HKS GT Supercharger (Rotrex) in development!

[uspspro]

Originally Posted by Exhaust

idk about no A/C in texas, i did it last year.. wasnt pleasant, race car or not.

I'm pretty sure that HKS would definitely offer a road-going kit that allowed for the AC to stay if it were possible. The market-share of those who want to keep AC is much bigger.

The first kit pictures show the kit with a recirculating BPV and the AC still there. I think the road-going kit will be closer to what we saw there.

[serialk11r]

By the way, I kept wanting to ask this, does anyone know how much force those stock belts are capable of transmitting? It looks like they used the stock belt for the supercharger...is this typically how it's done?

[old greg]

Originally Posted by serialk11r

By the way, I kept wanting to ask this, does anyone know how much force those stock belts are capable of transmitting?

It depends on how the pulleys are set up and, to a lesser extent, the tension in the belt.

[uspspro]

Originally Posted by serialk11r

By the way, I kept wanting to ask this, does anyone know how much force those stock belts are capable of transmitting? It looks like they used the stock belt for the supercharger...is this typically how it's done?

When I ran Rotrex at 17psi on my old MR2 setup, I removed the AC and installed the SC in it's place. IIRC I used a slightly smaller belt, just because of the difference in pulley size. But the belt setup and tensioners were all stock.

[poormans_LFA]

[u2b]q4u_r7_6PjQ[/u2b]

[Exhaust]

Originally Posted by uspspro

I'm pretty sure that HKS would definitely offer a road-going kit that allowed for the AC to stay if it were possible. The market-share of those who want to keep AC is much bigger.

The first kit pictures show the kit with a recirculating BPV and the AC still there. I think the road-going kit will be closer to what we saw there.

Hopefully your right good sir.

[OldSkool86]

I read this/that...crazy...it is possible to up the hp via supercharge even with the current CR ratio...it comes down to the tuning...

[(Stealth Inc.)]

There is a company called GTM Motorsports in SoCal that has experience with the HKS Gt7040 supercharger and, has modified it to produce a bit more HP not just by reducing the size of the pulley but to the actual supercharger it's self.

http://www.gtmotorsports.com/product...roductid=16769

[ESBjiujitsu]

NICE!!! http://www.gtmotorsports.com/product...cat=322&page=1

You can get your HKS SC upgraded to their standards for only $500.00
"We perform precision internal modifications to increase the efficiency and airflow. This works especially well when paired with other modifications such as our GTM HKS 90mm Supercharger Pulley"

This could add a few extra hp to those who just want to use the HKS GT SC with a completely stock engine setup like myself going to use the K.I.S.S principle with this car!

Here is a video with a centrifugal supercharger being used on a subaru boxer engine.... nice sound!
[ame="http://www.youtube.com/watch?v=tqkM9O75ZOU"]http://www.youtube.com/watch?v=tqkM9O75ZOU[/ame]




Also anyone heard of http://www.raptorsc.com.au/
They make centrifugal SCs for toyotas and subarus....seems like the perfect tuner for the FRS/FT86/BRZ platform!

[Tomzilla]

So, let's talk a little about forced induction, primarily superchargers.

Pros, cons, maintenance, install, price, etc.

Now, I've done a fair deal of research and leisurely reading on superchargers and this is what I've come across. Correct me if I'm wrong, please.

-Powered by the belt instead of exhaust waste like turbos, therefore more immediate power. However, the downside to this is the parasitic effect on the engine's inherent horsepower.
-Easier maintenance versus a turbo. (Not sure how much easier, though)
-Some superchargers like a centrifugal, may not need intercoolers due to the less amount of heat they generate versus a turbo.
-More expensive than a turbo.

There are things I've missed, I'm sure. I'd like to hear some of your opinions on superchargers versus turbos. I personally, would rather a supercharger due to the "ease" of maintenance and install.

So, let's have it.

What's that whistling noise?

[Aznek]

EDIT:: Ignore my post below lol... it's completely wrong.

Turbo chargers and superchargers both just force more air into the combustion chamber to produce a more Stoichiometric combustion.

The turbo uses the exhaust waste but since a super charger requires some of the engine's power to produce it's extra power it means the somethingmajig needs to be able to withstand the total power + the parasitic power lost.

In the case of an FRS turbo, the somethingmajig needs to be able to withstand the 200hp(stock) + 100hp (turbo hp gain).
An FRS supercharger's somethingmajig needs to be able to withstand the 200hp(stock) + 100hp gain (net hp gain) + 45hp? (the hp lost to the super charger).

