Which supercharger.

[menno]

Hi,

I run a Fiat twin-cam engine on twin 45's in my westfield. Although i love the engine, i cannot help but wanting more power. It is a lighly modified engine (rally cams, pulleys, etc...)

I was toying with the idea of putting a supercharger on my engine. My knowledge on superchargers/turbos is nil.

What type of supercharger do i need. Could i use a supercharger from another vehicle, or does it have to be specific to Fiat.

What bhp/torque increase should i expect.

How complicated is the installing of a supercharger. Are there any ECU's involved, or is it a basic bolt on conversion which needs a rolling road tuning and off you go?

Regards,
Menno

[Fiat CC]

The Eaton M62, from the Merc 230 Kompressor motor is fairly easy and cheap to find over here (Aus), and I think would work OK for a 2 litre. You'd need the right pulleys belts etc, a customised inlet manifold, fuel injection would probably make tuning it easier, but you could make carburettor(s) work too.

I'm going to try it in my 124 Sport once I collect more of the parts for it. I'm going to use forged conrods (originally for a Dodge Neon SRT) and pistons for it also, but I think you could get away with l using standard Fiat parts to a certain point. I'm sure what cams to use for this yet, but I expect they'll be quite different to the cams in my NA motor. Guy would have cams to suit though I'm sure. I'm going to use EFI, although I'm not sure what type yet, but something relatively new and versat ile.

Theres a fair bit of time, effort, money and patience involved, but I'm looking forward to finding out the results.
Hope this at least gives you a starting point.
Reuben

[menno]

Thanks Reuben,

The Eaton superchargers seem very easy to get hold of around these parts of the world too, for sensible prices.

Does anyone have any experience with the small electric superchargers made by ETS? They claim to give an extra 20bhp. This is a cheap and simple bolt on kit.

Menno

[Testament]

Thanks Reuben,

The Eaton superchargers seem very easy to get hold of around these parts of the world too, for sensible prices.

Does anyone have any experience with the small electric superchargers made by ETS? They claim to give an extra 20bhp. This is a cheap and simple bolt on kit.

Menno

Electric supercharger = snake oil

don't even let someone else touch them with a barge pole

[sumplug]

If you look at the shape of them, there is no way they would make any difference to your power. Probably make a bit of noise and actually rob you of power!!

Andy.

[Guy Croft]

Would any of you (apart from me) care to write a thoroughgoing resume of the equipment and mods truly necessary for professional conversion of an engine to supercharged? I do get rather tired of hearing about 'bolt on kits' I must say.

GC

[Fiat CC]

I don't know about a full in depth article, but I'll try to elaborate a little on what I wrote above.

First thing I should clarify is I haven't actually done this build yet, it's a work in progress. I have started to collect parts and information so I'll share what I know.

OK, first thing you will need is a super-charger of a size suitable for the engine you will be charging. Eaton have several options and I have chosen the Eaton M62, for it's price, availability and it's quite a good match for the 2 litre twin cam I have been told. It came standard on the Merc 230SLK Kompressor as I mentioned above, so there are second hand units available. There are several other brands, however I know nothing about them. Fitting the supercharger to the motor will generally require some custom pipe work in terms of air intake, inlet manifolding, oil feed...

Depending on how much pressure and rev's you wish to run, stock internals may survive (depending on what motor you started with), however I have chosen to use forged conrods and forged pistons, to lighten the bottom end and add increased durability and revability. I am starting with a brand new block and bottom end, but if you were using an older block you would likely need to tidy things up a little around the bores etc to get the best out of the build. I will be using aftermarket bearings to suit the new forged 'rods.

Choice of cams and induction system is also important. I can't tell you anything about cam profiles, but I do know that good cams for a supercharged motor will likely be different to hot NA cams and getting it right can add a lot the the performance of the motor. You may also want/need to modify the head in terms of some porting work, valve material, size and length, valve seats etc to get the best from the cams and SC. I have chosen to use after market electric fuel injection, to replace the Weber carbs on my car at the moment, although I have seen carburettored supercharged motors. Either option is going to involve custom bits to some degree to mate the supercharger to the inlet manifold and the selected fuel supply option. I have not decided the best approach to this on my build yet, although I am thinking along the lines of a Weber DCOE style manifold with injectors mounted on the manifold, linked to a custom adapter from the manifold into the outlet of the supercharger. As far as I know you will also need to get an oil feed from the motor to the super-charger, although i haven't gotten to that stage of my build.

