Tuning Your TD
1 and Phase 2 pre '99 Turbo Diesel 306 came with two different types of
fuel pump, the Lucas Pump or Bosch Pump, and two different types of Turbo,
the KKK turbo and the Garret T2 Turbo. With a couple of simple modifications
to these components, the power of a standard Dturbo could be raised from
92bhp to around 115bhp. Many companies will charge stupid amounts of money
for these modifications, when it is very simple to do yourself.
given here is designed mainly to help those with a Lucas Pump and Garret
turbo on their Phase 1 306. There are however various references to
the Bosch Fuel pump, but the pictures used are from my own Peugeot 306,
which as you may have guessed, has a Lucas Pump and a Garret turbo.
This is just a guide, if you don't agree with a certain method, then
do it another way, this is simply what I did to alter my settings.
|Boost compensator Fuelling|
|The procedure to increase the boost compensator fuelling is similar on both the Lucas and Bosch pumps. The boost compensator unit can be recognised by a brass coloured diaphragm assembly connected to the intercooler by a vacuum hose.|
The Red Arrow points at the Vacuum hose, which you can see connecting to the Intercooler. This then leads down to where the Blue Arrow is pointing which is the Brass coloured diaphragm Assembly.
A closer look at this assembly shows that there is a cap covering the Lock Nut and the Adjustment Screw. This is a warranty seal style idea, and needs to be broken off in order to access the Screw.
|Unscrew the external 14mm lock nut and turn the adjuster anti-clockwise. The adjustment range is about 1.5 to 2.5 turns (adjustment can be made in half turns). The setting is not so critical; running the car rich from the compensator does not make a great performance difference.|
|Maximum Fuel Settings|
|A large plastic plug is found on the front of the pump.|
This must be unscrewed in order to access the maximum fuel screw. In order to unscrew this plug you will need a Large flat headed screwdriver. Press the screwdriver hard into the plug to make indents, this is then the leverage to unscrew the plug. As soon as the plug is removed the pump will empty its contents of diesel, so you should put a plastic bag over the alternator to protect it. Using a small mirror look inside the pump and you may see a hole with a recessed socket head bolt. I think it's about a 5mm size Allen key. If this can not be seen put the engine in gear and slowly push the car backward.
|You will see a cylinder assembly rotate in the pump. It will need to rotate about 180 degrees to reveal the maximum fuel screw. The screw will need to be turned clockwise. To access the screw you will need to insert the long part of the Allen key. Do not use a ball type driver, as the ball may break-off in the pump. The screw to quite tight and so a spanner will need to be used on the end of the key. The range of adjustment is a relative 20 to 40 degrees (40 degrees is rich, make adjustments in about 10 degree increments). Replace the plug; prime the pump and test drive. Look for evidence of smoke off-boost. Repeat the procedure until the desired performance, smoke level and economy compromise is reached.|
|With the Bosch Pump the procedure is much easier. The maximum fuel screw is located on the top right side of the pump. It will have a tamper proof fitting on it, which will need to be removed. This screw is adjusted clockwise up to about 90 degrees (again use about 10 to 20 degree increments).|
|Turbo Pressure Increase|
is rough guide for those with a Garret T2 turbo
The wastegate arm is accessible from underneath the car. Positioning yourself with your legs pointing out from underneath the front bumper, you should be able to spot the wastegate arm as seen in the picture below:
|The Blue Arrow points to the Wastegate arm. Notice that there appears to be two sections of the arm. A rod (rusty looking bar) and then a sleeve over it. The sleeve is actually threaded, and must be screwed onto the bar - this effectively making the arm shorter. In order to screw this sleeve further onto the bar, the arm must be released from the other section (the flat plate). This is done by removing the spring clip, as pointed to by the Red Arrow - try not to lose it, you'll need it later! The Wastegate arm can then slide off, and the flat plate can be moved out of the way:|
= The Flat Plate
Blue Arrow = Wastegate Arm
now should be able to turn the Wastegate arm (sleeve part) shortening
the arm, in relation to the flat plate. On my car every full turn was
1psi higher, this may not be the case for all cars, and therefore I would
not recommend measuring your pressure by the method.
The KKK turbo has a small lock nut on the end of the turbo, the actuator is all enclosed. But you can sort of make it out, its on the drivers side. Unlock the 8mm nut and tighten the small allen screw, I think its 3mm, try 2 turns at first.
order to see what pressure your turbo is actually running at, you will
need a pressure gauge. This is easy to temporarily set up, simply while
you are measuring the adjustments made above.
The pressure gauge can be connected up along the Vacuum hose indicated when we looked at adjusting the Boost compensator Fuelling.
Red Arrow = This is where a T-Piece must be inserted for the Pressure Gauge. Another long piece of tube must be connected onto the T-Piece which will connect up to the Pressure Gauge, the gauge will be read while driving and therefore the tube used here will need to be long enough to reach inside the car. The tube should be able to handle the pressures being dealt with here, and so can be fed through the door seal without being crushed.
Green Arrow = Using another piece of tube, this is where the third end of the T-Piece should connect up to. This is the original connection used by the Vacuum Hose on the intercooler.
Blue Arrow = A nice pressure gauge
standard the pressure being produced should be around 1 bar = 14.7psi
I have increased the pressure on my turbo to 18psi at peak. The peak pressure
the turbo will produce should be when it is under full load, so when testing
the pressure of your turbo, find a straight road, preferably a dual carriageway
or motorway, and slip it into 5th, foot right down, around 3000rpm the
max pressure will be produced.
The performance gains above 15 PSI boost diminish quite quickly as the charge temperature raises rapidly. However, if the car produces less than 15PSI boost the increase in boost to standard will yield a relatively higher gain in performance than above. I would not recommend raising the boost above say 18 PSI (peak boost) unless uprated intercooling was used. Remember, the boost pressures and fuelling are not independent on a diesel engine. The waste gate is a final mechanical pressure blow-off, if the fuelling is the limiting factor, additional boost will not be gained. Hence, when tuning the car check the boost as the fuel increments are made.
used here originated from the Peugeot Sport Club website, I have expanded
on it, using knowledge from my own experience. If you have any more information
to add, please email it to me: Shilakadaddy@hotmail.com I would like to
include pictures and instructions for the KKK Turbo and Bosch Fuel Pump
in order to create a complete guide for all 306 TD owners
Brought to you courtesy of Shilakadaddy : Peugeot GTi Autosport Club