STEvil

So I picked up a 1986 SR5 pickup.. it has a Turbo 22R in it.

The fuel mileage sucks (dont think i'm gonna make 350km on the 65L tank!).

Tips?

I'm going to work on the air intake system to make it flow better and see if I can find any "small" 12v fans to make a bit of intake pressure (nothing like a supercharger just enough to act somewhat like a forced induction intake), intercooler(s), 3-Y headers if I can find them for a reasonable price, cat-bypass (valved Y-pipe to divert exhaust into cat for smogging if needed..), and undecided on the exhaust pipe size as of yet (I want torque).

I figure a boost guage might be handy as well so I keep out of the turbo a bit more (I fully admit to overusing it lol).

Hope to make this truck a little less like the average bulemic supermodel (stuffs face then pukes, gutless with no torque!) hopefully..


Oh yeah, 30mpg? I wish. 25 is more doable I guess

kd

no fan is going to make any more boost than that turbo. it will actually restrict the flow and make your econ worse. go to a muffler shop and tell him you want a "test pipe" for your truck. it is a pipe made to take the place of your cat and you can easily switch it around if you need to smog the vehicle or have it inspected. a boost gauge is nice but all you need to do is listen for the turbo to start spooling, when its spooling your econ is going to suck so if you want econ, drive it nice and slow especially when taking off. you will get very good mialage that way.

tc

The stuff you propose will help power and perhaps volumetric efficiency at the expense of economy. More air = more fuel, no way around it - especially on a fuel injected vehicle.

You want the best mileage possible?

Do a tune up - plugs, wires, cap, rotor, timing, O2 sensor

Keep your tires inflated to the max.

Lose ALL possible weight.

Mind your right foot.

michalik_piotr

small street tires and no roof racks.

abecedarian

you've got a few things working against you in the mileage department- low compression ratio, conservative ignition, turbo and your foot.
I suggest you do a foot mod first- learn to stay off the pedal.
and realize that almost everything you do to your engine to increase power is going to hurt mileage because of the fun factor.

wardriver

If that little fan breaks apart - you engine is hosed.

Also, don't overlook the obvious. Plugs, wires, cap, rotor, tire pressure, oil change, clean intake and fuel system. Sometimes it is all about restoring power/mileage instead of adding to it.

misterzee

I dont' think Toyota's intent with the turbo model was 'economy' was it?

you're getting good advise here.... get the engine back to factory spec, cleaned and tuned and serviced, don't spend $$ on add-on crap. Fancy intakes and fancy exhaust only help imperceptably on the high-output end.... reduce rolling resistance, and reduce weight.

if you want to have a little fun training your foot, buy a vacuum guage, they're cheap, and mount it somewhere easy to see. Use THAT to train your foot! :-)
Keep your vacuum HIGH.

kd

first off turbos are great for economy they give you the best of both worlds, pwr and econ. you only have to use them when you need them. if you know what youre doing you could drive all day and almost never use that turbo ands get great econ. and reducing restriction and backpressure is going to give you better fuel economy, not saying that free flow is the way to go, but a good reduction in backpressure and restriction from stock is deffinately going to make your engine work less ie. better economy, if you arent stomping on it all the time. and the fan idea is a joke not trying to be an a-hole, its been tryed and tested before and it doesnt work plus you already have a fan (the turbo).

CJM

You will never see that kinda mpg out of that thing stock or tuned up, its to large and un-aerodynamic.

STEvil

I was being a bit sarcastic.. but i'll address a couple points for fun though.

KD - The fan is not meant to replace the turbo or produce high static pressure. It is only meant to slightly overcome the effects of the restrictive intake system. If you wish to debate the facts of positive intake pressure I suggest you look up some notable "muscle" cars from the 70's and 80's which used forced air induction provided by a hood scoop or inlets at the bottom of the windshield. The effect was a more responsive throttle, more HP, and better mileage when you didnt have your foot into the throttle..

TC - Yes, however if you produce more power you wont have to put your foot into it so far which means overall a possible fuel savings. Alternatively it could help acceleration slightly thus reducing the time you are consuming more fuel to accelerate. The effect is largely untested (more correctly not used) in current vehicles however.

Wardriver - Why? Any danger will be negated by putting it before the air filter. Its all about installation.

As to a vacuum guage, yes one of those would be handy as well. A combination boost and vacuum guage would be even better!

Thanks for tips so far, nothing really new though.

