mounts, with hard mounts i think you can make the engine to fit because less clearence is required. Not sure about the trans mount yet, i can try it on the car this week i hope!
But the bellhousing to gearbox bushing measurment seems to be pretty much the same ZF310/320 vs. Getrag 260.

If you understand what i mean :P

[nando]

Mounts aren't the issue, its that the diff and oil pan occupy the same space as the steering rack. :(

Mount arms for the engine pretty much have to be custom fabricated..

[Nisse Järnet]

I think it can work! Ok the pan sits ON the rack there but its a little high in the rear there so with hard mounts and right angle you should be able to have like atleast 5mm between the rack/diff/pan, should be enough? :)



This is offcourse based on not using stock rubber mounts.

And i compared to my RWD M50 E30 and the pan seems to sit pretty much in the same spot and i havent touched the firewall in that car. (i didnt measure very carefully though so this could be a bit off)

Maybe im just being optimistic :D Just washed the engine compartment so now its ready for the M50 to be lowered down. Just have to clean up the M50 first... :P

[flyboyx]

I think it can work! Ok the pan sits ON the rack there but its a little high in the rear there so with hard mounts and right angle you should be able to have like atleast 5mm between the rack/diff/pan, should be enough? :)



This is offcourse based on not using stock rubber mounts.

And i compared to my RWD M50 E30 and the pan seems to sit pretty much in the same spot and i havent touched the firewall in that car. (i didnt measure very carefully though so this could be a bit off)

Maybe im just being optimistic :D Just washed the engine compartment so now its ready for the M50 to be lowered down. Just have to clean up the M50 first... :P

nice work. the engine bay looks like new. can't beat that for a northern car.

well, put it together and let us know how it goes. you really can't compare a rwd e30 to an ix because you don't have the constraint of lining up the hole for the front axles. also, the subframe sits behind the oil pan and not in front. i really hope you can make it work.

i don't know if you have time or resources, but if you could bolt up a 24v engine/trans to that pan and drop it in the bay with the axles attached, that would tell us a lot. making motor mounts wouldn't be necessary at this point if you can set the engine on blocks or a jack in the position it should sit in the car?

[nando]

I think it can work! Ok the pan sits ON the rack there but its a little high in the rear there so with hard mounts and right angle you should be able to have like atleast 5mm between the rack/diff/pan, should be enough? :)

This is offcourse based on not using stock rubber mounts.

And i compared to my RWD M50 E30 and the pan seems to sit pretty much in the same spot and i havent touched the firewall in that car. (i didnt measure very carefully though so this could be a bit off)

Maybe im just being optimistic :D Just washed the engine compartment so now its ready for the M50 to be lowered down. Just have to clean up the M50 first... :P

I think you are making the same mistake that flyboyx originally made when mocking up the E34 oil pan. if you just lay it in there it appears to fit. but what you are not seeing is the motor is now a couple inches too far back.

if you imagined the motor moved forward to where the M20 was, the diff will severely foul the steering rack. I'm not against moving the motor back a little, but look at the M20. it's already just a CM or so away from the firewall. There's not 20-50mm of room to play with unless you want to start cutting things and I learned my lesson on making permanent, non-reversible mods long ago.

with the E46 rack mocked up it was better but still a bit too far back (1/2" or so). I don't even know if I can find a combination of inner and outter tie rods to make the E46 rack work, but if I can't I'm not sure I can use the E34 pan at all. :(

however if I'm wrong I'd love to hear it! it's just that with the E34 pan as far forward as I can get it, it's on top of the steering rack and nowhere close to being forward enough for the stock ix shifter/trans mounts to work, unless it doesn't have to be as far forward as I think it does.

the one lucky thing about the ix is the rear driveshaft is telescoping and there's probably at least an inch of room so I don't think we have to worry about that too much.. :)

[Nisse Järnet]

nice work. the engine bay looks like new. can't beat that for a northern car.

well, put it together and let us know how it goes. you really can't compare a rwd e30 to an ix because you don't have the constraint of lining up the hole for the front axles. also, the subframe sits behind the oil pan and not in front. i really hope you can make it work.

i don't know if you have time or resources, but if you could bolt up a 24v engine/trans to that pan and drop it in the bay with the axles attached, that would tell us a lot. making motor mounts wouldn't be necessary at this point if you can set the engine on blocks or a jack in the position it should sit in the car?

Thanks! Im pretty happy with the result :) There is a little more to do but ill let it be for now :P Its not that fun...

Yeah i know but i just meant the oil pan to firewall distance with the pan all the way against the rack looked pretty similar as my RWD M50 E30 :)
But, tomorrow i will clean up the M50 and E34ix pan and then we will se how it really fits in there!

