Possible to Turbo e92 M3?

[Boosted_Brian]

Waiting for some to come with the "auto cross/track" argument....

[xxs65xx]

Originally Posted by Boosted_Brian

Like I said....

guess you missed what i said? here it is again...

Originally Posted by xxs65xx

anyway like some have already said there is no point

Originally Posted by Sean18337

I have yet to see a supercharged car make more torque than a turbocharged car.

wait and you shall see

[Boosted_Brian]

There is no point to what?

The tq to tq battle, is completely relative.

[Boosted_Brian]

Originally Posted by TrackRat

There's no magic in FI folks. An engine can handle a specific cylinder pressure before detonation for a given fuel/ignition/air temp. BMEP = torque. The more cylinder pressure the more torque at any given rpm point.

A turbo or supercharger can both provide enough boost to meet the maximum pressure point - at some but generally not all rpm points. A fixed displacement supercharger can usually only hit the max pressure point over a narrower range because of it's fixed displacement vs. the engines flow requirements to reach that point. A properly sized turbo can usually meet the max pressure point over a wider rpm band because a turbo's speed is not a direct function of crank speed.

Thus you can for instance have xx PSI boost with a turbo set-up from 2000-6000 rpm where as with fixed displacement superchargers you can't reach the xx PSI boost at 2000 rpm without running out of boost before 6000 rpm or over-revving the supercharger and damaging it. With variable displacement or variable speed superchargers you can widen the torque band but it takes proper sizing and drive ratios to achieve the same torque under the curve as a properly sized turbo and that is often not possible for many applications.

In addition a supercharger has parasitic losses that some folks find unacceptable. A properly designed and implemented supercharger system does however provide instant throttle response where as a turbo tends to be a softer initial hit, particularly at lower speeds where the turbo isn't running at high rpm.

I think you did a better job at explain this then I did.

The problem with most turbo setups is that folks want the biggest baddest turbo, but never get close the turbos maximum efficiency range. This causes poor performance across the power band, and typically a power band that is not usable till the last 4000 rpms.

Another thing to consider with a turbo setup, is that on day to day driving/cruising, there is no added stress to the motor and many times MPG is improved with a turbo setup.

However, many someone can explain this to me. it seems that with BMW s/c is the standard why is that. Is it a profit problem for shops, or what?

[xxs65xx]

Originally Posted by Boosted_Brian

However, many someone can explain this to me. it seems that with BMW s/c is the standard why is that. Is it a profit problem for shops, or what?

have no idea what you just said

[Richbot]

Originally Posted by Boosted_Brian

Like I said....

Welcome to M3Post, where opinions are facts, the more misinformed the opinion, the more factual the fact. It's kindof like watching cable news networks.

[Richbot]

Originally Posted by Dannys 335i

I am surprised no one has approached STS turbo about a kit. With some cooperation from the current tuners this could be a feasible forced induction option a lot cheaper than the current superchargers. Even the current procharger kits for vettes with twin intercoolers and tune, installed cost less than $6000. I have yet to see a supercharged car make more torque than a turbocharged car.

That's what jumped instantly to mind after the first time I looked under my car. Lots of room out back, not much up front, just like a 'vette. Hell you could probably fit one inside a hacked-open stock muffler if you wanted to be really stealth, and the rear "diffuser" hole would show off the turbo nicely if you're more into blang.

[Boosted_Brian]

Originally Posted by xxs65xx

have no idea what you just said

Sorry I was half asleep when I wrote that. What I was trying to ask was: I have noticed that in the BMW community s/c is much more popular than turbo applications. What is the reason for that?

[Boosted_Brian]

Originally Posted by Richbot

Welcome to M3Post, where opinions are facts, the more misinformed the opinion, the more factual the fact. It's kindof like watching cable news networks.

Yea, its like that everywhere. I remember reading somewhere in here someone making fun of the fact that "LED" and "Carbon Fiber" are the two hottest selling points on the forum. I laughed, because its true almost everywhere... LOL

[M&M]

Whole lot of great points on here, mostly theoretical. The point is that a powerful RWD will inevitably have a problem putting all this power down. It will become a dyno queen which resorts to high speed rolling runs on youtube to have any credibility.

A super has the advantage of a progressive, linear powerband. And even then the traction is still a problem. As the revs climb, the boost increases and the power increases with the rpm. A turbo has a whole heap of power in the mid as the boost comes in hard.

Not only does this have a negative impact on traction, but it causes detonation, strain on the gearbox & drivetrain, bottom end, etc. Ultimately a big turbo setup should make more power & torque than super, but with the disadvantages just mentioned & the underbonnet heat soak issues & having to mod the exhaust manifold.