Robert m

iTrader: (2)

i dont get it. if your going to ask for advice, why are you going to argue the advice that you are getting? just go and do all the mods that you want to do anyway. only then you will figure out that putting a fan in front of a actual turbo will only increase the restriction of the intake system the first time you make any boost.
you know that people also sell ecm chips on ebay that will give you like 60hp, you should look into those too.

misterzee

I think you're on the wrong website.

abecedarian

not so sure about the 'if you make more power you don't have to put your foot into it' argument. I wonder how much horsepower a new 'vette actually puts to the wheels when cruising at 65... anyone? I'd bet it's not 300, 200 or barely even 100. mileage is ultimately determined by using the least amount of horsepower to acheive and maintain speed.

putting a fan into the intake system may work at say... when the engine isn't running. do some math- calculate the cfm required by the engine at idle... say the 22re / 2.4L is 146 cubic inches. since each piston draws in air once every two revolutions, the maximum air drawn into the engine considering 100% efficiency is 73 cubic inches every revolution. Now, at 750 rpms, 73 cubic inches drawn in per rev, means the air is drawing 54,750 cubic inches of air per minute. that calculates to 31.684 cubic feet per minute. so you'd need a fan that can flow that much air at idle just to keep up with the engine at that speed. that may not be too hard to find, but find one that does not become a restriction itself once the rpms outstrip the fans ability to flow air. on top of that, no matter what cfm rating the fan has, it means little-to-nothing to the engine if it cannot increase manifold pressure above 1 atmosphere, and most scroll fans simply cannot do it.

turbo and superchargers work because they are either positive displacement- the air cannot travel backwards through the pump and the pump delivers more air than the engine can suck in (thus producing 'boost'), or move so much air that it takes a lot of backpressure (boost leaking backwards) to do so.

now for the 'scoops'... the work based on a ram effect where the vehicle moving forward forces air into the intake. they do not appreciably raise manifold pressure above atmospheric pressure since the air will back up through the manifold until. the do allow colder air to enter the engine though. also, many (if not most) factory scoops had bypass mechanisms that required either a certain throttle position (typically full throttle) to work, or were operated off of engine vacuum. some were manually operated to prevent sucking rain into the engine. you'll also be wise to note that the cars that had functional factory hood scoops, shakers, whatnot's, scoops were also considerably modified over the stock engine; larger carb, different cam profiles and the like; and did not get near the same mileage as the base engine.

good luck!

kd

im familiar with ram air, im also very familiar with turbos. as for the fan, you arent the first person to think of this and if they worked id have had one a long time ago. im not trying to argue i understand it sounds like it would work.

STEvil

Correct. So if i'm making 50hp @ 1/2 throttle 115kph now maybe i'll do 50hp @ 7/16th's throttle 115kph after? Its a small difference but possibly worth it

Absolutely correct but for fun lets toss a few numbers around. A bog standard 2500rpm 8cm PC cooling fan (the average power supply has one) can push 30cfm no problem. 12cm PC fans that push 100cfm are quite easy to obtain and there are ones rated to 200+ cfm at 12v.

Lets say this engine goes to 5500rpm's. That is 7.3 times the speed of 750rpm's and for this we would need 227cfm (31x7.3333333). I'd say things are almost do-able. Too bad I dont have access to a dyno, i'd do some pulls for you guys when I get around to this. Maybe something to kick the fan over to 18v at 3000rpm+ would be handy?

Again I agree, but if you look at the "deckplate mod" and whatever the others were (forgot now, been too busy lol) some people have mentioned notable differences (some not) in MPG and performance.

Also on the note of turbo's and such, the fan(s) will not restrict them very much (if at all) but the turbos might cause them to overspin a bit.

tc

You burn a certain amount of fuel to make 50 HP whether it's at idle or WOT.

tulsa_97SR5

30+ mpg is doable, at least hwy mpg,


http://www.evworld.com/article.cfm?storyid=870

Kiwipushrod

Hey Guys, STEvil,

Max EGR Flow,(reduces pumping losses), Retard Timing, open face spark plugs, light oil, Restrict intake, Lay Off Brakes as much as possible, Rock hard tires, Light acceleration, good bumper valance, drive speed limit,.....25MPG possible.

Thanks, Kiwi

edit: You'll need about 100 ft lbs torque to run 60 miles per hour.

Herblenny

I'm a newb here but since I been working with turbo charged cars and organized few EFI seminars, I'll put my 2 cents in..

1. I'm very confused about so called fan in the intake system. Most turbo guys use fan on intercoolers (IC) to cool down intake charge as turbo(s) heat them up. Besides that, I don't see how fan will help.

2. gas mileage is only increased via leaning out the system. Obvious reason, you wouldn't want to do this while you are in high boost (for us rotary guys, one detonation = bye bye engine). There are many turbo guys that leans it out to 16:1 AF during cruise and get fantastic MPG. But in order to do all this, you would need a stand alone ECU that you could fine tune (timing, fuel, etc). Since I'm so new to the 4Runner scene, I have no clue what kind of turbos or ECUs are available. But I'm sure if you guys want to go all out, you could go with any stand alone ecu for this set up. But cost of tuning, dyno time, etc might be not worth doing this. Also, like others have said, weight is a big factor in speed, MPG, and handling....

wardriver

Oh yea...I also forgot the get out and push it mod. That one will get you a few extra MPG.