M52 Swapped E30 Build - SPANNER RASH

[zoona]

My 316i came with a 4.27. I would be surprised if you had a 3.46, which I think was the sporting diff.

I took a risk with my m52b28 swap and bought a 3.15 Torsen LSD because I wanted a freeway flyer. I was willing to give up some acceleration at lower speeds. I don't think I have given up very much at all. With the lightened flywheel it is very revvy and pulls strong and linear up to 6000. I don't think I would want to accelerate any faster since my shifts would be faster than the G260 is good for, and because 1st would be useless. Your mileage will certainly vary.

4000 rpm 1st:23 2nd:40 3rd:62 4th:87 5th:108. 80mph all day at 3000 rpm and 25 mpg.

Have some fun playing around with the gearing calculator. https://e30goodies.com/gearing-calculator/

This is a medium case, so definitely not original. I will wait until my chip is here, and look at the revs. But i have spun the diff/wheels and counted. It is just under 3.5. Closest ratio is 3.46.

But we are hijacking Spannerrash's thread...

[SPANNER RASH]

This is a medium case, so definitely not original. I will wait until my chip is here, and look at the revs. But i have spun the diff/wheels and counted. It is just under 3.5. Closest ratio is 3.46.

But we are hijacking Spannerrash's thread...

Medium case 3.46 sounds like a good compromise for a 24v swapped car. I think I am after a 3.64 personally as it is a weekend car. Get that 6-cyl plug swapped ASAP and it will all make more sense.

[SPANNER RASH]

Big news, the M52 E30 is now officially street-legal!

I ran out of excuses not to have another shot at the MOT, on the build up to it I installed a fresh PAS pump on the M52 engine, to remedy the horrible grinding noises the original one made, plus I played around with the headlamp aim using some shims to compensate for the stuck adjusters.

Finally, I fitted some nice coilover covers which should protect my new suspension from the elements nicely.

All said and done, the car ended up passing the MOT test, and to celebrate we took it out for its first proper rip.

And boy, does it not disappoint. This 24v swapped E30 is far more savage than I anticipated. It's very responsive, much faster than I anticipated and the M52 really does sing. It's quite remarkable how much it's exceeded my expectations.

It is however very harsh and "busy" in the handling department on our terrible UK roads zoona I now understand your complaint properly. I'm sure softer spring rates will sort this though.

It's also obnoxiously loud and people turn to look what the noise is, even when I am just cruising which is kinda awkward. Absolutely epic fun when you are giving it a thrash, but possibly a bit too much the rest of the time. I think with a few tweaks to tone some things back it will be perfect. Cheers!

[Panici]

That first proper drive feeling is always amazing! Nice work.

M52B28 feels just right in an E30. With a tune and M50 inlet you're right at 200whp which is "enough" in a car weighing ~2700lbs.
It's also not enough power that you have to get crazy with suspension and bushings to keep it under control. Can be managed with a softer and more streetable setup.

[zoona]

That first proper drive feeling is always amazing! Nice work.

M52B28 feels just right in an E30. With a tune and M50 inlet you're right at 200whp which is "enough" in a car weighing ~2700lbs.
It's also not enough power that you have to get crazy with suspension and bushings to keep it under control. Can be managed with a softer and more streetable setup.

I agree... i had all sorts of plans for increasing poswer, but as it is NA and I am used to turbo cars this just feels so much faster. It's just the right amount.

[SPANNER RASH]

That first proper drive feeling is always amazing! Nice work.

M52B28 feels just right in an E30. With a tune and M50 inlet you're right at 200whp which is "enough" in a car weighing ~2700lbs.
It's also not enough power that you have to get crazy with suspension and bushings to keep it under control. Can be managed with a softer and more streetable setup.

Couldn't agree more, I'm really pleased with the performance so far, the car really feels alive.

[SPANNER RASH]

Having put around 200 miles on the E30 so far, I can report it hasn't really skipped a beat, I've been really enjoying driving it. Don't get me wrong, there's plenty more to do on the project to make it more me. I think there are a couple of things that need toning down to be Frank, but I will go into more detail on that in the near future. I'm planning to make a video discussing how the car drives, what I like and what I don't so far, so stay tuned for that.

