Lightweight e30, have platform/engine ideas, leaning 318is/N52… talk me out of it

[varg]

RE the torsional rigidity question, still don’t understand how good this makes the E30 look (or how different the M3 is from standard E30).

Bentley Azure - 18,000 Nm/deg
Bugatti EB110 - 19,000 Nm/deg
Bugatti Veyron - 60,000 Nm/deg
Bugatti Veyron Grand Sport - 22,000 Nm/deg
BMW E30 M3 - 23,000 Nm/deg
BMW E36 Touring - 10,900 Nm/deg
BMW E36 Z3 - 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) - 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) - 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) - 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) - 12,500 Nm/deg
BMW E46 Convertible - 10,500 Nm/deg
BMW E53 X5 (2004) - 23,100 Nm/deg
BMW E90 - 22,500 Nm/deg

But are those numbers accurate/reputable? That's the real question. To me the idea that the E30 M3 chassis has better torsional rigidity than an E46 when a regular E30 is well known for being pretty bendy seems suspect. I haven't seen an M3's bare chassis compared to a non-M though so I don't know to what extent they reinforced it with extra features, seam welding, etc.

i can't believe how cheap eveything is in the states. 20k here is kind of a basic paint job with perhaps some minor bodywork. a 15k e30 would need 25k here lol.

One of my least favorite things about this forum software since the update is that it doesn't show people's location anymore until you go to the profile. Sounds like things are rough up there. Down here a good paint job seems to start at $10k USD now, which is why I'm going to learn how to paint and restore my own E30 because my experiences with body work done by others have been bad.

[digger]

to me with the budget you're going either want to start with an engine that was already fitted to the chassis or one of the cheaper swaps (well trodden and simple path where you can buy all the bits "off the shelf")

[moatilliatta]

https://store.vacmotorsports.com/vac-motorsports-billet-aluminum-wet-block-bmw-s54-p4808.aspx

Final boss.

[hoveringuy]

Coming from lots of time spent on M10s, I was also shocked by how rough the M54 headwork is.
It would take a bit of careful testing to avoid making it worse, but there's potential
to clean up flow on both intake and exhaust.

BMW likes incremental improvements, so I can't help thinking they left this in their pocket for later...

t

Except the exhaust port is also really small and there's not much room for expanding it.

[TobyB]

the M54 is still rough cast and the parting lines in the exhaust path are galling.

Coming from lots of time spent on M10s, I was also shocked by how rough the M54 headwork is.
It would take a bit of careful testing to avoid making it worse, but there's potential
to clean up flow on both intake and exhaust.

BMW likes incremental improvements, so I can't help thinking they left this in their pocket for later...

t

[OSAH racing]

Quotes from OP: I can do some of my own mechanical work (have pulled engines/trans and swapped suspensions) but don’t have a ton of time and don’t do well with electronics/computers so in general prefer OEM like kits/simplicity. Willing to spend some money to get there

Was looking to spend 10-15k to get a nice car with clean body and interior (I dislike body/interior work) and then limit a swap to $10k total (parts and labor, labor divided between myself and a shop depending on level of difficulty)

Unless I missed it have you mentioned test driving ? 25K budget. Money gets spent quickly on swaps. You should go drive 3 types of e30's that are most available and make a decision after that. The 318is will highlight handling over power and end the debate over what version of engine is best for canyon carving. Kits are available and K-power will even do your swap. The 325is m20 or an M20 stroker with suspension mods would help you in terms most easy to modify and may be enough for you. S50 swapped e30. more power and a longer engine but again a OEM type kit. If you prefer the 24 valve set up its time to get a shop quote you the N52 cost for the work your not gonna do. what every you do get a build going on the project forums and document it. There is still lots of enthusiasm for the e30.

[82eye]

Was looking to spend 10-15k to get a nice car with clean body and interior (I dislike body/interior work) and then limit a swap to $10k total (parts and labor, labor divided between myself and a shop depending on level of difficulty).

i can't believe how cheap eveything is in the states. 20k here is kind of a basic paint job with perhaps some minor bodywork. a 15k e30 would need 25k here lol.

[Maxhouse97]

Was looking to spend 10-15k to get a nice car with clean body and interior (I dislike body/interior work) and then limit a swap to $10k total (parts and labor, labor divided between myself and a shop depending on level of difficulty).

[digger]

to me the question of of the OP's budget hasn't been discussed unless i am missing something

[Maxhouse97]

RE the torsional rigidity question, still don’t understand how good this makes the E30 look (or how different the M3 is from standard E30).

Bentley Azure - 18,000 Nm/deg
Bugatti EB110 - 19,000 Nm/deg
Bugatti Veyron - 60,000 Nm/deg
Bugatti Veyron Grand Sport - 22,000 Nm/deg
BMW E30 M3 - 23,000 Nm/deg
BMW E36 Touring - 10,900 Nm/deg
BMW E36 Z3 - 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) - 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) - 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) - 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) - 12,500 Nm/deg
BMW E46 Convertible - 10,500 Nm/deg
BMW E53 X5 (2004) - 23,100 Nm/deg
BMW E90 - 22,500 Nm/deg

[hoveringuy]

S54 is effectively a pricey N52.

