Supercharger Vs Turbocharger

[Cal]

As said, factor in import duties. I got slugged another ~$500 to get my ~$1600 coilovers in...

so two and a bit times that, maybe count on another $1000-1500 landed...

WTF? Import duty on car parts is 10% and the first $1000 there is no duty. Race car parts are 5%. So if you told them they were for a race car, you should have paid $30 duty.

Cal.

[Sean]

Wow this topic is moving along smokingly with lots of grgeat info and input!

Here's a suggestion that i think might help you make the decision for what is better in your MX5.

Ask around the people in your area who have turbo'd or super charged thier MX5s and see if they will take you for a pin or even let you have a drive.

Discuss the setups with the owners and see how much each setup really costs (costs can end up considerable more than the basic kits to get a perfect setup).

Decide which you like the best with cost, performance, noise etc all considered.

$5k Is a reasonably large investment into any MX5, so get out and try before you buy.

[The Pupat]

Here's something out of left field...the VW Golf now comes in GT form, which is a 1.4L twincharger, 125kw but mega-economy apparently:

http://www.autocarmag.com/FirstDrive_Su ... _ID=217183

Sh!t me, 2.5 bar through a factory engine. That's just insane especially for a petrol motor.

[The Pupat]

A
I like turbocharging, though twincharging is also cool. Superchargers are a lot of hassle in my mind for little gain especially the JR kits. Ohh and the loss to a turbo is a lot less than a turbo. The standard rule on the positive displacement superchargers is that to make 100hp you need to need to make 130hp whilst turbos only need to make 105hp to make 100hp (IE 30 percent loss to 5 percent loss). Though different superchargers will all have different efficencies.

Horsepower to compress air in a supercharger is CFM x psi divided by 229. That is for a 100% efficient supercharger. Divide by the efficiency to get actual shaft drive horsepower.

O/k let's say your 90Hp engine requires 15 psi and 225 CFM to get 170 gross Hp. That is 14.7Hp theoretical to compress that air. If your supercharger is 60% efficient it really requires more like 24 Hp to drive it. And you end up with 146 Hp at the flywheel.

Back pressure on an engine kills power by roughly about 1% for each psi. (trust me here, but this is roughly correct). Now your turbo engine that develops 15 psi, will probably require about 20psi turbine back pressure, if the turbine is sized to give a reasonably wide boost range.

If net engine power is 170Hp, turbo back pressure will reduce power by 20% or to around 136Hp at the flywheel. A lot depends on turbine size. A relly big turbine will have less turbine back pressure, but it will be a very peaky laggy engine. A smaller turbine will reduce top end power considerably through back pressure.

So which is better ??? I really don't know.

A supercharger is pretty predictable in performance, the results from a turbo vary considerably with how it is sized.

Interesting. I read that HP example somewhere but I've forgotten where now.

[Babalouie]

Here's something out of left field...the VW Golf now comes in GT form, which is a 1.4L twincharger, 125kw but mega-economy apparently:

http://www.autocarmag.com/FirstDrive_Su ... _ID=217183

Did you read my post on page one of this thread ? I have already twincharged a Mazda B6 motor myself.

Oops...didn't realise you mentioned that already

[Matty]

As said, factor in import duties. I got slugged another ~$500 to get my ~$1600 coilovers in...

so two and a bit times that, maybe count on another $1000-1500 landed...

WTF? Import duty on car parts is 10% and the first $1000 there is no duty. Race car parts are 5%. So if you told them they were for a race car, you should have paid $30 duty.

Cal.

Not quite - anything under $1000 usually gets in free, above that and they'll hit you with duty - for the full amount. I'm not great at lying but didn't know about the race car thing anyway. So full duties.

Then GST on top of that.

Then the import agent's fee on top of that... (another ~$100)

[Cal]

I'd be doing everything I could to make sure no one item cost more than $1K in that case. No reason why fronts could not be sent with rears ect.

When we live in one of the highest taxes countries on the planet, I see no reason to give them extra for no reason at all.

Why did you use an import agent? I have been buying stuff for the race car from the UK and the US and just having it couriered to my door. No duty, no import agent fees and no GST.

Cal.

[mossy]

can someone hurry up and buy a BRP kit then, I wanna see some results.

[93_Clubman]

can someone hurry up and buy a BRP kit then, I wanna see some results.

mossy, not sure if you've seen this over the last few days:

http://brpforum.infopop.cc/eve/forums/a ... 7701080842

[Matty]

BIGGAR in the Vic club has a BRP MP62 hotside kit...

[mossy]

can someone hurry up and buy a BRP kit then, I wanna see some results.

mossy, not sure if you've seen this over the last few days:

http://brpforum.infopop.cc/eve/forums/a ... 7701080842

Just read it, 230 rwhp, I like the sound of that.

Matty does BIGGAR come out to the track days, I'd love to go for a drive.

[mmx005]

i tried the above link as a 230rwhp s/c made me sit up and take notice, but it doesnt seem to work for me???

[Matty]

Matty does BIGGAR come out to the track days, I'd love to go for a drive.

Don't think so, the car's only just been built. Only seen him at one run so far.

[93_Clubman]

another interesting post...

http://brpforum.infopop.cc/eve/forums/a ... 6241036752