You can get all the HP and TQ that the existing driveline can handle with 4.8 aftermarket mods. You can purchase a made for 4.8 supercharger kit, Dinan mods, meth injection , nitrous, custom cylinder heads etc. Changing to a different engine is inviting never ending problems. Even if I had to spend a thousand or two more I would not consider changing to another engine unless I could buy everything I need to make it plug and play and didn't lose any of the features/benefits of the current cluster or have warning lights glaring at me all the time. Exhaust all opportunities to mod the devil you know before going to the devil you don't know.

who makes the SC? i've looked all over for one.

Call KO Performance and see it they can put one together for you. Going to be around $10,000 if they can. When I went to nitrous I checked out going to twin turbos or a supercharger. At that time neither passed my value equation. I would be spending much more and getting less performance than Meth and 150 shot of nitrous on top of the Dinan mods I did when it was new.

The downside of modifying E53-E70s is even if you go dangerously wild the HP/TQ numbers are ho hum compared to current modded M vehicles and you will have more invested in mods than the vehicle is worth. You can still have a great sleeper and be lots of fun. Only reason I am going further is that I don't intend to sell my X5, don't care if it is reliable and am OK if I blow it up.

Anytime you have a 15+ year old vehicle with 75,000+ miles mods are already high risk. If I was just starting mods the only things I would do are low restriction exhaust, Dinan engine, transmission, airbox mods plus lower gear ratio diffs. Would be cost effective and they would be safe and reliable mods. For added fun I would upgrade the suspension.

Now that's the spirit... You need to run for some election somewhere...


What's your max output currently with mods and meth/nos?

Appreciate your interest and I feel sure it is sincere. However, based on past experiences, it is not something I talk about anymore.

No problem, I understand. Let me try another way, would you do it today on a second hand car? mostly thinking of the Dinan mods and similar since meth/nos is quite illegal here.

Yes, I would. The Dinan mods--Air box, exhaust, throttle body, MAF and automatic transmission software per Dinan results in following:

stock 4.6 340HP 371 TQ at 5700RPMs
With Dinan Mods 369HP 382 TQ at 5700RPMs

Dinan engineering and testing is extremely thorough. They never push the engine into the danger zone and their performance claims are conservative.

Its not that big of an increase in number (<10%) but I'm guessing the curves is where the difference is.



However it appears not to matter as the parts are no longer listed on their website.

Low end HP and TQ curves are very similar until 3500RPM. Dinan curve then ramps up and peaks at 4500RPMs and then difference continues to be about the same to 6500RPMs. Since an X5 weighs so much and most of street fun is light to light, I focus on torque curve improvements much more than Horsepower gains. Torque gets you going and horsepower keeps you going. Dinan no longer offers most of the components. They were the only game in town in 2002 that I could buy that would not impact my MFG warranty.

The problem with starting on modding a 4.6 is stock 0-60 time is 6.2 seconds. Today performance vehicles come off the showroom floor with 0-60 times in the high 3s. I am going to take mine to the next level next year with a turbocharger but I bought an X5M a few months ago that is an example of today's baseline performance SAV that I want to start on early next year.

If I were you I would add a tune, trans software, make it sound better and drive on.