Bullet superchargers

Kain · Postby **Kain** » Tue Mar 03, 2015 3:03 pm

NitroDann wrote:Guys Novice used to have a turbo 1st/2nd gen, a centrifugal 150kw NC is NOT a 200kw turbo na/nb, be realistic.

Novice's NC has a M62, it's a positive displacement style NOT centrifugal. The powerband should be more or less opposite to what you've described.

Novice1 · Postby **Novice1** » Tue Mar 03, 2015 3:11 pm

Problem with the 4:1 diff and supercharging is 1st is barely useable and second gear is to high for quick takeoffs.

Novice1

Sailor · Postby **Sailor** » Tue Mar 03, 2015 3:13 pm

Indeed, even with a 3.7 it's a struggle to keep traction in 1st

Postby **NitroDann** » Tue Mar 03, 2015 4:22 pm

Kain wrote:
NitroDann wrote:Guys Novice used to have a turbo 1st/2nd gen, a centrifugal 150kw NC is NOT a 200kw turbo na/nb, be realistic.

Novice's NC has a M62, it's a positive displacement style NOT centrifugal. The powerband should be more or less opposite to what you've described.

This isnt true, most superchargers tend to give a flat torque increase, unlike turbochargers.

Dann

Sailor · Postby **Sailor** » Tue Mar 03, 2015 4:36 pm

Dan,
The MP62 comes on pretty quickly.
It uses a bypass/recycle system and produces boost at good levels even at low rpm.
The bypass closes as soon as the throttle is opened and you have a big jump in HP/torque instantly that continues to build as rpm increases, obviously.
This is unlike the Rotrex/centrigugal or turbo systems in this respect.

Postby **NitroDann** » Tue Mar 03, 2015 4:48 pm

Sure, but it doesnt change the fact that torque is low compared to a turbo HP equivalent, super low compared to a 200kw turbo engine, and the NC is heavier. IE, Im sure the car is good and novice will like it but trying to convince him its a rocket when he has had a turbo NB is silly.

Kain · Postby **Kain** » Tue Mar 03, 2015 5:07 pm

I call shenanigans. A turbo that can produce that level of torque at low RPM will surely choke out before reaching 200 kW. Got a dyno plot that says otherwise?

Postby **NitroDann** » Tue Mar 03, 2015 5:15 pm

No one is saying anything about how low in the rpm a cars torque is, because it means nothing in terms of whether its 'a bullet' or not.

The reality is that small displacement supercharged cars do NOT produce the level of torque over the useable performance band that turbocharged cars do.

Dann

Kain · Postby **Kain** » Tue Mar 03, 2015 5:49 pm

NitroDann wrote:
Dann

It's what you said, in your MS paint "graph". And as specific as "it's a bullet" is as a criteria, it's just your opinion that low-end torque doesn't matter. As a rotary driver, I very much disagree with you.

Postby **NitroDann** » Tue Mar 03, 2015 5:54 pm

<3000rpm torque means absolutely nothing to outright performance.

Dann

Kain · Postby **Kain** » Tue Mar 03, 2015 5:59 pm

Kain wrote:It's just your opinion that low-end torque doesn't matter. As a rotary driver, I very much disagree with you.

Postby **NitroDann** » Tue Mar 03, 2015 6:02 pm

No one said it doesnt matter, I am saying that the torque advantage at 2000rpm that a 150kw blower on an NC has doesnt help it be near as fast as a 200kw turbo NB.

Kain · Postby **Kain** » Tue Mar 03, 2015 7:07 pm

I'll just leave this here:

NitroDann wrote:No one is saying anything about how low in the rpm a cars torque is, because it means nothing in terms of whether its 'a bullet' or not.

NitroDann wrote:No one said [low rpm torque] doesnt matter, I am saying that the torque advantage at 2000rpm that a 150kw blower on an NC has doesnt help it be near as fast as a 200kw turbo NB.

In terms of what you're actually saying (as opposed to the words you've written down?), a 150kW supercharged NC feels less powerful than a 200kW turbo NC simply because of the power delivery? Are you sure it's not just because it only has 3/4 of the peak power, and therefore a lot less under the curve regardless of what the curve looks like?

trickytrev · Postby **trickytrev** » Tue Mar 03, 2015 7:14 pm

Hey guys Ron myself sailor have all gone the way of S/c because that's what we wanted. If I could have got mine through NSW rego turbo fitted I would have but we can't. So that's the way I went an as a few of you know mine is booked in for a full rebuild later in the year to run on E 85 with full Haltech. We are only guessing as I'll be the first to go this way we should get over 300hp at the rear may be more we really don't no. You can't compare the difference between turbo an S/C different strokes for different folks.

Postby **NitroDann** » Tue Mar 03, 2015 7:16 pm

The shape of the power curve, Ie, the delivery, means that the average power in the used band when attempting to achieve maximum performance is lower, even if a turbo nb had only 150kw and weighed as much as an Nc it would still be faster.

Ie, more 'bullet like'.

Dann