After a couple of driving school you will want more out of your BMW E34, one way to do it is to remove you all weather tires and invest in a good set or high performance tires or even track tires.

The following results are from a Dyno Test on an E34 535i with 3.73 Diff Ratio, Free Flow Exhaust, K&N Air Filter and a Jim.C. Chip.

The test results:
Maximum HP: Up to 229HP (171kW) from 208HP (155kW)
Maximum Torque: Up to 243lb/ft (332Nm) from 223lb/ft (305Nm)

*Standard Diff Ratios: Manual (3.64), Auto (3.91). ( * In the Australian Market. )
I wouldn't recommend going above the 3.73 in an E34 535i Manual.

The only other modifications you can make, that aren't completely over the top in terms of cost are Schrick Cam and Mass Airflow Sensor (MAF).

The MAF delivers 10hp to the rear wheels of a stock E28 535i. They can be purchased from either Modern Performance in West Long Branch, NJ, on (732) 222-3679 or Split Second. Modern Performance has a box that sits between the MAF and the cars wiring harness that performs the signal conversions, so it looks like a standard Airflow Meter to the Motronics. The Split Second unit is far more complex. It's electronic box mounts inside the cabin near the driver, so that the driver can alter Fuel Delivery parameters (Low, Medium, High RPM and Acceleration) on the fly. It has an Oxygen Sensor Display that also requires installation for this to work. It is a much more sophisticated unit than the Modern Performance system with increased complexity and cost... and possibly more to go wrong when the unit is a few years old.

The Schrick Cam delivers a noticeable increase in power, especially above 3000 rpm where the engine seems to come on cam. This is an improvement over the standard E34 engine which seems to come on cam at 3400 rpm. And of course, above 4000 rpm's the Cam really makes itself felt. Unfortunately, no one has been able to show me Dyno Results for an engine fitted with a Schrick Cam to quantify the power increase, but I'm told by an engine builder they typically see an extra 10hp at the rear wheels.

Power Chips: Interestingly Powerchip, APE, Bavarian (BAS), BMP and Jim.C. all claim the same sorts of power results for their engine chips. However, just about everyone will tell you a diff ratio change delivers a more noticeable result, which seems to indicate that chips really don't do very much. However, independent car magazine tests have shown a greater than 1 second 0-60 improvement for older cars such as the E28 and E34 535, whereas newer cars such as the E36 don't get as much benefit, possibly because the factory have done a better job in this area and therefore there is less room for aftermarket companies to play with. A recent chip test in European Car showed almost no difference in 0-60 times for the latest cars such as BMW E36's. Only one or two showed a very small improvement in drivability, such as when overtaking on a highway.

Whats Left: At reasonable cost, not much; a set of extractors or modification to the Automatic Transmission to a higher stall Torque Converter.

If that's not enough, and you have money to burn, then look at either an M5 Engine Conversion or Turbocharger installation, or a Turbocharged M5.

Horsepower Chart:             208HP E34   (Incl. Cam + Chip + Maf + Diff + K&N)  248HP E34

Kilowatt Chart:                   155kW E34    (Incl. Cam + Chip + Maf + Diff + K&N)  185kW E34

# Cam designates Schrick Camshaft   (see specifications below)
# BAS designates Bavarian Autosport. HP same as Powerchip
# J.C.  designates Jim Conforti / Turner Motorsport Chip
# Schrick Cam used by Alpina and Hartge
# K&N Filter adds 2kW, 5Nm
# MAF adds 9kW
# Rev Limit Stock  E28 535 6100rpm, E34 535 6300rpm
# SAE HP Figures
* Represents an estimate - figure not yet available

Schrick Camshaft  (022.01.840-04)   for  Motronic  2  (9/84-);  without fuel pump drive

  Cam Lift      Duration °CRA      Valve Timing      Valve lift
(valve lift)    Intake/Exhaust         °CRA            at TDC
  I/E [mm]       Peak Timing        IO-IC-EO-EC       I/E [mm]
 
  8.7/8.6        284/280/110        32-72-70-30       1.9/1.7
(10.9/10.8) 

Recommended Valve Springs: 1985- (056.02.062/022)

Date: Fri, 30 Jun 2000
From: "ra rabmw" <rabmw@hotmail.com>
Subject: Re: [uuc] Performance upgrades for E34 535i

Mike;
I have used the Bilstein HD/Eibach/750 combination to almost 
perfect effect in my E34 535i.  But, you and others seem to leave out the other 
nesessary part of the suspension; you also should have better swaybars to 
balance the car's upgrades properly.  I used Racing Dynamics bars, but I hear 
the UUC system is excellent.
For added performance, I had a 3.91LSD diff. from a 525iA installed  to 
replace the stock 3.45LSD, and the loss of about 2/3 mpg on the highway 
was more than justified by the drastic increase in acceleration.  It meant that 
no exhaust, intake, etc. mods were necessary for me.  Of course the chip is  there.
Since I also spent several weekends at schools, being an instructor 
after 20 some years, I upgraded brakes with race-shop gas-slotting and track 
pads for weekends, and used R.D.16x7.5" or 17" wheels with race compound 
tires.  This combination put me just a hair slower than E28 M5's, which my E28 
535i "trick" car does eat for breakfast.
For the street, I used the 16x7.5's to great effect, running 
225/50/16 BFG VR4's, and could leave the steering wheel "no hands" at 140mph 
without even a lane change by the car; it was damn near perfect.  It took 
off-ramps at 70/80mph.
The combination of Eibach's, and the wheel/tire combination 
lowered the car 2"+,but only 1.2" was suspension, and it took any kind of 
rough road with ease.  And I still had 80% of a nice, normal, comfortable road 
ride.  The 17" R.D.'s looked awesome on the street, but I liked the ride of the 
16" wheels/tires better, they got me many compliments, and could corner with 
"M" cars.
This should definitely give you some food for thought.  If you want 
the 3.91, I know where they hide.
See the UUC guys for exhaust, and check out both Dennis Kirban's 
intake (Bavauto has 'em among others), and Jim C's design.  They're about the 
best I've found.  Have fun!