Yep, that would be best....even better would be to dyno two or three of each to eliminate the any variance between individual vehicles.

Dave

 

Another great post; thank you. I noticed the figures the quarter mile calculators came up with too.....one thing is for certain; S or R, these things are strong. I've been in many fast cars including 800+ hp drag cars and my F type felt much faster to me than I expected from 488/495 hp.

This has been an interesting discussion and I've learned alot. My sense at this point in time is that the R indeed has a hp boost....but that it's more along the lines of the 503 vs. 542 that you mention and that there are real variations between individual vehicles, never mind the flaws and subjective criteria of various tests and dynos. Some of the V8S's that have put up big numbers may be anomalies though if you consider a 35 - 40hp difference and add in another couple hundred lbs for the AWD system (the typical calculators come up with 200lbs being worth about 27hp) and it's no wonder the times are sometimes very close. In THEORY, a V8R RWD should be fastest in the quarter (excluding SVR's and P7's of course).


Dave

 

Excellent read; thank you.


Dave

 

here is my before and after for my V8S:



So I showed considerable less hp than yours in stock. The car pulls like a freight train compared to before .... once it hooks ....

Interestingly enough I was told by Eurocharged who tuned my cars that I could not get to the same result on the V8S as for the 550hp cars.

My XKRS on the same dyno, tuned by Eurocharged, tuned by the same shop ended up with 500whp. Unfortunately the shop "forgot" to save the base dyno for the XKRS so I do not know what that looked like. The F-Type always pulled harder, subjectively, than my XKRS. My reasoning for that is the 8-speed with shorter 2nd and 3rd gear compared to the XKRS 6-speed and most likely more docile torque converter/programming.

The only straight up comparison I can find, same driver, same track is Randy on Laguna Seca.

53 Jaguar F-Type V8 S Randy Pobst 1:40.81 495 / 1665
54 Chevrolet Corvette Z06 (C6) 1:40.90 512 / 1437
55 Porsche Cayman S (981) Randy Pobst 1:41.26 325 / 1320
56 Porsche Cayman R (987) 1:41.64 330 / 1320
57 Jaguar F-Type R Coupe Randy Pobst 1:42.00 550 / 1665
58 E 63 AMG S T-Modell Randy Pobst 1:42.39 585 / -
59 Lotus Evora S1:42.49 351 / 1437
60 Jaguar XKR-S (550 PS) Randy Pobst 1:42.90 551 / 1843

The tune made the car pull harder, no question, how much faster, how much more hp ....???? It is definitely more fun and was definitely worth it to me.

 

Cool; thanks.


As far as the dyno goes; I'll go back to Cam's point about every dyno being different. The important thing is the difference in your car which is ....well, huge. Congrats.

Not sure why they'd say that the V8S and V8R couldn't get the same result; everything I've read so far would suggest that the hardware is identical, down to the supercharger and pulley diameter.....the only thing I could see is that if the computer has changed so that the same program couldn't be uploaded but even that wouldn't prevent someone from writing V8S software that could take you to the same place. Maybe I'm missing something....

The track tests have even more variables than a drag strip but the fact he was faster in the S than the R coupe certainly doesn't make figuring all this out any easier! LOL.

Cheers,
Dave

 

Oops; went back and re-read Cambo's first post and he said that there is a difference between the 2014 and 2015 wiring connections so I'll assume that's the reason for Eurocharged's comments.


Dave

 

The wiring may be different, and the exact tune file cannot be used, but the same absolute results are achievable if the tuner identifies the right maps to adjust.

 

Yes, that's what I'd think; no reason for it to be any different....at least none that I can find.

Dave

 

but that is EXACTLY the issue ... isn't it. We do not know who "really" can tune the ECU and who just uses the original file and tweaks a few parameters, mainly A/F. The interesting thing at the end in my case is that I was told that the V8S cannot get the 550 tune resulting in somewhere around 600hp. Yet my V8S on the same dyno, tuned by the same people and using the same tuning company ended up with 12 more whp than my 550hp XKRS whatever the actual hp really is. Both subjectively feel much stronger than before, my wife said that the XKRS really hunkert down when i stepped on it which it did not do before.

Subjectively my V8S gained 100hp and the XKRS about 50, or there abouts.

 

At 512 RWHP, your net crank HP should be right around 600 anyway.....

Dave

 

Yes, exactly. No reason a tuned V8S can't put down the same power as a tuned V8R. Same issue with the V6: No reason a tuned base V6 can't put down the same power as a tuned V6S.
Of course, we have to assume that knowledgeable tuners exist.

 

Though the V6 and V6S have slightly different final ratios.

 

Yep; if the hardware is the same, the ultimate potential is the same.

Dave