X5 2004 - Twin Turbo Help

[ne0c0de]

Hi

We are undertaking a new project with MST motor sports germany to build a new generation valvetronic X5 engine 4.8L to be bored to 5.0 and reduce the compression ratio to install a twin turbo system.

We need the best twin turbos to be chosen with combined power output of around 520-550 horsepower, which the turbos should be able to support. We dont want too big turbochargers for their top end power and rather medium sized for quick initial acceleration. The BMW factory already suggested not to go over the 520-550 HP range for the gearbox can face problems over these power ranges and the cost of upgrading the gearbox cud be expensive.

This will be an expensive project and I wud be grateful for any help i cud find.

Pictures attached are of the old 4.6L engine bored to 4.8L low compression pistons. ASA supercharged and water intercooled and gives around 500 horsepower.

Thanks in advance.

Nishad

[BeArs]

First time I'm hearing of this kind of project. All I wonder is how well could a vehicle that size possibly handle with that much hp/tq? What will be the overall purpose of this project?

[Jimmyz2]

"The BMW factory already suggested not to go over the 520-550 HP range for the gearbox can face problems over these power ranges and the cost of upgrading the gearbox cud be expensive."
Why not put in a 6 speed and really have some fun?

[ne0c0de]

It just goes over budget set for this project.

[ovlov28]

i would have to say, that a ball bearing turbo, or even needle bearings would be a good place to start looking for turbos, as well as water cooled, longevity is gonna be your friend with that monster. no specific turbos in my mind though

[littlefeat]

Originally Posted by ne0c0de

Hi

We are undertaking a new project with MST motor sports germany to build a new generation valvetronic X5 engine 4.8L to be bored to 5.0 and reduce the compression ratio to install a twin turbo system.

We need the best twin turbos to be chosen with combined power output of around 520-550 horsepower, which the turbos should be able to support. We dont want too big turbochargers for their top end power and rather medium sized for quick initial acceleration. The BMW factory already suggested not to go over the 520-550 HP range for the gearbox can face problems over these power ranges and the cost of upgrading the gearbox cud be expensive.

This will be an expensive project and I wud be grateful for any help i cud find.

Pictures attached are of the old 4.6L engine bored to 4.8L low compression pistons. ASA supercharged and water intercooled and gives around 500 horsepower.

Thanks in advance.

Nishad

This is a bold undertaking and I would love to hear about your project as you move forward. As far as turbo selection is concerned ,there is quite a bit of information available at Turbonetics and other turbo specialty outfits. Sizing the turbo and the primary tubesize (header) will need to be well matched to spool the turbo up quickly. Too small will spin the turbo nicely at first but will be a restriction at higher rpms and large tubes will have the opposite effect. They can run some math models to narrow down your choices.

The valvetronic system is a very advanced engine. I guess you know the valvetronic system will require some pretty advanced tuning. No throttle body! The throttle body only functions as a slave for other airflow/restriction functions....Intake airflow is done with variable valve lift. Welcome to the future!

The nice thing about valvetronic, (once you can find someone to tune it), is you can control your (drivability) boost control up stream of the turbo.

LF

[ne0c0de]

Well there will be the progress of this setup soon as the turbochargers are selected. The installation will done in germany and all the tests dynoed.

I will check with precision turbos as to what turbos goes best.

Thanx about the header info i read about it in a lot of places.

BMW says in two years they are going to release twin turbo cars as to what models i dont know ...

[Jimmyz2]

Yes,please keep us informed.Very interesting project!The reason why 2 turbo's instead of 1?Are you using the cooler in the pic's with the ASA supercharger?If not,I'll take it(and the S/C set up).

[ne0c0de]

Its an eight cylinder engine. It spools up faster even though the new turbos dont lag either. Other than that you can see there is space limitations and so using two is better than one big one and inefficiently routing the two banks together.

Nishad

[EMC]

Use two GT28R's....ball bearing turbos and you can get at least 550hp between the two of them.

[racerboy777]

are u serious? BMW will start making it so that certain models of their cars will come twin turbo from the factory?

[ne0c0de]

Its not a joke because for my project i really need the help from the BMW factory for the valvetronic electronics and their electronic engineers are preparing the setup for completing the complications of the valvetronic engine.

They said that they are already testing and will be surely bringing twin turbo cars which they didnt mention the model two years from now. If you are really interested i cud get you some info.

This is the first time we approached the factory and so they just said that they are already testing and release time is nearly two years...

[ne0c0de]

Use two GT28R's....ball bearing turbos and you can get at least 550hp between the two of them. <<<<<<<<<<<<<<<<<

Are u sure that this turbos are good and they are properly sized cuz i have to buy them from U.S and send them to germany to test this car.

Do you have any good suggestions???

[Dado]

Can't go wrong with the GT28r's. The lag should be minimal.

[Jimmyz2]

Have you asked Alpina for advise?.I know they have turbo'd BMW's in the past.And their reputation is quite outstanding.