If you were to spend $1100 on your car right now, would you tune the engine or put that money into upgrading the audio? This would be for a 2011 XF 5.0 N.A. (pre-facelift) with the base 9 speaker audio system. My 2005 XJ VDP has a much better system in place and it also has the surround sound feature (cant believe that still isn't offered as standard!!!).

So the engine tune would add a little over 32 HP and about 35lb-ft of torque.

What could you get audio wise for that same investment?

 

Really...On a naturally-aspirated engine.
Ooooookay

 

That's the numbers I was given by the tuning outfit. ETG. Is this something that is not possible?. I guess from your post you have experience with tunes? Can you give me your opinions with this because I do not have any experience with tunes and I am trying to see if I can get info regarding this before I go ahead with it. TIA.

 

Being a naturally aspirated engine it is very difficult to get big hp gains out of it without major work...heads, cams, porting, exhaust, and so on.

I too am highly suspect of the numbers that the tuning company gave you, if all they are doing is flashing the ecm with new curves then I would suspect more like 10 to 15hp at the most.

The reason for this is all you can do with this method is remap and change the timing, fuel usage and the throttle curves, possibly the transmission shift points but that does not add power. Therefore making significantly more horsepower is very limited, you need forced injection to increase the ability to make bigger numbers.

 

I would not be surprised to see these kinds of gains from a Supercharged 5.0, like mine. After all, increasing the boost makes the power go up.

On a N/A engine there is not much you can do (especially for $1100) to gain more power.

Did they explain what does the N/A tune do? How do they achieve their CLAIMED power? Have you seen their pre-tune and post-tune dyno runs? How were they verified?

 

Personally I'd do an exhaust mod like Mina - the noise is terrific and will make you feel like you are getting tens of hp increase. My personal view - 20-30hp on a car like this and you just won't feel it

 

I would invest in the Mina exhaust first and then later on go for the ECM tune as that would take the exhaust free flow into consideration for the tune.....That way the cart is behind the horse.

 

Mina exhaust is already in the works. The tune will definitely come after it is bolted on. I also have done the center muffler and resonator delete, which added LOTS of torque to the 2K-5k RPM range in the lower gears. I am after the torque gains to get out of the hole quicker. Even you guys with the S/C cars don't really benefit from the added HP since, from all the dyno charts I have seen the increase comes at higher speeds where no one really uses that gain in HP. By the time you get into those gears, the car with more torque is at the next light laughing at you right or already taking the exit ramp to gas up..lol..

...so no one would spend that money on audio upgrades then???...i guess for the money all I would get out of a stereo upgrade is a Audison Fiber-optic amp...would still need to get speakers and a cleaner sub...

 

I have tuned NA cars before and I would say that it is "worth it" for the added throttle response and a little more power however those tunes were a LOT cheaper than those for this car. If you had a supercharged or R, that price point could be justified for a tune because you'll pick up an assload of power. With the NA Jag at that cost honestly I wouldn't bother. $1100 would give you a great start to a pretty sweet sound system if you are into that kind of thing.

 

I will definitely look into getting he tuning company to provide some numbers for me before i make a decision.

 

By the way..I found this post from a forum member that tried this tune on his XK.

 

I don't have experience with tunes on NA cars so I can't help with that choice specifically.

I did both to my car, but I didn't have to do the full audio system. I started with the B&W system so all I had to do was put in more amplifier power and a sub box. I don't know what the base system sounds like, so I don't know what truly needs to be done to make it sound good, but I'm assuming it will cost more than $1,100 unless you do all the work yourself.

Not trying to deter you from doing either, but make sure to do your research, know what needs to be done, and what you'll get before you start.

 

DONT spend any money on an engine tune- or upgrades. Unless you are prepared to be in it for the long haul before seeing any meaningful results. First of all, jaguar engineers are not stupid, the reason you have the power curve you do now is because it works best. If 30hp could have been had for near nothing they would be the first to do it.

On top of destroying the torque curve that is really fantastic on a jaguar, you will have BIG problems down the line with carbon buildup with those silly engine tune. On a DI engine how long the valves stay open determines the cleaning efficiency of the heads. Lets put it in other words- when Ford was having premature loss of power due to carbon buildup the remedy they came up with was remapping the valve timing.

