I would have to travel back to the dyno shop and ask them to do that. Soon as time permits I will gather that. Of memory I do know that stock it hit redline at 6500 and with this tune it went to 7k but a print out will show all the other RPM info you want as well.

 

Time to head to the 1/4 mile track!

 

Can someone explain this to an ignorant person like myself ? wouldn't it be bad for the engine if it allowed the RPMs to go higher then it's supposed to?

 

VelocityAP ECU tune coming to me via DHL. Should be installed next week.

 

The stock file in the XE is supposed to cut fuel at 6,800rpm(limiter is 6750rpm), his file is bumped 200rpm to 7,000rpm(limiter is 6950). The 200rpm bump won't do any further damage. Now if the driver was shifting at 7,000rpm every time, then yes we might have some concerns, but the concerns wouldn't be any different if the driver was shifting every time at 6,800rpm.

The rpm bump is beneficial to ppl that might weekend track the car, if you were on a circuit track and always ran out of rpm in say 3rd, a few feet before the area you would normal start braking into a particular corner. This 200rpm bump would allow you to stay in that 3rd gear for a few seconds longer, and not require to upshift at the time your almost about to start braking for that particular corner.

I've yet to run an XE on the strip but it would be the same idea when approaching the end of the 1/4 mile. If you always had to shift a few feet from the end of the run. You could now keep the selected gear and use the 200rpm bump(providing the 200rpm bump helps and that your still not bouncing off of it, otherwise it wouldn't be helpful)

 

That does explain it well thanks ! but he said it redlined at 6500?

 

Looks like they used different roller-to-tach conversion number between the two runs. The conversion is needed to calculate torque if tach(rpm) pickup was not used during the runs. Since both Tq and HP scales are the same, where the HP/TQ curves cross would correspond to 5250rpm.

http://media.caranddriver.com/files/...mance-data.pdf

According to Car and Driver, 4th gear ratio is 14.1mph/1000RPM and tops out around 96mph, so at 5250rpm, the speed should be 14.1*5.25=74mph. This is pretty close to the post-tune dyno run, but very far off from the stock baseline.

The peak power output is not affected by the tach conversion ratio but the torque output is, which would explain why the baseline Tq numbers seem lower than expected.

 

Correct, They don't have a tach pickup so the operator uses a calculator to set the RPM-MPH for the runs.

 

That makes sense. Looks like they punched in the wrong number for the baseline. Based on the Power vs Speed data, the stock baseline peak Tq should be ~280ft-lb.

 

Thanks Airboy. Something seemed off the me as the tq/hp intersection should have been at the same wheel speed (the speed corresponding to 5250 rpm in 4th gear) for both stock and tuned runs.

Your data makes more sense, and it still looks like a pretty serious gain. The AUC gained for torque is especially impressive.

 

There seems to be a drop in power after 6000 rpm in the tuned run while the stock tune remains flat (albeit at a lower overall hp).

Is this unavoidable or could perhaps be fixed with improved cam phasing/ignition timing?

I'm sure the VAP team noticed this when designing the tune but I'm interested in their answer nonetheless.

In either case it suggests shifting before the new 7k rpm redline is a good idea if you're going for 1/4 mile times etc.

 

I would like to note that it is possible for this run that the XE was in NORMAL mode as Dynamic timed out and the car upshifts on its own near redline unlike holding the gear like Dynamic does. I don't think peak power is affected though in either Dynamic or Normal mode at full WOT near redline with the exception of the upshift?

 

Damn! I wish I would have read this thread two months ago, to snag that discounted price.

 

Hey BigCat, did your AWD XE code out while on the Dyno? (prolly not... i'm guessing.) My RWD will flash check engine light, and when downloaded the ECU codes are 31 and 34 (speed sensors). We speculate that while I am accelerating on the dyno....the car thinks there is something wrong and goes into limp mode before i can hit peak RPM, because it senses no speed on the fronts and thinks there is a ABS failure.

Do you know of a "Dyno Mode" setting for the ECU? I know Merc and others have made this an accessible option on their cars.

(I also have a call into Jaguar Service Dept in Austin, I will post the reply here.)

 

Even if your car is RWD you still need to use a AWD linked dyno or the car will freak out. I had those same issues with my XFR.

I still had some minor issues with the AWD dyno on my XE but I just shut the car off and lock the doors for 5 min and then tried again. That reset it for me.

I only knew of Dyno Mode for my AMG cars, can't find anything for the Jags just yet.

 

Yes, turn the car off, and let it sit 5 min between runs...that works.

 

Bear in mind this thread stopped in 2017

 

I discovered the pulls I published were done incorrectly, my fault. Please disregard my dyno chart quoted above by Fraser Mitchell, its not accurate at all. Turns out there is a learning curve involved when doing a dyno on a jaguar XE. These were conducted in the wrong gear, by 2. Although bigcat ran his pulls in fourth gear, next time I'm going to do mine in 6th, which has a 1:1 ratio according to this:
https://www.caranddriver.com/jaguar/...xe_2017/381507

Thanks for the compliment Fraser Mirtchell! Yes, I thought the dyno chart subject should be continued on bigcats original post, as that is the polite thing to do on a forum, even if he sold his Jag. I'm betting the forum monitors prefer this method, rather than having more/multiple threads in the XE forum on dyno results.

I'll also mention these fourms have been a great resource for me, I learn things daily.

For example, velocityap contacted me same morning after reading this post, and based on what they told me, I now believe the dyno pulls above were in the wrong gear (I think were in 4th gear, verifying) , Stuart mentioned they should have been pulled in 6th where there is a 1:1 . ( I think my dyno guy based the pull on ZF8 info for the wrong tranny system, and I think I confirmed wrong info.) So I am pulling the chart I posted as it is not relevant to anything. I will get it done again properly and post again here, for those who ARE interested.

BTW: That's great post sales support from those velocityap guys!

 

Has anyone measured 0-60 with the VelocityAP tune? with or without the pulley upgrade?

 

Best Data I have for you is 4.59 Seconds in an FPace 35T. This is with the tune only. The owner did not do any baseline runs, but Car & Driver tested it at 5.3 seconds when it was released in 2017.