With a stock SC14 supercharger running 5-6 psi on a small four banger, would it be a waste of time to intercool it?
With a stock SC14 supercharger running 5-6 psi on a small four banger, would it be a waste of time to intercool it?
Given how cheap ebay intercoolers are, it seems like cheap insurance
personally i feel like theres always a benefit to having an intercooler, even with low boost
Superchargers seem to have a lot more heat in the air versus turbochargers, so it''s probably a good idea to add an intercooler or at least some meth spray.
Just adding an intercooler won't really do a whole lot. You are cooling the air to create a lower temp, denser airflow, which should resist detonation better. However, by cooling the air through the intercooler, you are decreasing volume, which also decreases boost pressure. With a turbocharger, if you take the wastegate reference pressure from after the intercooler, no change. With a supercharger, you may have to gear it up to retain the same manifold pressure.
I'm thinking with relatively modest power goals - 170 hp from a 1.5L DOHC Hyundai - and a relatively big supercharger - the SC14 originally came on big straight sixes - an intercooler wouldn't make up for the weight and pressure drop with extra power.
In reply to turboswede:
I thought it was the other way around. Generally a Roots type might add 100 degrees, whereas a turbo might add 200 or more. Transfer heat off the exhaust side.
I'd always heard it the other way as the blowers aren't nearly as efficient and the air is more impacted by the rotors, etc. I guess some research is in order to find out the "truth" hopefully I can find some actual data.
There is another method of cooling after supercharging that seems to work pretty well. I have two additional fuel injectors in my intake tract, downstream from the supercharger. They cool and atomize the already supercharged air. They also add needed extra fuel under load.
Rupert wrote: There is another method of cooling after supercharging that seems to work pretty well. I have two additional fuel injectors in my intake tract, downstream from the supercharger. They cool and atomize the already supercharged air. They also add needed extra fuel under load.
That doesn't really actually cool the charge.
In reply to Swank Force One: I haven't added thermocouples to actually test the temperatures. I just go by what the designer says his tests have shown. However, after a few years and some pretty hard running, I can say it works.
I'm pushing over 12# of air into the intake. I've never had a knock or other sign of too hot air or too lean a fuel charge. I would think someone looking at a 5# boost would also do well using a similar setup, without all that extra plumbing.
If the gas from the extra injectors has any time at all to evaporate that would provide some cooling to the intake air charge. I don't know if there is enough time for that to occur as the air is not just hanging around waiting to be cooled off, but there is some cooling benefit, at least in theory, of injectors in the intake.
It's not cooling... it's just a way of raising the detonation threshold.
Similar results, entirely different method. Neither air or fuel/meth/whatever you're spraying is sticking around long enough to be cooled any amount worth talking about before it's combusted.
It DOES work, but it doesn't work the way Tom says it does. 
sounds like you want an aftercooler.
I know from experience that an sc 12 on a 4ag gets hot enough to leave your finger prints burned to the case after a surprisingly short run time.
I'd cool the charge regardless of method used.
I've seen a setup using fuel as an "intercooler" blow a lot of engines. It's always blamed on something else, but statistically it's an outlier.
One thing to consider is throttled volume. On a SC setup, your throttle is usually pre-SC. So all the air volume between the supercharger and the intake ports will have an effect. Higher volume adds some lag but more importantly it'll add to idle droop and general poor idle behavior. I'd rather run a methanol injection system with some failsafes in case of a methanol delivery failure.
Dunno what an SC14 is, but I know that intake temps on an M45 running 6 psi on a 1.6 engine are over 200F. Not sure how much over, the sensors we were using at the time peaked at 100C.
Swank Force One wrote: It's not cooling... it's just a way of raising the detonation threshold. Similar results, entirely different method. Neither air or fuel/meth/whatever you're spraying is sticking around long enough to be cooled any amount worth talking about before it's combusted. It DOES work, but it doesn't work the way Tom says it does.
Physics suggests that changing physical states absorbs heat energy. If you have a liquid changing to a gas in the intake tract, it cools the intake charge.
Streetwiseguy wrote:Swank Force One wrote: It's not cooling... it's just a way of raising the detonation threshold. Similar results, entirely different method. Neither air or fuel/meth/whatever you're spraying is sticking around long enough to be cooled any amount worth talking about before it's combusted. It DOES work, but it doesn't work the way Tom says it does.Physics suggests that changing physical states absorbs heat energy. If you have a liquid changing to a gas in the intake tract, it cools the intake charge.
It's not changing to a gas due to heat in the intake tract, though. No amount of fuel being injected a whopping 6" or less before your throttle body will magically decrease your IATs by 100F or more by the time it's ingested into the motor.
This is why nobody really calls it "intercooling" and instead calls it "Meth injection" or "water injection" Not "Meth cooling." 
In reply to Streetwiseguy:
Yes, that is true. The latent heat of vaporization of gasoline is an actual number and the process does require energy, which it gets by removing heat from the surrounding air. The thing I question is whether there is enough time for this to take place before the air/fuel mix ends up in the cylinder.
http://www.ggmfg.com/products/madetoorderparts.aspx and chemical cooling
@ OP. Yes!!
On MR2's the SC14 is an upgrade to the SC12 found on the mk1 supercharged cars. I'd look at that setup and compare notes, see what the usual upgrade path is and work from there.
Stock is intercooler over the engine, not very efficient.
Perfect compression would heat the charge only by Charles Law (Sterling Engines come close).
Turbine compressors do a pretty good job of smoothly compressing the air, but some of the mechanical drive energy is still converted into heat.
Positive displacement (Rootes, etc.) supercharger compressors chew the air up while compressing the air, and a lot more mechanical drive energy is still converted into heat.
Compare the compressor maps of a turbo and super delivering same flow and pressure.
The turbo maps typically already show % efficiency.
You will usually have to convert the super power required to the equivalent % efficiency.
There's a good reason Diesel trucks don't use superchargers anymore: efficiency.
Keith Tanner wrote: I've seen a setup using fuel as an "intercooler" blow a lot of engines. It's always blamed on something else, but statistically it's an outlier. One thing to consider is throttled volume. On a SC setup, your throttle is usually pre-SC. So all the air volume between the supercharger and the intake ports will have an effect. Higher volume adds some lag but more importantly it'll add to idle droop and general poor idle behavior. I'd rather run a methanol injection system with some failsafes in case of a methanol delivery failure. Dunno what an SC14 is, but I know that intake temps on an M45 running 6 psi on a 1.6 engine are over 200F. Not sure how much over, the sensors we were using at the time peaked at 100C.
With what I'm planning to do, the throttle body will actually be about a meter behind the supercharger. Like the picture, but since I'm transverse and interested in making the install as stealthy as possible, mine is going to mount under the powersteering pump, wrap around the bottom of the intake manifold and then attach to the factory throttle body location.
mr2peak wrote: On MR2's the SC14 is an upgrade to the SC12 found on the mk1 supercharged cars. I'd look at that setup and compare notes, see what the usual upgrade path is and work from there. Stock is intercooler over the engine, not very efficient.
This is definitely my ignorance speaking but ...
Would a rootes blower make more boost on a smaller engine, all else equal?
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