New Z4 gets a 4 banger!

[SCHMOUPE]

http://e89.zpost.com/forums/showthread.php?t=475051

Automobile has just tweeted some interesting news on the base Z4. If their report is correct, the base BMW Z4 will soon be powered by a turbo 4-cylinder instead of the current naturally aspirated inline 6-cylinder. This would not come as a huge surprise as recent rhetoric from BMW has pointed to the likely use of turbo 4-cylinder engines in future BMW base models (i.e. next generation F30 3-series), especially with improvements in forced induction technology and the overall goal of increasing efficiency throughout its entire fleet.

The exact tweet states "BMW new 4-cyl coming this year in Z4 roadster. Replaces nat asp 6, so at least 200 hp" but we're hoping the 200hp is a conservative low-end estimate since the current base Z4 has 255hp.

[lstratos]

Wonder if they'll ever make that z2 they were talking about

[mhughett]

I heard Porsche was also playing around with the idea of using a 4-cylinder turbo engine in its base models too. For BMW, I'm not sure what good this will do. The N52 engine is already very efficient--much more so than competitor's smaller turbo engines. I doubt that a turbo/4 will get better mileage and certainly would not be as smooth or as powerful. It has now been over 15 years since BMW has sold 4 cylinder engines in the USA. I think they have forgotten why they stopped.

[vicj]

It was my impression from what I read, that they stopped selling 4 cylinder engines because of where they wanted to position themselves on the market as a premium brand, not because they didn't sell. The 318I was, and continues to be, a very sought after model for many.

I read that if and when BMW brings 4 cylinder engines back to the US, they will probably be the 4 cylinder diesel engines that are so popular in Europe. Those engines WOULD make a very large difference in the overall mileage ratings of the fleet.

[chickdr]

The E85 had a 4 cylinder variant in other parts of the world so it isn't too surprising. The issue to me is why can't it have the same if not more power than the current 3.0 motor? GM had a 260hp 2.0T 4 cylinder in the "Skystice"(which could be factory chipped to 290hp) so BMW should easily be able to match it.

[epbrown]

Originally Posted by chickdr

GM had a 260hp 2.0T 4 cylinder in the "Skystice"(which could be factory chipped to 290hp).

Ya don't say?

[The HACK]

Originally Posted by chickdr

The E85 had a 4 cylinder variant in other parts of the world so it isn't too surprising. The issue to me is why can't it have the same if not more power than the current 3.0 motor? GM had a 260hp 2.0T 4 cylinder in the "Skystice"(which could be factory chipped to 290hp) so BMW should easily be able to match it.

The 2.5 liter Turbo 4 in my WRX makes 265hp stock.

But the way it makes power SUCKS. There's nothing there until about 3,000 RPM. Before that it pretty much feels like a stock 4 cylinder saddled with 3,200 lbs of weight.

So we can all bemoan the fact that other companies can make a turbo 4 make XXX HP (heck, Hyundai has a turbo 4 that makes 275. Why don't we shoot for that?). The simple physical limitations would dictate, that unless it's got a tiny turbo, the spool time is going to make the engine super peaky. And with a tiny turbo, a 2.0-2.5 liter 4 cylinder turbo isn't going to make much more than 230-250 hp.

I think BMW is making a huge mistake by saddling a peaky 200-240ish motor with a 3,400+ lbs frame. As if the new Z4 isn't "tuned down" enough, a smallish turbo 4 is going to make it darn near un-drivable.

Heck it'll probably drive like my old Z3 1.9L at 2,600 lbs and change and 140 hp on a good day. Except it won't corner as well, stop as well, and accelerate as well.

[Rated M]

twin turbo 4 cyl????? this would solve the power delivery lag..


just sayin...

[SteveInfante]

Twin charge anyone?

[epbrown]

Originally Posted by The HACK

So we can all bemoan the fact that other companies can make a turbo 4 make XXX HP (heck, Hyundai has a turbo 4 that makes 275. Why don't we shoot for that?). The simple physical limitations would dictate, that unless it's got a tiny turbo, the spool time is going to make the engine super peaky. And with a tiny turbo, a 2.0-2.5 liter 4 cylinder turbo isn't going to make much more than 230-250 hp.

The GM turbo 2L in my Kappa avoids the spool-time issue the same way BMW does wth the N55 - a twin-scroll turbo rather than twin-turbo. I'm betting they do the same with the turbo 4.

[chickdr]

I don't hear many complaints about power delivery in the Audi A4 2.0T either. Theirs "only" makes 211hp(258ft-lbs) and the car weighs 3600lbs.

