Your top 5 performance mods?

[Amur73]

Hi all! Today the question is: what are your top 5 performance mods to your E21 for daily (or weekends only) driving? Would it be stiffer suspension or breaks upgrades?

Thanks and enjoy your day!

[Jeroen]

Nice initiative! Let me share my 2 cents...

1. Front strut brace. Such an easy and affordable mod, and it makes any E21 steer sharper and practically makes it insusceptible to deep tracks in the asphalt. Rear version doesn't make much difference imo.



2. Set of bigger sway bars front and rear (for example from Suspension Techniques). Reduces body roll dramatically without making the suspension any harder.



3. The usual suspension upgrades, Bilstein dampers and Eibach springs for example

4. Better brakes. Front upgrade to Wilwood, Volvo, Ireland BBK ; rear upgrade to E30 ; combined with decent pads like Ferodo DS2500
Why isn't this my Number One mod: stock E21 brakes aren't all that bad, but usually need some TLC after decades of regular service. With a full caliper overhaul, fresh brake hoses and decent pads you will already make a giant leap forward.

5. Further front suspension improvements like lower front brace (Alpina style), fresh sway bar bushings, reduce freeplay on front trailing arms

[uwbuurman]

1: bilstein-eibach setup. Not to low, not to hard, but much better than oem.
2: sportgearbox. So much fun driving in the mountains
3: pop out windows rear side. Combined with the sunroof they'll cool the car, even in hot summer conditions
4: e30 rear brake upgrade. Much better balance in the car when braking harder and more often. (See #2)
5: a blonde babe, such as my daughter. So much fun driving around with that female mini-me. Building memories.

[petroscf]

I am still struggling to keep the initially asked number of five, but if I have to do this, then I risk of no replying at all. Thus, please all excuse me, but, I will mention a bit more than just 5 mods, all top value if you ask me, as my car started from a low basis compared to other E21 models (a humble 316 pre-facelift, comparing to 320 and 323i), and I had to do a lot.
Also, for some of these mods, I have to thank Jeroen and a lot of guys in here, as if I was not a member in this forum, I would probably have never learned about existence of these mods.

So after the intro, let's go...
Not in respective order, just as they are coming to my mind:

1) Engine with Alpina specs (at least one that works, for those who know my adventure)

2) Suspension upgrades, especially the current with Bilstein B8 and Eibach springs: As uwbuurman said it: Not too low, not too stiff, certainly an upgrade.

3) Front strut combined with Alpina style stress bar (installed these two together)

4) Wilwood front calipers - yes fantastic change (although I had already upgraded for Alfa Romeo GTV calipers some years before). Here I could mention the rear Arms and discs from 323i but as the drums were already quite all right, I will leave it for now, and maybe re-mention it if I ever install the E30 325i rear calipers)

5) C/R gearbox, for sure a strong upgrade as well, makes you want to drive the car non stop!

6)Steering wheel upgrades are also a top mod, resulting in a totally different car. Both two mods here, together: The Kiley clinton quick rack combined with the EZ power steering. Although these were installed with 3 years difference in my car, I consider these as one, the quick rack makes such a difference, but then the electric column is so much needed.

And closing with 7) a lot of mods I had done in the car earlier in the years, such as the rear ARB - my car came from factory without rear one, the Recaros- that gave a totally different car as well once I drove the car one them, plus some more...

[Smartie]

1. 15 inch wheels
2. recaro seats + leather sportsteer
3. fresh shockabsorbers and springs, Bilstein/Koni and small lowered springs 50/50
4. fresh bushings preference on PU
5. fresh brakes or newer example willwood

[Mihajlo]

1. bilstein all around
2. rear sway bar
3. disc's all around
4. LSD
5. (maybe most important) hard rear subframe bushing's

hello to you all

[Wilmo]

I would say brakes on number 1. Brakes are ok, but they overheat quite soon. For the rear I have the Golf IV brakes with integrated handbrake. Second is the brake adjuster so you have always the same brake force on the rear.

Eibach/Bilstein only if you have a six cilinder. The M10 is too light so your nose is in the air.

The seats are bad. I couldn’t drive more than an hour…

For an M10, take the carb out and the ignition. It will be so much nicer.

