[CobraMarty]

Hey Gavin,
You can't get PM's.
So tired of the naysayers.
How's things going?
Are any of the VF SC systems close to fitting the N52? At least the hardware pieces. They have so many kits for the I6 I can't believe that one of them isn't close. Have you teamed up with Vortech or VF?
I like the ESS twin screw SC system. Have you seen these? Better and easier packaging than vortech. I bet one of these would bolt up with minimal modifications.
Just thinking.
Do you have a 07 crank pulley? What were you going to use? Were you going to use the stock belt/pulleys or a second pulley and belt?
Marty.

[issabmw]

Let me alleviate your inquiries the best way possible.

Things are going well. Its a centrifugal, not a roots (twin screw). I have an ESS Twinscrew on my e46, its a pretty easy system, but not ideal for the N52.

Centrifugal will give us what were aiming for: reliable, safe power.

New belt is used of course.

It's right around the corner so don't lose sleep over the kit. It'll be done soon enough. Any other questions feel free to contact me. Keep it general, as I cannot give any details.

[just4kickz]

woowoo

[CobraMarty]

[QUOTE=issabmw;9936238 I have an ESS Twinscrew on my e46, its a pretty easy system, but not ideal for the N52.[/QUOTE]

That is interesting. Why do you feel the twinscrew like on your e46 is not ideal for the N52? What kind of power curves does it make? What is the boost curve like?- pretty flat 5psi 1500 to 6000? Verses the vortech which rises with rpm- like 1psi at 1000, 2psi at 2000, etc, 6psi at 6000rpm.
Wouldn't the twinscrew make more lower end boost/TQ which is just what the N52 needs.

[inline607]

Looking forward to good news! Would love to purchase a SC kit that's street use reliable!

[issabmw]

Originally Posted by CobraMarty

That is interesting. Why do you feel the twinscrew like on your e46 is not ideal for the N52? What kind of power curves does it make? What is the boost curve like?- pretty flat 5psi 1500 to 6000? Verses the vortech which rises with rpm- like 1psi at 1000, 2psi at 2000, etc, 6psi at 6000rpm.
Wouldn't the twinscrew make more lower end boost/TQ which is just what the N52 needs.

Thats the problem. A flat curve. The twin screw does not retain the daily driveability and natural aspiration properties of the centrifugal.

Ideally, I would not want to consistently make torque on an already fragile motor and tranny through the powerband, forcing the methanol to constantly inject to keep the engine load light.

In short, you can take the car out, rain or shine with the supercharger. When I drive to the grocery store or the mall, I dont plan on bringing it above 3k rpm. Saves the engine, the methanol, and most importantly the transmission.

It will save the hassle of lightly treading, for those of us with heavy right feet. Also for us awd guys like me, torque that low down and no wheelspin means thats tranny is taking all of the stress under heavy starts or launches.

Now I don't want to instill the idea that our transmissions are weak. As far as I know the ZFs and GMs are rated to an average of 330 ft-lb to the flywheel. That gives us plenty of room to work with, but as we get near the limit, the more cautious we need to be.

Another reason is that the twin screw would require fabrication to create a manifold of bolt-on properties. For the sake of simplicity of the system, and in prevention of costs being driven up twofold, this was an obviously unfeasible option. The simplicity of the centrifugal kit was unparalleled.

Everything points south when considering a roots style blower. Its a great system, but theres a time and place for everything, and this isn't one. The most feasible option, I believe, is the option that we took.

Plus, who doesn't like winding up that sweet 6

Hope this helps

[issabmw]

Originally Posted by CobraMarty

Wouldn't the twinscrew make more lower end boost/TQ which is just what the N52 needs.

No no no you got it all wrong....
You gotta wind that thing up

Originally Posted by inline607

Looking forward to good news! Would love to purchase a SC kit that's street use reliable!

Boom, there you go. Key words reliable and street.

[bpas328xi]

Originally Posted by issabmw

Thats the problem. A flat curve. The twin screw does not retain the daily driveability and natural aspiration properties of the centrifugal.

Ideally, I would not want to consistently make torque on an already fragile motor and tranny through the powerband, forcing the methanol to constantly inject to keep the engine load light.

In short, you can take the car out, rain or shine with the supercharger. When I drive to the grocery store or the mall, I dont plan on bringing it above 3k rpm. Saves the engine, the methanol, and most importantly the transmission.

It will save the hassle of lightly treading, for those of us with heavy right feet. Also for us awd guys like me, torque that low down and no wheelspin means thats tranny is taking all of the stress under heavy starts or launches.

