More on torque, power, and gearing (perhaps too much more)

[Dank]

As I’ve made recent power-related upgrades to ‘Snailey’ (as my wife and I refer to our little toyhome), I’ve really started thinking about torque, horsepower, gearing, driving habits, etc. I have a theoretical scenario below with some related questions, and if you’re the analytical type, I’d like to hear your thoughts. I think that in this day and age, most folks don’t know or care much about these things, but when you find yourself with a barely-adequate engine, they become more relevant! If you have a V-8 in your toyhome, or word-problems scare you, then this post probably won’t be very interesting to you…J

Otherwise, here’s our theoretical toyhome gearing setup: ( please don't brow-beat me over the numbers- they aren’t accurate… just examples)

Gear RPM speed (mph)

4 3500 65

4 3200 60

4 2800 52

3 3200 40

3 5200 60

Engine redline (max RPMs) = 5800

Torque peaks at 2800 RPMs and stays flat to 5800 RPMs

Horsepower steadily increases until 5800 RPMs

I’m cruising on a flat road at 55mph, approaching a mile-long uphill, constant grade . My speed begins to slow as I start up the hill, so I push the accelerator. The truck settles in at 52mph, no matter if I push the accelerator further or not, and remains there for the last ¾ mile.

1. Why does this happen? Why doesn’t it help when I offer the engine more fuel and air (via the gas pedal)?

2. If I had begun my ascent at 65 miles per hour instead of 55, would my truck have slowed to 52 anyway (given enough time), or would the extra horsepower when beginning my ascent have helped to hold my speed higher? In other words, does it benefit me to speed up before a big hill?

3. What if I downshifted at 52 mph to 3^rd gear. Would I then be able to speed up and hold my truck at 60mph in 3^rd gear?

4. Is it better (for my engine) to run my engine in 4^th gear at its max speed up this hill (52mph – 2800 RPMs), or to run 52mph in 3^rd gear at 4200 RPMs? Which is better for gas mileage?

Perhaps I’m too much of an analytic, but if we consider these questions and their answers, it may change the way we drive, or at least help us better understand why our little Toy engines behave the way they do. These little guys force us to think about every bit of power and torque we can muster.

Hope this was interesting to at least a few J

Dan

Edited June 21, 2012 by Dank

[tumolt]

Let's face it folks. We're not driving a race car with horse power. What we typically see is a severe lack of power going up hills, The weight to horse power ratio difference between a race car and a motorhome is enormous. Race car 600 hp, weight 2400 lbs., motorhome 275 hp, weight 12,500 lbs., Toyota Motorhome 90-150 hp., weight 4000-5500 lbs. It doesn't take a genious to figure out why you can't maintain speed going up hill. No air filter K & N, no headers, no valve job, no increase in compression, no bigger pistons will make any difference if the weight to horse power ration isn't changed dramatically. What you will do is spend more money than it is worth and make gas mileage go up not down.

[waiter]

Everything Tumolt said. (one note - 22RE puts out about 115hp)

Downshift, put the 4-ways on, and slide in behind an 18 wheeler. Thats my power strategy..

JOhn Mc

88 Dolphin 4 Auto

[Dank]

Tumolt,

It's all about expectations and tradeoffs. While the things you say are usually true, sometimes a few extra horsepower and foot-pounds can make the difference between between "acceptable" and "unacceptable" (or unsafe) driveability. I'm willing to trade "barely acceptable" for good gas mileage, but I want to make sure I'm getting all I can get (within financial reason) from my little engine.

Dan

[Maineah]

Toyota never intended these things to be motor homes the coach makers decided to put houses on their backs. What one has is a very neat little MH that you can park most any where. It's small enough not to be a pain in the back side, you can leave the camp ground go to dinner in it you would be hard pressed to find another class "C" that you would want too. I guess it is what it is yeah it's slow but what's your rush?

[86rader]

As you have discovered, putting it to the boards does just one thing, waste gas. You get a feel for how much gas pedal is the right amount after driving one of these things for a bit.

As for downshift, it generally helps quite a bit. I haven't owned a 4 speed, but the A43D auto has a very tall OD gear which is great for loping along 2 lane roads at 45 50. If you get on the highway, however and want to go any faster than that, or have to climb much of a grade at all, third is the place to be. The 22R will spin 4K in third gear for ever and not complain a bit. Your ears may, however.

