D2 S8 Remap - worth it or not?
 

I can't recall how but I ended up looking at various companies offering remaps of the D2's ECU.

Claims of 20BHP gains and some more torque were banded about and the cost seemed to be between £300-£400.

I'm one for keeping a car as original as possible, however the thought of an extra 20BHP without major work does appeal. That would mean something getting close to 380bhp before adding any subtle and appropriate upgrades; another way to look at it would be to restore some of the BHP that's been lost so you're close to the original amount they supposedly had when new.

Either way, on paper it sounds appealing.

Has anyone done this and found the end result worth it, or is perceived wisdom to leave well alone on D2s (S8 in this instance)?

My old S8 had some sort of remap (a chip-swap soldering job) done by the previous owner, though I never did get to the bottom of exactly what it was - the paperwork from whoever did it wasn't very illuminating.

He reckoned it was to change the gearbox behaviour to make it more sporty, though from what I could see it was more likely engine-related.
Given that I didn't find my FL S8 to feel any quicker that's plausible I guess.

The services I've looked don't require any chip-swapping, more updating the existing software.

I'm thinking that 20hp isn't going to feel that different is it? And that's assuming they achieve the full increase that they claim to be able to make.

The PF cars couldn't, when they were current, be remapped without an EPROM change. Not sure if that has changed, but not an issue on facelift cars.

There's a small number that've had Revo maps on D2s that have felt they added something to the car. If you want an extra 20bhp, or at least what feels like it, if you run regular unleaded swap to high octane stuff and you'll feel that increase and then some!

I looked into the Revo option, even as far as having my map read off the ECU because they didn't have a file for the ECU version I have. I decided not to do it because I wasn't convinced that what I would get would improve the car without the risk of damage. I also started a job where emissions control is a major part - what I learnt early on from that job (which I still do) is that mapping is a whole lot more complex than a lot of remappers would have you believe. The difficulty is telling the ones who know what they're doing from those that talk the talk. Even big companies haven't impressed me when questioned.

I wouldn't bother.

Since these cars are normally aspirated, and already tuned quite optimally from the factory, there's little room for improvement, as I found out myself a while ago.

I was fortunate enough to be invited along to Superchips' workshop in Buckingham several years ago, to spend a day with them learning their remapping procedures. I took along the '8 I owned at that time, a '97 4.2 (non-sport), and they kindly offered to roll it and map it for me, using their 4wd dyno.

After taking a copy of the original fuel map, they spent half an hour or so tweaking and customising the map in an attempt to get the best performance increase possible. We then re-rolled the car and compared results, only to find it was DOWN 5bhp from the original! They decided to try again, and an hour or so later they produced another map, which increased the bhp this time by about 5-10bhp. The difference was of course barely noticeable on the road.

I suspected as much, thanks for your replies. I'll save the money for something more important.

I use V-Power all the time and there is a noticeable difference if I have to use another brand, and even then I'll only put enough of that in to get me to the next Shell station.

Tesco do a 99 but the flake keeps clogging up the fuel filter.

I spoke to a respected mapper on the Audi circuit when i had mine (Rick @ Unicorn) and he opined he could but wouldn't bother as the gains will be so marginal, i probably wouldn't notice it / be worth the outlay.

User - A8 Doc - on this forum used to be involved in remapping, no idea if he still does but worth a quick email I'd think

I doubt you could get 20hp extra without changing the exhaust. The stock S8 has 400cpi cats, and baffled mid and rear box probably not optimal for performance.
So before re-mapping you would definitely need to change the exhaust and cats.
To get a even a bit more power you would probably need to port & polish the intake manifold and get some long tube headers made up (very expensive). Then a remap after all the physical changes. Have a look at JHM S4 videos on youtube, they got a lot of power out of their S4, it has more or less the same engine as the S8.

https://www.youtube.com/watch?v=3n7xVwjWWD0

The other way to 'power' is actually to reduce weight. Acceleration = Force (torque) / mass

Mine was remapped before I bought it. The graphs that came with it show about 5-10 BHP increase at best, although I do think it picks up a little better at lower revs than my previous S8, but you'd probably not notice the difference unless you'd been told.