Diesel tune and dyno

Try here.

i was hopeing to get a reply form the great minds of exploroz instead of going to that other forum..

Why not do it yourself? If you fit an EGT (Exhaust Gas Temperature) gauge, you'll be able to monitor it at all times when the engine is working hard (not just on the day it's on the dyno, which might be cool and humid - very different to pulling a heavy camper-trailer up a long slope in 40+ degrees) - and use it to optimise the fuelling to your satisfaction.

[Yes, I do sell them but I honestly believe every modified turbo-diesel (i.e. aftermarket turbos or 'tuned' factory turbos) should have one. Otherwise you have no way of knowing how close to the limits your engine is working. If you don't like mine, buy another brand - but do get one.]

Out of curiosity, did your kit come with instructions on setting boost level, adjusting fuelling, timing changes etc.? I suppose your 4-Runner will have the original non-compensated pump so, if it has not been adjusted at all from standard, your gains so far will be solely from the improved 'breathing' as no additional fuel is being injected at any rpm. If this is the case your probably quite safe, EGT-wise, as the extra air charge should actually lower the maximum EGT at full load.

To get extra performance you must now add extra fuel to the extra air to achieve the optimum power output without excessive EGT or producing smoke. With injection pumps without a manifold pressure compensator, this will always be a compromise but quite safe, acceptable results can be achieved. The only adjustment available on the pump is the maximum delivery screw and locknut. This should be adjusted with care, in small increments, and only while monitoring EGT at full load.

This is basically all a 'Dyno tune' is - using a rolling road to load the engine and check maximum EGT between adjustments. You can do it yourself (albeit a lot slower) with a suitable 'test hill' (somewhere you can maintain full throttle at, say 2500-3000 rpm, for a minute or so, preferably in 3rd or 4th - and within the speed limit!). After each adjustment, take a run up the test hill, looking for signs of black smoke and/or excessive EGT (typically up to 720 C upstream of the turbo or up to 530 C downstream).

Before any 'tuning' you'll need to make sure all normal maintenance is done - valve clearances correct, injection timing correct (either factory standard or as advised by the turbo kit maker (if specified), and a temporary boost gauge to check that the wastegate is correctly set would be handy too. [Once set, wastegates (and hence boost levels) rarely change, so a permanent boost gauge is of limited value. They really only tell you whether the wastegate is working or not. And it not, it's probably been damaged by excessive EGT!]

Hope this helps,
Ian

I support Ians response in the main.

Unless you inject more fuel, the installation of a turbo is not likely to show more than minimal power gains. To inject more fuel adjustments will be required to the injection pump or/and injectors. You should strongly consider the boost compensator to keep the amount of fuel injected to a level related to level of boost (othrrwise you risk overfueling & consequence damage)

A decent exhaust system is a pre-requisite to turbo installation (if you have not already done so). You would be looking at a 2.5" to 2.75" system for the 2.4 litre 2L engine. the 3L, 5L or 5L-E engine would have been a better starting point.

A pyro (EGT gauge) is high on the list of tools for tuning the engine. A dyno is not required (unless there are prior known power levels for that particularl engine/turbo combination) if you can find a long steady hill. The one on the hwy just west of Bachuss Marsh is ideal.

A boost gauage can aide in fuel economy, if you keep the boost level low while driving. The slightest adjustment of the accelerator can make several PSI (and hence consumption) difference.

Dave
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