$25 Air Intake Modification for Prius II. Air now originates at the catalytic converter and is routed via 90" long, 2" diameter tube into the air filter. Initial tests show increased AIT of 8 - 14F over ambient. Without mod, 3 - 5F over ambient. Higher deltas expected in cold weather.

See pics in the Prius Share Section.
https://www.greenhybrid.com/share/category9.html

Thanks to xcel who provided part numbers for the hoses. The install took about 30 minutes.

 

Hi Krousdb:

___I just sent you a rather lengthy E-Mail with some more details/tricks that might help improve the WAI (Warm Air Intake mod) even more. Keep us informed …

___Good Luck

___Wayne R. Gerdes
___Waynegerdes@earthlink.net

 

Normally the goal is to get colder air into the engine so that more power is attainable because colder air = more air. I guess this mod would help it out in the winter though, will be interesting to see how that works out.

 

Hi Schwa:

___CAI’s for power are a hindrance to FE in our hybrid’s for many reasons.

___Good Luck

___Wayne R. Gerdes
___Waynegerdes@earthlink.net

 

Hmm, I wonder if there are some other ways to detune the Prius' ICE for better FE over power? I would imagine there are several things Toyota left intact to maintain a reasonable amount of power at times that most hypermilers could do without, for the most part.

I wonder how hard it would be to patch Toyota's firmware so that taking your foot off the gas would not engage light regen? That alone would go a long way to improve efficiency.

 

Hi Schwa:

___It does not detune the Prius in the normal sense of the word because you will not feel any difference between WAI and CAI on one. There is too little Atkinsonized ICE torque vs. MGSet torque to make a difference in this regard. What we are after is optimal intake temps for maximum FE. > ~ 73 + degrees F ambient for example will let you approach maximum FE if all other variables are conducive to it. At that point, an AIT should be in the high 70’s +. 62 degrees ambient with 65 - 70 degree AIT’s will not. All we are attempting to do is move an AIT closer to an area where maximum efficiency can be achieved and this is exactly what the WAI mod does. It is not a miracle cure but in the winter, it can help by a good deal over not having one at all as I am sure you are well aware.

___Letting off the gas w/ no-regen would be a great addition but there is that ICE spin up and synchronizing of the MGSets that have to be dealt with as well. I also hate creep mode and hope it will disappear in the 07 Camry although I can understand why Toyota included it in all HSD equipped automobiles to date.

___I have a lot more to say (rather verbose opinions anyway ) about future hybrid and non-hybrid designs vs. the paradigm most of the driving public is stuck with today but will save it for a more appropriate thread.

___Good Luck

___Wayne R. Gerdes
___Waynegerdes@earthlink.net

 

There's a big gap between what we really want (or could have as soft options) and what the large manufactureres "think" we want. It's like asking a kid, or probably most people if you would prefer an ice cream cone or broccoli... Much of the auto industry is aligned with this type of 'demand' to maximize profits because from how they look at it you have to make what the people 'want' and so we get SUVs and tons other 'fun' guzzlers galore. I guess the real problem is education and knowledge, once you are aware of the instant FE and how driving (and what you drive) affects it then you are prepared to 'want' cars with better FE, over cars with better performance and size and then manufactureres will have to bend to those desires, as they are starting to.

I wonder why Toyota left the warm air intake off the Prius? Even my Colt has a warm air tube coming off the first catalytic converter that gets switched to at lower temperatures.

 

Hi Schwa:

___In terms of the gap, if the next gen Prius were to show a 75 mpg city/55 mpg highway per the EPA because of a few slight design modifications including regen on brake use only and ICE off on all 0 degrees of accelerator pedal angle after 2 + seconds, you can bet the American public would accept it. The 60/61 that it is rated for now is what woke America up to it today. That and $2.25 - $3.00 gasoline

___Your Colt’s OEM WAI is by far the minority on today’s automobiles unfortunately Here in the states anyway? The Pre-Heater hose that Krousdb is using was originally designed into and used on 1970’s based Ford Trucks IIRC? It was probably used 80 + years ago on something else that I do not know about as well? Same idea. Pre-heat the intake air for more fuel efficiency in colder temps and a thermostat to control the location where the intake charge is being pulled from. Today, most cars and trucks are manufactured to the lowest common denominator ($’s) and with that, we lost quite a bit of FE in the little things like radiator shades and warm air intakes. I believe in the near future, we will see this type of HW re-instated if the Japanese 10-15, European’s whatever they are called?, or the US FTP75/HWFET/US06 tests implement the cold temperature testing throughout these same test cycles. They have but you won’t see Congress mandate those horrible numbers to be displayed on any vehicle even though in the real world, most automobiles are doing even worse in that cold temperature environment! If you did see a cold weather cycle posted, all of these little tips and tricks would be back in full force because Honda or Toyota would not allow an 05 Honda Accord or Toyota Camry to show 10 - 12 mpg in the US06 at 20 degrees F if the 06 Ford Fusion was pushing 20 mpg over the same cycle at the same temperatures because of a warm air intake and radiator block. If you did see that result on the Mulroney sticker, all manufacturers would be embarrassed and would fix this problem immediately even if it did cost $25.00 more per vehicle.

___Good Luck

___Wayne R. Gerdes
___Waynegerdes@earthlink.net

 

I presume this is not an official mod for the Prius but home-made.
I wanted to make a similar modification come the winter, but thought it might be better to route a shorter pipe to the exhaust manifold. Any reason why you went for the cat'? I would just be concerned about more dirt/water entering from down there but it looks like you have it aft facing so it might be ok.

 

Yes,
I have already changed it to intake hot air from the exhaust manifold. It works well, but I have removed it because there is no benefit during the summer. I will put it back on when it gets cooler.

And no, this is not an official mod. All of my mods are "unofficial"