Engine Remapping

fRostiE

fRostiE

fRostiE

Soldato
Joined
20 Oct 2002
Posts
6,212
Location
UK
So i see a lot of posting about carbon cleaning or re-mapping on social media at the moment... i understand the concept but are there lots of people on here who've gone ahead and done it?

I bought my current car Leon FR 184 with a view to investigating the option of having it remapped with a warranty... thinking along the lines of someone like Revo etc.

I'm sure there's loads of important detail to know, like safe tolerances and if the remap has been tested on equivalent cars / engines to verify its not putting the car under too much strain.

What kind of things should i be on the lookout for if its something i'd like to pursue? Everywhere seems quick to provide potential gains and benefits but what are the risks, if any?

Obviously as its performance enhancing there's a need to notify the insurance company.

[edit] Forgot to ask, how does it affect manufacturer warranty, MOT and servicing?

Thanks,
 
it won't be under warranty any more. as for MOT i don't see how it makes any difference unless you modifiy other thing like DPF, etc. as for servicing as your now putting everything under more strain you should try and over service it. as in if the car asks for one every 2 years, do it every year. or every 18 months do it every 9 months. as in the simple things oil, oil filter and air filter, brake fluid and coolant. other things like gearbox and diff fluid rather than once every 6 years try and do them once every 3-4 years.
 
Just had my truck mapped. Providing the AFR is safe then it's robust.

Dealer can overwrite it but it's very unlikely they'll look for it when diagnosing problems unless your engine is completely toast.

Best thing to do is take it to a dealer and ask for any ECU/TCU updates that are available prior to getting the map put on, that way they'll see it has the latest.
 
If you remap you as said will instantly void the engine warranty as it shows a TD1 flag when it is scanned. If it needs any warranty work then it will be scanned regardless of what the claim is for, even if the map is taken back to stock it will show that it was mapped. Even if the dealer is fine with you getting it done warranty work goes through Seat and they say yes or no should something happen.

As for if it is worth it, yes, without a doubt. I had the X6 40d mapped and it made a huge difference to power, torque and how smooth it delivered the power. Also it was much more economical as the engine was not being restricted by the OEM mapping. Makes no difference to the MOT or servicing.

If you don't want to risk it get a tuning box like a DTUK one and/or even a pedal box that won't ad power but makes the throttle more responsive.
 
You need to get it tuned by someone who knows what they are doing. A bad tune will slowly kill the engine.

Don't use those plug-in things, they don't do things properly and override some of the safety features for the engine.
 
I thought tamper flags could still get set with a piggyback ecu. If not, then some ecu values could be out of the manufacturer's tolerances, so it would be flagged a suspicious?

With the growing popularity of pcp & lease deals, as well as mapping, I've always wondered what would happen if ecu tamper flags start getting checked at the vehicle return, much like bodywork damage. In some respects, it's worse than a scratched door, because that can be repaired while keeping the warranty, but once a car is mapped it's permanently "marked." If there's a tamper flag on the ecu, then could someone argue it's worth less, as ever if it's still within the warranty period there could be problems with a warranty claim for the next owner (as you say, the flag is still present even after being returned to stock, so the next owner could be oblivious until it is scanned).
 
Finglonga said:
If you don't want to risk it get a tuning box like a DTUK one
Click to expand...

Tuning boxes are still detectable even if they don't throw a specific "tamper flag", they modify the sensor values that the ECU sees, and any historical logs would be identifiable (e.g. against an unmodified car) - they are generally not as "safe" as a an actual remap, as by fooling the original ECU with incorrect readings, you are limiting what adjustments the ECU is able to make in the event of an otherwise correctable fault.

Finglonga said:
and/or even a pedal box that won't ad power but makes the throttle more responsive.
Click to expand...

Pedal Boxes are snake oil - fooling the ecu into applying more throttle at any given pedal position doesn't make it any more responsive, instead it reduces the sensitivity and range of input you have.
 
For carbon cleaning, the cheap cleaning products/services usually just take off the top layer of carbon deposits and doesn't give a thorough clean at all. Which means after a few weeks the car feels the same as it did. For a proper clean walnut blasting is required, and if the engine is very thick in deposits it might even need doing twice. This is maintenance rather than "free performance" like a remap, and you can definitely feel the difference.
 
Ryan-3 said:
For carbon cleaning, the cheap cleaning products/services usually just take off the top layer of carbon deposits and doesn't give a thorough clean at all. Which means after a few weeks the car feels the same as it did. For a proper clean walnut blasting is required
Click to expand...

