DIY HAI and heat shield on Saturn SL2

[itjstagame]

Then you need a vacuum controlled flapper to switch off hot air and switch on cool air based on load.

I realized this on my truck, felt the lack of air/stumbling and so I put extra holes as mentioned above. Seems to work good, I have enough hot air for idle and get a lot cooler air at WOT.

[GasSavers_BEEF]

just remember also that this works best on vehicles that are slightly overpowered. my vehicle weighs very little (relatively speaking) and has 115hp. my metro has about half the horsepower as my current car and of course weighed less. I figure I can get away with about 80-90 hp and be fine.

someone that is already having power issues may want to rethink doing this to their car because of the problems stated above about power loss. It worked fine for me. I can't beat anyone from a stoplight anymore (not like I really could before) but that is fine with me.

[guest001]

hot air = less dense air and less power. less air ie clogged air filter, equals more throttle to compensate for the restriction.

HAI seems pointless to me.

[theholycow]

Why would it be pointless? You just described one of the major points -- wider throttle. Unlike a clogged air filter, there is no restriction before the throttle, and being able to open the throttle more means less restriction there too. That's less pumping loss, which is a good thing.

[diamondlarry]

Originally Posted by theholycow

Why would it be pointless? You just described one of the major points -- wider throttle. Unlike a clogged air filter, there is no restriction before the throttle, and being able to open the throttle more means less restriction there too. That's less pumping loss, which is a good thing.

I agree. As long as you keep the rpm's down, a wider throttle opening is better.

Project84, I would suggest that you consider an SL2 manual but swap in the 5th gear set from a '98 or later SL1 manual. This ends up lowering the cruising rpm to the same level as the SL1 as the final drive ratios are the same for both vehicles.

[guest001]

Originally Posted by theholycow

Why would it be pointless? You just described one of the major points -- wider throttle. Unlike a clogged air filter, there is no restriction before the throttle, and being able to open the throttle more means less restriction there too. That's less pumping loss, which is a good thing.

It's pointless cause your doing something that's making the motor less efficient. Its the equivalent of not changing your oil, or having 2 or 3+ year oil spark plugs, fuel filter, etc.


if you add a hot air intake the engine has to rotate faster in get more air. which equals less mileage.....

[theholycow]

Originally Posted by guest001

if you add a hot air intake the engine has to rotate faster in get more air. which equals less mileage.....

No, actually, that's the exact opposite of how it works. Instead, it rotates at the same speed, and you have to open the throttle more to get more air.

A closed throttle causes what's called "pumping loss", where the engine has to waste energy just trying to pull air past that closed throttle. Just imagine the muscle exertion required to inhale or blow the same amount of air through a coffee stirrer vs. a jumbo straw. The lack of a throttle to close is one of the reasons (but certainly not the only one) why diesels are more efficient.

See also:
http://www.google.com/search?q=%22pu...+throttle+bsfc

[guest001]

hmmm, ok this is interesting. I'm going to do some more research before I say anything else.

ok, so what are typical gains from this?? I have turbo on my car so my iat's are higher then cars without a turbo anyway.

[theholycow]

I'm not sure what the typical gain is, but it's significant. However, it doesn't work for every car. I haven't studied the success/failure reports enough to predict which vehicles it works for.

A turbo might change how the WAI/HAI works, since they both work with air density (and the WAI/HAI may also work with some other concepts, like recycling heat back into the engine).

[GasSavers_BEEF]

everyone that I have talked to are seeing 5-10 percent increase. there are the few that see none at all. it works really well on the cavaliers and the saturns. I can't really say for other models. I averaged two tanks to see what the gains were and got around 8 percent. I then went on to other mods but the two tanks were over about 900 miles which I feel substantiates the claim (at least in my eyes)

research is the key and also reversability. if anyone is skeptical of the WAI, I say to try it (in a reversable way). if it works, make it permanent. if it doesn't, take it off.

many of my modifications started as prototypes that could easily be removed and were replaced with permanent and relatively eye pleasing additions to my vehicle.