Of course talking SAE Net//BHP....What will it take?....Don't want to change any exhaust components if possible...No NOS or meth injection...Aftermarket intake, pulley, remap, SC porting? Anyone here think they have achieved this number, or close to it? What is the exact HP of the R model from year to year?

 

The real method to create HP is compression, either increase boost, or raise compression ratio. Your problem is both structural and fuel. Change to 11:1 pistons, un-shroud the valves, bringing compression down to 10.5 or so, think about rods, and find where you can get 93 octane. The next component you would need to address, is camshafts, as it determines dynamic compression, however, you would more than likely have to have to have a machine shop build-up a set and then custom grind them.

 

I did a lot of research in this forum and in general on the Internet.

Lots of differing opinions on what does and what does not work.

In the end I bought a used SC on Ebay and had it modified with gearing and rotors from a 2009 super charger.

I did that because the 2009 has "better" gearing than my 2005 XJR.

Also had porting done and a 2.6 pulley on the snout. So I did as much as is possible on the Eaton Gen IV supercharger.

In the process I cleaned all the gunk from the charge coolers and the throttle body and the elbow Also polished the elbow and did minor porting on it as well.

I added an in line IC radiator with 2 6" fans as well as an upgraded IC pump.

When all assembled I was quite disappointed with what I perceived as "not much increase in power". However during the first few dozen miles of testing with the pedal to the metal the gears were changing well before red line.

That changed when I touched the disconnected battery leads together and
I did notice a dramatic change in the "feel" of thrust in accelerating.

People here have said that you cannot reset the transmission that way well I beg to differ.

A few miles later and a "brand new" rear needle bearing went in the SC!

I now have my original stock SC back on and will rebuild the "rebuilt" one myself when I feel like it.

Getting the very expensive gearing and rotors from a 2009 car as well as the porting I feel was a waste of money. The pulley maybe not.

Btw I could not find any company that would or could remap the ECU on a 2005 Jaguar.
Those that did reply to my inquiries said they no longer handle any jaguar from 2006 and older.

 

It clears the PCM's learned values but not the TCM's. It's not obvious that you'd even want to clear the TCM.

 

did you change out your old cats ?
i think even in good condition the stock cats are a restriction for a modified set up .
i done a lot of mods to mine and did not get the net result i was after as also .
until i swapped to 200cell sports cats . that sure woke it up .
then i think all the mods were unleashed . to be fair my cats were blocked . so it was always going to be a big difference .
but after seeing what these poor engines have to breath through from the factory , id say it is toucher on a performance engine for it to have to gasp through those .

on the remap subject have you spoken to cambo ? i believe he might be able to point you in the right direction .

 

Is that the new Eaton put in the 5.0 SC of the X351?
I thought that it could not be installed on the 4.2 engine (different design)...
How did you proceed?

 

You are correct the 5.0 SC is a different and superior design and will not fit the 4.2 engine. Amongst other improvements the rotors are more efficient.

I am talking about the Gen IV Eaton as used on the 4.2 engine from 2004 up until about 2009 (US model years).

 

No I have the stock cats and probably will not change those as I have spent too much money already on trying to improve on what is already very good performance.

In 2006 some significant changes to the "electronics" of the XJR were applied so all the work done on remapping a 2006 ECU could not be applied to prior models and there is just not the volume to warrant the expenditure of maintaining "old" stock.

I have new needle bearings for my "rebuilt" SC and when I feel up to it will rebuild that unit myself. It does have the smaller pulley.

 

That's some disheartening news guys...The R goes good as is as Jackra stated, but with the newer crop of cars these day 390 hp is not all that much for a 3900 lb car...And Datsports comment makes sense that if your going to increase the superchargers capability to breathe and flow more you may be choking the additional HP off with restrictive cats...

 

I should have said that I bought a SC from a 2004 XJR.

Just out of interest look at the rotors of the SC I bought on Ebay just about all the ablative coating has come off the rotors this at 140,000. So who knows at what mileage it started.

Later years had better ablative coating. My 2005 SC rotors looked really good.

Also note the crud on the elbow when I first got to it and then think what the charge cooler cooling fins inside look like. This was at about 103,000 miles.