Generally this is only needed for a few specific engines that suffer badly from carbon build up: R56 Mini Cooper S and B7 Audi RS4's are the one's that spring to mind.
 
I thought all the VW DI engines were pretty bad for it.

More recently manufacturers have been putting port injection back in alongside direct injection to prevent it. I know Subaru have.
 
Last edited:
Nasher said:
I thought all the VW DI engines were pretty bad for it.
Click to expand...

They are to some degree, but as I understand on the RS4's it's more noticable as a large loss of power. On the earlier 2.0TFSIs some of the problem is related to PCV failure which then allows excessive amounts of oil through, further adding to the deposits.

Nasher said:
More recently manufacturers have been putting port injection back in alongside direct injection to prevent it. I know Subaru have.
Click to expand...

Fairly sure Audi/VW have gone this way with the newer TFSI/TSI engines
 
Sounds like its certainly a cheap way of unlocking some extra performance... but not without caveats such as this TD1 ECU modifier flag.

I was wondering about one of those plug in 'DTUK' boxes which could then be removed. Their website says in fitting takes only 10 minutes, but i hadn't realised those boxes achieved the same results in a less 'safe' way. if for example the DTUK box simply overrides the inputs and safety features of the engine, isn't that the same as replacing the ECU software and raising those limits direct on the ECU? Just without the ability to disconnect and be back to stock figures?

The flip side of having a map applied over/onto the cars ECU is that its then not removable, and again even if it was this 'TD1' identifier still gives you up. Much less of an issue outside of engine warranty period though. Unless im misunderstanding some of the larger/more established companies warranty against engine damage. Though i'd not like be in that position as i'm sure the remap supplier will do everything they can to avoid blame/cost.

Servicing more regularly makes sense, as does no effect on the MOT.

I guess each insurance company looks upon ECU modifications differently so no point asking what to expect from that point of view.

Had a quick livechat discussion with someone at DTUK and when asked about the 'TD1 flag' they said:
"The TD1 flag is in reference to a ECU remap, as we don't touch the ECU and tune the vehicle downstream at the sensors no trace is left on the vehicle once removed."

Still tempted but not fully convinced :rolleyes:
 
fRostiE said:
I was wondering about one of those plug in 'DTUK' boxes which could then be removed. Their website says in fitting takes only 10 minutes, but i hadn't realised those boxes achieved the same results in a less 'safe' way. if for example the DTUK box simply overrides the inputs and safety features of the engine, isn't that the same as replacing the ECU software and raising those limits direct on the ECU? Just without the ability to disconnect and be back to stock figures?
Click to expand...

No they aren't exactly the same - remapping is essentially just tweaking a lookup table that tells the ECU how much fuel (and possibly other parameters e.g. timing, boost) to use for a given engine rpm and load e.g.

V2ksAYJ.png


All of the ECU's existing functionality and safeguards usually remain in place.

A plugin tuning box can't modify this directly, so has to plug in between sensors feeding information to the ECU, and/or connections to e.g. the injectors in order to override what is going on. Essentially it "tricks" the ECU by making certain readings look lower than they are, in order to force the ECU to respond - by doing this though you are using some of the ECUs existing margin of error to correct genuine minor issues/faults that may crop up.

fRostiE said:
Had a quick livechat discussion with someone at DTUK and when asked about the 'TD1 flag' they said:
"The TD1 flag is in reference to a ECU remap, as we don't touch the ECU and tune the vehicle downstream at the sensors no trace is left on the vehicle once removed."
Click to expand...

As above though, some of the correction ECU's perform (e.g. Long Term Fuel Trim) is logged though, so I'd be surprised if someone experienced couldn't still spot some anomalies.
 
Sounds like they simply 'warp' the input figures going into the ECU, if you ever had a problem you could simply disconnect the unit, then the battery overnight and I'm fairly sure it'd remove any logs.

I have the Techstream application that Toyota uses to modify/log/update their vehicles and the ECU doesn't save logs, they can be read real time but not past drives.

I think people are worrying far too much, my truck is tuned at the ECU and is only 18 months old, my R6 was tuned almost immediately. Both still going strong. Worse case I'd 'flash' the truck and simply pull the cable out mid flash, dead ECU = not going to be read = new ECU on warranty.
 
You must log in or register to reply here.
Back
Top Bottom