Now I don't want to instill the idea that our transmissions are weak. As far as I know the ZFs and GMs are rated to an average of 330 ft-lb to the flywheel. That gives us plenty of room to work with, but as we get near the limit, the more cautious we need to be.

Another reason is that the twin screw would require fabrication to create a manifold of bolt-on properties. For the sake of simplicity of the system, and in prevention of costs being driven up twofold, this was an obviously unfeasible option. The simplicity of the centrifugal kit was unparalleled.

Everything points south when considering a roots style blower. Its a great system, but theres a time and place for everything, and this isn't one. The most feasible option, I believe, is the option that we took.

Plus, who doesn't like winding up that sweet 6

Hope this helps

I want low end torque. After 4500, the engine winds out fine for my tastes. I just think it needs some more power low down for that "put you in the back of your seat" feeling that I like so much.

As for the flat torque curve problem, it's flat anyway because of the VANOS. I.e. 200ft-lbs (minus drivetrain losses of course) from 2000ish to 6500ish.

Just my .02 .

[issabmw]

Originally Posted by bpas328xi

I want low end torque. After 4500, the engine winds out fine for my tastes. I just think it needs some more power low down for that "put you in the back of your seat" feeling that I like so much.

As for the flat torque curve problem, it's flat anyway because of the VANOS. I.e. 200ft-lbs (minus drivetrain losses of course) from 2000ish to 6500ish.

Just my .02 .

It will still be spooling low down, just not as much as a roots blower. "After 4500" you will inevitably have boost with any supercharger, its just a matter of how it delivers. The roots will start to run out of steam, while the centrifugal will help itself to the whole upper powerband.

Not to mention the lesser discharge temps, and ease of installation. Roots SC is not a walk in the part to install.

You will still get that thrown into the seat sensation especially compared to the power you have now, just without the tranny wrenching stress.

It's already finished and *surprise*, its a centrifugal unit. I don't think we will ever make a roots style kit.

If its not to your liking, dont worry. I'm sure there are plenty of kits out there

But seriously this is the safest compromise between power and reliability. Better a balanced boost of power than a blown engine with no power.

Excuse me, I use the terms roots and screw type interchangeably. By roots I always mean screw type.

[issabmw]

Originally Posted by bpas328xi

As for the flat torque curve problem, it's flat anyway because of the VANOS. I.e. 200ft-lbs (minus drivetrain losses of course) from 2000ish to 6500ish.

Regarding the flat torque curve, regardless of the VANOS, the issue still stands. While the variable timing cures the natural torque delivery, the centrifugal will not succumb to those properties due to its boost inclination in congruence with the corresponding rpm. As in, the VANOS system cannot force the unit to spill more boost, as the unit only functions on an rpm basis to deliver compressed air.

Hope this helps

[bpas328xi]

Originally Posted by issabmw

It will still be spooling low down, just not as much as a roots blower. "After 4500" you will inevitably have boost with any supercharger, its just a matter of how it delivers. The roots will start to run out of steam, while the centrifugal will help itself to the whole upper powerband.

Not to mention the lesser discharge temps, and ease of installation. Roots SC is not a walk in the part to install.

You will still get that thrown into the seat sensation especially compared to the power you have now, just without the tranny wrenching stress.

It's already finished and *surprise*, its a centrifugal unit. I don't think we will ever make a roots style kit.

If its not to your liking, dont worry. I'm sure there are plenty of kits out there

But seriously this is the safest compromise between power and reliability. Better a balanced boost of power than a blown engine with no power.

Excuse me, I use the terms roots and screw type interchangeably. By roots I always mean screw type.

I knew that the kit was going to be a centrifugal setup from the beginning anyway... I'm just saying, power is power and boost is boost no matter what it comes out of.

Are you guys going to be providing a hand-held tuner with the kit? Gavin has mentioned this in his previous threads. I hope this is still the case.

[issabmw]

Originally Posted by bpas328xi

I knew that the kit was going to be a centrifugal setup from the beginning anyway... I'm just saying, power is power and boost is boost no matter what it comes out of.

Are you guys going to be providing a hand-held tuner with the kit? Gavin has mentioned this in his previous threads. I hope this is still the case.

The tune will most definitely come with the car. Sending the ecu would be a huge hassle.

This kit is very DIY friendly so open up the beer and get crackin'

[CobraMarty]

Looking forward to the finished product and dyno sheets with boost graph and A/F ratios. Love the 'user' friendly, don't have to pull the ECU out for programming.

