Hi, I find my 97 XK8 fairly low of real work torque in daily driving. Does anyone know if a Dyno based retune / remap of the ECU will make any difference, or is it endemic in the 4.0 design? I have replaced the exhaust with a more useful exhaust but thats it really. Cheers Morro
Did you notice any change in power when you changed the exhaust? I wonder if you moved the torque figure up the rev range?
Dont think it made much real world driving difference at all. Sounds way better but thats about it
Out of curiosity, did you change out the over axle exhaust or just the mufflers? I know those pipes are really flattened up there. As far as the remap, I’d be curious about it too. However, let’s face it, the car was not designed to be a race car despite it’s looks. You figure an almost 37-3900lb car being pushed by a 290 hp 290lbft motor, going through a 5 speed auto going through a 3.06 rear makes it not a rocketship. For the day it was comparatively sprightly! If they kept the power figures and built a 5.7L (lol) it would have been putting out roughly 414 hp! Wooohooooo! However going through the 3.06 rear would still hurt take off. That being said it was designed as a $70,000 grand tourer. So keep that in mind. Unfortunately yes it will get beaten by most everything newer on the road today. But it looks better than most anything else on the road today too imho 
Hi Jason. I replaced the lot from behind the cat back. No crushed pipes any more. I understand your point about the design. But a Kia will leave it standing. And by the way so does a 4 litre XJS and a V8 Xj8 with the same motor. Go figure!! Cheers
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I’ll say I know my 97 xk8 coupe will out run my 93 4.0 xjs convertible, however that is based on an intersection that I pull out from and run full throttle until the end of the guard rail lol. (Really scientific I know lol) the xk8 gets almost 8 mph more there. I’d love to try them side by side sometime.
Wow. Maybe its just mine. Sigh
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Or maybe it’s just my xjs 