As maineah said, what's the rush. Stay on the 40-50 mph 2 lanes where the toyhouse shines. If you gotta get some place fast, buy a plane ticket.

[Allen]

Hi Dank,

I agree with you in regards that "a few extra horsepower and foot-pounds can make the difference between "acceptable" and "unacceptable" (or unsafe) drivability", especially going uphill, or even getting on the freeway for that matter. Everything from here on is my opinion, and if you do decide to follow it, you do so at your own risk.

In regards to downshifting to go faster, if it goes faster when you downshift, then do it. I used to lug my 22RE, it worked okay, the engine did not complain; however, I had to adjust my valves more often and I believe that it hurt the gas mileage.

In regards to getting more power out of your engine, you can do what hot rodders have been doing for years. Advance the timing and letting it breathe better, this includes the exhaust. Try advancing it 5 degrees first. If it does not ping when going up hills on hot days, then you can probably advance it more. If you have a pretty good exhaust system, you can advance it more. If you like the power increase and it pings slightly, then run a better grade of gas. Even if it does not ping, you can run a better grade of gas anyway for insurance. I run premium. I would not recommend advancing it more than 13 degrees. Note: If you have to get your MH inspected and they check the timing, make sure you put it back to stock when it is inspected, else it will fail the visual inspection.

For the exhaust, I recommend that you first start with the CAT and everything behind it. If you have to replace the CAT, get one that has a 2.5" pipe. The stock one is only 2". I am going to install a Magnaflow 22767 Direct Fit CAT tomorrow, since the previous owner welded in 2.5” CAT has been getting weaker and it failed the last emissions test (it barely passed the previous 2, every other year). It is an 1/8" shorter than the stock one (at least the 4 cylinder) which is nothing. I would then put in a 2.5" free flowing exhaust system. For a muffler, I am using an Aero Turbine AT2525. Unfortunately the company went under with the economy; however, you can still find them on eBay. They claim that it will improve your mileage, especially if you have a diesel. I put one on my wife's 2002 Malibu and it increased the mileage by 5% (and it also makes it sound like a sports car!). It is on the louder side, but it sounds nice. They make an AT2525LX with a built in resonator, and it greatly reduces the sound.

Let me know your results if you try any of these. Advancing the timing costs you nothing. A larger exhaust system costs a little. You can always wait until the later need replacing. An exhaust header is expensive. If you do opt for this, I recommend a Tri-Y header, they give better torque at the lower rpms. A 4 in 1 header is good for the higher rpms. If you do opt for the header, chances are you will have problems with the oxygen sensor at an idle (I did, and searching the Internet at least one other guy did too). You would then will most likely have to wire in a 4 wire heated oxygen sensor to get it to work right at an idle, over the factory 1 wire oxygen sensor.

Good Luck!

Regards,

Allen

[stamar]

I do not follow that last thing about a 4 wire oxygen sensor. the ecu will not sprout a new oxygen sensor connection with the header installation. It will be a 1 wire oxygen sensor ecu unless you upgrade it.

on the other hand the header should fail the visual inspection of a smog regardless.. Basically do not get a header if you have smog inspections.

hmmm aparently you can connect a 4 wire to a 1 wire and it just heats it. I stand corrected definitelya new ninja tactic.

It doesnt read it but iy heats it.

[WME]

Two basic rules to follow.

1. Speed (power) cost money, so how fast is your wallet?

2. The only substitute for cubic inches is cubic money.

HP=rpm, lugging your toy up a hill in 4th, you reach a balance point where hp= drag and incline. Down shifting gives you more rpm and thats more HP. As long as the hill isnt "forever" downsfiting is better on the engine and doesnt effect the overall MPG very much.

[Bob C]

I have talked to the owner of a car shop that specializes in Toyotas and Honda vehicles. He told me that the sure way to end up with a Toyota 22R in his shop is to lug it under heavy load. He constantly tells people that 22R or 22RE engines love to spin up high a lot more than lug down low. I stopped in and showed him my MH and he said forget OD and consider 65 the top speed.

[5Toyota]

as i have owend a 1978 moter home and truck and a22re truck i back that all the way. these engines are 5 main bearing strong made. they need to wind. within the limits. last fall i got an 87 dolphon 22re auto i apreate the advice on the a43d. as all of my prevous 6 toyotas were standred shift.

