Side project continued.....Supercharging the spit

Mattius

Mattius

Mattius

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As some of you remembered a while back i was humming and hawwing about turbo charging the spitfire, well that has now been transformed as i worked out it would be much simpler to supercharge it.

So the project has gone go tonight, as i have ordered the inlet manifold today !! whoop!

This is the setup im settled on

757c_1.JPG


Although i am running two belts, one going from alt to crank and one going crank to super, i have an electric water pump so no need for any more pulleys.

Its not the most efficient way of using the supercharger but i dont think i will loose that much will i??

Next up is to find a cheap eaton MP45 supercharger and work out carburation.
 
my main concern is that with the supercharger on top of the exhaust manifold i will over heat the fuel mixture which has already been heated going round the superhot supercharger. Seing as the carb bolts onto the charger you cannot run a charge cooler.
 
yeah but you need to have the air compressed on its own and then into the charge cooler, then into the carbs where you mix fuel.
 
Mattius said:
my main concern is that with the supercharger on top of the exhaust manifold i will over heat the fuel mixture which has already been heated going round the superhot supercharger. Seing as the carb bolts onto the charger you cannot run a charge cooler.
Click to expand...


Can you make up any sort of heat shield? Also wrap the exhausts, or get them ceramic coated to reduce the temp given off. As it stands, in that pic, I'd worry about under bonnet temps anyway and I'd be ensuring some kind of cold air feed as well as coating. My GT6 was a pig on warm days in standing traffic. Hot air going in, plus a blower, would probably have seen it stop altogether.
 
The M45 doesn't compress the air ;) it simply gives you a set volume of air per revolution.

The best way to use one would be to identify where in the rev range the engine pulls the hardest (peak torque), find the compression map for it on the eaton site and cross-reference your revs to 6psi (if you want to run without an IC, 9 or 10psi if you want to run with one) which will give you the pulley ratio you need. If you run an IC (Frontera TDIs have an all-alloy one that's nice and compact) then mount the blower low down on the 'cool' side, use an outlet adaptor to fit a hose to the IC then from the IC to a plenum chamber and bike carbs. Modern Bike carbs are constant velocity and will take up to 1bar of pressure without qualms.

Make sure your drive belt has plenty of wrap on the pulley and mount the blower solidly.

*n
 
On my phone - can't see it very well but that does look like a suck-through setup. Nasty.

I seem to recall you were going on about an 'ultimate' engine build a while back; why are you wanting to use carbs?

*n
 
Yea, if you fit a blower you might just see 120, possibly 130BHP. Maybe. Draw through carb is a horrible compromise though and you'd be much better off going all the way to fuel injection, especially as you've already got mappable ignition.

What's the point of accurately controlling the burn, anyway, if you can't control the fuel supply with the same precision......

And yea, Penski, 'tis draw-thro. Ick!
 
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penski said:
He should see a nice fat spread of torque though...

*n
Click to expand...

Don't think it's got anything oddball like that, pretty sure it's non-siamesed because you can run twin DHLAs and they all have their own runner - but I'm not overly genned up on 'em.

Torque, yes. Enough to shear the crank :p
 
If it were mine, the inlet and exhaust side of things would go thusly:

M45 blowing 9psi through a Frontera IC into a plenum chamber attached to modern Bike TBs, Megasquirt 'n' Spark controlling juice and leccy.

Nice 4-2-1 fannymould (is it that or 4-1 that's best for torque? I keep getting them mixed up) and straight-through exhaust...Perhaps with a cherry bomb ;)

Oh and mount the blower straight off the block using a 4mm aluminium board. Resonates, y0.

;)

*n
 
it doesnt have siamiesed inlets just a siamesed manifold.

i hate fuel injection so im avoiding that like the plague.

the point of using the supercharger is the crank cant handle high revs due to oil starvation. The supercharger should boost power considerably.

and yes the last person to do it snapped a crank and a driveshaft but he was reving the thing over 7000 with 10psi boost.


i looked at cherry bombs but they were too damn loud, and wouldnt get in track regulations. I have a sorted exhaust system already.

Definatly not using fuel injection just now.
 
Why hate EFI? As Lewis pointed out you're already using managed spark so manged fuel is no more complicated.

Please don't go suck-through if you're obsessed with carbs though...

*n
 
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