Brakes for an S52 Swap...

[iXBeater]

I haven't been impressed at all with the (stock - Girling) brakes that came on my S52-swapped E30. I was kinda planning to slap new rotors and pads in there this Spring, but I bought some wheels from Tire Rack that are supposed to fit, but the fronts rub the damn caliper pretty close to the center:


So... I could send these back, but now I'm suspect of many of the wheels I wanted, or at least my trust in Tire Rack is a bit diminished. I'm in short-term need of more winter-compatible tires. I don't live in the Snow Belt, but the Falken Azenis tires are worn to the bar at the front and getting close to replacement-time on the back, and they are sketchy in cold w/ rain - I have zero desire to find out what they're like in any kind of snow.

I could try to save the wheels with some spacers, but I hate the idea of spacers. While I know people run bigger spacers, I don't want to be one of them past 5mm. I'll probably get the car in the air in the next day or two and mock up some 5mm spacers out of cardboard.

I've also toyed with the idea of smacking the caliper carrier a bit with a grinder. I believe it's rubbing right here:


I'm not entirely comfortable with that idea wither...

Another idea is remove these rotors/calipers and sell them. Contribute that, the $400 or so some H&R 5mm spacers and the regular pads/rotors would cost and some extra cash on top and get a Wilwood setup like this one for around $850:

https://www.silverminemotors.com/products/1982-to-1994-bmw-325i-318i-e30-front-wilwood-brake-upgrade-kit-swap-performance-non-m?

I have no clue whether the 944 brake booster has any issues with that idea...

My goals are to have brake performance that's up to the S52 in daily-driver world driven with gusto, but also up to to VIR for some enthusiastic laps or similar with credibility. I'm wrenchy enough to pull off the swap, so it's the cost of the hardware. I do not want a cray track-monster setup. I do want it to fit with my current 15" wheels (the BBS RM and hopefully the Kansei wheels).

Any suggestions/thoughts are appreciated!

[mtech325]

What size are the Kansei wheels, 15x7 or 15x8? If they're the 8 inch wide, generally you need to be around et20 for them to work on an e30 4-lug car.

What is it about the stock brakes you'd like to improve? Pedal feel & bite or just durability hard driving at the track? For a mild BBK the kit above will probably work fine (looks very similar in dimensions to Massive's 280mm sport brake kit). Wilwood pads are a bit slimmer than stock which helps with caliper clearance, but the tradeoff is they may need to be replaced a little more frequently. Another option is 5-lug but that opens another can of worms!

[iXBeater]

What size are the Kansei wheels, 15x7 or 15x8? If they're the 8 inch wide, generally you need to be around et20 for them to work on an e30 4-lug car.

They're ordered as 15x7. Kansei does make a 15x8, though Tire Rack didn't show it for an E30 (probably because they're not made in ET20).

I'll go down and eyeball them - kinda wonder if a 15x8 ET25 set got pulled by accident...

What is it about the stock brakes you'd like to improve? Pedal feel & bite or just durability hard driving at the track? For a mild BBK the kit above will probably work fine (looks very similar in dimensions to Massive's 280mm sport brake kit). Wilwood pads are a bit slimmer than stock which helps with caliper clearance, but the tradeoff is they may need to be replaced a little more frequently. Another option is 5-lug but that opens another can of worms!

Even if I had the money to devote to a 5-lug swap I wouldn't - too many other needs in front of something like that for this car.

The brakes just don't inspire confidence - my E36 M3 was so damn balanced - it always seemed that whatever speed you could generate with the motor could be scrubbed off without drama by the brakes. This car doesn't seem to have the pedal feel or raw stopping power of that car. I mean, it shouldn't - no ABS/TC, smaller tire footprint, etc., but what I'm looking for is more confidence. This little guy is way fun, and I want brakes that can tame the speed. And it seems like they'll offer more clearance for wheels (the description says some 14" wheels would work...)

