BMW 4.4 TT ends up in Lotus

Wagner · #1 02-16-2008, 08:36 PM

http://www.autoblog.com/2008/02/16/2...twin-turbo-v8/

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noncom23 · #2 02-16-2008, 08:44 PM

Yeah had a hot Lotus Elisse(spellcheck) blow buy me with a hot woman putting it through its paces yesterday. Nice cars. That Espirit will be tough with that engine...

FSETH · #3 02-16-2008, 09:03 PM

That article said that this engine produces 400 hp in the BMW at modest boost, but will be tuned to 500 hp in the Lotus. Why doesn't BMW tune it up a little more for thier own cars? Is reliability the biggest factor?

Eric5273 · #4 02-16-2008, 09:41 PM

Quote:

Originally Posted by FSETH

That article said that this engine produces 400 hp in the BMW at modest boost, but will be tuned to 500 hp in the Lotus. Why doesn't BMW tune it up a little more for thier own cars? Is reliability the biggest factor?

I think the Lotus version will be considerably more noisy and rough, which is ok for a sports car, but not for BMW which tends to want a smoother and quieter car. For example, the Lotus version will probably redline about 1000k higher than the BMW version, and the peak hp & torque will probably be at a higher rpm.

FSETH · #5 02-17-2008, 01:14 AM

For example, the Lotus version will probably redline about 1000k higher than the BMW version, and the peak hp & torque will probably be at a higher rpm.[/quote]

You are right, no need for that in the X6, which is more suited for a smoother engine and more torque at low rpm. I should have thought of that. I wonder if BMW will up the boost if that engine makes it into a 5 or 6 series. They could probably make a compromise between the 400 hp X6 and the 500 hp Lotus.

JCL · #6 02-17-2008, 02:57 AM

Quote:

Originally Posted by FSETH

That article said that this engine produces 400 hp in the BMW at modest boost, but will be tuned to 500 hp in the Lotus. Why doesn't BMW tune it up a little more for thier own cars? Is reliability the biggest factor?

If you consider that the 3.0 twin turbo uses the same technology as the 4.4 litre, the V8 is actually detuned from the inline 6. The 3.0 is rated at 300 hp, but appears to be making about 320 based on chassis dynos of stock vehicles. Even using 300 hp as a base, for the same specific output (hp/litre) it would give 440 hp in the V8. There are lots of chips or maps available for the 3.0 that are adding 60 hp simply by changing boost parameters and fuel maps. Even the Dinan ECU flash for the 3.0 is getting into that range, probably a little lower than 60 hp.

Factor all that together, and it would be easy to get 500 hp from a 4.4 twin turbo, completely smooth, same redline, same exhaust, same air intake. Play with exhaust and air intake, and 550 hp will be available in a few months from introduction, at the same redline, IMO. Increasing the engine redline is unlikely unless the turbos are also changed, as they are small and limited by maximum turbo speed.

The 400 hp rating is BMW conservatism, while they produce a few and get some real world data. Expect even the factory version to climb significantly in hp a year after introduction. This also fits with the marketing department concerns; BMW officially rated the 3.0 tt 300 hp which kept it well under the M3 rating, and it will help if the 4.4 tt is kept under the M5 ratings until the turbocharged V10 is in production.

FSETH · #7 02-17-2008, 01:02 PM

Quote:

Originally Posted by JCL

If you consider that the 3.0 twin turbo uses the same technology as the 4.4 litre, the V8 is actually detuned from the inline 6. The 3.0 is rated at 300 hp, but appears to be making about 320 based on chassis dynos of stock vehicles. Even using 300 hp as a base, for the same specific output (hp/litre) it would give 440 hp in the V8. There are lots of chips or maps available for the 3.0 that are adding 60 hp simply by changing boost parameters and fuel maps. Even the Dinan ECU flash for the 3.0 is getting into that range, probably a little lower than 60 hp.

Factor all that together, and it would be easy to get 500 hp from a 4.4 twin turbo, completely smooth, same redline, same exhaust, same air intake. Play with exhaust and air intake, and 550 hp will be available in a few months from introduction, at the same redline, IMO. Increasing the engine redline is unlikely unless the turbos are also changed, as they are small and limited by maximum turbo speed.

The 400 hp rating is BMW conservatism, while they produce a few and get some real world data. Expect even the factory version to climb significantly in hp a year after introduction. This also fits with the marketing department concerns; BMW officially rated the 3.0 tt 300 hp which kept it well under the M3 rating, and it will help if the 4.4 tt is kept under the M5 ratings until the turbocharged V10 is in production.

I see what you are saying about BMW not wanting these engines to rival their step-up M cars. BMW has unleashed a lion with these twin turbo engines. I have read posts here talking about people getting 350-400+ hp out of thier 335 with boost and exhaust upgrades. With modest upgrades the 335 is going to be closer to M3 performance wise than any top of the line 3 series in the past and I am sure that would be the case if they dropped the 4.4 tt in the 5 or 6 series cars now.

JCL, I see your slogan "no mods" does that mean that you are not considering pumping the boost on your 535?

JCL · #8 02-17-2008, 04:03 PM

Quote:

Originally Posted by FSETH

JCL, I see your slogan "no mods" does that mean that you are not considering pumping the boost on your 535?

It was a reaction to the endless "mods are good" threads when X5World started up. There were debates over mods vs stock, with a lot of strong opinions tendered. Every thread was about a push bar, CAI, lowering, tint, 4.6 badges, chrome gauge rings, DVD headrests, etc. None of that is bad, but it seemed for a while that this site should be X5worldmods.com It has all cooled down somewhat now, and oil separators are probably the most talked about item. I should change the tag line I guess.

I am thinking about an ECU flash for the 535, but the car is really coming alive now with about 5000 km on it, so I will wait another few months and decide. If I do one, it would probably be the Dinan flash, or a BMW performance flash which may yet be announced. I am less inclined to buy the Vishnu kit, and not interested in the Juice Box, Turbo Tuner, etc. I don't need a flash, but I want a flash. In the meantime, I am going to do the CDV on the X3, and Axxis pads on the 535 when I put the summer wheels back on (MSport wheels with double spokes; cleaning is a pain). I guess those are mods too, but at least they are functional ones.

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