[Maineah]

22R/22RE engines made their HP at about 4800 RPM so you got to wind them up! Noisy but it won't hurt them.

[Dank]

I appreciate the responses and advice from each of you. I'm generally not in a big hurry to get somewhere... I just don't want to get run over on the interstate or stack up traffic on the back roads.

When I was in the Toyota MH market last year, I drove one with a 5-speed manual tranny. I was scratching my head, wondering why they would even bother... 5th gear seemed pretty useless. Now I'm thinking it would be really nice to have a 5-speed and change the rear ratio to a 1:4.56 or 1:4.88... a small O/D with one more gear choice just might be the ticket... I often find myself wishing I had a 3.5 gear

Allen,

I'd be curious to know what kind of changes you see with the 2.5" exhaust on the MH. I've read that 2.5 is a bit big for the 22R (except the turbo version), and that it would hurt torque in low and mid RPM ranges.

Thanks,

Dan

[Derek up North]

I'm thinking it would be really nice to have a 5-speed and change the rear ratio to a 1:4.56 or 1:4.88... a small O/D with one more gear choice just might be the ticket...

I agree. 5 gears, closer spaced to make it easier to drive in the 'sweet spot'.

[90toydolphin]

to avoid getting run over on the freeways i avoid where posible, as far as back roads i pull over a lot to keep the cars from pilling up. the pulling over seems to get many thank you waves, feels good )

[Derek up North]

Do I recall correctly hearing decades ago that you can get ticketed in some places (California?) if you've got more than 14(?) cars tied up behind you?

[waiter]

Calif the number was 5. your supposed to pull off and let them pass. very hard to enforce... go up US 50 between Sacramento and Lake Tahoe.

John Mc

88 Dolphin 4 Auto

[Derek up North]

Calif the number was 5. your supposed to pull off and let them pass. very hard to enforce ...

John Mc

88 Dolphin 4 Auto

At least there's a law on the books where they could ticket someone who was being a real dink with a line of 30 cars behind it. No law, no recourse!

[Bob C]

I live in a very rural area. The only time we get 5 cars backed up is when they are following a combine or four wheel drive tractor with duals all the way around. I drive 38 miles each way to work at 5:00am, I usually see 3 or 4 cars on the entire drive, and that is driving through Wisconsin Dells (tourist trap supreme.

I would love a good 5 speed and shorter gears in the MH. I am afraid that if it was the same tranny that my SR-5 had, fifth gear would crap out on me again. I was told that it was a poor design.

[Allen]

Hi Stamar,

From the Bosch Oxygen Sensor Catalog (http://www.bosch.com...or__Cat_WEB.pdf, page A6):

• Single Wire Sensor - the original design, sensor output voltage via the single pole connector, grounded via the sensor body
  
• Two Wire Sensor - for improved earth reference of sensor output signal, a reference wire is also connected between control unit and sensor.
  
• Three Wire Sensor - heated sensors provide various advantages including,
  
  • Earlier cut-in for closed loop operation
    
  • Lower emissions with new and aged sensors
    
  • Lower sensor deterioration caused by thermal stress
    
  • Extended service life (from ~ 50,000km to 80,000km +)
    
  • More accurate fuel management system calibration
    
  • Greater flexibility in sensor location
    

  [*]Four Wire Sensor - heated sensor with integrated earth reference/supply circuit, these sensors may be either grounded through the body or earth isolated depending upon engine management system design and customer requirement. Earth isolated sensors are provided with an earthing circuit for the measuring cell by the engine management control unit. The engine management control unit purely references the earth of a sensor that has its body grounded.

See also pages A8 and A9 for the evolution of the oxygen sensor.

Basically, a 4 wire sensor is heated over a 1 wire. This allows placement remotely, I mounted it at the collector (this way is can sample all 4 cylinders). 2 of the wires get attached to power, a switch 12V line and ground. The other lead is connected to ground, and the remaining wire to the original 1 wire sensor. The issue I had was that the original 1 wire sensor did not get hot enough at an idle with the header, so it was running rich and failing the smog test.

