FriarTook

I see that a few people on here pay £££££££££££'s to have their ECU's Re-Mapped.

Sometimes it's because it is an Import and needs to run on Uk Fuel, sometimes it is to take account of modifications.

But, sometimes it is simply done to attempt to release extra power.

In this latter case there must be some kind of trade-off ..... or Subaru would do the same to sell a more powerful car - but they don't, why?

Does Re-Mapping make the car less reliable?

Does it result in poorer fuel consumption?

Does it damage the engine?

Does it result in an engine rebuild sooner than would normally be expected?

There is no such thing as a free lunch, so - what is the trade-off?

Terminator X

iTrader: (7)

It's not free, it's £500

TX.

bioforger

iTrader: (1)

Nope. However if your clutch is worn it will probably need replacing as well.

No, it can in alot of cases actually improve consumption.

Nope

No, not unless your running crazy supporting mods, and then ragging it to death.

Probably coz it isn't free, remap alone is at least £500. Then add cost of supporting mods to make any gains after the remap. This is typically a decat and performance/panel filter. So total mods for a base upgrade you are looking at nearly a grand.

Do it, I did last year, just a decat and tek3 remap and now running 265bhp and 272lb/ft of torque and haven't regretted a single moment. The increase in torque is the main factor here, it transforms the car.

rigga

iTrader: (4)

Its all good.........

FriarTook

Where did I say FREE UnckleBuck?

Free lunch was in relation to the trade-off .... not the cost of the re-map.

dpb

About a 6/7 new boys sucked into your thread psLewis

Sonic'

Subaru don't map the cars more than they do, because not all engines are identical, so therefore they have to find a common map that promotes reliabilty, emissions and fuel consumption (and probably more) but which results in a compromise

The PPP ECU was a step up from the std ECU with improved performance but still a trade off against the things listed above, and was/is supported by Subaru and Warranties

People pay 500 + for remaps as they are tailored for their specific engine and any supported mods (decat, bigger injectors etc) however they are unsupported by Subaru and void any Warranty the car may or may not have

Since I added a PPP and full decat my fuel consumption was better but my emmisions worse

But didn't you know all this anyway

Engine rebuilds and reliability are mainly down to unsympathetic driving style no matter if the car is modded or not

scooby-tc

iTrader: (2)

downside is you wallet is lighter other than that its all good.One day i'll get my car mapped for UK fuel when funds allow

FriarTook

Subaru would, if there was no downsides, push out 300BHP instead of 215BHP - wouldn't they?

After all, they have some of the smartest car minds in the business - they could do what any mapper could do, why don't they? There must be a trade off somewhere?

Is it a warranty worry? More cars will require work under warranty by running higher BHP?

easyscoob

i love remaps, especially from a certain mr forrest i gather your a nooby and if you are i would think of it this way:- subaru can sell lots of cars at say 15grand at say 220bhp that will return them profit. you could buy that car and get remap and a few extra bits to take it to a reliable 300-320bhp but it will cost an extra couple grand, why would subaru want to do that when they can make more money or sell it on as an sti or wr1 etc. anyhow ive had too much to drink remaps are good, Andy forrest is a god. NUFF SAID

FriarTook

It only costs extra because you are changing something which is already there!

Subaru spend £££££$$$$$$ Millions developing their maps and ECUs etc. - there is NO extra cost to deliver 300BHP instead of 215BHP.

There is a reason and I think that reason is the loss of reliability.

gpssti4

iTrader: (6)

Remap for fuel or power????

Imports may require a remap for UK fuel so should make them more reliable.

Remapping after mods may increase reliability, but also makes the most of the mods. Naturally, if the engine is producing more power then the engine will wear faster.

Shark Man

Not per say. But if its used to increase BHP by a large margin, yes.

Both: It can optimise fueling to get the most out of the engine BUT it can also allow more boost. Therefore more power and more fuel needed.

If its incorrect or to close to the limits without enough safety margin with regaurd to fuekling and ignition, then yes it can.

Also bear in mind: MORE POWER = MORE ENGINE WEAR. Get two identical engines used in identical conditions: one mapped for 320bhp (with supporting intercooler, injector and turbo mods) the other for 250bhp. Take a guess on which usually last longer?

As above. Arguably if you potter about like a sunday driver 99% of the time on a 400bhp car and rag a 250bhp car 99% of the time, it could be the reverse. But that is a rare exception.

[/quote]

Exactly. Alot of people think they can. But it is a trade off. With the exception of correcting optimising intial fueling and ignition and retaining similar BHP one can get better economy and no harm reliability, and gain 10 to 20 horses as a bonus. But if the mapping is used to increase boost pressure and is aimed at pushing the BHP envelope, then sadly there are trade offs.

FriarTook

Good post Shark Man, in a nutshell then - the trade off is generally a less reliable engine.

Conversley, if it is done on an Import to run UK fuel then it may make it more reliable.

Varboy

Disadvantage - It's a slippery slope as you may begin to crave more and more power. Each time you satisfy this lust, you increase the addiction.

