Other E21 tuners

Schnitzer BMW 323i turbo

Schnitzer used their experience gathered with their racing champion the 1978 E21 320 turbo using a 1426cc M10 engine developing 400 BHP.

They took a stock 323i M20 engine, lowered compression and fitted a KKK turbo unit set at 0.55 Bar combined with a huge intercooler. The combination of a waste gate and bypass valve helped reduce turbo lag and nervous engine response. Modifications included the intake manifold, the cylinder head and the K-Jet fuel distributor.

The important figures: max power 200 BHP @ 5.000 RPM, 272 NM @ 4.500 RPM. Top speed 225 KMH, acceleration 0-100 KMH 6.7 sec.

Further modifications to the chassis, suspension and driveline (compared to stock 323i): 25% LSD with 3.45 ratio, diff cover with big fins for extra cooling capacity and 2 mounts (quite like Alpina), uprated suspension with progressive springs and Bilstein gas pressure shocks, power steering, 93 litre long range fuel tank, 6+7Jx15” BBS alloys with 195/50 and 205/50 tires, turbo pressure gauge and 240 KMH odometer, sports seats, modified stainless exhaust system, deep front spoiler (resembling the BMW Motorsport front spoiler), trunklid spoiler, decent front and rear badging and optional Schnitzer striping all around.

Hartge

Hartge went a different way and even had a choice of 2 models. The 323i RS using the 2.3 litre K-Jet M20 power plant and the H35 335 using the 3.5 litre L-Jet M30 from the 635CSi.

323i RS: clearly based on the stock 323i Hartge modified the cylinder head, fitted a faster camshaft and a exhaust manifold and exhaust system with better flow. A trunklid spoiler, decent badging and a leather Hartge steering wheel made the car look sportier. And so did the ASS sports seats in Hartge style cloth. Handling improvements were a 25 mm lowered suspension combined with Bilstein gas pressure shocks, 15” BBS alloys with 205/50 and 225/50 tires. Optional was a set of 3 gauges including oil pressure and oil temperature to be fitted on top of the dash.

Specs: 180 BHP @ 6.200 RPM, 220 NM @ 4.300 RPM. Top speed 215 KMH, acceleration 0-100 KMH 7.5 sec.

H35 335i: this was the big step further: as said before the big 3.5 litre M30 engine and matching gearbox from the 635CSi. The engine was slightly modified as was the suspension to cope with the extra power. The rear subframe was reinforced, a 40% LSD with extra mount was fitted as well as stronger transaxles. The front brakes were uprated using 4 calliper brakes and 271 mm vented discs. Further mods (compared to 323i RS): adjustable front and rear sway bars, front strut tower brace, deep front spoiler (again similar to the BMW Motorsport example), side mirrors sprayed in paint colour. The set of 3 gauges was also standard equipment on the H35 335i.

Specs: 240 BHP @ 5.500 RPM, 320 NM @ 4.000 RPM. Top speed 240 KMH, acceleration 0-100 KMH 6.4 sec.

MK Motorsport (Autohaus Krankenberg)

MK Motorsport modified both 320 engines (m10 4 cil and M20 6 cil) as well as the 323i engine fitting faster camshafts:

BMW 320/4 MK: several setups possible using Weber carbs with engine powers 125-155 BHP.
BMW 320/6 MK: several setups possible using Weber carbs with engine powers 137-163 BHP. They even offered engine modifications to 2300 or 2500 cc with
175-200 BHP. Most common:

BMW 320 MK 60/3A: ‘affordable’ faster car with improved engine response based on 320/6 M20, faster camshaft fitted, modified intake manifold to accommodate three dual Weber IDF40 40 mm carbs. Uprated and lowered suspension and a modified exhaust system.

Specs: 148 BHP @ 6.800 RPM, 162 NM @ 6.500 RPM. Top speed 203 KMH, acceleration 0-100 KMH 8.6 sec.

BMW 323i MK 66/2: based on the 323i, reworked head and faster camshaft, uprated and lowered suspension using Bilstein shocks and MK springs, free flow exhaust manifold, 15” BBS alloys and a MK leather sports steering wheel.

Specs: 180 BHP @ 6.200 RPM, 222 NM @ 4.300 RPM. Top speed 216 KMH, acceleration 0-100 KMH 7.3 sec.

Upgrade to MK 66/3 was possible: displacement 2500 cc and 200 BHP.

MK also offered a wide range of tuning parts, engine and suspension upgrades as well as bodykits, all available separately.

US tuners
As the US only had the E21 320i, many turbo conversions were done, for example
by Callaway and Dietel. Dietel did several 6 cilinder conversions as well
including a very special project: the Dietel 345i using the E23 745i
turbocharged M30 engine. Only one car was built and it's still on the road. It
was even offered for sale recently!

Back to main BMW page