Diesel Tuning ?

Why are they different to Petrol engines, from a tuning point of view ?

More fuel in a Diesel gives more power - where does the extra air come from ? If there is none, then doesn't it run rich ?

Surely it's pointless putting induction kits and stuff on a Diesel car, cos it doesn't need any extra air ? If so, then why ?

Reply to
Nom
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Air in a diesel isnt throttled like a petrol, its all just chucked in. The turbo is basically connected straight on to the inlet manifold (sometimes via an intercooler) - if theres more air there, then more will go in. So theres often enough air going in to tweak the pump a bit and add some more fuel and get bigger bangs. So i guess that the more air you can get in there, the more you can turn the fuel pump up.

Reply to
Carl Gibbs

I find with my Xantia TD that when the air filter is dirty it loses power in the hot weather i.e. restricting air flow reduces power, so retstricting the airflow will reduce power.

If you want to tune a turbo diesel, to get more power you need to increase both the fueling and the airflow into the engine (more boost), since you can only burn fuel when you have air.

-- James

Reply to
James

Diesel engines normally run lean (no throttle) At full accelerator, they run _slightly_ rich. By tweaking the fuelling up, the engine runs less weak across the range of acclerator positions, and at full accelerator runs a richer mixture. This does give you a small increase in peak power (charge cooling?), but also higher peak cylinder temps/pressures (reduced engine life) and reduced economy.

The increase you get this way is small, and to get significantly more power you need to increase the boost, to get more air, and the fuelling to match.

Yup, completely pointless. Because of muppetry.

Reply to
Albert T Cone

When they are built they are set to run very lean to stop them smoking because it might put some people off buying them.

When tuned for maximum power output a diesel engine will smoke like hell. I personally prefer maximum power. :-) It only smokes when you put your foot to the floor anyway.

You can get a significant increase in power throughout the rev range without touching the boost. Of course increasing the boost can give even more power as long as you can keep the air cold. At least pinking isn't an issue on a diesel, so you can run a pretty high boost.

I think the idea is more to do with reducing the restriction than getting more air in. Reducing the restriction means that the engine doesn't have to fight as much to keep turning. Although it is a bit pointless when you look at the size of the pipework on a turbo. As long as the filter is clean and the air is cold it's not really worth messing with.

Shaun

Reply to
Shaun

Shaun raved thus:

:: When tuned for maximum power output a diesel engine will smoke like :: hell. I personally prefer maximum power. :-) It only smokes when you :: put your foot to the floor anyway.

Ah, that explains the smoke screen observed when the diesels are on in tractor pulling. Yes, I used to watch tractor pulling on Eurosport, but only for those multi-engined machines... And there was a guy with the first name 'Pekka'.

Reply to
¤¤¤ Abo ¤¤¤

The amount of black smoke with tractor pullers is not so much to do with burning the fuel to make the power- which it doesnt- black smoke = carbon which is incomplete combustion- its done as a charge cooling effect- as the excess fuel in the cylinders and then the little bits of carbon can absorb alot of heat, without which the engine would melt.

Some are usuing upwards of 120psi of boost from 4 turbos, no intercooler will withstand this or the air flow, so they use water injection in the manifold to keep the cylinder temps down and rely on excess fuel to keep the exhaust valves and turbos cool to stop em melting.

Tim..

Reply to
Tim (Remove NOSPAM. Registry corupted, reformated HD and l

Hi, This seems like a funky ng so I figure I'll ask.

I've an old 78 Peugot 304, front wheel drive, with a 1300 petrol engine. I want to replace it with a diesel. There was a diesel option for this car years ago, but I'm sure it was a clanker/dog. The motor on this car is weird as it has the trans bolted under the engine and share the same motor oil. The car is McPherson strut.

So, my question is can anyone recommend a newer turbo diesel engine that might fit in this car? The more recent Peugots came with front wheel drive, and nice turbo diesels, so a motor from one of these might fit...

AFAIK, if I find an engine that fits physically, and manage to mount it, the big job would be cutting/welding the new motors half-shafts to the cars existing axles. Besides a vacuum pump, anything else tha I might have to do?

Anyway, the reason for this is I have access to big amounts of veggie fuel...

regards,

nicolas boretos P.S If possible, cc any replies to my email also...

Reply to
Nicolas Boretos

how about propane (lpg) injection? gas is injected into the inlet manifold

you add it aswell as the diesel and on good turbo diesel engines you can apparently get up to 40% more power and torque

Reply to
Tim

Not too clued up on the older Peugeots, but i think this would be an XY7 or

8 engine as fitted to some early 205s.

Not sure how big the 304 engine bay is. What was the biggest engine that it came with? You might be able to get a 1.8TD in there, which are pretty cheap and easy to get hold of. I would imagine that all the engine mounts are different though, and of course it has a gearbox on the end that you wouold have to fit in. You would probably also have to change your hubs to something like a 205 version, and possibly shorten the driveshaft(s) so that they fit. So it would be quite a big job, if it even fitted in the first place. Of course theres the smaller 1.4/1.5 diesel lump, but they didnt come with a turbo, and you'd probably end up slower than with your current petrol engine.

Reply to
Carl Gibbs

The 205 was fitted with the same engine, as was the Samba, LNA and Visa, and also with the XUD so it will fit.

Reply to
yeha

in general, you don't want a nice new turbo diesel engine to use with vegetable oil. Older engines with indirect injection work better than new direct-injection engines and turbos also cause problems.

Probably not the news you want.

The favourites for use with vegetabel oil are old Mercedes taxis.

Reply to
Steve Firth

God, this takes me back a fair while. Mother used to have one of these- a 79

304 estate with the 1294cc engine in a nice metallic gold. They are *very* rare nowadays, especially the estate and 2 door coupe- your talking over £5k for a good one! A coupe in top condition is worth £10-12k!!

I'd be seriously wondering about butchering it considering the values (if its reasonable)!!

Anyways, as I'm aware this engine was only fitted to early 1.3 305 Pugs- its nothing like an XU or TU- being cast block and cast head, crossflow and OHV but with the biggest black rocker cover you've ever seen held on with 2 or 3 domed washers / nuts. Oil filler was on the rocker cover- a black plastic cap with a coarse gauze underneath. . I would imagine this engine first saw light of day in the 204 in a 1.1 guise before begin stretched to 1.3. The

1.5 engine in the 305 was something else- alloy head as I remmeber.

The plugs were tucked right at the back very hard to get at sandwiched between the rocker cover and carb, and the dizzy at the back on left side also- how on earth you'd change the points I dont know!

Must have been quite a short stroke design, as it ran like a sewing machine and revved very well- a real willing performer. Remember the gearbox being a very slick mover despite only 4 speeds. Never had to change the clutch, so don't remmeber anything about the transmission layout...

The engine bay wasnt especially big or small, but everything was packed tightly in. You may get an XUD in there, but how the gearbox would work out I havent a clue.

Hope this helps.

Tim..

Reply to
Tim (Remove NOSPAM. Registry corupted, reformated HD and l

This engine is refered to as the XL5, and you are describing it fairly accurately. The cam is actually chain driven OHC, but with rockers.

In servicing these cars, you have to get into the "designers head", as most of the procedures make sense after you do it once... The points are cool as you can adjust dwell/gap from outside of the distributor while the engine is running....

Mine also runs like a sewing machine, but does not really like to rev very well (at least as compared to Italian 4 cylinders...)

So, does the XUD series have the trans on the side, as most of the newer Peugots/most fwd cars, or on the bottom.

Some phone numbers of older Peugot shops might clarify some things for me...

sincerely,

nicolas

Reply to
Nicolas Boretos

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