[polov8]

I can only contribute from my personal experience of owning one E21 and it being a 1.8 M10 engined car, but it is in daily use currently, and any work on the car has been to restore it, improve its performance, or day to day usability.

1. First thing I swapped was the seats. The originals are terrible, like sitting on a tea tray on springs, and forced you to use the steering wheel to hang on to as well as just steering. Swapped out for recaros on a set of home made adaptor brackets. Relatively easy, and there's plenty of recaros from all sorts of cars all with the same bolt pattern, so you can fit a cheap set initially, and keep an eye out for ones that better match, or OEM ones (good luck!)

2, Steering wheel. The original was huge, thin rimmed, and once I'd got the seats in how I wanted them, too far away, so a smaller Momo wheel and a boss extender made the driving position absolutely spot on for my 6'2" (188cm) frame. stalks are a bit more of a stretch but no problem, and being metal I could always bend them carefully to a better shape.

3, Suspension, Making sure all the bushes are as new, I modified some Bilstein B6's to be coilovers, so i could spec my own springs (not to slam it, I drive it, and I need to negotiate speed bumps) I won't go into my specific specs, as it's personal preference, but a slow car that handles is more fun than a fast one that doesn't!

4, Brakes, I'm still running the stock rear drums for now, they're adjusted properly, and as the MOT test proved, are wrking perfectly, the handbrake is as good as any car I've owned, so they can stay for now. At the front, I upgraded from tired non vented originals, to EBC vented 323 discs and pads, with refurbished calipers with spacers to widen the them for the new discs. Replaced all the flexible hoses with Hel stainless ones, and overall I'm very happy with the brakes right now.

5, Wheels. I've from stock 5.5 x 13's with wrong sized 186/60 tyres, to 7x15 et10's with 195/50 Michelin pilot sport 3's all round, and am very happy with them. Wet grip, dry grip, noise levels, comfort, all great.

[Mihajlo]

I guess there are more than 5 favourite upgrades on e21.

[petroscf]

I guess there are more than 5 favourite upgrades on e21.

It is about our favourite car after all, isn’t it?

[Jeroen]

Love all the efforts and the variety in suggestions here, great to see people!

[Manitoba]

…
For an M10, take the carb out and the ignition. It will be so much nicer…

I’m not a technician but even I know that an M10 doesn’t run without carbs and ignition…

Just kidding…

Greetz,
Walter.

[Amur73]

Interesting is the fact that most of our favourites are to stop better or being more stable but not many people want to accelerate faster

[uwbuurman]

No that is for Tesla's. Better cornering, that is for drivers.

[BertjeConti]

Interesting is the fact that most of our favourites are to stop better or being more stable but not many people want to accelerate faster

I think most of us are very happy with the engine in their E21, well maintained these bmw engines are fun to drive.

I'm one of the few fellows here who don't own a E21, my fun to drive car is a E12. A little more weight, and two unused doors extra.

As Polov8 said, my first improvement was also a set of recaro's.
Swap the original seats for a good sporty set of recaro's, the car gives so much more feedback with the recaro's, you'll soon know what else needs to be upgraded or renewed, like all new bushings, shocks, springs and arms in the suspension setup and wider low profile tyres on bigger rims.

BMW brakes aren't bad, but to prevent overheating, replace the solid discs for vented discs. Swapping the rear drums for discs is only a upgrade if you also replace the pressure limiter for a pressure regulator.

My E12 is equiped with the M20B20 engine, engine is upgraded to the latest specs as they were in the E30 models, in fact the engine comes from a late E30 and was overhauled last year. I'm happy with the performance of this 2 Liter little 6 engine in the relative heavy E12 chassis, is't fun to drive.
Ofcourse not the fastest around, but still able to do a zero to hundred under ten seconds.

As we use our car for classic rallying, some special mods are done for that purpose alone:
Installed 4 extra driving lights (all lights are halogen, because LED is not allowed)
swapped the 55A generator for a 80A generator, so there is enough current for all the lights
placed a sump protection
Replaced the fueltank for a 90L in boot plastic tank (is this a performance upgrade? )
Replaced the exhaust end muffler for a absorbtion damper, sounds great
Did some weight reducing, like ditching the stereo, rear seat and read window drives.