Thats why I now have oil catch cans on both the low load and the high load breathers.

 

Are the 200cell sports cats legal in all states?

Are they bolt in?

How much do good quality ones go for?

 

I found these Jackra https://www.paramount-performance.co...onverters.html They aint cheap!

 

Of course the front ones too! https://www.paramount-performance.co...onverters.html

 

When you combine shipping from the UK they certainly are not cheap even with the big drop in the £ vs the $.

I wonder whether the HP gains are for the 200 cell replacements on their own or combined with the remapping?

I forgot 20% VAT!!!! Although they should not charge that if shipping overseas. I was thinking about picking up something like this when I visit the UK
where trying to reclaim VAT at the airport is a really big hassle.

When I buy something in the UK, such as jewelry, I find a place that will do a deal for cash!

 

Magnaflow do a vast variety of sports cats , including 48 state legal ones.
Mine are not , I bought pre OBD 200cell cats and wealded the 02 threaded bosses in each end , it's the cheapest way .
Mine cost $160usd each . And took about 2hours to fit .
And mine were Wealded in to the factory flange and down pipe .
The only bolt in kits I know of are paramount , and Nameless .

 

I have just been doing some research on-line and I see the less expensive ones are all "weld in".

This is something I might consider when I rebuild by "rebuilt" SC. I need to find a shop that I would trust with the welding tho.

 

Well I have started on rebuilding the "professionally rebuilt" supercharger.

Have dismantled it and extracted the rear needle bearings. I am waiting on an H frame press to be delivered and when that arrives I will press in new needle bearings in the rear.

Then when rebuilt I will run the SC using a vacuum to see whether I can hear anything untoward.

I will add pics of the rebuild when done.

At a later date, when my honey do list is whittled down, I will install it and see how it sounds.

If it still makes a noise I will then swap the snout with the small pulley with the snout on the original.

Later on I will seriously consider less restrictive CATS.

 

If Paramounts claim of 22-25 increased bhp across midrange is true without remapping then 450bhp should be within reach with the following mods :

Smallest pulley on SC, bored out throttle body, and 200 cell cats.

If you add in 2009 rotors and gearing which is supposed to add 10 bhp but VERY expensive $$/bhp and a less restrictive exhaust then it should be possible.

So I have the 2009 rotors and gearing and the smallest pulley as well as porting. If my SC rebuild is successful I will go for the 200 cell cats and throttle body bore out next year.

I also have significant extra IC cooling capacity with the in-line IC radiator plus 2 6" fans along with a stage I intake I made.

 

im afraid thats not quite the case . as that 22-25bhp is not added to your peak hp , from what I've seen you gain around 7-9 bhp at peak hp . however you do get quite a gain in peak torque and really when moving a heavy car down the road torque is were its at . i have seen a video that proved 9-14bhp added to peak power from the stage 1 caldoofy or quickets in take .
also there is around 20bhp peak to be gained from a free flow exhaust and x pipe witch needs to be in the right place though . so I'm sure a good healthy 4.2sc
will achieve 450 with the right amount of love.
i have seen videos of a xjr with NOS & meth pulling 580bhp but thats only on a cold 1st pass and only whilst the tank has some to give .
you really can't go past avos's TS set up for consistency . there is nothing better!
i would have bought one if i could afford it . but can't see it any time soon
fact is i could sell my jag and pay half the cost of the TS kit on top and just buy a gtr with 700bhp . or an 800bhp falcon typhoon . but i really want a v8 to listen to !
and I'm not giving up this luxury car for for any thing . I'm quite contempt with the jag . id say mine is over 430bhp and thats enough . isn't it ?

 

Had not thought of that Datsport. Your argument about adding to peak hp is correct I think.
I know about the TS SC but like you for me the cost is half what I originally paid for my 2005 XJR .

What other used luxury performance car can you buy at such a huge discount?

And it would not be a Jaguar. I have had BMWs, a Porche 911s and driven others including a Corvette and I still prefer the Jaguar that I have now.

I am 65 and grew up in England and this particular style of Jag has always been my favorite.