My Supercharged mx5 experience

[16bit]

methanol and or water injection.

[sailaholic]

Some also use a suck through carby set up so some of the heat goes into atomising the fuel I believe.


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[hks_kansei]

Some also use a suck through carby set up so some of the heat goes into atomising the fuel I believe.

Yep, there's a pretty big temperature drop across a carby, that's why a older carby fed cars often had coolant runnign through the intake manifold. It kept it warm enough that the moisture in the air didn't ice up the carby causing it to block/stick.


I imagine also on the charged V8s that the short distance from the charger to the port would help keep temps down, and the design of the supercharger itself probably would too.

[Dweezle]

Thanks for the info.

What about something like this?
That is EFi right?



Or are they just a low boost setup just like we would on the 5's with no intercooler?

[NitroDann]

That car is EFI.

Fuel squirted directly into the ports, and the fuel is gasoline. There is basically no charge cooling.

The blower is big enough to produce that airflow fairly efficiently, because it's large, and the engine is asking for little boost, the airflow is kept fairly cool.

It's probably still detonation limited, that is, they could make more power if they added timing, or ran it leaner or added more boost, but they are probably somewhere near the limit on that fuel with that setup.

The advantage to a blower is that if you already have enough power adding 20% more with no lag means that you can have a setup that is able to produce too much power all of the time.

If you are no way near enough power (ie na6) then having a turbo means more efficiency, intercooling, and the turbo doesnt take power from the engine, so higher hp and less fuel used on the same internals at the limit.

Basically, you need more serious racecar like systems like alcohol fuel and an extra tough bottom end, and no requirement for fuel efficiency to make a great blower setup. And in a car that already has enough power, like a V8, this is awesome.

In a compromised setup (gasoline, requirement for noise volume and fuel efficiency and engine life etc) a turbo just makes the most sense.

The ultimate mx5 engine would be one with 1000whp capable internals, making 500whp with a blower (putting 700whp worth of stress, wear, fuel etc into it, running the blower), and having alhocol charge cooling to stay away from being boost or det limited.

The other option is a low boost blower bolted straight to the inlet ports V8 style, with an intercooled massive turbo setup feeding it and alcohol. That would be a good (however complicated) compromise.

I think we agree 100% warren...?

The issue is that people in general view blowers as the simple easy way to power and on a simple easy to build setup, they just arent very good. (on an already very underpowered car, talking mx5's here)

Dann

[Dweezle]

Thanks Dann.
Makes sense.

I assumed it must just be a lower additional power setup where no cooling is required.

Like you said, 20% extra power on a high HP V8 is a lot of power
20% extra on a NA6 is almost nothing.

Dann or WOZ - doing a Turbo Fed Supercharger setup, would that add a tonn of extra heat or reduce it?

[wozzah1975]

Thanks Dann.
Makes sense.

I assumed it must just be a lower additional power setup where no cooling is required.

Like you said, 20% extra power on a high HP V8 is a lot of power
20% extra on a NA6 is almost nothing.

Dann or WOZ - doing a Turbo Fed Supercharger setup, would that add a tonn of extra heat or reduce it?

It would add heat. And with turbo & engine management systems these days you;re probably best just to turbo it anyway.

[wozzah1975]

That car is EFI.

Fuel squirted directly into the ports, and the fuel is gasoline. There is basically no charge cooling.

The blower is big enough to produce that airflow fairly efficiently, because it's large, and the engine is asking for little boost, the airflow is kept fairly cool.

It's probably still detonation limited, that is, they could make more power if they added timing, or ran it leaner or added more boost, but they are probably somewhere near the limit on that fuel with that setup.

The advantage to a blower is that if you already have enough power adding 20% more with no lag means that you can have a setup that is able to produce too much power all of the time.

If you are no way near enough power (ie na6) then having a turbo means more efficiency, intercooling, and the turbo doesnt take power from the engine, so higher hp and less fuel used on the same internals at the limit.

Basically, you need more serious racecar like systems like alcohol fuel and an extra tough bottom end, and no requirement for fuel efficiency to make a great blower setup. And in a car that already has enough power, like a V8, this is awesome.

In a compromised setup (gasoline, requirement for noise volume and fuel efficiency and engine life etc) a turbo just makes the most sense.

The ultimate mx5 engine would be one with 1000whp capable internals, making 500whp with a blower (putting 700whp worth of stress, wear, fuel etc into it, running the blower), and having alhocol charge cooling to stay away from being boost or det limited.

The other option is a low boost blower bolted straight to the inlet ports V8 style, with an intercooled massive turbo setup feeding it and alcohol. That would be a good (however complicated) compromise.

I think we agree 100% warren...?