[EDIT - I don't drive on the track much, so stock+ performance in that realm is just fine. I want great brakes for enthusiastic country drives, etc. that also fit the dang wheels.]

[mtech325]

Completely agree the e36 is an easier car to drive and more confidence inspiring over an e30. Have you tried any different pad options? The daily driver pads like Textar, Jurid, etc. were pretty lackluster for any sporty driving. I've used Hawk HP plus as an autocross pad before which has good bite once warmed up, but dusts like crazy and quite noisy on the street if that bothers you. Eventually I settled on PFC 08 and while a little noisy they were good on track and even worked alright on the street without too much trouble. It seems that all the cool dished vintage wheels wheels work easiest with the stock brakes (ran into the this with my 15x7.5 Ronal LS when looking for bigger brakes that would fit) and the BBK setups often require more modern wheels for additional clearance.

[iXBeater]

Completely agree the e36 is an easier car to drive and more confidence inspiring over an e30. Have you tried any different pad options? The daily driver pads like Textar, Jurid, etc. were pretty lackluster for any sporty driving. I've used Hawk HP plus as an autocross pad before which has good bite once warmed up, but dusts like crazy and quite noisy on the street if that bothers you. Eventually I settled on PFC 08 and while a little noisy they were good on track and even worked alright on the street without too much trouble. It seems that all the cool dished vintage wheels wheels work easiest with the stock brakes (ran into the this with my 15x7.5 Ronal LS when looking for bigger brakes that would fit) and the BBK setups often require more modern wheels for additional clearance.

My logic is that instead of putting money into the pads and rotors, use that money toward geiting pads/rotors and the new calipers (looks like most pad/rotor combos are somewhere between $250 and $350).

[moatilliatta]

Your pads probably are crap.

But for bigger brake kit check out Massive Brakes. Probably have to PM Lee on Facebook and let him know what you are looking for.

[iXBeater]

Your pads probably are crap.

You're probably right.

But for bigger brake kit check out Massive Brakes. Probably have to PM Lee on Facebook and let him know what you are looking for.

I don't really want "bigger" so much as "better with better wheel clearance for 15" wheels"

[Panici]

I personally wouldn't be looking at a BBK for just occasional track use with a stock S52.
Unless you're hunting for better lap times, it's just not needed IMO.

You'll be way better off with some active brake cooling and better pads.

As far as wheel spacers, just stick with a reputable brand, use hubcentric + lugcentric spacers, and appropriately extended length lug bolts. Doesn't hurt to check the torque between track sessions if you're paranoid, but I have never had one loosen up, installed dry, with new hardware.

----------------

If it's just feel you're after, it might be an issue with the booster in your setup. What are you running with the 24v swap to clear the intake manifold?

I like the E83 X3 Brake Booster paired with a manual rear bias valve in my E30.
It has a little more assist so inspires confidence, and I can modulate it well enough to get the tires howling without locking up (no ABS equipped).
Running Stoptech street performance pads just for reference; I don't know if they've changed the compound in the 10ish years since I got my set.

[iXBeater]

I personally wouldn't be looking at a BBK for just occasional track use with a stock S52.
Unless you're hunting for better lap times, it's just not needed IMO.

You'll be way better off with some active brake cooling and better pads.

As far as wheel spacers, just stick with a reputable brand, use hubcentric + lugcentric spacers, and appropriately extended length lug bolts. Doesn't hurt to check the torque between track sessions if you're paranoid, but I have never had one loosen up, installed dry, with new hardware.

If better pads and 3mm or 5mm spacer works, I'd probably live fine with that. The H&R spacers for this application seem to require that the existing hub flange still work for the wheels, which doesn't excite me. I'd definitely get longer bolts. I really (really) hate the idea of a spacer much bigger than 5mm...)

If it's just feel you're after, it might be an issue with the booster in your setup. What are you running with the 24v swap to clear the intake manifold?

