Diesel Turbos

[Kenobi]

do they run more boost generally as standard?

[markey b]

compared to a petrol engine?

[Kenobi]

compared to a petrol engine?
Yes sorry thats what i meant

[markey b]

i was under the impression that most run more boost pressure than an equivalent petrol engine, due to the engine being stronger and also less powefull without the turbo

[Woznaldo]

Diesel engines have a much higher compression ratio than petrol engines and as such they don't require much boost to get a good result in power. To put things into perspective, an Espace V6 TD runs a fairly small T25 size turbo.

A more important consideration is that diesel engines run a cooler exhaust temp than an petrol engines max (300degC cooler).

Adam L would be a better person to confirm this.

[Sparkie]

306/xantia/pug/cit older turbo diesel engines run 15psi standard.

[markey b]

306/xantia/pug/cit older turbo diesel engines run 15psi standard.

thats what i had in mind when i thought of a diesel turbo, 1.9 306 d turbo and their relatively high boost

[renault5gtboi]

thats what i had in mind when i thought of a diesel turbo, 1.9 306 d turbo and their relatively high boost


we love them vnt's ehhy mark!! :smokin:

[jonnyshaw49]

if i wanted to run a bigger turbo on my mk 4 cdti astravan would there be a upgrade available???? ive had the van mapped just wondered if i could get even more power :)

[Sparkie]

decent intercooler would be of more benefit?

[jonnyshaw49]

nice1 but how do you wind up the boost coz its not adjustable actuator and i think it has to be done in the map doesnt it???

[markey b]

if i wanted to run a bigger turbo on my mk 4 cdti astravan would there be a upgrade available???? ive had the van mapped just wondered if i could get even more power :)

butane injection (same as a nitrous setup) and also water injection are supposed to be good on dirtee dervs

[Kenobi]

Ive been asked a lot of turbo D questions at work today. All of which went str8 over my head.

Why wont a normal dump valve work on a VAG deisel engine? Why does it have to have a switch to the pedal wired in?

this lads running 200 ish bhp on his 1.9 vag turbo diesel and has an upgraded turbo running 2.2 bar. Which i though was ludicrous.

[MFaulks]

... because you don't need a dump valve :)
there is no throttle plate on the majority of the systems as diesel power is fuel regulated not air (some systems do but not many).

hence, there is no manifold vacuum to activate a DV - no closed throttle plate with engine pulling vac :cool:

the solenoid is just so those people desperate for the whooossss noise can have their fix, does absolutely nothing to the performance of the car, and nor is it required :laugh:

[Sparkie]

and when the solenoid fails, you have no brakes...well done.

[MFaulks]

.. hope they're not going off the vac pump, can't believe anyone would do that...

most of the dump valve conversions people put on to get the sound still only dump turbo air flow from the inlet manifold, hence the switch off a closed throttle and a solenoid.

should be no reason to tap into the engine driven vac pump used for the brakes etc... that really would the ultimate in stupidity...

[Kenobi]

.. hope they're not going off the vac pump, can't believe anyone would do that...

most of the dump valve conversions people put on to get the sound still only dump turbo air flow from the inlet manifold, hence the switch off a closed throttle and a solenoid.

should be no reason to tap into the engine driven vac pump used for the brakes etc... that really would the ultimate in stupidity...


VAc pump? I dont even know what you guys are talking about now. I think its something to do with throttle position.

[Sparkie]

as the diesel engine doesnt have a throttle, the engine cannot suck against anything, hence no vacuum, hence no vacuum assisted brakes, unless you have a vac pump running off the engine to create a vacuum.

[djinuk]

the peugeot , cit 1.9 engines etc run 13psi standard, anything more than 18 psi on them and the charge temps start going silly due to the top mount intercooler.

[Kenobi]

My mate has a turbo from a deisel car hes about to put on a mk2 golf vr6.

Are deisel turbos useable on petrol cars? something in my mind says no. I cant think why though.

[James5]

My mate has a turbo from a deisel car hes about to put on a mk2 golf vr6.

Are deisel turbos useable on petrol cars? something in my mind says no. I cant think why though.

I don't see why not will dependant on size as a petrol engine requires a bigger turbo compared to the same size diesel engine. don't forget a vnt is a diesel turbo and works fine on a petrol car

[Sparkie]

the metals used in the various parts are different due to the increased temp of a petrol cars exhaust gas.

[Kenobi]

the metals used in the various parts are different due to the increased temp of a petrol cars exhaust gas.


Ah ha, no good then for a vr6 turbo.

[James5]

the metals used in the various parts are different due to the increased temp of a petrol cars exhaust gas.


I thought Adam L has said in the past materials used are the same for diesel snd petrol :scratch:

[michael tierney]

i remember reading about diesel tractor pulling.these guys were running 3 stage turbos and had manifold pressures of 250psi!! the pipe work was something else!:)