The issue is that people in general view blowers as the simple easy way to power and on a simple easy to build setup, they just arent very good. (on an already very underpowered car, talking mx5's here)

Dann

To do it properly you are on the money with having it feed close to the inlet ports like a V8. A well thought out plenum with the blower mounted directly on it is the go.

Then you mentioned about the heat. Traditional V8 setups generally have the correct size blower, which is where new kits for all engines lack. Most of the off the shelf kits have undersized and overdriven blowers, which is fine for low boost applications, but turn into a hot air pump when you drive them hard. A rough rule of thumb that I use for picking blower size is that at a 1-1 drive ratio it should make 1 bar of boost. Most new kits are nothing like that. The other thing as you mentioned is how it is fed. As someone mentioned a venturi effect on the charger inlet creates a cool charge. This another reason to avoid big throttle bodies. A smaller throttle body will make the same amount of power, and be more controlled, plus if you set it up right the intake charge is cooler. Then if needed you can also run fuel through through it to cool it (not ideal in some styles of blower). If the correct size blower is used heat is minimal, and no cooler is required. If you have a setup that requires a cooler you're better off just turboing it.

Supercharging is fine on any engine, but it needs to be propotional to engine size so it is efficient. None of any of the current supercharger kits for the MX5 (and most late V8's for that matter) that I have seen cover these basic fundimentals. They are all undersized blowers and most are mounted too far away from the intake. Adding a cooler only makes it worse.

I think I have mentioned it somewhere else on the forum, but a mate who loves superchargers built an early GSXR supercharged engine for an open wheeler race car, and also built a very successful supercharged Mini sports sedan a number of years ago (one of the first to do it properly and get results). The bike engine was set up on around a 1-1.5 litre plenum with short runners, fed by a weber with small venturis fitted and on alcohol. The result was a 1400cc (from memory) engine that made a genuine 400hp, and the combination of an oversized blower, massive cylinder head flow, the venturi and alcohol effect used to make it run so cool that after a full noise run the supercharger had condensation on the outside of it. It was literally cold like it had been in the fridge.

It's all in the setup

Cheers
Woz

[NitroDann]

Same as everything.

The devil is in the details.

You see 100% no reason to twin charge?

How would you build the ultimate 500whp BP with the greatest drievability and area under the curve (lets assume everything built is 100% reliable).

Im thinking the big MP90 coldside kit where the blower is the inlet manifold, and a HUGE (GT35/40 maybe) turbo running low boost. And alcohol, probably directly after the turbo. Lots of meth or E85.

Dann

[wozzah1975]

Same as everything.

The devil is in the details.

You see 100% no reason to twin charge?

How would you build the ultimate 500whp BP with the greatest drievability and area under the curve (lets assume everything built is 100% reliable).

Im thinking the big MP90 coldside kit where the blower is the inlet manifold, and a HUGE (GT35/40 maybe) turbo running low boost. And alcohol, probably directly after the turbo. Lots of meth or E85.

Dann

In this day and age with ECU's, great turbo technology and E85 it's hard to knock just an outright turbo set up. Boost and anti lag and engine management controls mean you can just about have as much boost as you want whenever you want, and compression ratios can be kept high with clever combustion chanber design and control of fueling and igntion.

Hypathetically a genuine 500hp on a BP I would use the MP112, I think for those numbers you would be stretching the friendship of the MC90. I don't think making it "pleasant" to drive would be achieved, 500hp from 1800-2000cc will be angry I think you could do it without having to turn it over 7500-8000rpm though! To make it relaible you would need full internals, including as crank IMO. The std crank may last a while, but I think eventually it would fail. You would also look at block strengthening.

I am keen to see a well thought out super/turbo combo set up

Cheers
Woz

[16bit]

mp62 in a compound setup is plenty for 500hp.

this dude makes 680whp with one and a pt6262

http://www.speedhunters.com/2012/03/car ... ving_king/

[wozzah1975]

mp62 in a compound setup is plenty for 500hp.

this dude makes 680whp with one and a pt6262

http://www.speedhunters.com/2012/03/car ... ving_king/

I was quoting supercharged only figures, and Eaton recommend the MP112 for a genuine over 300rwkw application. A 62 on its own is well and truly out of puff before those power figures.

Woz

[16bit]

i get it, i want that setup though!

[Orphan]

Try to name a single currently supercharged available model that isnt supercharged for tradition (ie a mustang or something)

Yeah there aren't many outside of the U.S. manufacturers. The only others that come to mind are the Audi S4 with its supercharged V6 and I think Koenigsegg are still using twin centrifugal superchargers. At least for aftermarket options the newer more efficient superchargers combined with Laminova intercooler cores in the intake plenum have given supercharging a bit more life for some applications. Turbo is still the way forward. I am keen for some solid variable geometry turbo's to make it to the aftermarket.

[16bit]

sorry, the koneigigignineisnineineiseeggggsssssss are turbo now.