406oc.co.uk

I'm looking at what I can do with my HDi engine, and the thought has occurred that possibly the intercooler fitted to the 110 HP engines could be fitted to my 90.

Is this possible using standard parts, eg the large pipe that runs between the battery and engine, the intercooler itself etc? the intercoolers are going for about £20 on ebay, so this could be a cheap upgrade, that offers a few more HP's

Or could this end up with a world of hurt like many of my bright ideas?

Also does anyone know if the injectors are the same on 110/90 HP engines? on early VW TDi's, the 110 injectors would fit into the 90, and give a ready power boost, as the size of nozzle was a bit bigger

Are there any other differences between the 110 and 90 engines?

not a expert but if you fit bigger injectores dont you have to remap the ecu ?otherwise it will just deliver the same amount of fuel as before so you wont get any benefits

If you added bigger injectors, you'd need to inject more fuel otherwise your fuel will be injected over larger surface areas thus reducing the pressure as it enters the cylinders thus reducing atomisation and swirl thus reducing efficient mixing of fuel and air thus reducing combustion efficiency and thus reducing power. Crikey!

As for the intercooler, whack her in there and see what happens.

The common rail TDi's first used by VW (pre PD system) had a system to keep the emissions down, by where they had a surpluss of air in the intake, so the diesel would burn more thouroughly. As the fuel is supplied at a set system pressure, if you make the injector nozzle a size or two larger you'll get more fuel in the engine, and consequently a bigger bang. This didn't upset the mixture, as the extra diesel was detonating and burning up the extra air

The main differences between the 110 and 90 TDi's were: the 110 had an intercooler, larger injectors, the turbo had a variable inlet veins to give more grunt. Most of the major stuff like the injection pump was the same parts.

Basicly it was a case of swapping standard parts, and upping your power, theres a fair bit about it on the net. The increase is well within the ECU's capabilities to handle.

As for re-mapping well thats only needed if you start getting special or comparatively massive nozzles fitted, to stop the over injection.

I cant see why the 110 intercooler wont fit on the 90, might involve changing the inlet manifold on the engine aswell as all the extra intercooler pipework though, which is down the back of the engine and peugeot/citroen like to tilt the engine backwards.

Im sure you can do it with standard parts but dont think that means its going to be really easy

Will be a good upgrade though

I beleve that the injectors are the same.

The 90 has a mechanically operated wastegate on the turbo, on the 110 it is controlled by the ECU. The 90 runs 14 psi from the turbo, I don't know what the 110 produces.

The inlet manifolds are the same. There is a different plastic "subframe" which attaches the radiator, and air con if fitted, to the front panel. On the 110 it also holds the intercooler.

You will need the pipework from air filter to turbo, from turbo to intercooler and from intercooler to inlet. In addition to the intercooler and mounting panel.

I have the intercooler and mounting panel and plan to fit it to my Berlingo together with an intake temperature gauge to measure what's happening. Depending on the results from this I will then look at increasing boost pressure if necessary. It's a bit fiddly on mine because it was never fitted wit the I/C as standard, but on a 406 it should be quite strightforward as it came from the factory with this on.

If you are looking at injectors you should also be looking at fuel pumps. I see you are also on TDOCUK.COM and would advise you have a search on there, It is full of info on the HDi and getting the most you can from it

Col

Sorry guys, but I can't see any point changing the intercooler.

If you want an increase in BHP, the most straightforward thing to do is a remap.

As for common rail VW diesel engines, VW were always against them and never produced them until 2007, according to them, common rail is now the best thing since sliced bread.

Jasper,

Fully agree that the remap is the best result - if you can get one. The Siemens system in mine is notoriously reluctant to be altered. All the remap companies I have contacted have either said "sorry - can't help" or haven't bothered replying.

The point of the intercooler for me is to lower the intake temp (obviously!) and thus deliver denser charge, from there an increase in boost, together with a cheap "tuning box" to increase the fuelling should produce a bit more torque for me. Unfortunately for me, I only found out about the shortcomings of the Siemens sytem after I'd bought the car.

Ah right! I didn't know the Siemens system was difficult to remap.

I think you would need a fairly large intercooler to make a whole lot of difference, but I've never tried.

jasper5 wrote:Sorry guys, but I can't see any point changing the intercooler.

If you want an increase in BHP, the most straightforward thing to do is a remap.

As for common rail VW diesel engines, VW were always against them and never produced them until 2007, according to them, common rail is now the best thing since sliced bread.

Its not changing the intercooler though

the 90 has no intercooler

so its making it actually have one

Still wouldn't make much difference to the BHP, a lot of work for small gain.

cant really rempa it and turn up the turbo without it though to be honest

I don't have an intercooler at the moment, its a 90, and the parts are cheap on ebay, so I was wondering about this. Looking in the engine bay theres the two holes and rubber mounts for the bottom end of the intercooler already there. But the space it would inhabit is blanked by a plastic sheet to stop the airflow.

Looks like if i can get the bits from a scrapper cheap enough (the pipes, the intercooler and mounts etc) it could be an easy mod for the future. The main reason would be to get a sound basis to up the power gradually, combined with a de-cat, K&N, and a tuning box (got a seimens ECU )

jasper5 wrote:Still wouldn't make much difference to the BHP, a lot of work for small gain.

The installation of an I/C on it's own won't make much difference - probably not even noticable. But it is necessary if you wish to carry out further modifications.

The standard I/C is rather on the small side granted, but this disadvantage is balanced by the fact it was designed to fit there and the car was designed to have this particular one fitted. Thus to retro fit the 110 I/C into the 90 is relatively easy just getting all the bits and putting them where they "belong". The idea of fitting a larger/better I/C brings a whole new set of problems. Hence I'm happy to accept the compromise of the smaller standard one for the sake of a simple task

Col

Adding an intercooler to a 90 will do nothing, except create turbo lag.

On the 110 the intercooler is there to keep a lid on intake temps, in fact you do not want lower than expected intake temps on a diesel engine as it will cool the burn, reduce efficiency and create smoke.

These things are carefully designed on engine test beds and things like exhaust gas temps, smoke etc are all carefully tuned to create an efficient, smoke free, and reliable package.

The way to make a diesel engine more powerfull is too inject more fuel, that's it, but then keep things stable with an intercooler so the engine does not suffer peaks and troughs of performance.

To keep things simple the 110 burns more fuel than the 90 whilst accelerating, makes the turbo and compressed air side hotter than the 90 and therefore needs cooling before it goes back into the engine. The 90 does not need any of this because it runs 'cooler' all the way through.

Having said all this it appears the 90 does respond well to remapping and can achieve 120 bhp without any further modification but remember everything is under more stress and you should let the turbo wind-down properly after a fast run to help the bearings etc...