Does anyone know the redline (maximum RPM) for a 2003 XKR supercharged 4.2 V8, which I believe is type AJ27S?

I can't just go look at the dash of the car, as I don't actually have the dash.
The engine has (ahem) now been inserted into another car.

The figure is not in the owner's manual.
I have found various dubious online sources that suggest variously 6100, 6250, or 6600 RPM.
I can not find a good enough photograph of the appropriate instrument binnacle that I trust is really from the right model of car.

So, if you have a 2003-era XKR, what is the redline actually shown?

You may wonder why I'm asking.
For the standard car it's moot, as the auto box always shifts below that point.
But this one has now been mated to a 6 speed manual with a custom ECU.
So, it's nice to know at what level it's likely to blow up, and indicate that correctly on my tach.
(ignoring problems introduced by changing the ECU).

Thanks!
Jim

 

The spec book is here: VSB_2007_2004.pdf

Not sure it contains a hard number for you, but it shows rpm for max torque and power. As you already said, the best would go with what Jaguar put on the stock cluster. Generally, eBay has good pictures. You can search "XKR cluster", and see if you can convince yourself with what comes up. A quick search seems to show 6k rpm pretty consistently.

 

See if this gives you what you need. Look at page 8

Link http://jagrepair.com/images/AutoRepa...sb_09_2003.pdf

 

Thanks both for the links, but neither has what I need.
These table show the RPM for max torque and max power, but neither figure is the redline (max rpm) which is normally above both.
I guess they figure that someone reading the specs on an automatic *really* doesn't need to know that.
(Though following that reasoning, I'm at a loss to figure out why they include a tachometer at all...)

I have some some deep, deep googling but no luck so far.
No images that I can find reliably show this specific era of XKR tach.
Specifically, the 400hp version starting ~2003 but before variable valve timing.
(for example, I know the tach says "supercharged" on it, which many of these listing photos don't have)
I have found the Jag part number of the instrument cluster, but searching
on that part number gives illustrations, no photos.

A few ebay listings say they have it, but they also say it fits the XK8, which I know is different, so I ignore those.

Best info I have found (which I don't really trust) is
* Motor trend article, which says 390HP at 6600 RPM.
2003 Jaguar XKR - First Drive & Road Test Review - Motor Trend
I'm dubious because it doesn't match anything else I've found, the peak
power figure seems wrong, and the peak power won't be at redline.

* Some website called "street smart online"
?97-?06 Jaguar XK8 / XKR (X100) - Throwback
This mentions peak power at 6100RPM, something seen in many sources, so the redline is at *least* that high.
Matches the data in the tables in the documents linked, at least.
But it's not a redline.

* An article on the S-Type R, which had *almost* (but I believe not quite) the same engine.
2003 Jaguar S-type R - Road Test - Car Reviews - Car and Driver
This says " The solid redline is logically marked at 6250 rpm, just above the 6100-rpm power peak."
That sounds pretty plausible. But I'd like to confirm it, and confirm the XKR is really the same.

Another article I found said there's a fuel cutoff at 6200.
But again, it's not what I'd call a definitive source.

Really, I don't believe any of them that much.
I figure the best source would be to ask someone who owns one to go out
to the garage and have a look and eyeball it carefully, or (better) post a good pic.
Hence the post here at jaguar forums : )

Anybody here own a 2003-6 XKR?

Tnx again to all
Jim

 

Then I suggest you call an engine rebuild shop and see what they have on a Dino test for that engine.

Gus
www.jagrepair.com

 

On the tach the redline is indicated at 6000. More specifically, there is a 6000 mark in white, and the red range starts on the north side of that mark. From the dyno pulls I have done, the rev limiter kicks in at 6100 or 6150.

Now the more important question: What have you built using a Jag V8 and manual transmission?

 

As another data point, the red line on my XK8 tach (so, the normally aspirated 4.2 with no supercharger) is at 6250.

Are you looking for the graphics under the tach needle, for correctness purposes, or are you looking to program some form of fuel cut off in your custom ECU?

As requested above, feel free to share the specifics of your project, it sounds interesting.

 

Photo of my 2003 XKR Tachometer.

Hope that helps.

 

BTW - I think the 4.2L SC motor in the 2003-2006 XKR's are designated 'AJ33S/AJ34S'.
The AJ27s was the older 4.0L SC


https://en.wikipedia.org/wiki/Jaguar_AJ-V8_engine
2003-2006 Jaguar XKR, 400 hp (298 kW) and 408 lb·ft (553 N·m)

 

Same here on my '03 R. It's either 6,000 or 6,100, but that's where the line is drawn.

With the valve train we have (so little reciprocating mass), I'm actually surprised it's so low. But with the SC giving us all the mid range grunt we need, and being speed limited to 155, I guess a higher redline really isn't necessary, ..... and I'll be damned if I'd ever risk valve float in THIS engine! ;-)

 

Thanks hugely to all!

>>On the tach the redline is indicated at 6000. More specifically, there is a 6000 mark in white, and the red range starts on the north side of that mark.
>> From the dyno pulls I have done, the rev limiter kicks in at 6100 or 6150.
...
>>[image]

This is exactly the sort of thing is what I was looking for.
I think peak power is quoted at 6100, so that is presumably not above the redline.
But from what you say, it sounds like it also *is* the redline, which is a bit unusual.
Perhaps not, for a car which is designed to be automatics only.
I guess I'll stick with that 6100 figure. I need something to paint on the tach.

>>Now the more important question: What have you built using a Jag V8 and manual transmission?

As for what the engine is being used for, well, it has been grafted into an E-type of course.
Sounds heretical, but hey, it's still a Jag 4.2, right?
But now it has a 4.2 engine which has 135 more horsepower, which weighs 100kg less, and which has fuel injection and therefore starts first time every time.

A fairly major project.
It's at the 99% stage now, driving well but with a short "to do" list.
All credit to the shop, I'm just the one paying for it.

Jim

 

Some more info if possible please. Gearbox used. Ecu used. Clutch. Flywheel. Thanks.
here's my project

 

You could always do like the Muria and leave it up to the operators nerves to decide how far to go.


Hardly heretical IMHO. It is a very practical option for one of these old cars and makes them much more usable. Helped my dad do something similar to his 38 Ford Pickup and will do the same to my Sunbeam Tiger (if I can ever find the time to work on it).

Besides, you used a Jag engine, so it's more or less original, just mixing model years a bit.

 

Sweet mix of engine and auto...love to have you bring us some more on this.

 

My 4.2 S type. Starts at 5750. Hard red line at 6250

 

Very interesting!
A little different from other pics I have seen. Different red line, and text above centre line instead of below in the XKR pixs.
I suppose rumours that the engines were "identical" between the XKR and same-era supercharged 4.2 X-type seem to be off a bit.
Makes sense that at least the software mapping would be different---different target audiences.

What year is yours?

And my thanks, of course.

Jim

 

It's a 2003. Early car. Interesting that max bhp is quoted at 6100rpm. Max torque at 3500rpm.
Most important to keep the revs in the torque range.
The V8 isn't really a revvy engine.

Would be interesting to know actual max revs as there seems to be a few differences. I think I'll keep mine to 6100rpm.