New e70 owner with a few questions.
 

This is my 1st BMW. First German car in fact but I'm loving it. I picked up a 2008 X5 4.8i Sport that is monaco blue. I'm a big time modifier so I'm getting the bug already. I upgraded the HID bulbs and angel eyes bulbs and looking at an are kit next and having the black plastic body panels painted as well as a more aggressive hood.

The only issue I have would be the lack of aftermarket following the X5 has and on the forums every time someone talks about any kind of power adder people only tell them to trade it in on either a i50 or an M. I mean I had a WRX that I modded to out perform stock and most modified STi. I get starting with a better base is always the best way to go but come on. I can't imagine a 360hp motor being a bad place to start.

In any case I have a few questions I was hoping to get answered.

1. How much Wheel HP will the trans hold before letting go?
2. How much HP will the motor hold before it goes boom?
3. Can the ECU be custom tuned or are there only built maps for it?
4. Has anyone else done any custom turbo setups on the 4.8i?

I normally do "Dash before Flash" but with this car I think I'm going to tackle the looks of it first and then focus on the motor but I know at some point I'm going to want a power adder and after researching what is out there and the price it's most likely going to be a custom turbo setup. Nothing too big but something that can run with the X5M would be nice. But then again this is all on the idea that the ECU can be custom tuned.

Is it really worth it? I think that's the better question to ask [yourself]. Congrats on the purchase; I miss my 4.8i every day.

Well lets be realistic it's never "worth" it. I've built numerous cars and never once got the money I put into it back. So value wise, no. But for me the fun is in making the car mine. So for me the bragging rights of having the only twin turbo 4.8i running 11's would be a huge value. A lot more than saying I have a X5M running 11's. Could it be cheaper to just get an X5M? Maybe but where is the fun in that.

I'd rather buy a $2,000.00 car and spend $18,000.00 into it than buy a $20,000.00 car but that's just me. It's like a guy having an 1100hp Jeep SRT8, sure he could have built an 1100hp Charger SRT8 and been faster in the 1320 but that's been done before.

Wrong motor then


.Imagine.

You've confused the pig 4.8 in the X5 for other BMWs that are regularly modded. Should have done your research first- this is a microscopic market, with few choices and super high prices. You're on a custom path, all the way, based on my experience.

IMO

Well I may have picked the wrong motor but the G-Power "Typhoon" kit seems to be extracting enough power to matter from the 4.8i so it's possible.

I had a feeling I was going down the custom path which I'm ok with as long as the ECU can be tuned for it. I haven't seen any stand alone ECU's that can replace mine so it seems I'm stuck with it.

ANYTHING is possible, it is only a matter of money.


"Tuning" the ecu is the least of your issues. You will get jack spit from a tune alone...you need real changes that move air through the motor...a CAI kit and headers are not going do it. The g-power flash adds 4% or 15hp...

Supercharge that, and you'll be golden. the gpower SK1 can be purchased as a kit, not sure of the $$$. or are you going to cobble something together and try and find someone to tune it?

I wasn't planning on just tuning. My plan is some form of forced induction and tuning for out. I like the gpower but I can't seem to find anyplace to buy the kit without the full typhoons kit which is like 23k. Now I've turbo charged a few cars in the past but looking at the x5 I can't see enough room to do one unless it's an STS type system.

I'll admit I haven't done a ton of research yet but it seems hard to find threads of people like myself modding cars to that level. And I get that most people would say this car isn't the right car to mod like that but I can't help but want to take this car to that level.

I am a heavy modifier also coming from a full bolt on 335 convertable making 433hp/493tq. I was looking at 4.8 but once I found out that the base model LCI was quicker and better fuel economy than the higher model preLCI (4.8) I went for that. Not to mention the 35xdrive N55 engine carries over all te tuning capabilities of the other cars with the same engine.
I have a downpipe tune intake and exhaust and run e85. I dyno 333hp/525tq
Yes 525tq.
You didn't just pick a bad base. You picked a base where there is literally nothing you can do.
You can dinan supercharge for stupid money or go completely custom.
Sorry for the bad news.
An ecu will net you maybe 10hp