I have a 2011 XJ-L with about 30,000 on it and was wondering how much of a hassle it would be to add the supercharger. is this wise, and is it a simple (such as it is) drop in ,or other mods needed?
Thanks for any help
Griz








currently in garage
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1978 350sl
1989 635cai

 

Grizzley1, can it be done. Of course. But, the big problem that you are going to have is first finding one that will bolt on. If you are looking at installing the Jaguar one, then you have a lot of other work that needs to be done to the engine (ie, in short, complete engine rebuild). The big issue that you are going to run into is that the naturally aspirated (NA) 5.0L motor has a very high compression ratio (10.5:1 as compared to the 9.0:1 of a supercharged engine as I recall). What does that number really mean. Simply put, this is a measure of how much you are squeezing the air. The more you squeeze it, the hotter the air get from crushing the air (think about how hot an air compressor gets when it runs, same idea). You start compressing the air too much and the air can get hot enough that when you add fuel, it will immediately start to burn. This is what leads to pre-detonation/knocking. The benefit of having a higher compression is that the air/fuel mixture is in a smaller space and therefore can burn quicker, getting more power out of the engine.

Adding a supercharger to an unmodified NA motor will result in major problems unless you keep the boost way down (ie, very little power gain) or you run a very high octane gas (octane prevents the gas from burning as easy, allowing the air to be compressed more).

For what you can plan on spending, things would be much easier to simply trade in your current vehicle for a supercharged version with the same option. Either way is going to cost you about the same amount.

On a side note, if you are looking at the $300 electric superchargers that you slap into your intake to give you boost, save your money. In my truck club, we wanted to see what would happen if we used on of them just for grins. We actually lost power as the supercharger was more of a restriction than any gain it could provide.

 

Thrmo just mentioned the tip of the iceberg. Compression ratio is just one of many mechanical parts of the NA engine that differ from the SC version. And then there's the different electronics/programming that control fuel parameters and other interrelated functions. It's a can of worms you don't want to open, unless you enjoy watching your CEL go bonkers.

Sure, you can do it if you want to spend enough money. And what would you have in the end? It's still a 7 year old car that will probably be worth less because of that mod. Thermo's right - spend that money to move up to a later model SC XJ.

 

AGREE.

 

First let me say thank you for the responses
Second this was a sh@ts and giggles moment as I love my portfolio, and it's REALLY hard to keep it under ninety as it is, I think their horse power rating is a little low as I think this is faster than my 300c was, and that was massaged a little. I started to give it a thought when I saw a t-boned SC-XJ and wondered about making an offer on the SC as this thing was going to be parted out anyway. As for Thermo's response that was very through good for the newbies but I've been a motor- head for the past 40 years ,so I'm aware about octane and such, but it was a great answer nonetheless. However what's the CEL?

 

Grizzley, CEL, Check Engine Light. I am sure you are familiar with those being a motor head.

 

Yeah, but I call them Idiot lights like everyone else. No offence. Also
I already figured I would have to change out the ECU, which I would have taken from the wreak. You would think that Jag would still use some gauges, or at least have what the Chrysler had, a way of pressing and holding a couple of buttons on the steering wheel which gave you a bunch of other wise hidden info, they called them Easter eggs.