What is the difference between Brake Horsepower and Horsepower? Thanks as always. I know I should know this, but we don't use BHP in the states that much.

 

Same thing. The brake refers to the type of dynometer used to measure the power, it in essence uses a water brake to resist the power output and measures this force. This is the power right at the flywheel. A chassis dynometer will measure the "at the wheel" power which includes the loses due to frinction and resistance in the drive train.

 

subtract at least 18% from 231 and you get the approximate 'Wheel' horsepower of the X-Type.

 

Brake horsepower should be a British stuff considering Top Gear and resident UK persons use that term that much

 

At which wheels, the front or the back? Where does the 18% number come from?

 

ALL 4 WHEELS.

it is an AWD car.

60% to the rear, 40% to the front power distribution split.

An AWD dyno chassis is utilized to measure this. Or on some vehicles, the driveshaft can be pulled and RWD can be measured. Although I do not think the X-type is setup to do so.....

 

OK, Thanks, This is something I knew but did not know brake HP was at the flywheel. I had my Cobra tested many years ago and the HP was measured at the back wheels.

 

Is that for the 2.5L or the 3.0L I have a 2.5L and I've read it is rated at 195HP. Is this correct? As for that amount of horsepower the car is very peppy. It bogs down a bit around 80mph but gains power above 85 + mph.

 

I just guessing but I would think at both back wheels as it is AWD? And I do know that there is a lost of HP from the flywheel to the rear end. Oh, when I was looking around for a headlight unit, on one Jaguar dealer site I saw transaxle. Do these cars have transaxles? If so that would explain the excellent handling. Again I should have known this, but I never saw this mentioned in anything I ever read about the car. Thanks.


"Staying alive, oh, oh staying alive."

 

Brake horsepower is the same as the measured flywheel horsepower which is the number that all car manufacturers quote when giving HP figures (no, your 5.0 Mustang doesn't actually have 414hp at the wheels, that's BHP).

WHP (wheel horsepower) is the actual power that your car puts down to the ground through its drive wheels. All drivetrains induce a power loss in getting the power from the engine to the wheels.. Auto transmissions will face a larger power loss than a manual transmission and it varies from car to car. Most auto drivetrains will lose between 15-20% of power by the time it gets to the wheels... So on most automatic 3.0 X Types, depending on how well maintained they are, any mods, etc you are probably looking at a car that is laying down between 185-195whp. Mayyyybe 200whp for some of the guys with free flowing exhausts, intakes, colder plugs, etc.

 

Here's a youtube vid of a chassis dyno'd, slightly modded x-type. About a 60hp loss in the drivetrain

YouTube - Jaguar X Type 3.0 ltr with Quad exhaust Dyno Run

 

As you can see from the Dyno results on the curve, the exhaust
MAYBE' added 3hp and 2ft lbs torque. BUT, like all dyno runs, you can run the EXACT SAME setup twice and have a variation of numbers by that much. more than likely an axle-back exhaust adds none. I saw ZERO number changes until I did a full custom catback with high-flow cats, and ECU Re-map. I'm not sure why they didn't produce a full catback setup for the X-Type, it seems the demand is fairly decent....

 

....I can't wait to install my new quad-tips I found...

 

Adam Adam Adam - honestly have you not heard of google?
Click this:

Google

 

I'm not sure it was a before and after on run 1 vs. run 2. I think it was just a variance in the two.

I agree with you on the catback system. There are all kinds of horsepower robbing things in the way. I'd love one. I'd love highflow cats too for that matter.

 

 

trust me you will not get any horse power from any exhaust ..unless the car is turbo
but it may sound good

 

AWD saps the power
Mine was rolling roaded at 241BHP and only 182 BHP at the wheels (fully serviced etc etc)
Watch the rolling road vid on You Tube with results....
YouTube - Jaguar X Type 3.0 ltr with Quad exhaust Dyno Run

 

I am 65 years old and I have enough trouble trying to use email and Microsoft word. Google is great, but I don't think about these places especially when this forum has such smart people on it who probably know more than Google.

 

Nice Buck! I found and posted your vid earlier in the thread. . Did you have any other mods on your x besides the exhaust on this run? Did you run on the dyno prior to installation too?

Good vewing.