Couple performance questions

4

4RunnerChaos

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Hey guys, I've heard from a couple friends that if I remove my cat ill get better gas mileage? I was just wondering if this is true. I don't think we do emissions tests here so that's not a problem for me.
If I remove the cat, is there a rear O2 sensor I have to worry about? If so what could I do to not make it give a CEL? Anything helps guys..

Also, my friends told me I should invest in electric radiator fans for my truck and remove the belt driven fan. Anyone have good dimensions or brands for these fans? And should I do a double or single fan?

Anyone know where I can get a front valance that seems a little less like a wall made to catch wind.... It's like the least aerodynamic thing ever made Lmfao...
 
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I don't think the pro's outweigh the con's with removing the catalytic converter. You won't really gain much horsepower, unless the cat was clogged in the start.

Now, I'm not a tree hugging hippie, but you also create a larger carbon footprint without a catalytic converter. And, most of the places I see people posting up pictures of their 4Runners, I would hate for it to get smogged by a cat-less 4Runner.

Also, you might run into Bank 1 - O2 codes. Not a guarantee but down the road, the exhaust might trip the code.
 
Thanks, wasn't sure how much of a difference it would really make :p

Anything about the other ones?

Sorry for the double post, phone is actin up.
 
Changing your fan style won't add any power....you are transferring load one way or another. Instead of your motor having to turn the fan it is now having to deal with the increased alternator strain to run your electric fan
 
Brian757 said:
I don't think the pro's outweigh the con's with removing the catalytic converter. You won't really gain much horsepower, unless the cat was clogged in the start.

Now, I'm not a tree hugging hippie, but you also create a larger carbon footprint without a catalytic converter. And, most of the places I see people posting up pictures of their 4Runners, I would hate for it to get smogged by a cat-less 4Runner.

Also, you might run into Bank 1 - O2 codes. Not a guarantee but down the road, the exhaust might trip the code.
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It's not the carbon that the CAT deals with, it's unburned fuel vapors and other gases much more noxious and bad for the environment than CO2. If you remove the CAT, you will be doing more harm to the environment, your lungs, and everyone else's lungs by pumping out raw fuel vapor and other nasty's. I'm no tree hugger either, but the CAT really does improve the emissions with little to no impact on performance. Don't remove it.

And Brian is right, you will run into codes unless you buy an 02 simulator, which is probably illegal even if you don't get emissions tests performed. There still may be laws about modifying OEM emissions reduction systems even if they don't test. I'm not sure though.
 
Guys, I get the cats :p
Just saw a post on another forum about a guy who did the electric fan on his 03 taco and gained 3-7 hp (depending on rpm) and this was data from a dyno so there's something to it?

Can I just remove the fan? I don't see why I wouldn't be able to since my fan isn't ever under too much strain except when I'm accelerating.
 
You will gain gas mileage by removing the fan clutch and doing electric fans, but like others stated it will add strain to your alternator. Depending on your current list of mods you may need an alternator with more output... I know there is a kit available through Summit, but I'm not sure about how the on/off switches are setup... Especially with the A/C
 
Ok, so here's the deal with the fans. Racers will replace the fan with an electric because they can turn it off when they don't need it, and racers are almost always going fast enough that they don't need it. That does relieve an inertial load on the pulley and free up a couple horsepower.

For a truck that wheels or sees city traffic there's no gain though. Any time you're stopped or moving slowly, you need the fan on to keep the motor cool, and it doesn't matter if your fan is a) driven directly by a belt or b) by electricity generated by an alternator driven by a belt, it's still a drain. The electric fan is actually a greater drain when it's on than the mechanical fan because of the losses inherent in turning mechanical energy into electrical and back into mechanical.

There's really only two times you should replace the 4Runners stock fan - if you're turning in times at the drag strip, or if you regularly cross deep water.
 
Off topic here but about the Environment, as much as I care about it, we drive a carbonated 65 Mustang v8 with no cats lmao.
 
02_SE_Runner said:
Off topic here but about the Environment, as much as I care about it, we drive a carbonated 65 Mustang v8 with no cats lmao.
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Trust me you are not doing nearly as much damage as all the priuses on the road. The amount of lithium mined, destroyed more ecosystem and killed more species than our gas or diesel engine ever will.
 
KidVermicious said:
Ok, so here's the deal with the fans. Racers will replace the fan with an electric because they can turn it off when they don't need it, and racers are almost always going fast enough that they don't need it. That does relieve an inertial load on the pulley and free up a couple horsepower.

For a truck that wheels or sees city traffic there's no gain though. Any time you're stopped or moving slowly, you need the fan on to keep the motor cool, and it doesn't matter if your fan is a) driven directly by a belt or b) by electricity generated by an alternator driven by a belt, it's still a drain. The electric fan is actually a greater drain when it's on than the mechanical fan because of the losses inherent in turning mechanical energy into electrical and back into mechanical.

There's really only two times you should replace the 4Runners stock fan - if you're turning in times at the drag strip, or if you regularly cross deep water.
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Sorry I have to disagree... When GM switched to electric fans somewhere back in 04-05 the trucks gained 2-3 MPG with the same motor... The 40a load on an alternator doesn't put near the strain on an engine compared to a fan clutch
 
KidVermicious said:
The GM fan clutch must have sucked donkey schlong then. Toyota trucks don't have that problem. ;)
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Lol what? This fan always runs.. It's like a Duracell battery Lmfao... And the electric fans are only 12v, so it's just as bad as charging your phone Lmfao. Yeah I know someone's gonna come up with something else to make those a bs comparison but still you guys get it. :p
 
4RunnerChaos said:
Lol what? This fan always runs.. It's like a Duracell battery Lmfao... And the electric fans are only 12v, so it's just as bad as charging your phone Lmfao. Yeah I know someone's gonna come up with something else to make those a bs comparison but still you guys get it. :p
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My welder is 120 volt so it uses the same electricity as my 120v phone charger. Doesn't make much sense huh

Sure you may get 1MPG more, but in terms of power forget it. Also you would have to upgrade your alternator at any rate, stock can't keep up with big electric fan. So then you are turning an even larger alternator with bigger brushes.
 
4RunnerChaos said:
Lol what? This fan always runs.. It's like a Duracell battery Lmfao... And the electric fans are only 12v, so it's just as bad as charging your phone Lmfao. Yeah I know someone's gonna come up with something else to make those a bs comparison but still you guys get it. :p
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Yeah, we get it. I'm not sure you do. The stock fan has a clutch that lets the fan freewheel when you don't need it, so it's not always running. And you might wanna read up on a little thing called Ohms Law before you start comparing phone chargers with electric fans.

Seriously, you don't know what you're talking about.
 
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