Thread: Turbo boost

Adam
My Disco 200TDI tops out at 12 PSI and 625deg C on the EGT going up Kalamunda road hill. Its still at the factory settings. Just starts to lose speed on the steepest part in fourth gear.
I plan to tweek the boost up to 14 PSI which should bring the EGT down, then I'll crank the injection pump up to peak the EGT at 700 deg C.

I measure the boost from the plug on the intake plenum and the EGT probe in just before the turbo.

With your turbo lag get the main muffler removed. It made a notable difference to mine. Midland Exhaust did mine for $65.
No noticable increase in noise from the inside.
Regards
Graham

simple note.....

increasing your boost to 17psi wont do squat...... well you wont feel it...

the easiest way is to Tweek the pump...

I boosted my old fender and it did nothing.. not even the EGT came up...
So then i tweeked the pump, thats the ticket tubby

Then i tried it boosted and pump tweeked.... no difference...

So just tweek the pump like every other fast Fender has happened....

Even Rover will tell you a boost increase wont do anything to the 300 or 200... well 2 or 3psi wont... 20 might..

Perhaps no noticeable difference to normal driving yes, however it depends what your chasing...

Even a 2psi boost increase does make a difference if your towing a heavy load up a long hill or into a head wind.

More boost gives more charge in each cylinder and as long as there is time to burn it all then it translates to more torque. If there is not enough time then EGT will be seen to rise and the timing should be retarded a bit.

Fuel pump mods are limited by how conscientious you are about smoke emissions.

Originally Posted by Taz

Perhaps no noticeable difference to normal driving yes, however it depends what your chasing...

Even a 2psi boost increase does make a difference if your towing a heavy load up a long hill or into a head wind.

More boost gives more charge in each cylinder and as long as there is time to burn it all then it translates to more torque. If there is not enough time then EGT will be seen to rise and the timing should be retarded a bit.

Fuel pump mods are limited by how conscientious you are about smoke emissions.

Where do you get these figures from?????
ive tried it on 2 rovers and it does not do SQUAT. i also contacted some guys in the know about it ages ago and they said the same thing... Dont bother.... just fuel it up.. its not a Petrol engine and it does not behave the same.

Taz, retard the timing if you see an increase in EGT ?

Someone correct me if I'm off base here, but when you increase the fuelling in a diesel you are increasing the duration of the fuel delivery stroke at the pump and therefore prolonging the time of fuel delivery after TDC, increasing the chances of an incomplete burn and increasing EGT's.

I always thought that you had to advance the pump timing to begin the fuel delivery earlier so that injection didn't occur too far after TDC ?

Anyway, upping the fuelling works a treat and automatically upped my boost at the same time to approx 16.5psi from 15.5psi stock.

BTW, I don't have a tacho, but I'm guessing 80km/h is approx 2000RPM in 4th gear with my 33" tyres and I have full boost well below that level up a hill, full noise.
IIRC boost doesn't start to drop away till the revs get below 60km/h in 4th, but I can't remember exactly 'cause I've already gone down a gear well before then anyway. EGT's dictate that more revs = better efficiency (lower EGT's) e.g. 4th instead of 5th @ 100km/h up a hill = lower EGT's.

Originally Posted by rick130

BTW, I don't have a tacho, but I'm guessing 80km/h is approx 2000RPM in 4th gear with my 33" tyres and I have full boost well below that level up a hill, full noise.
IIRC boost doesn't start to drop away till the revs get below 60km/h in 4th, but I can't remember exactly 'cause I've already gone down a gear well before then anyway. EGT's dictate that more revs = better efficiency (lower EGT's) e.g. 4th instead of 5th @ 100km/h up a hill = lower EGT's.

While lower gears give you lower EGT's, you're pumping more exhaust at that lower temp. Your average diesel is most efficient at close to full throttle at around the peak torque rpms.

You can find BSFC maps for some diesels online which show efficiency islands based on speed and load. But I haven't found one for a landrover engine yet.

When you blokes talk about tweaking the pump,is that the stop screw or timing?.If it is the stop screw how many turns did you do,1 or 1 1/2?. Pat