So I've had the Jag for about 5 weeks in a row and it's still stock, which is not typical for me . The lowering springs & wheel spacers have arrived, but now I'm looking at tunes, etc. I got a little carried away with my M car, going catless/turbo/camber plates/port meth injection, etc. and it requires living with some fumes, rattles, and pulling the meth tank/purging every time I autocross.

I'm trying to restrain my primal urges with the fat cat. To get to the point and my question:

$2K stage 1 ecu tune and the trans tune. 605HP/542TQ. VAP says higher TQ allowance per gear and 200 more rpm/faster shifts. I did the xHP flash on the ZF in my bimmer and it made a significant difference.

OR

$1.9+K get stage 2 tune with lower pulley. For practical purposes, same cost. This yields 645HP/597TQ. While this is a significant increase of 40HP/55TQ, I'm more concerned with drivability. In addition, since I autocross and perhaps a track day, I'm worried about overheating. This can become a slippery slope of adding more cooling, meth, etc., etc. Trying not to go too far down the rabbit hole on the Jag.

As to the ever important 'use' question, I'm not looking for big dyno numbers to brag about, I'm more drive feel oriented. More track rat, than drag dog. But I do love me some HP, just trying not compromise this car as much as I did the M car.

Any experiences you can share between the two proposed paths would be appreciated.

 

While I haven’t autocrossed, I would think faster shifts would be more important than more power. Maybe even more important would be losing some weight - lighter wheels, brakes, battery, etc. Assuming you have unlimited money…

 

Ha! 2 kids in college, too many interests (just bought a new titanium bike-$$) So no unlimited funds, the car/springs/spacers/*lithium battery/tunes is it for this year. And total focus is not autocross, this is not a competitive car. I autocross to improve my driving skills/learn the car at the limit/have fun. I drive this to work a few times a week, run errands, if the weather is decent.

*Forgot to mention I also bought a battery.

 

Of your two options...I would go with the second one (tune and pulley). The cars run great with that set-up. If you do need cooling, I have a DIY on this forum...on adding Water/Meth injection too.

The tranny tune does help, and is nice, but if you have to choose, I do not think you will notice it as much as stage 2 (tune/pulley)

Good luck and enjoy.

DC

 

Begs the question- If I do go with tune/pulley, and I going to NEED xtra cooling? Especially pushing it on a hot day?

 

Extra cooling never hurts! But I ran all day at 1/2 mile airstrip races wide open about 30 times and hot lapped and forgot to hit the switch to turn on my Water/meth injection...Had NO heat issues...Ran great all day.

But easy enough to add, and relatively (key word) cheap and not too difficult to install.

 

Appreciate the DIY's you've posted! But not doing meth/water injection on the Jag. I might install a lager/more efficient charge cooler, but that would the extent of it. Maybe a simple radiator water spray setup, but no drilling/tapping kind of work.

But good to know on the 30x 1/2 mile runs. I know the extra HP/TQ would be much more noticeable, but was worried about the slippery slope of mods as mentioned. thought if the trans flash had a huge impact, plus a bump in power it would be enough for a substantial increase in drivable performance to be worth the coin.

 

I have the trans tune and stage 2, after the stage 2 when I put the Trans tune it felt more snappy when I stomp on it, if I'm cruising it's smooth and linear

 

Thanks for the input!

 

I've run Stage 2 in the '16R for a half dozen track days so far, ambient temps from 45F to 90+F, and while acceleration degradation was there as the 25-mins sessions wore on it was not severe. Would say it's similar to other FI cars like M3s in the same session.

Having waited Stg 1, 2, then TCU tune a year apart each with plenty of normal and track miles after each, Stg 2 unequivocally should be the first mod, followed by TCU. The crank pulley adds an enormous amount of power across the band (vs even Stg 1), and that ~5.5K+ range that used to lose steam is now extremely strong right up to 7K (shift points of the TCU tune). Looking forward to installing the upper pulley next month.

 

Good feedback, thanks!

 

The upper pulley is now by griptech so it don't slip,I don't if it's noticeable, maybe some one can chime in on that