I've compared a lot of dyno plots between my N52 and S54's on the same dyno. The S54 isn't really stronger than my motor until 3500, the DISA intake and variable valve lift really help the low-end (yes, reduced valve lift helps low-rpm power!). The S54 has slightly higher compression, more valve lift and a little more displacement. After 3500 or so the S54 just pulls away and it's ripping by 8000, whereas the N52 is tragically hamstrung by the intake.

With the N54 intake, the N52 is quite a bit more uncorked and keeps pulling past 7500. I was seeing somewhere around 260-265whp without really optimizing the tune. N54 isn't a great intake thought, "it just fits" and is really designed for FI.

Compared to the M54 the N52 is a jewel. Hollow camshafts, CNC machined intake and exhaust tracts whereas the M54 is still rough cast and the parting lines in the exhaust path are galling.

I really wish that the M division had gotten their hands on the N52. You would have seen essentially a factory MILV kit (bumps the valve lift from 9.7mm to 11mm. There are no aftermarket cams for the N52 because you can bump the lift with a simple set of shims!) probably a little higher compression and kick-ass intakes and exhausts.

[Northern]

I think that if lightweight is objective 1, and power is objective 2, you end up at K24. The end.


If you want the I6 smoothness, torque curve, or are a purist or find the "K swap the world" trend to be boring, the N52 is it.
AFAIK there's not much aftermarket for these besides tuning.

I love the sound of a built NA M20, but I don't think it has any place in this argument, a 24v is heavy, M54 just isn't a sporty engine, S54 is effectively a pricey N52.

[TobyB]

Shame about that crank-driven oil pump that they never did again, it's the one thing the M42 has over every other BMW engine of the era.

I have also wondered what the 'problem' with the M42 oil pump was. It does increase the amount of crankshaft between #1 crank throw and the harmonic balancer,
so maybe that makes a 6 cylinder crank more fragile? It certainly adds a number of centimeters to engine length, when every mm matters on a straight six.
Lots of V8 engines use the crank mount pump, but most more- recent 4 cylinder and v6 engines
have gone to chains, or even (shudder) wet bombs, (wet belts). hmm- is it a transverse thing?

t

[Jb325is]

The other stuff is what I always come back to when the E30 318is comes up. I read articles and forum posts about my 318is, people say "it loves to rev" or "revvy 4 cylinder" and I think: have you ever actually driven one? Have you ever driven anything else with a 4 cylinder engine? It doesn't love to rev, it's out of steam soon after 6,000rpm. It doesn't love to rev, the throttle response is unremarkable with its massive flywheel. Swapping my 318is and driving back to back within a week of each other, my M20 clutch and flywheel equipped turbo M42 was no more of a rev happy little engine than my turbo M20. A K20 swap is what 318is sounds like when described by an autoblogger, "poor man's M3", except it's better than an S14 because it's lighter and makes more power at a fraction of the cost.

E30s got popular because they were cheap and an excellent platform for modding. Easy to work on, strong drivetrains with easily available parts, handsome interior, easy on the eyes, pretty light. Once they started being $10,000 cars again they lost some luster imo. They need mods; stock steering sucks, the chassis is so flexible that it makes the doors harder to close when you jack it up, it has poor traction under power if you make power, and the shifter is the worst of any sporty car I've ever driven, even rebuilt with a DSSR. I love my E30 but the car has some drawbacks, which is why I said earlier in the thread to let an E30 be an E30 and appreciate what it is.

Now get on that M54 swap since you have them.

Completely agree with these points. I have the same thoughts whenever I read BaT commentors worshipping 318is' and other stock e30's. I can't understand how someone can drive a stock e30 and then drive any nicely modified e30 and have that sentiment.

As an instructor I've gotten to ride in quite a few E36's and the way they plant the rear still amazes me, like the harder you push them the harder they stick...

but I think a lot of it is also that they can run wider tires and larger plus a more modern selection of rubber.

Their aero is markedly better.

The funny thing is, I still keep up with them on my little 225's with trailing arms; it's just not as easy. I need to use 100% of my traction budget on cornering.

Agreed. Driving an E30 fast on track is edgy, but rewarding. Can't say I've done much of the driving FAST on track thing myself but I do know what it looks like :) Hope my he doesn't mind me sharing this but this is video from Road Altanta a few weeks back- a friend of mine (also a r3v member) driving the car that I built/used to own. This car has ZERO aero, stock M54, some fancy dampers/brakes, and 235/40's 200TW tires on 17x9's

https://www.youtube.com/watch?v=jFuw7EcBoTE

[Maxhouse97]

Love the comments/thoughts … keep em coming.

On the flexible chassis comment, see the below link:

https://www.bimmerforums.com/forum/showthread.php?1786165-Torsional-Rigidity-Humor-me

If a basic E30 is so flexible, how did they make the M3 so stiff? I’ve read about the bonded windshield, and some basic braces but it doesn’t seem that substantial. Chassis stiffness is import to me, could a glue in a M3 windshield as well?

Im in Cincinnati.