In the meantime, I decided to tear myself from the cockpit and take the opportunity to lock in my hard work on the underside by application of a Lanolin Oil underbody protection.

I did an awful lot of work getting the underside of the E30 to where it is, and while I'm very happy with my Dinitrol underseal, I'm still paranoid about the unrelenting march of corrosion we face here in the UK.

I opted for the great value Buzzweld Chassis Guard product over the more heavily marketed Lanoguard stuff. I imagine the products are very similar, both being Lanolin based, but Buzzweld are very well respected by car restorers and their product is a lot cheaper, so I decided to take a punt on it. So far I am extremely happy with it, it went on really easily and judging by how stubborn its been to remove from my garage floor, I would bet on it lasting a long time too.

Instead of spraying this stuff directly to rust, which is the most common usecase for it, I am using it as more of a sacrificial layer of protection to add extra resistance to the E30's underside.

I will no doubt follow up with an update about how its held up in 3-6 months time, but so far I can highly recommend it. As always, you can find links to stuff I used in the video description on YouTube.

[SPANNER RASH]

After putting a fair few miles on my M52 swapped E30, I'm ready to report back on how the car sits, how it drives, and the unexpected issues I'm facing with it.

The good news is the car has exceeded my performance expectations by quite a way. I was expecting to be disappointed with the M52 versus the S54 in my E46 M3, but the way this M52 is set up feels more like a junior S54 which is really quite well suited to the lighter E30 chassis.

However, it's not all good news. I've created an E30 which is more harsh to drive than I wanted, its loud and its too stiff. It's actually quite exhausting to drive normal. Epic when you're flat out, but the rest of the time it's quite tiring indeed.

I went out on a spirited drive to share a sense of how the car performs and the driving experience it gives, but I also give a bit of a project update, explain the problems I have with the car, and put forward some solutions.

Please do let me know if you have any ideas about the exhaust sound and resonation. The "pots and pans" map was an unexpected problem!

[jsta1109]

I spent a while undoing a lot of the more track focused mods on mine and I think I've got a fairly decent street-able setup that isn't too taxing, granted I think having the luxury of a newer vehicle will always make the E30 a bit more exhausting to drive.

Rubber mounts, Changing from poly engine and transmission mounts back to rubber was massive, it really toned down the resonance in the cabin. I run E46 M3 mounts flipped and standard trans mounts.

Suspension, the ground controls for me have been really pretty nice, I'm positive you'd be able to get the HSDs in a similar ballpark with lower rates and possibly re-valving. 440lb front (8kg) and 650lb rear (~11.6kg, just remember trailing arms have more leverage on the spring so rates need to be higher)

Exhaust, headers absolutely do make a difference in toning it down. I found I struggled with different exhaust configurations and it was only when I ditched the M52 manifolds was I happy with the end result. You may be able to add cat/s if you don't already have some and flexis as you've suggested might help a bit too. As far as mufflers are concerned I think you've already got a decent solution. You can't really fit much in the space available and aftermarket/generic mufflers that completely fill the space are pretty hard to find. You could possibly look at changing to a non-straight through muffler but I don't think this would help much with resonance, only volume.

Ditching the "pots and pans" should be really straight forward, check out https://sites.google.com/site/openms41/. If you're able to get the read and write sorted I'd be more than happy to get rid of the "pots and pans" for you.

[SPANNER RASH]

A few people have suggested about the engine mounts, I hadn't thought of that but it could well be one of the factors transmitting it into the cabin. My gearbox mounts are OE rubber though because I already knew I didn't want to hear transmission whine. :D

Thanks for sharing that info about the spring rates, currently having a hard time getting straight answers from Driftworks about what rates were sent with my kit, I think they are making some changes to their offering and it's not well recorded what they were sending out before. I will probably aim for something like you've suggested if I can find compatible springs (hopefully they can supply).

It's a bit of a shame about the exhaust because I was very happy with how it fit up, but something needs to change. I am arranging with Dan at BMConversions to get an ECU map without the burble overrun. I will be so glad to get rid of that pots and pans sound! Thanks so much for offering to help on the map side, that's extremely kind of you.

Another suggestion Dan made was the Scorpion exhaust has a tendency for the packing in the mid-box to end up ruined (funnily enough, pop and bang maps can be a cause), so I might look to see if I can get it repacked. I think you're right and the size of the boxes should be more than ample!

