strykersd

I've been considering an aftermarket cam for my 22re but I'm a little bewildered on how they make power. When I swapped cams into my other cars I needed to dyno or wideband tune them for fuel and timing. The part I never get is how aftermarket cams make power on the 22re without tuning the engine? Changing a cam makes it a totally different engine. Is it just that Toyota's fuel maps are really rich so that there is a smaller possiblity that some idiot can blow up his engine (a guy i know always says "lawyers make fuel maps" lol). So by putting a new cam in and pulling it more air leans out the air/fuel mixture in turn making power? That would make sense. And are aftermarket cams for the 22re designed to work at the same ignition and cam timing as stock? Thanks

-MUDSLINGER-

a good cam will give more lift and duration, ther fore more feul and air in and out, and the whole reason feul injection is so good is that the ecu make air- fuel adjustments from what its reading from the MAFS. so get a cam make sure you do your research on companys and what suits your driving needs. damn good question man.

strykersd

Yeah I know that lift and duration allows more air into an engine.
Isn't the mass air flow sensors on 22re's just the flapper? I could be wrong. How accurate could that be?

Jeenyus04

it depends what kind of cam you get. some are shorter duration for more torque and some are longer for more horsepower. compare the numbers to stock to find out or call and talk to who ever you order it from and make sure they know what they are talking about.

notanymore

the ecu also checks the fuel air ratio with the o2 sensor along with the maf, somewhere along those lines. while the flapper maf may not be the most accurate method, between the 2 of them it does alright for an engine designed for economy and reilability over 20 years ago

strykersd

But due to the rapid change of air/fuel ratios under acceleration doesn't the truck run off of closed fuel maps on the ECU? I know it does at WOT, but I wonder if it'll run open loop while accelerating giving it less throttle. The car should make more power cruising down the highway since it'll run as an open loop system with the O2 sensor. Good input so far. Keep it coming guys.

strykersd

Oh ok I get what you're getting at. So the aftermarket cams are just shorter duration but higher lift, in theory allowing the same ammount of air in with less valve overlap. In turn making more power with the same ammount of fuel. Does this sound right?

RC000E

Every ecu has a point to where you go from closed loop to opened loop mode. Closed loop, like stated, the O2, MAF, IAT, and other sensors are being considered and compensation is being made. Open loop though, your maps are your maps, and this is where tuning will yield power gains.

With N/A motors, a 12.5-13.0 air/fuel ratio is ideal. Going beyond stoich ensures that there's a fuel molecule available to completely burn as much of the available oxygen in the chamber as possible. You could use a simple AFC type controller for basic alteration of the maps.

Getting into cam science, especially speaking in terms of a stock motor, is a limited game. It's not so cut an dry as short duration=torque, and long duration=hp...it just doesn't work that way. That's similar to the small exhaust=torque that I see so often on this site.

Torque production comes from increasing low lift flow, increasing low rpm port velocity, and increasing the dynamic compression ratio. This is all accomplished by optimizing the cams ramp angles, lobe seperation, duration, and lift.

Pretty much any stock motor out there can benefit from further tuning. Engineers tune ecu's to meet the temperature extremes, and also tune a margin of safety to compensate for randomly low octane fuels. Their vehicles have to be warrantied, so a margin of safety is always a concern. For this reason, there is usually some areas on the maps that are just conservative.

ovrrdrive

I dunno, IMO all the cams for the 22RE do is move the power band around a little. You get a high rpm cam that pulls well up top but sacrifices some of the bottom end or vice versa. Most of the horsepower in the 22RE is made from mods to the exhaust side of the motor including from the cam, headers, and exhaust system. A fuel injected motor is only going to let so much fuel in regardless of how long the duration is on the cam. It will let in more air but the fuel is constant unless you make ecu or injector mods.

The way it feels to me is that an aftermarket cam just unstuffs the engine a little and unlocks power that was already there.

For a truck like mine that sees mostly street time and some mud, a cam is a nice addition. I have a Crane Stage 2 cam in mine which is a higher rpm cam and it works pretty well with my larger valves and exhaust system...

surf4runner

you cant.
matching the changes(w/cam) will yield the most power gains