Thread: Spercharged motor, Plate or fogger?

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HI!
I presently have a roots blower on my engine, fed through a two barrel holley. At some time in the future, I'm planning to fit a nitrous system to it. I read in the SA design/cartech guide to installing and tuning blowers, that although blown motors shouldn't need nos. the liqiud boiling into it's gas state in the intake of the blower, has a chemical intercooling effect. (As well as the chemical supercharging effect. OH YEAH!!!)
The blower my set up uses, is known as has not that flash an abadetic effeciency. (Roots blowers are all a bit like that) so I'm qiute keen on capitalising on this effect.
The other thing is, space limitations prevent me from using a four barrel carb. (My engine is pretty small anyway) So a four barrell plate wont fit my blower.

Do I
A, cut down a four barrel plate and retig it so it fits my flange,
OR
B, Just run a fogger nozzle or two into my carb adaptor plate?

What are your experiences? And which system do you think will have the greater chemical intercooling effect?

Thanks,
Bart.

From the engines stand point a and b are the same.Typically a fogger plate is under the carb and nozzels are installed into the intake runners,Typically nozzels are used when the shot becomes bigger than the plate system can handle and or to resolve distribution problems in a race enviroment.The plate is a easy consumer friendly piece that works good for a add on and requires very little machine work and engine dissassembly/assembly.The typical nozzel system requires machine work and dissasembly/reassembly to be installed into the intake runner or a special manifold. The nozzel may even have to be that close to the valve ,because of atomization issues ?

Only you can decide whether to cobble it together and see if theres any unknown issues or go down a proven path.I would call the big companies and ask there tech/service department if they make a plate for your application.
You might want to try to make a plate out of a spacer designed for your application ,rather than cutting down the existing plate to fit yours?

The intercooler effect is true,but I think there may be other issues/safety concerns with filling all that volume with the spray ,rather than injecting it in the intake runner only , on the street?

So as I read it you are going to run a nitrous plate beneath the carb and by latent heat of vapourisation it cools the entire intake charge. That will work, the further up the intake tract you place the plate the better the effect will be. I mean it will condense the charge of air, fuel, NOS mix by increasing its density.

There is only one drawback though, NOS mixed wth fuel is an explosive mixture and under compression in the blower manifold, under combustion in the cylinder where it is supposed to happen that is fine and gives you the jump in torque that you require. IF YOU GET A BACKFIRE INTO TH BLOWER MANIFOLD with the roots blower pushing a fuel/NOS mix you are going to get an allmighty BANG. You had better have a good pop of valve. I would go so far as to say get some good quality blower bolts and hold down straps and even install a blow out panel. Or else you might see your blower if it is mounted on top of the engine go into orbit !!!

Wise wisdom indeed!!!!
I don't actually have a pop off valve at present.I had a home made one, but the teflon poppet didn't seat very well, and charge was seeping from the valve into my engine bay. (Not good)
My blower wont go into orbit. It's actually mounted on an inline motor. The supercharger mounting bracket is the strongest part of the car. (Quite literally)
The manifold would certainly fail though. To get around the manufacture of a complex manifold, I have used silicon hose to join the blower discharger manifold, to the intake runners. (It was Bloody expensive too $168 per metre)
It does sneeze a little bit sometimes. But usually only at idle, (Or just off) and when cold. since I'll (For the most part) only be squeezing it on the strip, and once I'm up in the powerband of the cam, I don't think backfire's are going to be a problem. (Finger's crossed)
A pop off valve might (Read IS) be a good Thing to look into.
I'm only making 7psi at present. I'd like to go higher, but am afraid of the extra heat leading to detonation.

Originally Posted by southerner

So as I read it you are going to run a nitrous plate beneath the carb and by latent heat of vapourisation it cools the entire intake charge. That will work, the further up the intake tract you place the plate the better the effect will be. I mean it will condense the charge of air, fuel, NOS mix by increasing its density.

There is only one drawback though, NOS mixed wth fuel is an explosive mixture and under compression in the blower manifold, under combustion in the cylinder where it is supposed to happen that is fine and gives you the jump in torque that you require. IF YOU GET A BACKFIRE INTO TH BLOWER MANIFOLD with the roots blower pushing a fuel/NOS mix you are going to get an allmighty BANG. You had better have a good pop of valve. I would go so far as to say get some good quality blower bolts and hold down straps and even install a blow out panel. Or else you might see your blower if it is mounted on top of the engine go into orbit !!!

While this is true to an extent most people that use n20 only use a 50 to 75 shot just to try and cool the incoming mixture.