[The HACK]

All I am saying, is there's no natural way around turbo lag. To make a ton of power out of a 4 cylinder, you need a large turbo. Large turbo introduce lag. To reduce lag, you need smaller turbos. Smaller turbos make less power.

I mean, take a look at some of the engines on the market. N54 for example. Two tiny turbos. Makes ~40ish more HP from its NA counterpart. Little lag. Hyundai Theta II engine. Makes 70 more HP from its NA counterpart. One medium sized turbo. Moderate lag. The Subaru WRX engine. One giant turbo. Makes 90 more HP from its NA counterpart. Massive lag.

So here's the problem I see with the new Z4 with turbocharged inline 4. Let's say it comes with a 2.2-2.5 liter engine. Theoretically a NA version of the I4 at that size should make around 180-200 HP. Throw a couple of tiny turbos on it, let's say it makes an optimistic 30hp from the twin scroll or twin turbo. You're looking at 230hp (same as what the N52 3.0 liter makes. I'll bet this is the number they'll shoot for in the turbo 4) to move 3,400 lbs.

My wife's E92 328i (that we returned after getting the Tucson) makes 230hp and carries a 3,300 lbs frame. It is a DOG. Dynamically it's barely as exciting as my old 323Ci making 173hp (actually the 323Ci was far more dynamic due to the 3,100 lbs frame and high gears). Acceleration times were comparable. Even if BMW were to throw in a 7 speed auto and a super short rear end to mask the deficiencies, you're still looking at a dog of a car. At least with the current Z4 line-up, your choices are a very capable and dynamic N52 that's the same as what was equipped in the old Z4 3.0Si, or the Twin scroll N55, or the overboosted N54 to haul around that lard-@ss of a chassis.

[dazed^]

Yeah, 4 cylinder engines are nothing new. Fingers crossed for no M version in '12.

[Finnegan]

Originally Posted by The HACK

All I am saying, is there's no natural way around turbo lag. To make a ton of power out of a 4 cylinder, you need a large turbo. Large turbo introduce lag. To reduce lag, you need smaller turbos. Smaller turbos make less power.

I mean, take a look at some of the engines on the market. N54 for example. Two tiny turbos. Makes ~40ish more HP from its NA counterpart. Little lag. Hyundai Theta II engine. Makes 70 more HP from its NA counterpart. One medium sized turbo. Moderate lag. The Subaru WRX engine. One giant turbo. Makes 90 more HP from its NA counterpart. Massive lag.

So here's the problem I see with the new Z4 with turbocharged inline 4. Let's say it comes with a 2.2-2.5 liter engine. Theoretically a NA version of the I4 at that size should make around 180-200 HP. Throw a couple of tiny turbos on it, let's say it makes an optimistic 30hp from the twin scroll or twin turbo. You're looking at 230hp (same as what the N52 3.0 liter makes. I'll bet this is the number they'll shoot for in the turbo 4) to move 3,400 lbs.

My wife's E92 328i (that we returned after getting the Tucson) makes 230hp and carries a 3,300 lbs frame. It is a DOG. Dynamically it's barely as exciting as my old 323Ci making 173hp (actually the 323Ci was far more dynamic due to the 3,100 lbs frame and high gears). Acceleration times were comparable. Even if BMW were to throw in a 7 speed auto and a super short rear end to mask the deficiencies, you're still looking at a dog of a car. At least with the current Z4 line-up, your choices are a very capable and dynamic N52 that's the same as what was equipped in the old Z4 3.0Si, or the Twin scroll N55, or the overboosted N54 to haul around that lard-@ss of a chassis.

There's nothing here I disagree with. And my DD is an 07 STI--holy lag and delayed throttle response Batman! (Once it does kick in though it's fun--but not something that's precise or great as a "sports-car"--to hard to control the throttle).

I suspect the whole thing with the 4 cylinder is simply a strategy to comply with CAFE and EU CO2 standards and so on. A way to get fleet averages down and probably a way to net some more profit as well by selling a "lower end" Z. I think BMW assumes that a lot of potential Z owners (and this isn't people on this board) like how the car "looks" and are buying that and "brand" not actual performance. Coming from their Camry or Prius, it will probably be "fast enough" for them and "look cool". Why do I think that's what will matter to a lot of buyers?

