"twin Turbo M5 Update" - The Unofficial BMW M5 Messageboard (m5board.com)

LGREM · 13th February 2003, 13:37

I got the price for a twin turbo set up for the M5, its $14,500.00
at a speed shop in New Jersey, each turbo will put out 100 horses, so your talking 600bhp at the engine 530bhp at the wheels, they said that the turbo package will put less stress at the engine than a blower would.

Any one interested from the tri state area???

He said we would get a group package discount if I can get 10 guys to do it.

Im really, really interested, imagine what kind of performance your car can have, also if you want you just turn down the boost and the car is stock or if you want to play with a zo6 or viper or diablo just turn on the boost and blow them away.

Let me know who is interested, this saturday i am going to the shop to get measured for all the pipeing.

Oak · 13th February 2003, 14:34

Hardware shouldn't be too difficult to mfgr. But it sounds like a tuning nightmare. Good luck. I doubt there would be 10 guys to go for this unless they have had some type of track history. Beware of tuners that make everything sound good upfront, they promise you the world with no problems. You can get anyone to take your money, but how they handle problems if you have any is how they should be measured. Sounds risky.

LGREM · 13th February 2003, 16:11

This shop is in business since 1973, he specializes in turbos, they also have a CNC machine that can make any part or bracket you can think of, they upgraded my VR4 with larger turbos and a shi t load of other stuff.

This guy is a member of a lot of clubs and also a sponsor of a lot of autocross events.

He know his stuff trust me.

DoctorV8 · 13th February 2003, 16:59

Good luck...looking forward to hearing your progress.

But be wary of turning up the boost on a stock M5 motor, as the 11.0:1 CR doesn't leave much room for error. Even intercooled, 8 psi is probably all you can get away with (assuming 93 octane), and that's not going to give you 530 rwhp (roughly 200 rwhp over stock.)

Just as a comparison, my 9:1 compression Mustang with the same displacement as the M5 (302 cubic inches) makes close to 460 rwhp with 10 psi and a conservative street tune. I have big valve heads that probably flow similar to stock M5 heads. Easy to turn up the boost on a 9:1 motor....not so easy on an 11:1 mill.

However, low end TORQUE is the strong suit of the TT setup...I make 510 ft lbs at the wheels, 400 lb ft at only 2200 rpm....and that's with a 140,000 mile motor....with factory forged pistons.

Does anyone know if the factory S62 pistons are forged?

What does $14.5k get you? What kind of turbos? What kind of intercooler? Big injectors? Fuel pump? Is he going to use an FMU to ramp up fuel pressure, or does the M5 have a returnless fuel system? Exhaust modifications? Who is going to tune the car? Does he have a wideband O2 sensor and a load bearing (Mustang) dyno? Who makes tuning software for BMW? Is the VANOS adjustable or defeatable?

All very important questions.

Sanjay

FAST 5 · 13th February 2003, 17:45

man, it sure sounds as if you know your stuff! two thumbs up for you my friend!
Robert

jmott · 13th February 2003, 18:33

I would go further and say that any forced induction on an 11:1 compression ratio motor is lunacy.

=)

Adam · 13th February 2003, 18:57

Sounds interesting, good luck...

all the best
adam

AJ · 13th February 2003, 19:17

mmm i dont think so. even if they tune it right, reliability will be a big issue. besides, getting 50% more hp on stock 11:1 engine is not my idea of good product.

good luck

alex
02 gts
few other cars

FAST4DR · 13th February 2003, 19:26

Quote:

Originally posted by jmott
I would go further and say that any forced induction on an 11:1 compression ratio motor is lunacy.

=)

I strongly agree!

DoctorV8 · 14th February 2003, 18:58

Thanks for the compliment, Robert!

Forced induction with intercooling can be done reliably on a high compression motor as long as expectations for power gains are modest. The secret to engine longevity is all in the tuning...and this is where the M5 is in uncharted territory.

I've seen blown NSX's and S2000s....both with high compression...but power gains on those mini motors were less than stellar.

I'm considering an intercooled supercharger on my 11.0:1 C5 corvette, but it does have custom forged pistons and tweaks for better cylinder head sealing. I won't run more than 6-8 psi.

Looking forward to your updates, LGREM.

Philip · 14th February 2003, 19:26

Quote:

Originally posted by DoctorV8
Who is going to tune the car? Does he have a wideband O2 sensor and a load bearing (Mustang) dyno?

Sanjay

What is the importance of a "load bearing" dyno? Are you suggesting that this "load" is adjustable or fixed during dyno testing?

jmott · 14th February 2003, 19:38

Quote:

Originally posted by Philip
What is the importance of a "load bearing" dyno? Are you suggesting that this "load" is adjustable or fixed during dyno testing?

On the Mustang Dyno, the load is adjustable, so you can simulat the various loads on the car that you experience at various vehicle weights and speeds etc.

dynojets just have a free spinning wheel, so the load is fixed.

Tuning on a dynojet can have drawbacks since you may not get detonation there, but out on the road when loads increase you do.

its always good to do some street tuning too.