Remmaping the gearbox

[srreck]

Hello there,
Has anybody any experience with gearbox TCU remmaping offered by these guys?

http://www.jrtuning.co.uk/gearbox-remap-tcu-tuning...

Thanks

[pherlopolus]

Which car is it for?

I had a jaguar update to the box in my s-type and it made a huge difference.

[srreck]

2008 xkr 4.2

[8bit]

Can't comment on their product but they quoted me approx £1200 (including the engine remap, you can't buy the transmission map without it) which scared me off a bit.

If you do decide to go for it then please let me know how you get on, I have an 08 XKR as well and am keen to hear what this stuff is like.

[Effjay]

Somebody started a thread over on jagarforums.com detailing the issues they had with some tuning on a 5.0 XKR and how it was resolved.

It was an American guy and basically a couple of Tuners had mapped his car, but it was reverting to stock.

Anyway a company called RSC (one of the mappers) ended up sorting this out by employing the help of a mystery tuner over here in the UK. Whilst he was sorting the issues with the ECU/tune the guy also adjusted the gearbox map to remove torque limiters and increase shift speed by about 20%. The guys who's car it was seems to have nothing but praise for the adjustments (and that's on the later ZF6HP28 box which is already a quick gearbox). So it does work, and there's plenty of feedback for these type of modifications on Mercedes boxes, DSG's etc.

Funnily enough RSC offer remote tuning using an OBD device with a pre loaded tune for the engine and gearbox, and the unit looks VERY similar to that which JR Tuning sell; so if you put 2 and 2 together it looks like RSC may just purchase the remap files/equipment from JR, who are the main developer, and who were the mystery British tuner.

I've enquired with them myself for an engine and gearbox remap, but £1200 is steep, and they only offer about 25bhp gain, where as others are offering more (dyno proven) for significantly less minus the gearbox adjustments. I haven't seen anybody else offering a gearbox map for Jaguars in the UK, but I'm sure there must be people who can do it.

[8bit]

You're unlikely to get big numbers out of engine maps on non-turbocharged cars, even on supercharged ones the only real way to increase boost is to change hardware. Where you do make gains on N/A or supercharged engines is in response and power delivery and most of that will come in the mid range. Anyone telling you they can get an extra 100bhp out of a N/A or S/C engine with only software changes is almost certainly grossly exaggerating.

[Effjay]

100hp from the 5.0 is achievable with a smaller pulley and a remap by somebody who knows what they're doing, a remap alone is good enough for about 70. All of the 5.0 supercharged Jags use an identical engine, just with different software (and some have slightly different exhaust systems).

It's very torque limited from stock; several well respected tuners (Rica, Eurocharged, ETG, Evolve, DMS) are seeing those figures.

Edited by Effjay on Wednesday 14th January 20:45

[8bit]

I'd like to see some (ideally independent) dyno figures proving a 70bhp gain anywhere in the rev range from stock purely from software upgrades personally.

[SportsCarShop]

8bit said:

I'd like to see some (ideally independent) dyno figures proving a 70bhp gain anywhere in the rev range from stock purely from software upgrades personally.

I have to agree that there is nowhere on a normally aspirated or supercharged car to make huge gains, just customers being sold lies. Large gains can be made with a turbocharger, pulley swops on a supercharger. If the gearbox map can genuinely be modified effectively, then I do know the person to turn to.

[jamieduff1981]

The 550ps 5.0 engine is just the same as the 510ps and 485ps versions. Jaguar write in the sales blurb that it has bigger air intakes on the bumpers etc but it's just the map really.

FWIW I find the XFR-S traction limited on 295 section P-Zeros through 1st and 2nd gears. If we're talking about road use I have to admit I can't see an immediate application for any additional torque on 5.0 s/c cars.

The XKR is proven to handle itself rather well with the big engine though, which implies that there is room to play with the 4.2 without immediately converting it all to tyre smoke.

[srreck]

Thanks mates for your replies.
I have to say that I already have the engine remap done some time ago by Spires with good results. What I'm looking now is to improve the gearbox response when using the paddles. I feel she a little bit lazy, smooth and comfortable for normal daily driving but definitely out of game for trackdays use.
JR offers their "new" ByteFlash programmer with the software at £945 Vat included.....I will think on this.

Cheers,

[8bit]

Ah, so they do sell the TCU map separately to the engine map? When I asked them (last summer) they said that wasn't an option; they could do the engine map on its' own but the TCU map had to come with their own engine map. Interesting. Still seems like an awful lot of money for what it is.

Personally I've learned to instinctively just click the paddle a fraction earlier to work around the slight delay.