Hi all,

Getting ready to pull the trigger on the VelocityAP power upgrades, had a few questions. I have a V8S, and was wondering if anyone has done the crank and the supercharger pulley? Trying to get as close to I can to 600rwhp

 

That may be a bit ambitious. I don't believe anyone has reported over 700 hp on a load bearing dyno.

 

Let him try. We will read about the results in another oil starvation thread in a month or so. Pushing it past SVR power level is going to be dicey. You will likely need bigger blower and a lot more cooling.

 

You definitely won't get 600 whp, best you'll see is about 640 bhp. I believe that's about where i'm at, but that's just by doing math and not using a dyno. 640 bhp is somewhere around 512-544 whp, so you're a long way off. And dynos are all over the place in terms of what they read.

Kinda sounds like you just picked 600 whp because its a nice "claim" number, but i suggest you not think about that and just mod your car till you're happy with it.

 

Because boost causes oil starvation... Many of us are well past SVR power levels and are doing just fine.

 

From what we have seen, increasing boost on AJs increases blow-by a great deal. If you end up on the wrong side of tolerances, boost that engine some more via tune and/or SC mods, and then don't check oil level you will end up with a dead engine. Because JLR failed to install low oil level light.

 

Have you taken your car to the track and actually put your tuned engine through the paces? What about heat levels? What about blow-by? What about cat overheating and car going into safe mode, negating your tune after 10 minutes of spirited driving? Please let us know.

 

Yes. Never had it go into safe mode. Don't have blow by problems. Cat overheating temps is an issue with the stock car and not really any worse on a tuned car since its just a calculated value and not a real measurement. Even so, it doesn't really choke the car too much. The problem i'm having now is not enough tire grip in 1st/2nd gear. Need to switch to PS4S this winter.

 

I'm not familiar with boost "increasing blow-by a great deal" but i'll take your word for it. I surely don't have any oil consumption issues and I would expect you'd pop a ringland before you had tolerance issues.

 

Thanks guys, love the info and back and forth here. I'm coming from a 10 second CTS-V2, so with the weight savings and 8 speed it might be close eventually.

Is there a reason to choose the crank pulley over the supercharger pulley, or vice versa? which produces better results (im assuming the crank?) Hard to find this info anywhere.

 

The crank pulley is much easier to install and results in more overdrive (11.6%) than the SC pulley (6.5%). The sizes of these pulleys are dimensionally constrained at the front of the engine.


Combining the two pulleys will not increase peak power by very much, but you will be able to get more midrange power and potentially more torque.

 

Thanks again Unhingd. I see you have both on the V6. Wondering if anyone with the 8 has done both as well.

 

I believe a couple have, and they've been safe so far. I haven't because you destroy the upper pulley in the process of installing the new one and I like to have the ability to return to stock.

Something to keep in mind on this platform compared to your Cadillac is that we will never have the amount of aftermarket support you're used to. So far we've only had one person in the tens and he had to port the S/C and add nitrous/drag slicks to get there; on top of full VAP mods. Outside of that myself and another AWD R member have been the closest at 11.3X. The other member claims to have been stock but haven't seen him around much.

Ive constantly (albeit slowly) been working with VAP to fine tune my engine and try to get to that 10.9 mark. But have constantly been running into little issues such as grip level and cat temps that have prevented me from getting any closer.

 

Awesome, this is what I wanted to hear. hopefully someone with a V8 that has done both upper and lower pulleys and tune w/ downpipes and their results.

620rwhp @ 4200lbs is about 6.77lb / HP.
540rwhp @ 3670lbs is about 6.79lb / HP, which I would be happy with.

Anything over 550 with the better tech and 8 speed, I'd be ecstatic.

I'm working with stuart now to see if they have a tune for both pulleys now... I guess no one has done catless downpipes yet?

 

Hate to burst your bubble, but the V8S Convertible weighs in with a 3957 lb curb weight (all liquids and fuel), as compared with the 4280 on the CTS-V2.


Here are actual scale weights for the different F-Type models: https://www.jaguarforums.com/forum/f...4/#post1473925


These numbers are without fuel, so add about 111 lbs to get to curb weight.

 

And isn't that really the one thing keeping the Jag from being an out of this world sports car....

 

You nailed it.

 

WTF? how the hell did jag come up with 3670

https://www.edmunds.com/jaguar/f-typ...st-specs1.html

 

Talked to stuart - dunno if I should do both the crank and supercharger pulley.

Car makes 15psi boost on the stock pulleys. Supercharger pulley adds 1.5psi. Crank pulley 3.5psi. At 20psi starting to run the blower at a speed the is right on the limit of the efficiency range.

he advises picking one or the other because 20PSI will require 100% functioning of coil packs, injectors & plugs and in high temperature environments even then intermittent misfires are possible due to heat soak unless you upgrade the charge cooling system - which isnt available yet to my knowledge

 

Would that be a dry Base coupe?