Under non spirited, every day normal driving an less than 75% throttle, the twin screw SC will put out minimal if any boost. Even if it put out 6psi all the time and you drove WOT all the time, the max TQ this engine will produce is about 265 well below the trans/clutch limit. Have you dynoed your car with the twin screw SC?

[issabmw]

Originally Posted by CobraMarty

Looking forward to the finished product and dyno sheets with boost graph and A/F ratios. Love the 'user' friendly, don't have to pull the ECU out for programming.

Under non spirited, every day normal driving an less than 75% throttle, the twin screw SC will put out minimal if any boost. Even if it put out 6psi all the time and you drove WOT all the time, the max TQ this engine will produce is about 265 well below the trans/clutch limit. Have you dynoed your car with the twin screw SC?

Yes the user friendly is a huge plus and the primary goal.

The usage of a screw type would require different goals, aspirations and power expectancy. It would be a different ball game.

The centrifugal is expected to make more than that estimate, at a safer powerband.

Now with the 75% throttle inference, that would consist of no hard launches, no fast takeoffs. When cruising on the highway, I typically leave it in 5th or 6th and overtake with WOT on the higher gears. This would involve usage of the entire output of torque.

Understanding that the situation is unavoidable, through any means while the powerband is that low, you end up with far more use of the full amount of torque when not intended or needed.

With the engine or transmission not warrantied, this is the most reliable solution against anything close to stressing either the engine or transmission.

Understand that so long that the torque figures are reached, a constant flow of methanol must be utilized to ensure this amount of power doesn't upset the engine. In this case the advantage of the centrifugal's steadily climbing pressure allows methanol conservation, management, and prediction, as the rpm position is congruent to the amount of methanol being dispensed, given the properties of the centrifugal SC: rising pressure as the rpms climb.

The engine would also have to suffice with the higher discharge temps, which would compromise the intricate cooling. Not only that, but the engine's structure coincides with a natural endurance for higher revs, which coincidentally applies to the centrifugal's nature. The roots would not provide adequate pressure within the higher rev band, where a natural supplement would be preferred, but at lower revs, where the problems I've described occur.

The centrifugal is natural, reliable (far more than the screw type, ask me how I know), more efficient and much easier to install.

I have dynoed the e46 long ago, logs are probably on a hard drive somewhere. The low down torque is fun, but it feels unnatural as you lose steam up there, rather V8 like.

[CobraMarty]

No matter how you slice it, dice it, chop it up, hope and wish, 6 pounds of boost will only give you 33% increase in HP/TQ. 8 pounds can give 44%. Best case.

So for a stock 328 with 230HP/200TQ you will only see 306HP/266TQ at 6 pounds or 331HP/288TQ at 8 pounds at the crank.
With 22% driveline loss you might see 238HP/207TQ at 6 pounds or 258HP/225TQ at 8 pounds at the wheels.

So why won't the twin screw bolt on to the N52 head? Ignoring the accessories for now, I believe that the intake pattern is the same.

[mike-y]

You'd need to tool and manufacture a new intake manifold for a roots blower as well. Our IM's are plastic as well, so you would need to add some sort of support to carry the additional weight of the blower.

sounds like it would be a heck of a lot more work to fit a twin-screw on the N52. The centrifugal is much easier, even though the power delivery is less than ideal.

[CobraMarty]

Here is a better graphic representation of what I am talking about. This is the AWD dyno results of 328xi with PE and EURO intake in RED, predicted vortech/centrifugal SC in ORANGE(actually looks red), and predicted twin screw SC in GREEN, with boost numbers at the bottom. The twin screw will put out 20-30 more TQ at lower rpm- hardly V8 territory or trans breaking, but lose a little TQ at rpm over 5000.

Don't get me wrong, I have had both SC in the past, neither is better, just different.

[CobraMarty]

Originally Posted by mike-y

You'd need to tool and manufacture a new intake manifold for a roots blower as well. Our IM's are plastic as well, so you would need to add some sort of support to carry the additional weight of the blower.

sounds like it would be a heck of a lot more work to fit a twin-screw on the N52. The centrifugal is much easier, even though the power delivery is less than ideal.

It's already been done, That's what I am saying. Check out: (OK it's for the e46 but I'm sure it would fit N52 head)
http://www.esstuning.com/products/M5...28TS1%29-.html

[issabmw]

Originally Posted by CobraMarty

No matter how you slice it, dice it, chop it up, hope and wish, 6 pounds of boost will only give you 33% increase in HP/TQ. 8 pounds can give 44%. Best case.