Eventually you will end up with an empty bank account and a pile of molten engine bits.

There is an element of sense here. Decide what you want power wise, then go get it.

amahrap

The answer is no there is no trade off.

Car manufacturers don't spend millions developing the best car they can, they spend millions building the best that they can manufacturer in the quickest time, for the lowest cost and the best average reliability.

A production line knocking out engines all day will produce a product that conforms to an acceptable tolerance band. The OEM map will take this into account so perform well enough across this range without overstressing the lower range of the quality band but not taking any advantage of those at the upper end of the band. The OEM base map may also contain restrictions to enable the passing of Govt measures for fuel consumption and emission which may manifest themselves in overall sub-optimal engine loading and performance.

A custom map on a standard car therefore seeks only to optimise the way the ECU controls the engine and in doing so may well also improve fuel consumption. For example the base map on some Subaru’s over fuels slightly as a crude method of cylinder cooling and in doing so could cause deposits to form or promote wear in the cylinder bores so it could be argued that a custom map to control/optimise this would actually increase overall reliability. The custom map seeks only to take account of all the variables of engine production and ancillary component fit as presented by the specific vehicle being worked on rather than the one size fits all average of the OEM map.

Of course you are correct that reliability and fuel consumption may be affected by modifications, but this is more a factor of the extra loading on the engine as a whole rather than the fault of the map. However, a highly modified unmapped car would drive like a pig and the reliability would be atrocious.

Prasius

iTrader: (1)

It's all about production tolerances. A generic ECU map has to be conservative enough to not cause any issues when applied to a number of engines that are spread over a tolerance band. A custom ECU map doesn't have to be that conservative because it is only applied to one engine with known characteristics.

Amahrap - have to say this sounds like a Pete-type thread, but as he is an Engineer I would expect him to know all about production tolerances *ahem*

T5OLF

iTrader: (4)

It seems you know all the answers to the questions your asking
you also call TX Unclebuck...I smell a rat....Pete?

New_scooby_04

iTrader: (4)

Subaru produce a car that develops a comfortable power output for a given specification with a nice wide safety margin. Up the specification (as they do with the STi) and you can up the power output without undue concern. Unfortunately, this also means a hike in price (as with the STi). It's the same with modding and mapping: do the right mods, get it mapped correctly and you can up the power without signficant detriment to reliability.

The trick is, knowing what mods to do and how to map it. That's where you need help from the experts who know as much, if not more than Subaru do about the limits and capabilities of these engines, as they've seen them tested with specs that Subaru wouldn't have done research on, and they also have feedback about long term reliabilty.

Someone as knowledgable as Pete already knows this but I'm sure the noobies are wondering.

Head over to Andy F's website for lots of useful info on mapping and tuning a Scooby.

Ns04

Varboy

Son of Pete?

Should have seen that.

WRX_Rich

iTrader: (5)

pick the wrong mapper and you could have serious problems

stick to the big names and you should be fine and in theory it will be more reliable than stock as it is done to your car rather than a generic one size fits all map

fivetide

iTrader: (1)

Additionally the EU laws play a big part. My 03 WRX has 3 cats in it and i've removed just one of them with a remap that has taken it to 273bhp.

As standard the car over fuels a lot because the EU say it needs those cats. A decat system actually allows the fuel to be leaned out producing more performance, less fuel consumption but higher emissions.

A good example of this was a test in RiDE mag with a new Honda Fireblade. The EU has now forced cats to be fitted to bikes too but with a full (no cat) exhaust system and a map RiDE managed to have a bike that put out slightly higher emissions, had another 15bhp (about 10% more power) and did an extra 5mpg

In summary the EU forces regulations that decrease emissions but actually use more fuel i.e. pointless. If they let manufacturers get on with it it themselves instead of forcing things onto them then they'd do much better.

The point about best generic map is true though, look at the different bhp people get from a map because that is what their engine is performing as.

Mine cost just under a grand (exhaust, first decat, intercooler hoses and map - no point getting a panel filter unless you want the noise) and still passed the MOT as two cats are still fitted.

What it has done is raise the boost to 1.4 bar and bring it in lower down the rev range. To that end i'd say engine damage wasn't the issue, it would be more likely to increase turbo wear. However, if you have a custom map done they will do whatever you want to your engine.

5t.

Graz

Trolling again Pete, you clearly are a "special case"

Here's hoping your special group of infractors are out in force today to get your latest incarnation banned. How paranoid

lunar tick

iTrader: (2)

Great quote and sadly all too often the case!

Terminator X

iTrader: (7)

You seem to be struggling to let this one go "Friar"

TX.

dunx

iTrader: (3)

My car has had no reliability issues since it's re-map.
But yes I agree that it's lifetime will be reduced overall, "No such thing as a free lunch !"
75,000 miles ( another 6 years away ) instead of 150,000 is something I can live with.... Besides I'll probably get bored (out) to 2.1 or larger to increase the torque....

DunxC

T5OLF

iTrader: (4)

Stop feeding the troll.......