I wonder, does this mean that a turbo is more fuel efficient in comparison to an SC as well?

Oh and lemme know if what I said above is absolutely incorrect and I will delete the post. I don't want to spread false information.

[ESBjiujitsu]

yes lets!! thank you. Im pro....procharger as well. :happy0180:



The FACTS are we are getting one for this platform because HKS already has one....soooooo love it or hate it the kit will be out there so for those of us who will be buying the kit we will enjoy discussing it. like ME! I was in the process of trading in my MS6 for a RX8 and wanted to go the super charger route until stumbling on the BRZ/FT86 a year ago, now im so excited for the entire platform and most importantly a centrifugal supercharger. I have had a turbo car and i love it and I have driven centrifugal and roots type supercharged cars and love those too but I personal really want this car with the HKS GT supercharger on it. I think its a perfect fit for the performance im looking for. Im shocked its the first setup available but happy because im crossing my fingers its available through the factory at some point. We shall see

[serialk11r]

Originally Posted by Aznek

stuff

Okay I'll try to avoid the physics details...

"more stoichiometric" is completely wrong. The reason you want more air is that a more dense intake charge lets you burn more fuel (and air) per combustion event, which means more power per engine revolution. In short at least...

A turbocharger is using partly exhaust waste, and partly putting a restriction on the exhaust. The energy is not completely free, but it's a bit complicated, for a detailed explanation you can go search the Engine Tech thread or one of the "electric turbo" discussions.

A supercharger is purely running off shaft power though. The wikipedia article talks about it in terms of stress on the engine or something, but I think it's better to think of it in terms of efficiency, and think of engine and supercharger separately. Under full load (this distinction is very important), if you have a belt driven supercharger and a turbocharger (correctly sized and running at an efficient point) pumping the same amount of air into the engine at the same temperature, and ignore the losses from the forced induction, the engine will give you the same power. However, the supercharger usually takes a little bit more energy from the engine to compress the air, so you end up with less power.

The reason why this matters is because as you probably know, there is a limit to how much air you can stuff into the cylinders before the engine will blow up. In addition, peak load efficiency for any supercharging is usually worse, because extra fuel is pumped to cool things down, among other things.

Now there's the issue of compressor type. On cars we usually see centrifugal, Roots, and twin screw. Centrifugal tends to be more efficient, but the amount of pressure it creates is related to the speed at which it spins (since a turbocharger spins independently of the engine, and relatively quickly, this is what they come with). Roots superchargers and twin screw superchargers pump the same amount of air per revolution, so they are usually driven off the crank since you can keep pumping the same amount of air into the cylinders at any engine speed. Roots and twin screw tend to be less efficient (more precisely though, their efficiency is extremely speed/pressure dependent), but they create nice flat torque curves because they essentially pump the same amount of air into the cylinders no matter the engine speed, so the engine's thermal efficiency becomes the only determining factor for power, rather than both thermal efficiency and volumetric efficiency.

As far as fuel efficiency goes, it depends on a lot of things but in short, superchargers usually have a bypass valve so they don't consume much power when you're just cruising. Roots will sap almost no power under no load, centrifugal and twin screw will sap a small amount and hurt fuel efficiency a little. Turbochargers create restriction in the exhaust, and will thus sap power, but how much restriction depends on the turbine, and I won't get into details but if you have an engine that uses clever valve timing to throttle output (so Nissan VVEL, BMW Valvetronic, Fiat Multiair, or Toyota Valvematic), then the turbo will return some of the energy back to the engine and possibly increase efficiency by a (probably) negligible amount.

[Brian S]

Originally Posted by SVTSHC

I'm fairly confident we'll see more than a 20hp/20lb-ft gain from a supercharger, especially if they offer us a way to drop the compression.

Cheapest way to do it without replacing rods and pistons would be to getting a thicker headgasket and while the heads are off possibly port and polish while getting stiffer valve springs. If I find a slightly longer duration, bigger lobe camshaft I might be tempted to add that as well. Oh yeah cant forget about the bigger throttle body and intake.

I like the idea of just opening up the top end and slightly lowering the compression with the gasket to get what I want from this car originally with a SC. I remember working on them old Buick Regals and some old Thunderbirds with their SC's and was surprised how effiective and reliable they were.