You will need to setup a pulley system to drive the SC, which will involve a pulley at the crank of the motor, and a pulley on the SC, plus most likely a tensioner somewhere in the loop. Finding the right ratio for the pulley system is important in how much pressure the SC will produce, and will involve custom, or aftermarket pulleys and belts. You will most likely need to make a bracket to mount the tensioner.

I don't know anything about intercoolers in terms of super-charging, however I believe that some types of SC's don't require intercooling. I will be looking into this further....

I hope I haven't missed anything too important in that lot. Once you've built the motor, tuning it properly is obviously important, otherwise you can damage or destroy parts of your motor. Depending on how much you have increased the engines performance, a new clutch may be required, and other drive train components may be placed under a lot more pressure.

It is not a cheap or easy process to add an aftermarket super-charger setup. There is a lot of custom work involved in making things fit and work together properly. It will likely take me another year at least and a sizeable chunk of my income in that time, to finish this project. I don't posess the skills to do much of the work myself, so if you are handy in a workshop it will be a cheaper exercise, but there are a considerable amount of hours invovled.

Feel free to add to this, or correct me on any mistakes... It's been a long day...
Thanks,
Reuben

[Guy Croft]

Very good start there Reuben!

I shall watch with interest, and hope maybe to see some issues like this covered too:

Blower placement, brackets and mountings
Inlet ducting inboard/outboard
Filtration
Head gasket and bolting
Piston design eg: rings, lands, CR
Ignition system
Fuel octane
Engine and intake running temperatures
Exhaust setup
Fuel system and calibration
Lubrication
Clutch

Be nice if this became a source reference, so those with actual experience of doing this preferred, to take the 'guesswork' out of it, there's enough of that on the internet already

GC

[sumplug]

First job i would do if its a new block, is chuck it outside to "weather" it. This will settle the block.
Supercharger needs a bleed off valve on the rear to enable good idling. We do not need boost at idle!!
Use a single Throttle Body connected to the nose of the charger, and fabricate a plenum inlet chamber for expansion. Injectors will be fitted to said plenum. What size Throttle Body?
Blower would sit above the exhaust with heat tray to make it as compact as possible with a flexible inlet rubber hose to the plenum. This would allow for a shortish belt run from bespoke crank pulley to bespoke smaller charger pulley.
You will need some kind of knock sensor. I believe engine safe system electronics are available to control this. Maybe a black APC box from a Saab Turbo to control bleed idle valve and knock sensor?
Maybe Guy can answer the Piston type and compression question?

Andy.

[Guy Croft]

All that will happen if you put the block outside is that it will rust. Keep directly on topic here. Look, conversion to supercharging is complicated enough without telling people they have to age their crankcase. They don't, that's an old carrot from the 'cloth cap and half-pint of shandy brigade' anyway who thought it was a very funny story in the club bar (one of those 'we know something you don't ones..), and metallurgically refined (post 60's) casting and heat treatment techniques obviate any such requirement, especially on modern thin-wall lightweight units.

GC

[Fiat CC]

Perhaps I should point out that by new I mean never been used. The block has been sitting in a warehouse for more than 20 years in it's grease proof paper and cardboard box. I think that ought 'settle' it more than enough. Also, I'd envisaged running the super charger down low on the inlet side. Less heat problems, and less piping to get to the inlet plenum. I haven't gotten to mounting brackets yet, but i can see quite a lot of time going in to measurements, and getting it just right.

I am planning to use 9:1 compression ratio pistons, although the exact design is undecided. I think in a 2 litre Fiat Twin Cam, that will be quite close to a flat top piston, possibly a very slight dish. The rods I am using are nearly 3/4's of an inch longer than the standard Fiat rods, so that will dictate some of the parameters. I am also planning on using a custom fitted aluminium radiator, a big winged baffled sump and oil cooler to aid engine cooling. Obviously the sump will help with high speed cornering, in terms of preventing oil starvation. I had planned on running piping for air intake to the front of the car, just behind the grill/headlights, for cooler air, running back to a single, quite large (don't yet know exactly how large, but I'm thinking around the 80-90mm mark), throttle body. Probably end up with some type of pod filter arrangement on there, although that will be decided later in the piece. I also intend on using a Ford EDIS type system for spark, controlled by an aftermarket computer. Fuel will be 98RON unleaded, as that is the highest octane pump petrol you can buy in Australia, (for street legal use...).

Obviously some of these details will be different depenging on what motor you are trying to convert. For example, a piston design that gives x:1 compression in one motor, could give very different CR in another type of motor.

Once again, feel free to add anything, or correct me on anything too.
thank you,
Reuben