Cheers for your input mate.

[e30m3s54turbo]

Great project..
I watch your videos on your project. When building a car to your taste take some time.
one of my second projects I built a s38 m car to a Hartge H35-24.clone It took me some time to cater to my needs. I have owed it for 30 years. I will never change any thing on it.

Yes change your suspension on your e30.
The exhaust is a tad load for me.
Good luck on your project.
keep posting. I will be looking forward on projects.

I’m also building a other e30 turbo project.

[SPANNER RASH]

Great project..
I watch your videos on your project. When building a car to your taste take some time.
one of my second projects I built a s38 m car to a Hartge H35-24.clone It took me some time to cater to my needs. I have owed it for 30 years. I will never change any thing on it.

Yes change your suspension on your e30.
The exhaust is a tad load for me.
Good luck on your project.
keep posting. I will be looking forward on projects.

I’m also building a other e30 turbo project.

Wow sounds like an incredible car you've built. I'll check your threads out. Really glad you're enjoying my vids. More to come for sure! Cheers

[SPANNER RASH]

Following on from my video about how the M52 swap E30 drives, I set about addressing some of the problems with the car.

On the advice of many, I picked up a 3.64 differential, in medium case limited slip form. It'd been sitting around for 10 years or so removed from a 90k mile 325i sport by a breaker. Very expensive at current values, but not too bad after a haggle.

As you'll see in the vid, it was in a poor state when I got it, but once I'd cracked it open and verified that it looked good to go, I went ahead and gave it a good cosmetic refresh and threw it on the car.

While my two diffs were on the bench, I took the opportunity to share all of my knowledge about E30 differentials. Hopefully useful for anyone trying to identify an E30 diff, or avoid getting scammed over an LSD.

Before I was done with that I'd been in touch with Dan at BM Conversions again and he offered to supply me with his special sauce M52 E30 map. Convinced that the "pots and pans" pop and bang effect the car has was down to some kind of silly drift car burble tune, I snapped his arm off and sent my DME over to him.

I took the opportunity to trade a few messages with Driftworks support about the stiffness of the HSD Monopro coilovers they supplied back when I did the 5-lug swap. Unfortunately, they couldn't confirm what my current spring rates are but suggested I run them with zero pre-load.
Wanting to show willing, I went ahead and removed the 5mm preload from the front springs, just to be sure I was right in thinking that would have no effect.

When my ECU arrived back from Dan at BMConversions-UK, I went right ahead and fitted it, eager to find out if my changes had solved my issues.

I'd go as far as to say the change to the 3.64 LSD has transformed the car, it's far more natural now and cruising at sensible revs. Sure it may not accelerate quite as savagely in the lower gears, but I'd make the change again any day of the week. The diff also locks up like it should and there are no leaks or whines from it. I've been extremely lucky with this diff, just like I was with my recent E46 M3 diff swap. Lets hope that continues!

Regarding the suspension, removing the preload has definitely made a noticeable improvement, it feels less crashy on rough roads now, although still too stiff and I still have the dampers on full soft. That's to be revisited, but I will take a marginal improvement for now.

Sadly, even though Dan's ECU tune will be far superior to the previous one I had, it hasn't solved my pots and pans. I'm a bit gutted about that as I was convinced it was in the tune, but at least we can now rule it out. I suspect it's pointing to some other running issue with the car, or a physical issue with the Scorpion exhaust, quite probably the mid-box which is notorious for failing.

All in all, I am happy to be making progress on the car.

[Panici]

You've deleted the SAP pump/system and installed blockoff plates?
That's the first thing that comes to mind when you're talking about popping from the exhaust.

[SPANNER RASH]

You've deleted the SAP pump/system and installed blockoff plates?
That's the first thing that comes to mind when you're talking about popping from the exhaust.

I don't think this engine originally had the SAP, no trace of one anyway.

The exhaust noise is more like a clanging when I lift off, I thought it was all in the ECU tune, but evidently not. I think a physical change to the exhaust is the only logical next step.

Unless it's related to some kind of over-fuelling problem. Lots of checks to do now I think. I will probably start by switching the cam sensor.