Regarding headers made by either Doug Thorley or LC Engineering, both offer 50 state legal ones

• http://dougthorleyheaders.com/faqs/
  
• http://www.lceperfor...5-p/1041030.htm
  

Hi Dank,

I installed the Doug Thorley TriY header 2 months after I got the MH. Afterwards it went straight to the muffler shop for the 2.5" exhaust. I am running 12 degrees advance on my 22RE (7 degrees over stock (5 btdc)) best results for my setup, more than that slows down the response and power. For reference: On my 22R pickup (commuter) I am running 13.5 degrees advance (13.5 degrees (0 btdc)), it has a 2.5" CAT back system that I added. Both greatly picked up overall power after the timing was advanced. Power was what I was after for the MH, not mileage (i.e. to make it more acceptable, in your words). Note: Adding the larger exhaust without advancing the timing more did reduce the gas mileage and low end power in the pickup.

Note: You should do what you feel comfortable with.

Regards,

Allen

[stamar]

nice thanks. I did look that up mmyself.

[Galvanized Knight]

I have a 20R four speed in my 1980. I was wondering what you guys thought of the DUI distributor with the matching live wires? http://man-a-fre.com/pa/duitoyota20rand22rperformancedistributor.htm . I currently have a header on my truck. I only reason I installed it because I had issues sealing the doughnut and it was a cheaper choice then a new manifold. http://www.ebay.com/itm/OBX-Exhaust-Header-75-80-81-Toyota-Celica-2-2L-20R-/160814058046?pt=Motors_Car_Truck_Parts_Accessories&hash=item257143ca3e&vxp=mtr#ht_1431wt_1110

I have a Weber carburettor 32/36 install on my 1983 shortbed 4x4 pickup with a 22r it seems to run nice, didn't notice any real gains.

I am wondering how my 20r would perform with the header, a 38 Weber and a DUI with live wires? Is it even worth the trouble? Or just replace them as those pieces break?

I have alot less weight to deal with compare to most motorhomes [ 830kg (1830lbs) on the front axle and 1400kg (3090lbs) on the rear axle ] but I am turning 33x12.5's and have 4x4.

I don't need to get anywhere quick either and 4 lo does some amazing things.

GK

[Allen]

Hi GK,

That is a great price for a header! I did not know that one could buy a new one for that low of a price! Unfortunately for most of us living in California, it appears that header nor that DUI distributor would work for us, since either one would fail the bi-annual smog check because of no EO number (at least I could not find on their websites).

If you are happy with your motorhome currently, I would just replace the parts as they are required. If you want a hotter spark, a lower cost way would be just to add a hotter ignition. MSD used to make an inductive ignition, Blaster Ignition (pn 5900). It has all the performance benefits claimed by your DUI distributor (since it is inductive), plus it has an EO number. In fact, I installed one on my Sunrader (see picture below). They are still available new out there, but you will have to look for them. The lowest price that I saw was $139. Whatever ignition that you do buy, just make sure that you get a tach adapter (http://www.msdigniti...ch_Adapter.aspx), else your engine will not run.

Regards,

Allen

Note: The tach adapter is not shown in the picture, since it is hidden by the power brake booster.

[Maineah]

The expense of the parts for the gain is not worth it there is just so much you can get out of 2.2 liters and still have some thing you can drive every day. The design is good, a cross flow head, overhead cam, strong bottom end what's not to like? The greatest gains would be with a carbureted 20-22R the stock carb lacked a lot. Great little engines just to be able to haul around that much weight at all. There are any number of things available for the engines from cams to tail pipe hangers but dollars to HP figures are pretty lame. No matter what your closest competition is going to be a loaded log truck.

[86rader]

.... there is just so much you can get out of 2.2 liters .....

or 2.4 liters, for that matter.

The bottom line, as you say is, it's one of the best damn motors ever made. You can spend $$$ and get $ worth of performance increase, which in the end, still makes you one damn slow vehicle, compared to the rest of the rats in the rat race.

I believe that if you are gonna spend some coin in hopes of making a hotrod out of your toyhouse, just go ahead and swap over to a different engine. The smart folks at toyota didn't leave a whole lotta room for improvement in this magnificent little motor.

[Bob C]

I had an 82 Toyota P-up with 225,000 miles on it. The engine ran great but the body fell off of it. The 22R engine is one of the reasons I decided to get my Toyhouse. I live with its limitations and love the gas mileage.