Night and day difference isn't it? Unfortunately APR does not do Jag.

Walt

 

I do agree that to be taken seriously vendors need to be transparent about gains and I too struggle to understand any reluctance to show and before and after dyno reports taken with the same car.

Still, my primary issue is that Jaguar dealers (and Jaguar corporate) just aren't generally supportive of these modifications and the probable ramifications if an engine failed or developed issues after the tune and/or pulley swap. That contrasts with my experience with local BMW/Porsche dealers who seemed more comfortable with the concept. The other thing is general reliability. With, say, a Porsche, I'd be relatively unconcerned about engine issues after a tune. With the Jag, I'm just not quite as comfortable. I certainly don't have many reliability concerns about my car, but I'd struggle to say that long term reliability doesn't cross my mind.

 

From my sophisticated and extremely accurate "seat-of-the-pants" RWHP estimator (and until I see a few dyno numbers, a confirmed weigh-in or two, and some 1/4 mile slips), I'd venture my R is a few doors down from 550.

 

I think the weight is something that needs further investigation.

Not an F-Type, but an example worth noting, the specs for my XJR state 1665kg as the vehicle weight, I put it on a certified weigh-bridge last year, and it came in at 1760kg, and that was without the spare wheel or tools/jack in the boot and less than 1/4 tank of fuel.

It sure would be interesting to see what the cars really do weigh, anyone able to get to a weigh-bridge?

As for dyno figures, yeah i'd be taking them with a grain of salt myself, every dyno is different, and you get a huge range of results from little things like how the car is strapped down, tyre pressures and even the type of tyre that you're running (a guy here in Australia got ~100rwhp less on a dyno by running drag radials instead of street tyres, on a 500rwhp car, not a Jag but still a good example).

Powertrain losses? you can pick whatever percentage you want, it will be nothing more than a best guess. 20%? 18%?

Then there is the issue of fuel quality, temperature, altitude/elevation, so many variables which will affect power.

At best you can use a chassis dyno as a reference for improvements from modifications, but chucking a car on a dyno and trying to compare it to factory stated flywheel numbers, you will just end up confused, angry or both..

 

Here is my little chart of various cars, HP and 1/4 miles times.



I'm most interested in the 1/4 mph speed since this should negate traction off the line. All these figures are from Edmunds except the SL65 AMG BS (Motor Trend).

The F-Type R's 122 mph seems right in line. If anything, the R out performs other cars base on power to weight. I'm more interested in these numbers than dyno numbers. Dyno numbers just aren't very reliable. I have yet to see a review/article where anybody says the R is down on power. Last article I read about the R they said down the straight at VIR it was Ferrari F12 fast territory

From personal experience at the track down the front straight, I couldn't believe how fast the R is. I exited turn 13 at thunderhill ridiculous slow (beginner driver). Still managed to get to 125mph before chickening out well before braking zone. Watching other videos of more experienced drivers in GTRs, Turbos, etc., and their relative exit speeds vs top speed, I have no doubt the R has all 550 HP.

Make sure it's in dynamic mode + sport shift if you think the Jag is slow (I actually forgot to put my old 991 in sports mode at the drag strip before and was annoyed how sluggish it felt )

 

I'm going to scout one out this weekend. Gotta know.

I'll take 18% with lock-up.

One can go nuts tying down the variables, but got to start somewhere. The cooler October air in auto mode should yield fairly consistent trap speeds that can be converted into estimates of relative power (BHP). Assuming decent traction, I expect the R to see 119-120 mph with a 11.7-11.8 ET. (Source:Drag Racing 1/4 Mile times - DragTimes.com)

Now where is that scale?

 

Living in Ag country, we have plenty of truck scales all around me, I will weigh my car when it arrives and report back.

 

Walt, not sure if you saw this but some very interesting stuff about APR lately:

http://www.audizine.com/forum/showthread.php/615294-APR-woes

 

Appears there is some internal strife going on there at APR. Probably some truth and a lot of innuendo. Will have see how things shake out.

 

119-120 mph, 11.7-11.8 ET has already been shown (see my spreadsheet comparison. Unless you think Jaguar is giving more powerful, non-production F-Types to testers.

 

That would be really odd if Jaguar chose to represent 0-60 times that are worse than the true times (which they undoubtedly did with the V8S convertible) but present HP ratings that are better than the true rating.

 

Posted just after yours--didn't spot it. Thanks for working that chart up.

I was only trying to say that I'll get a pretty good idea whether my R is producing up to Jaguar's specs once I start seeing more data from the track, that's all. Agree that dyno numbers can be deceiving at times; but, actual timesheets and consistent runs under decent conditions (density, altitude) will give me a good sense of where things stand for the 5.0L, power-wise.

On the subject of factory ringers, they are both fact and fiction. I have no idea how Jaguar treats that issue when offering up cars for testing.

 

I tend to agree with the comments that the claimed weight of the Type R is the specification that is likely off. In respect to HP/acceleration, from a seat of the pants feel, I think that the numbers are roughly accurate. It feels similar to my 09 GTR before I heavily modified it for track use. Regardless, the I think that the Type R is an amazing car for its intended purpose, a beautiful, refined sports car for the street. I've had mine for 5 months now and absolutely love it. If you want to hit the drag strip or track where HP/weight are important, there are several other cars that are better suited to the task.

 

I too bought the F-Type for many reasons, none of which involve a drag strip ("Client-friendliness" for one). In the end, the topic of this thread simply intrigues me since I built small-blocks years earlier, where my version of "Friday Night Lights" was the strip.