Saying none of your customers have had no issues is not the same as saying your customers have sold the car and the tune is not detected. The tune would invalidate my warranty so if eg. I did want to sell this might be an issue.

 

That dyno sheet shows whp. 618hp to the engine

 

Thanks for the response. Okay, maybe a little more detail would help:


The Torque curve on the V8 is a 'table-top between 2500-5500rpm. As this engine has a mechanically driven supercharger, it ought to be an inverted u-shape. This strongly suggests that boost is being bled off between the 2500-5500rpm to maintain a constant level of boost and torque (with the help of appropriate fuelling and ignition timing).

Sticking a smaller pulley on the supercharger, but making no other changes will extend the table-top to the left, but probably at the expense of the right hand side as the efficiency of the supercharger drops off earlier as it is spinning faster.

Additionally, as you mention, driving the supercharger faster is going to soak up more of the engine's output.

So, back to the original question: Wouldn't it be more effective on this engine to leave the pulley as is, and make changes to the software so that boost isn't limited? Projecting the edges of the table-top suggests a peak of 675Nm @ 4000rpm would be the result before you start optimising the fuelling and ignition timing.

Questions? Comments?

 

The tune would only be an issue if you have an issue with the car & Jaguar Cars saw the non factory software on a printout from the IDS computer. I am sure if they asked one of their Jaguar dealers to do a simple vehicle scan they would see what I mean. The other comment about doing 4-5 cars a day is almost 100 Jaguars a month. That sounds like an awful lot of cars.

To the gentleman questioning the pulley installation, I have done quite a few myself & never had a problem. The only thing we did differently was instead of using a torch we put the pulley in a toaster oven for 1/2 an hour on 350. The pulley will slide on just make sure you slide it back as far as the original.

To anyone out there with doubts on the pulley & tune, just do it. It makes a world of difference. You will be truly amazed how much faster the car is.

 

Imagine what the R could do w/tune & pulley.

 

Yes, I assume the R would end up with more than 618 h.p..
Lawrence.

 

I presume your figures are for a convertable!
If so thats an improvement of over 120bhp, if this is the case what do you expect from the coupe R!!

 

Dremorg,

Did you catch this one?

 

Here's a video of a stock V8S doing the quarter mile in 11.9 seconds.

 

Type R did pretty well against the Ferrari

 

We take the R to 627hp

 

Yes it did. Like i said, imagine with tune & pulley....

 

I think i'm just going to pull the trigger on both tune & pulley.

 

So my R which starts out with over 50bhp more than the vert, ends up with only 10bhp more and for the same money.
Doesnt sound great to be honest, why isnt the tune comparative to what they both start with!!!

 

I'm just guessing, but I assume they hit the limits of the engine valving and displacement and also, perhaps the limits of the inherent strength of the crank etc.. etc...
Lawrence.

 

Your feedback would be really interesting if you go ahead with this. I might consider it next spring.
Lawrence

 

The 470hp, 495hp, 510hp and 550hp have the same engine. The R has a sports exhaust.

When it comes to the R, we only recommend it with a pulley. Even though Jaguar states 550hp the car measures lower (520-530hp), with the ECU tune only the car ends up at 575hp.

 

Agree on the curve effects. As I noted, pulley swaps should be accompanied by an ECU remap because otherwise you are just increasing the air-fuel ratio in the engine, which can actually decrease output and cause other problems like engine knock.

I suspect the reason folks try not to exceed the tabletop is for risk management. You can "borrow" from the right side of the tabletop, but if one just goes above the engine performance envelope you risk serious engine damage, for example the engine may run hotter than the cooling system can compensate for and you end up with one of those awesome melting videos

From the ideal gas law, pressure x volume / temperature is constant, so by introducing greater pressure into the chamber (via supercharging) and more fuel (to match the added pressure) operating temperature goes up also. So the entire engine runs hotter. To achieve higher power at lower RPM with the same engine on the same octane fuel, you have to increase pressure and optimize air-fuel ratio....but as you do this temperature necessarily increases also. So limiting the output for a given RPM is the easiest way to keep the engine within acceptable operating limits.

 

Can you guys do the install at your location in the L.A. area and if so, how long does it take?

 

Yes, It will take 3 hours. No longer.