Very very much +1...

And I'm quite sure you could get a turbo shipped to you or even find a local shop that can build the kit for you.

As for the ragtop, while its nice on an old beetle or an MGBGT, might even be fun on a classic range rover, on an X5, it will ruin the comfort and silence. The odds are also not great on long term waterproofing.
You might also consider a ragtop makes stealing a car or what's inside it much easier.

Can you buy a nitrous kit there?

I agree with you scourtaud23, i forgot about the stealing part :rofl:, as for nitrous kits its aginst the low in here apperntly, a supercharger kit from ess is there it costs 11k.
Buying and fitting a motor of 4.8 new x5 m series will cost 13k, and naturaly i would assume that my engine will need a whole new sets of pistons, pipes, reinforced gasket and other thing to withstand the turbo kit, so that will be around 17k project.

Although it sounds like something I’d watch other people attempt it’s not rational or cost effective idea. Just buy a 4.8is it’s same body with light touches. І взагалі цей проект хіба що на YouTube для просмотрів. I had a 4.6is and my cousin had 4.4i and it wasn’t a big enough difference to warrant this undertaking. Just my humble 0.02 cents.

As far as i know the 4.4l engine on x5 00-05 is the best, least problematic engine bmw has made, and the 40 hp difference isn’t much, and I already spent 7k on it to bring it to a good condition (replaced and fixed lots of things with some fixation on going) so selling it or getting another one is not a possible option.

There are 2 variants of the supercharger kit available in here one is 108-42H the secon is 108-42L difference is in price and the letter no other info are provided.

I googled both quickly, one is 6PSI (-42L) given for 400hp, the other is 8PSI (-42H) given for 422HP.

The complete kit seems to cost arond 5500$ so similar to a turbo setup. I don't have experience with one or the other but the supercharger may be nicer to use even if that means loosing the turbo kick.

Whould you recommend a turbo kit which is sutiable for the e53 pre-face lift, if there is one what comes as the extra work (i mean the engine is 17 years old) could it take the toll of that turbo/supercharger ?

The bottom end of the 4.4 will handle a supercharger without modification. The more you get out of a mod the greater the risk. You spend ya money and takes ya chances.

In addition to the supercharger you would need a matching tune, bigger injectors, high flow MAF and throttle body and to maximize benefits, lower restriction exhaust. Dinan offered a kit many years ago (no longer available) that took the 4.4 to 421HP and 404FT/LBs of torque. That kit also included the above and an intake manifold that had larger runners.

Turbos are more efficient and with twins there is very little lag. My research is dated but I found that good twin turbo kits and supercharger kits were about the same price. The supercharger kits are a less time consuming install so if you aren't DIYing labor install cost of turbos will be more. Other mods like lower ratio diffs are great values. I make my go fast decisions on dollars spent per HP/TQ improvement, focusing on improving 0-60 time. Due to weight of the X5 torque percent gains are more important than horsepower improvement.

Thanks to scourtaud23 and “bcredliner”
Would you recommend a turbo kit for that matter, i wouldn’t be DIYing it, but i own the autoshop so the installation will be free of charge (yay!:).