I like the E83 X3 Brake Booster paired with a manual rear bias valve in my E30.
It has a little more assist so inspires confidence, and I can modulate it well enough to get the tires howling without locking up (no ABS equipped).
Running Stoptech street performance pads just for reference; I don't know if they've changed the compound in the 10ish years since I got my set.

I've got the Porsche 968 (?) brake booster folks do for an S52 swap. (I don't have ABS either)w if they've changed the compound in the 10ish years since I got my set.[/QUOTE]

[hoveringuy]

I agree with Panici on this, unless you're going to be tracking then stock brakes with grabbier pads is fine. I even tracked mine that way for several years, the real motivation for me to change to BBK was more to do with constantly changing rotors because I'd crack them so fast more than stopping power, but that's more of a track issue.

Also consider the Mk60 ABS. The stock ABS "works" but the newer system will make the existing brakes seem twice as big.

[iXBeater]

I agree with Panici on this, unless you're going to be tracking then stock brakes with grabbier pads is fine. I even tracked mine that way for several years, the real motivation for me to change to BBK was more to do with constantly changing rotors because I'd crack them so fast more than stopping power, but that's more of a track issue.

Also consider the Mk60 ABS. The stock ABS "works" but the newer system will make the existing brakes seem twice as big.

I don't have ABS on this car.

I get the idea of more aggressive pads on the stock setup, but I'm trying to solve two problems: So-so brake performance and wheel clearance. I'm suggesting that if I'm going to slap new pads/rotors on the car, I'd rather solve the clearance issues I have with the 4-pot Wilwoods (if possible).

[hoveringuy]

Is the car an Ix?

I'm not clear on how you can be having clearance issues on stock brakes, and then solve that with Wilwoods.

I can run exactly one wheel over mine

[Panici]

If better pads and 3mm or 5mm spacer works, I'd probably live fine with that. The H&R spacers for this application seem to require that the existing hub flange still work for the wheels, which doesn't excite me. I'd definitely get longer bolts. I really (really) hate the idea of a spacer much bigger than 5mm...)

If anything, I wouldn't trust the thinner spacers, because of the issue with the existing hub.
Smallest that can work with the existing hub while having their own separate lip are 10mm(?).

I have a set of 5mm spacers on the front of my E30 with an interesting taper to allow the wheels to center even though the lip of the hub is obscured.
But AFAIK they are NLA. Haven't seen the same design from another spacer manufacturer.

https://assets.ecstuning.com/product_library/1009992_x800.webp

FWIW I have 20mm spacers on the rear of my E30 with 20mm longer lug nuts and haven't had any issues.
Haven't seen any track time yet, but I plan to stretch it's legs there eventually.

Once you get to 25mm they have a separate set of lug bolts go into the hub and studs to bolt on your wheels.

[iXBeater]

If anything, I wouldn't trust the thinner spacers, because of the issue with the existing hub.
Smallest that can work with the existing hub while having their own separate lip are 10mm(?).

I have a set of 5mm spacers on the front of my E30 with an interesting taper to allow the wheels to center even though the lip of the hub is obscured.
But AFAIK they are NLA. Haven't seen the same design from another spacer manufacturer.
https://assets.ecstuning.com/product...9992_x800.webp

It seems like the H&R spacers have something like that. I'm kicking around the idea of 3mm or 5mm, but I lost comfort quickly beyond that. If they're necessary beyond that, I'm just going to send back the wheels to Tire Rack and get wheels that do work. (That's assuming the brake solution isn't going to work either, which I'm quickly losing faith in...)

FWIW I have 20mm spacers on the rear of my E30 with 20mm longer lug nuts and haven't had any issues.
Haven't seen any track time yet, but I plan to stretch it's legs there eventually.

Once you get to 25mm they have a separate set of lug bolts go into the hub and studs to bolt on your wheels.

I'm not getting anywhere close to 20mm.


All this makes me wonder if the H&R coilovers Mike installed changed the geometry here somehow. The guy I ordered with at Tire Rack immediately said no, but...

[iXBeater]

Looking at how tiny that hub is does not make me love the idea of spacers. at. all.