I think you are making the same mistake that flyboyx originally made when mocking up the E34 oil pan. if you just lay it in there it appears to fit. but what you are not seeing is the motor is now a couple inches too far back.

if you imagined the motor moved forward to where the M20 was, the diff will severely foul the steering rack. I'm not against moving the motor back a little, but look at the M20. it's already just a CM or so away from the firewall. There's not 20-50mm of room to play with unless you want to start cutting things and I learned my lesson on making permanent, non-reversible mods long ago.

with the E46 rack mocked up it was better but still a bit too far back (1/2" or so). I don't even know if I can find a combination of inner and outter tie rods to make the E46 rack work, but if I can't I'm not sure I can use the E34 pan at all. :(

however if I'm wrong I'd love to hear it! it's just that with the E34 pan as far forward as I can get it, it's on top of the steering rack and nowhere close to being forward enough for the stock ix shifter/trans mounts to work, unless it doesn't have to be as far forward as I think it does.

the one lucky thing about the ix is the rear driveshaft is telescoping and there's probably at least an inch of room so I don't think we have to worry about that too much.. :)

As i wrote above, the pan to firewall distance looks pretty much the same. But it hard to say for sure without a real measurment or test fit :)
With the pan up against the rack the diff didnt hit anything when i tried it out? (pic above) The CVs were not touching anything either.

But i will know for sure soon when i test with a complete engine :) Fingers crossed!

I measured the gearboxes with TCs today btw and they seem pretty much the same. Bellhousing to shifter, bellhousing to rear driveshaft, bellhousing to front of TC etc. So if we can get the engine in the right place everything else probably fits fine! And as you said the rear driveshaft can take a little diffrence!

[nando]

Yeah, I laid it out like that too. my original assumption was it had to go all the way up to the "bumper" on the subframe. it seemed to fit OK then. but going by Will's measurements of the oil pans (bellhousing flange to front edge of sump), I didn't have it forward enough.

does anyone have a measurement from the bellhousing face to somewhere on the subframe? I could crawl under and measure I guess but my car is like 2" off the ground. :p

[Nisse Järnet]

My car didnt have any bumper on the subframe? Maybe someone removed it earlier :)

Do you mean on a stock car? I can measure with M50 parts.

[nando]

I'd want something there, it'll keep the motor from running into your radiator :p

yeah, on the stock car. If the motor could be mounted further back than I think it needs to be that would solve some things. another way I could do it is if I had some spare ix mount arms, I could bolt them to the block and see where it needs to line up (even if it would be at the wrong angle).

[Nisse Järnet]

Ok so after todays tests with a M50 in there im 99% sure we have to do something with the firewall!
Hopefully removed insulation and brake pipe clips will do it but it might not be enough.

With the engine like 1cm more back the CVs and diff clears everything, its veeeeery close as it is!









Will do more tests tomorrow! (engine is not 100% positioned on the pics)

[The Dark Side of Will]

NICE!

That's the E34 oil pan and diff, right?
What mount arms are on that engine? It looks like you could just pop mounts into place and have the engine sit on them.

I think that the bumper will have to be removed. The front face of the sump will be EXTREMELY close to the center "tube" of the iX steering rack. Interference between the spool valve assembly on the rack and the diff can be dealt with by tilting the rack forward, as long as the engine mount arm is designed/built/modified to allow for that.

The critical dimension, as you note, is the longitudinal distance from the rear face of the cylinder head to the front face of the oil sump.

I'm not above carving lightly on the sump to put the engine far enough forward. I also think that I could build a custom crossmember that would keep the control arms in the same locations, but move the rack forward an inch. Moving the rack forward would change the ackerman (which isn't great on an iX to begin with), but would not change the bump steer.

As long as everything can be made to fit, don't waste time worrying about where the axle centerline is. The CV joints won't notice the difference.

As far as axles go, due to the different lengths, the inners are going to have to match the oil pan and diff. The differing lengths of the shaft on the right side inner joint and the constant track width of the E30 means that the same axle shafts won't work with different oil pan/diff/inner joint setups. Interesting.

I have an E46 diff and an E53 diff... I can see what's necessary to pull a side gear out of each to compare the splines.
The Quaife for a Z3 1.9 fits the front of an E53, including the axles, AIUI. It's probable that BMW uses the same side gear spline for ALL 168mm applications, front and rear.

That means that a RWD output flange may work on the left side of the front diff. Obviously a matching flange for the right side would have to be custom made... but once that was done, axles could use the RWD 86mm CV joints (at least at the inner end) and maybe be more modular.