Ironically if you want 30+hp, clean your heads out or otherwise get car back to new specs. Which I see no one mention here.

 

Uummmmmmm I'm not even sure where to begin with this....but first I'll say to anyone who read that post, please ignore it. I don't mean to be rude, but there are a lot of people, both members and guest who come to these forums for knowledge. No one can be right 100% and we all make mistakes but what is posted above is filled with statements that are just flat out WRONG.

First of all, there is nothing wrong with spending time and money on getting a proven tune from a reputable tuner. You car will run better, smoother, stronger and more efficiently if tuned correctly.

Jaguar Engineers indeed know what they are doing. That is why they have duped the general public into believing that the difference between cars like the XF Supercharged and the XFR are really worth the super premium they charge. In reality its just a tune and a body kit. The XFR-S does receive some suspension changes but it too is essentially a different tune/more boost on the exact same engine with the exact same transmission. So to say that if it could be done then they'd do it, isn't a good argument. They are doing it!

I'm not sure who taught you how engines work but I don't even feel like getting into how much hogwash your comments about valve timing is. Carbon buildup that actually creates known issues are sporadic at best. Also, the biggest factor of buildup is that fuel is not being prayed onto the back of the intake valve as in a conventional injection systems. Also, the combustion quality is a big factor, the cleaner the better as there is less carbon to deposit. The better the fuel ratio is, the cleaner the engine burns and that is exactly one of the parameters a good tune will address.

Lastly, a dirty engine does indeed perform worse than a clean engine. Simple logic there. But to suggest that you can get 30+ horsepower by cleaning our engines is just ridiculous. Where people come up with this stuff used to be a mystery to me but then I realized one source is posts like yours that spread misinformation which is the only reason I took the time to respond to this.

 

Just to add, I doubt the basic tunes that these companies are selling have any valve timing adjustments in them at all. From what I understand they are mostly just ignition timing and fuel trim adjustments. Though, I could be completely wrong.

 

Glad the last two posters jumped in before I could. Definitely someone needing to seek out MUCH more knowledge before speaking up so definitively.

 

You have just underscored what the problem with most people suggesting engine mods WITHOUT even basic knowledge of what they are talking about.

With admiration for a fellow Jag owner, let me humbly enlighten you, as your servant.

Merely polishing the throttle body gets 12hp gain in some cars. Thats just removing the carbon film from an area there is no combustion whosoever.

YES carbon buildup on DI engines is a huge problem- it robs 20% or more of the power! that can be over100HP. You have a hard time believing that 30hp could be gained.

Here is an entire article supporting what I wrote- NAMELY that the best thing that one can do for carbon buildup us having the correct valve timing!! show me one article that supports the stuff you pulled from your rear end.

Solving Carbon Deposits In Direct Fuel Injection Engines

 

Here you go 100hp loss on a 325hp motor.
Dyno proven!
Direct Injection Fouls Some Early Adopters - AutoObserver

what amazes me is that I merely wrote what I knew without insulting anyone. You insulted someone without having any knowledge or empirical data. Incredible.

 

LOL where do people come up with this stuff called knowledge. Why dont you read the forums right here genius. Note the say 20-30hp PER 10,000 miles.
https://www.jaguarforums.com/forum/x...charged-94489/
Spread knowledge not insults.

 

For the record, I have never seen a tune on a well designed car that has a net positive effect.
On my 5.0SC they can increase the top end of the curve, but also drop the the bottom end. The most incredible aspect of the factory setting to me is the linearity in the response cure. Most importantly how it performs on the bottom end- i.e more power quicker, its what gives a Jaguar its unique kitten like performance. One of the tings that Ian Callum speaks about, the audi v10 (lambo) does 50 to 70 in 2.9 seconds, the 5.0sc does it in 1.9. Clearly the target was street performance vs track.

Look I understand how unpopular it must be to tell people that their efforts of adding their little personal touch has not made the car better, but consider the inverse emotion as well, which is letting folks know that they have one of the best factory tune on the market- Which is what this thread was about- a guy asking if what he has is good and what is the best thing that he can do. There is no question that the best thing he can do is to at least get the car to original specs.

Those of you sore about the revelation of your 'custom' tune not being good enough, prove me wrong by posting a dyno reading showing that the bottom-end has not gone down after the tune.