my 2000 s has 43,000 miles on clock, it is very well looked after but when i really go for it, it seems to struggle going past about 110mph, now i know its not the done thing but going on its book speed i would say its not running right or something

 

Well, 110 is pretty fast I suppose and air resistance with the top down is crap.

Air resistance is also the square of velocity

Try holding them gears as long as possible to get the maximium from your engine.

110 is still 4th gear!

 

agreed but after 100 or so it doesn't seem to pull, not matter if its bouncing off the limiter or lower gear, roof up or down still the same

 

Is it a Japanese Import?

 

You thinking of poor fuel?

Speed limiter had no effect on my acceleration upto it.

 

No uk car

 

i did adjust the valves the other day which helped a bit, found the inlets to loose and the exhausts to tight

 

Import would have limiter.....

 

its not a limiter its an underpowered issue

 

What fuel do you use?