Last spring when I was at my dealer looking at the Z4M coupe they had on the lot the SA said they were having a hell of a time selling it because "it doesn't have an automatic or a retracting hardtop" (car was on the lot 5 months in fact). They also had current MY on the lot with a manual and it had been there 9 months. no takers as it had it a stick. That says a lot about your typical Z4 buyer! I chatted with the SA a bit and he said the current batch of Z4 potential buyers he'd worked with were not "enthusiasts", wanted automatics, and didn't ask any performance questions (MPH however, yes). That, and like my wife says, most Z4 drop-top buyers--again, not folks here but the masses--are chicks into a certain "look" who wouldn't know performance or driving if it bit them....

So I don't think a bloated chassis, the turbo 4 (especially if set up like the N55) is going to matter much to the typical Z4 buyer. They'll think "wow, I can get a nice bimmer with an automatic and better gas mileage for cheaper than that top-of-the-line model, and I can get some extra time in working on my tan while driving to the beach."

[epbrown]

Originally Posted by The HACK

So here's the problem I see with the new Z4 with turbocharged inline 4. Let's say it comes with a 2.2-2.5 liter engine. Theoretically a NA version of the I4 at that size should make around 180-200 HP. Throw a couple of tiny turbos on it, let's say it makes an optimistic 30hp from the twin scroll or twin turbo. You're looking at 230hp (same as what the N52 3.0 liter makes. I'll bet this is the number they'll shoot for in the turbo 4) to move 3,400 lbs.

I agree with your prediction - I think BMW will shoot for 230-260 from the new I4, and I would expect torque would be about equal to horsepower; that's higher than the 3.0si, and so should actually give the base model Z4 a performance bump. I don't see why the twin-scroll 2-liter's power delivery would be inferior to the twin-scroll 3-liter, and you seem to find that acceptable.

[mhughett]

The problem is that even if they are able to match torque and 0-60 times with the N52 engine, I seriously doubt that the turbo 4 will be more fuel efficient. After all, the N52 can achieve close to 30 on the highway and easily does low-mid 20's in town. So what have they really gained? They end up with an engine that is not as smooth and refined and gets about the same mileage. Doesn't sound like such a good deal to me.

[pokeybritches]

Rather than two turbos, why not add two more cylinders? Perhaps in a straight line? Maybe that would require too much in the way of engine development (N52, M54, S54, SOMETHING), throttle response, durability, reliability, harmonic balance, history, power delivery, and prevent the overboosting of a stock engine unbeknownst to the following owners and semi-supported dealership. Reliability in the 135i was spectacular, and the naturally aspirated M3 was terrible...

Wait... we've got to concern ourselves with the polar inertia of a long block slant six, and its effect on handling. Nevermind the 3600 lb car requiring massive brakes and unsprung weight, 19" wheels and RFTs, and higher spring rates that compromise in the ride and cornering over broken pavement.

Nevermind. I just watched Fast and Furious. The sound of a buzzing 4 banger is SEXY, especially when revving to the moon! (The moon being 6500 rpm or so).

[ga41]

I dont think this will replace the 3.0 as the base engine in the US. You guys are forgetting that the E89's base engine in Europe (and maybe other places too) is the N52B25, a 205 hp, 2.5lt six cylinder. I'm guessing this new 4 cylinder turbo will replace that, not the 3.0...

The E85 came with an entry model 2.2lt six when it was first introduced and then that engine was replaced with a 2lt naturally aspirated four when it was facelifted. I personally see nothing wrong with a 2lt turbo Z4... The 4 cylinder Z4s, SLK, TTs and what not have always been the best sellers here in Europe and i dont think BMW would miss out on that with the E89.

[thekurgan]

Does anyone think BMW may offer the 4 cyl turbo diesel like the one offered in the EU 120d/118d? That thing had plenty of bottom end torque, really smooth and sweet mpg on top.

[The HACK]

Originally Posted by thekurgan

Does anyone think BMW may offer the 4 cyl turbo diesel like the one offered in the EU 120d/118d? That thing had plenty of bottom end torque, really smooth and sweet mpg on top.

YES. They'll have to to meet the higher EPA averages.

If I were to ever buy another new BMW, it'll have to have a 4 cylinder diesel in it.

[chickdr]

Just saw the official word is out on the new I-4 2.0T. 245hp and 255ft/lbs. Not as strong as GM's Skystice 2.0T(260hp/260ft-lbs) but not too far off. Seems a pretty good replacement for the 3.0si motor in the base E89 should BMWNA want to go that route. Supposedly very amenable to tuning as well. http://www.bimmerpost.com/forums/sho...d.php?t=477882

[ANUSTART]

The horsepower to weight ratio is probably in the same ballpark. The Skystice is a relatively beefy car compared to the Z.