Tuning Diesel Methods (How ?)& Insurance - Surrey_Scientist


Just been looking thru a Diesel Car mag and noticing the Ads for tuning diesel engines.

(A) What are insurance co. attitudes to this ? On average what is the approx increase in premium - will all Ins. co's cover a "chipped" diesel - how do they work out the increased premium - from an engineers report on the BHP increase ?

(B) What methods are used by the chipping Co's.

I see some remap the existing ECU memory , others use an exra ECU, I presume this interecepts the engine management signal and modifies it somewhat.

I know some power/torque increass are by increasing Turbo-Boost at lower revs

One Co. advertises "Upgrade does not increase turbo-boost, therefore no extra load on mechnaical components".

If it doesn't increase boost, how does it work ?

Surely if it just increases amount of fuel injected, extra boost will be needed to provide the extra air required to burn the extra fuel, otherwise the engine will surely be running rich and emissions/smoke will greatly increase.

I know some Co's claim they can modify the power characteristics depending on application eg. performance, economy or for towing, but how do theyir adjustments differ to suit each of these criteria ?

What do people reckon is the best way to go for tuning - Remap or extra ECU, and any recommendations ?

I am possibly thinking of buying a Jap diesel, either Avensis, or Accord. Generally town driving, but some , longer trips to holiday home in N. Wales, and also possily towing a large caravan maybe just onvce a year - so real mix of uses, and quite like a car that has plenty of low-down grunt and not having to work the gears !!!!
Tuning Diesel Methods (How ?)& Insurance - glowplug
Some of the 'tuning boxes' work by altering the signal from the pressure sensor fitted to the common fuel rail. I would guess this means they lie to the engine management that the fuel pressure is less than it actually is and so the ECU ups the fuel pressure which means that for a given amount of injection time more fuel is injected, and so on.

Steve.
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Xantia HDi.

Buy a Citroen and get to know the local GSF staff better...
Tuning Diesel Methods (How ?)& Insurance - Group B
(A) What are insurance co. attitudes to this ? On average
what is the approx increase in premium --


Some insurance companies will say "no chance"; others will be more sensible about it. Would advise you check with insurers first before going ahead with it. I waited until renewal time so I could change insurers as my previous one wouldn't entertain it. I've heard of premiums increasing £0 to £100+, but depends on all the usual stuff. I had to state the make and model of tuning box on the insurance forms. When getting quotes I had to state that the power increase was 25bhp.
Surely if it just increases amount of fuel injected, extra boost
will be needed to provide the extra air required to burn
the extra fuel,


Thats the explanation I heard for how some plug-in tuning boxes work, not sure whether the same method is used by companies that do ECU modification. Also for a tuning box, it was recommended to me to get a performance air filter element, as restriction in air supply can (apparently) cause overfuelling and elevated intake air temperatures.
I know some Co's claim they can modify the power characteristics
depending on application eg. performance, economy or for towing


I have a tuning box which works very well (and I got it cheap second hand). But some people say a rolling road remap is better because it can be tailored to your individual car. Some engines may have flat spots in power/ torque curves; a remap may be able to identify and sort these out, but a generic map in a tuning box will not. And AFAIK some places do a remap as cheap as the cost of a tuning box.
Tuning Diesel Methods (How ?)& Insurance - Group B
Forgot to mention, have you seen the dieselcar.com forum? There are model-specific sections and a tuning section, (warning: its a very slow site).

HTH,

Rich.
 

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