So for a stock 328 with 230HP/200TQ you will only see 306HP/266TQ at 6 pounds or 331HP/288TQ at 8 pounds at the crank.
With 22% driveline loss you might see 238HP/207TQ at 6 pounds or 258HP/225TQ at 8 pounds at the wheels.

So why won't the twin screw bolt on to the N52 head? Ignoring the accessories for now, I believe that the intake pattern is the same.

I calculate it, for that matter, by a 6.8% constant value given the fact that at 14.7 psi, the ground atmospheric pressure, one psi of compressed air divided by the atmospheric pressure of 14.7 results in a 6.8% net gain per psi boost added, at sea level of course. That is the constant value of net gain. Given the 6psi leap, multiply that by 6.8, yielding a 40.8 percentage yield gain. That factors out to 323.8 for the 328i at the flywheel, 281 foot pounds to the flywheel. Considering the limit is around 320~330 at the flywheel for the transmission, that is awfully close. Now for 8psi, that yields a 355.1 horsepower estimate and a 308.9 torque estimate. Thats around 15 ft/lb away from the average limit of flywheel torque that transmission can take, as rated by the manufacturer. A little too close and a little too much right foot management.

We're going to be making better figures than 266 foot pounds; a set fact as a separate entity, independent of any boost figures mentioned. Fact of the matter is we are running higher figures, and no matter how you dice it up, the N52 will not coincide with the properties of a twin-screw, and for long term reliability, its a definite no. Were not after moderate gains with the slightest preservation for the sake of the transmission. It would be much more feasible to build an NA machine. And also, you can never escape the inevitability of immediate torque consumption rather than caution; the average driver will not respond to mildness, especially with the demands of driving.

This, once again, isn't a mild application. If it were, take a guess at how many people would shell out 6-7k for a moderate gain, with the same boost properties of a 335, engine response as a 335, less reliability, and a responsibility of constant methanol injection. Aggressive, twin-screw, and N52 do not go hand in hand.

The twin-screw out of the e46 will most probably not bolt up to the head of the N52, completely different manifold design as designated by the variable intake properties, or so I assume. I wouldn't test a twin screw on the N52 without an elaborate chamber cooling system in place.

A stage 2 is planned as well, bringing us closer to that transmission limit. Factoring in that margin of error for the maximum torque leaves us awfully close to what can and eventually will go wrong had a twin screw been used.

With a twin-screw application, the 'go buy a 335' argument clearly stands and inevitably wins. Low down torque? 335 has plenty of it. Roots offers less torque estimates, diminished reliability, constant methanol injection, and descending power at the upper powerband is more than enough to factor out the twin screw. The 335 offers the twin-screws properties without the hassle and pricetag.

The centrifugal was the best bet for this application. No doubt about it. This isn't an iron M20 or S54, or aluminum M52/54. Its an AluMag N52 and if 140-160k miles is on your wishlist like me, this is the way to go.

[issabmw]

Originally Posted by mike-y

You'd need to tool and manufacture a new intake manifold for a roots blower as well. Our IM's are plastic as well, so you would need to add some sort of support to carry the additional weight of the blower.

sounds like it would be a heck of a lot more work to fit a twin-screw on the N52. The centrifugal is much easier, even though the power delivery is less than ideal.

You are very correct.

It would be a hell of a lot more expensive for you. Costs would be driven up the wall, and you would be paying 10k for 335 power delivery. Not feasible at all.

Plus, that is an ESS kit. There is no partnership here. The kit we are selling is an MMW homegrown kit. Taking an already accomplished kit for an M52, refabbing it to our own making us the second hand consumer, then selling it again is a business negative.

[issabmw]

Originally Posted by CobraMarty

It's already been done, That's what I am saying. Check out: (OK it's for the e46 but I'm sure it would fit N52 head)
http://www.esstuning.com/products/M5...28TS1%29-.html

This is for the M52B28, which is two generations before the N52 and one generation before the M54. This is e36 territory. And a 2.8 application. This wont work at all.

[bpas328xi]

Originally Posted by issabmw

With a twin-screw application, the 'go buy a 335' argument clearly stands and inevitably wins. Low down torque? 335 has plenty of it. Roots offers less torque estimates, diminished reliability, constant methanol injection, and descending power at the upper powerband is more than enough to factor out the twin screw. The 335 offers the twin-screws properties without the hassle and pricetag.

For the "constant methanol injection" argument... How about propane. It's cheap and has an octane rating of about 114.

Are you using the methanol for an octane boost or to cool the intake temperature?