A super comes in progressively which means less detonation, better traction & less strain on the transmission & engine. It's easier to bolt on & off. And the most important thing to me is that the car will still feel like an M3. Albeit an M3 on steroids, but the curve will mimic the factory curve. A turbo M3 will not feel like an M3 at all.

[ersin]

Generally speaking, since a turbo is not directly connected to the crank it can spin faster for a given rpm than a supercharger. You can have maximum boost at a low rpm and even throughout the rev band with a turbo; not so easy to do that with a s/c. So when measured over the whole rev band a turbo can potentially make more power. I don't know how well the S65 engine can take more boost than current s/c systems now give so the extra boost you could get from a turbo may not be usable.

But, given that boost is not linear with a turbo as with a s/c, it is probably harder for the engineers to tune the ECU. IDK, just a gut feeling. Still, if you have the will (i.e. money) I don't think there is any reason to believe that it cannot be done and might be able to give more power than current s/c add-ons. HPF is making ridiculous amounts of power out of the E46 M3 I-6 3.2L engine. So, I'm thinking there's probably more hp to be made with the S65 than current s/c solutions are making.


Cheers.

[xxs65xx]

Originally Posted by Boosted_Brian

Sorry I was half asleep when I wrote that. What I was trying to ask was: I have noticed that in the BMW community s/c is much more popular than turbo applications. What is the reason for that?

one major reason that there is no kit available right now is that there is no room in the engine bay, possibly a small single turbo could fit but ideally a twin turbo setup would be best and the only way to run a turbo setup would be under the car...all this is pointless anyway unless you have the cash money to do it, which was already stated

superchargers are the best route at this point, I am hoping HPF will find someway to get a kit out eventually maybe towards the end of production like the e46 m3

[Boosted_Brian]

Originally Posted by TrackRat

^^^^ Not exactly...

You can engineer a turbo system to do whatever you want it to do including mimic a supercharger boost profile. You're trying to convince yourself a supercharger is better when in reality it isn't necessarily better. It depends on the individual's goal(s).

If you've ever driven an Audi/VW OE configured 1.8/2.0T you'd know immediately that smooth supercharger like power can be had from a properly configured turbo vs. sudden explosive boost like from a 1977 Porsche 930 turbo which has a light-switch shot-out-of-a-canon boost response. If traction is an issue - fix it.

An FYI - Turbo companies like Warner-Ishi have actually built beautiful billet test superchargers to see if they could produce as good of results with a supercharger as their turbos and in the end the turbos always produced better power and driveability even though Warner-Ishi was hoping to break into the small specialty supercharger Biz.

The bottom line is use whatever makes you happy as long as you understand the pros and cons of each approach.

The old turbo Porsche. I believe that year the engines were air cooled. Correct? So the reason for the lager turbo was not to over heat the engine at low speeds with hot compressed air to keep the intake temp. low when the amount of air passing the motor would not be able to cool it.

[Boosted_Brian]

Ill admit, I am bias toward turbo. I have never owned a s/c car, but the sound of a turbo, along with an open atmosphere waste gate.... gets me everytime.

[M&M]

Originally Posted by TrackRat

You're trying to convince yourself a supercharger is better when in reality it isn't necessarily better. It depends on the individual's goal(s).

The bottom line is use whatever makes you happy as long as you understand the pros and cons of each approach.

I do understand. I have tried 3 or 4 different turbos & trim combinations on my E30 before settling on the turbo setup I have. If you want big horsepower you need a big pump. End of story. And with a big pump comes some issues. No matter what boost control setup you use, it's gonna' be nigh on impossible to bring the boost in progressively like a super.

I have a low boost-high boost setup, & I have a thumb button on the steering wheel to engage high boost. But it's still dramatic when it kicks in. And then there is the ever-present problem of lag on any big-turbo setup. If you don't have lag, well then you don't really have power.

[Boosted_Brian]

Originally Posted by M&M

I do understand. I have tried 3 or 4 different turbos & trim combinations on my E30 before settling on the turbo setup I have. If you want big horsepower you need a big pump. End of story. And with a big pump comes some issues. No matter what boost control setup you use, it's gonna' be nigh on impossible to bring the boost in progressively like a super.

I have a low boost-high boost setup, & I have a thumb button on the steering wheel to engage high boost. But it's still dramatic when it kicks in. And then there is the ever-present problem of lag on any big-turbo setup. If you don't have lag, well then you don't really have power.

Invest in an anti-lag system. All the true rally drivers do... lol
*This is sarcasm btw*