Boost Gauge advice needed

[Jimmy Two-Jacks]

Hi all,

I have recently fitted an uprated intercooler and tweaked the fuel pump a little bit on my 200tdi. I would like to fit a boost gauge and wondered what would be the best one to get either Bar or PSI, electronic or mechanical as many abound on the "Bay of E"?

Just out of interest what should I expect to see as A top limit to the boost for my 200tdi to be in a safe range?

Cheers

J2J

[western]

no more than 1 bar max or 15psi,, either connect at the wastegate actutor Tee pice or drill the manifold.

[jad]

Some people boost higher than I do. Mines runs up to 1.25 Bar with no problems and apparently smokes plenty. Must get around to installing an EGT gauge! No need to drill the manifold on a disco 200. I fitted a banjo connection to bolt hole in the middle of the manifold. I have a durite one which I think may be dying at the moment.... (Needle doesn't always move smoothly) so may be best to avoid. Jad

[TheRecklessEngineer]

I gave up on all the automotive gauges. They all looked a bit 'boy racer' for my liking.

Eventually settled for a 0-2 Bar 50mm pressure gauge. Fits nicely in the clock hole with a bit of sealant.

[vulcan bomber]

Cant beat VDO for getting your monies worth.

200TDi's are set at 12 PSi from the factory and IMHO shouldnt be run above 14.5PSi/ 1 bar, reason being that the turbo is gonna create more heat and pressure but not flow anymore air (doesnt make sence does it).

Wether it reads in PSi or bar is upto you. makes no difference it just depends on if you like working in old or new money.

Personally I think your better off knowing what your turbo is doing, not the pressure in your manifold.

[rick]

Cant beat VDO for getting your monies worth.

200TDi's are set at 12 PSi from the factory and IMHO shouldnt be run above 14.5PSi/ 1 bar, reason being that the turbo is gonna create more heat and pressure but not flow anymore air (doesnt make sence does it).

Wether it reads in PSi or bar is upto you. makes no difference it just depends on if you like working in old or new money.

Personally I think your better off knowing what your turbo is doing, not the pressure in your manifold.

I've had a 50mm VDO gauge for years.

Remove the clock and it slots straight in (a little smaller than the OE size IIRC, but not an issue with an O ring behind the bezel)

I just used the 15psi one but boost to 16.5 these days, but isn't an issue, it just reads off the scale a bit.

I teed into the boost compensator connection on the turbo.

[rick]

Some people boost higher than I do. Mines runs up to 1.25 Bar with no problems and apparently smokes plenty. Must get around to installing an EGT gauge! No need to drill the manifold on a disco 200. I fitted a banjo connection to bolt hole in the middle of the manifold. I have a durite one which I think may be dying at the moment.... (Needle doesn't always move smoothly) so may be best to avoid. Jad

Apparently I don't get any smoke at revs and I can cruise past 720*C easily, and I run a 3" dump and exhaust.

I'd be installing a pyro.

I had to back mine off initially, It'd blast past 750* easily and smoke a bit.

On trips I get excellent fuel economy too.

[Ex Member]

Yes, get a pyrometer first. That is most important for not destroying your engine. A digital one with max memory and audible alarm is a good choice so that you do not need to stare at it. These guys sell on eBay UK and are cheap, http://www.auberins.com/

For a boost gauge, I like the VDO Vision 30 psi gauge. It is cheap and looks good on a Defender.

[Jimmy Two-Jacks]

Thanks all,

Do I need a pyro (I say it like I know what one is) if I have only tweeked the pump a small amount?

"I just wanted to have a little better throttle response not break a land speed record "

Thanks again, its food for thought even if I do need to WIKI Pyrometer

[vulcan bomber]

Thanks all,

Do I need a pyro (I say it like I know what one is) if I have only tweeked the pump a small amount?

"I just wanted to have a little better throttle response not break a land speed record "

Thanks again, its food for thought even if I do need to WIKI Pyrometer

Exaust temp gauge... Erm, no you dont need one actually, with a good deal of common sence and no more than a haze of black smoke at full crack your EGT's will be fine.

My 200TDi has had the pump messed with loads but sticking to the above rule i've not melted anything. I've found no where anyone give a sensable reason asto why the run at no more than 700 or 720 or 750 degrees or what ever.

[rick]

[snip]

I've found no where anyone give a sensable reason asto why the run at no more than 700 or 720 or 750 degrees or what ever.

The pro diesel tuners all give 720-750* as the safe maximum temp pre-turbo for long term durability. This includes the boys in the US playing with Cummins and Power Stroke engines, engines that are significantly stronger and run much more boost than a little Tdi.

Any more and you reduce the life of the turbine blades, exhaust valves and pistons significantly.

Pump timing is also pretty critical in this, as cylinder pressures/temps can vary significantly depending on timing and may not be reflected accurately in the pyro reading, but it's the closest thing we have to see what's going on in the chamber.

Slightly retarded pump timing will give higher EGT's as the cylinder pressures/temps are lower, (and less power and worse fuel economy, relatively speaking) more advanced timing lowers EGT's as more work is being done in the cahmber so we have higher cylinder pressures/temps which in turn gives more power/better fuel economy.

What does this mean ? In a nutshell, if your engine is tuned properly, EGT's are more critical as more advanced timing is increasing temps within the chamber.

I suppose it all comes down to how many miles you do and do you rely on your Tdi or not ?

Mines a daily driver/work vehicle and I can also be thousands of km away from home on a trip so I don't really want it to go pffft in a puff of smoke if I can help it. To me a pyro is as essential as a reliable coolant temp gauge when you start increasing the fuel.

Landys aren't overly common here either, so second hand bits aren't that easy to come by if I need a new engine.

If it was a Land Cruiser or Patrol it'd be a different story.

The other point is that the bottom end isn't really that strong, bearing size, crank, rods are little better than the original 2.5 diesel. The TD5 is much beefier/better designed to take abuse (read power)