There are downsides to tuning. Tuning is not a free lunch, free power waiting to be unlocked, it also has substantial downsides and hidden costs that need to be discussed and understood.

First, and most substantial downside is that tuning permanently and irreversibly voids any and all engine-related warranty. This includes factory warranty, extended warranty, and even third-party aftermarket warranty. This is not limited to damage that can be linked to tuning, even warranty coverage of manufacturing flaws would be denied and you will have to go to court to recover your costs. More so, once your car is flagged as tuned by JLR it will become harder to get approval for any other warranty work. While denying warranty for unrelated modifications is illegal in US, there is sufficient gray area to make your life difficult.

Second, tuning is irreversible. While it is possible to apply original tune, any tuning whatsoever creates permanent red flags in multiple systems that cannot be removed. Consequently, you can’t un-mod your car.

Third, tuning puts more stress on your engine and drive train. This will reduce longevity and reliability of your car. This is especially true for increasing peak power. While specifics are highly dependent on how you use your car, and in some cases extra stresses could be negligible. Tuning will also make your car more sensitive to extreme heat and bad fuel.

Forth, tuning drastically reduces resale value of your car. Even buyers that intend to mod cars prefer to start from unmodified examples.

Fifth, not all tunes are created equal and not every tune is ‘safe’. There are many instances of careless inexperienced tuners causing damage. Tuning modern cars is a very complex process that requires deep subject matter expertise. More so, many tuners exaggerate their claims. Don’t trust and always verify.

Sixth, tuning a leased car opens you to liability if you return it in without full disclosure. If the next owner suffers engine failure and warranty coverage is denied due to your tune, the new owner has a case to go after dealership. This is turn can end up your problem as tuning is explicitly against terms of any lease agreement you signed. Dealership would have a case for seeking damages.

If you still decide to tune your car, here is how to mitigate some these risks:

1. Wait until after engine break-in period is complete, this will drastically reduce the chances of experiencing random failures. Ideally, wait until after warranty expires, this way you will not be wasting your warranty.
2. Only purchase tunes that are backed by dyno data and have wide install base. Popularity of tunes alone will not determine their quality and ‘butt dyno’ is too easy to fool with various gimmicks like adjusting throttle pedal mapping.
3. Adjust service schedule of your tuned car. You are putting more stress on the car, this in turn requires more frequent fluid changes.
4. Consider minimum necessary modifications to achieve your goals. If your goal is a better handling car, upgrading tires might be the safest way to achieve that goal.

 

It could not have been said any better.

 

+1

 

Could one swap ECU's? Leave the original one stock, tune only the spare one? To stem the arguments - This is merely a question, not condoning dishonesty.

 

Technically yes, the dealer will need to reprogram your VIN in it. HOWEVER the P167F code is stored in multiple places...

 

 

No question it voids the warranty. For a car OUT of warranty, though, how dangerous is it? From what I can see, the driveline (diff, axles, gearbox) is the same on the S/C 5.0, whether it is tuned for 470 hp or 550 hp. Surely, the 5.0 tuned at 470 puts less stress on the driveline than it can handle, but I am not sure I would stress too much about it, since it was built to handle more. I think that is what the advocates of tuning assert. Are the engine internals any different between the two flavors of the 5.0 s/c? The impression I had is that the only real difference is the tune, and therefore, the "danger" is minimal. I am still undecided, as my car seems pretty quick already. Not sure an added 100 hp will help much in Chicago traffic.

 

I believe V8S, V8R and SVR are all mechanically identical, though the SVR does have slightly improved cooling.
If I had a V8S or V8R and was out of warranty I'd probably just request an SVR or P8 map, that way you get a map which was written by Jaguar and though I am sure the tuners are very talented, I'd probably prefer the factory map as JLR/SVO would of done a lot more research and development, putting a lot more money into it.

If under warranty and you want to keep that warranty, then I believe Lister is the only approved tuner that retains your warranty, however I think this is only valid currently in the UK region, also the Lister power pack is hugely expensive at £10,000 at which point its probably worth taking the gamble and using the money saved by not going Lister should you have any engine problems arise.

I was gonna tune my SVR, but I am now simply not going to bother, the car is far quicker than I expected and though more power is always nice, its going plenty fast enough, having just ran an 11.1@126mph and the only power mod is some basic ITG cone filters and some very minor weight reduction.


The only other option is Racechip, which won't put a flag on your ECU, but if our cars are recording boost and pressures, then should you have an issue and JLR interrogate the black box as to speak they will no doubt be able to see the car was running higher boost, at which point they could try to invalidate a warranty claim, of course it would be there word against yours but it would be rather tricky ground.

 

There are two types of danger - danger of improper tune and danger of tune putting extra stress on your engine. Danger of improper tune is quite substantial, it isn't simple to tune these complex cars. However, going with a known tuner like VAP will minimize that. Danger of tune putting extra stress still remains. Your engine and drive train longevity will be reduced. It isn't unlike doing burnouts - yes, your tires can take it for some time, but if you do it all the time your rear tires will quickly get used up.

 

I think much more noticeable upgrade for you going to be summer performance tires. Tune only will get you more power. Better tires will improve your take off (less slipping when putting power), will improve your cornering (less slipping when taking sharp corners), and stopping distance (less slipping when braking).

The only downside of going with summer performance tires is that you absolutely cannot drive them in the snow.

 

The danger is essentially the same whether you're in or out of warranty. The difference is, without the mod, the repairs are at JLR's expense.

 

I guess another thing to consider, if you're doing more than just a pulley the cost can really start adding up. If one decides for both pulleys, your cost is not just upper pulley, lower pulley and tune. It is those 3 and more such as the high flow cats, more cooling etc.

 

 

lol 110 lbs is hardly minor. That combined with what the SVR is already down from a stock R, you're looking at 150+ pounds advantage. That's pretty huge.

 

If I get the wife to drive it, that is nearly 100 lbs savings right there... LOL

 

 

I'm going with the theory my 150 lbs in weight savings means I put less stress on my engine, driveline and suspension, which more than offsets any additional stress added by the tune.

Really gents, this seems like an odd thread for an enthusiast's forum. After decades of trouble free modifications to numerous cars (most receiving much more than a simple tune) I've found driving and maintenance habits have lots more to do with a vehicles longevity than some intelligent upgrades would. In the neighborhoods where I work, I see late model cars abused to such an extent that they are effectively destroyed in just a few months, and the only mods they have had involve the driver ingesting copious amount of drugs and/or alcohol.

But hey. if folks want to worry about things like the increased stress on their door hinges from faster acceleration, it's your choice....





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If someone is that worried about wear & tear, they should just not drive the car. BTW, replacement parts and regular maintenance will take care of that. Gotta pay to play.

 

There are some cars that have fatal flaws that would result in engine damage due to track use. Last generation Subaru WRX comes to mind as a recent example - without baffles in the oil pan it will suck in air and experience oil starvation leading to bearing damage. Interestingly, Subaru STI doesn't have this problem, as Subaru designed oil pan and pickup with this in mind.

Fortunately, I am not aware of any flaws like that with V6S F-type, with only "mod" that is needed is to remove engine cover. JLR seems to design it to withstand that kind of use case. Kudos to JLR for beating up on F-type on the track during design and testing stages, they delivered and I am happy with the result.