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Hello All,

 

I am a new proud owner of a 1985 18ft Sunrader and this is my first post! I have found searching through the archives of this forum to be incredibly helpful but I thought that I would create a post for some clarity pertaining to my needs. I live in Northern Colorado at 8,000ft with many hills and am hoping to gain some insight regarding practical performance improvements that can be made. I do plan to travel between CO,NM,AZ & OR so I am hoping find the best balance between the mountains and highways.

 

My Sunrader has a rebuilt 22re w/ 25k miles, a 4-Speed Manual Transmission that was rebuilt last year and a One Ton Axle. The Driveshaft was rebuilt last year as well.

 

-It definitely struggles going up hills which is to be expected but I am wondering if changing the gears to 4.56 or 4.88 would be of benefit with a 4-Speed Manual Transmission? I would like to go with slightly larger AT Tires such as 27x8.5r14 which I believe people has installed successfully. I imagine that could affect the decision in regards to gearing?

 

-Due to living in the Rocky Mountains I think that adding a bit of lift would be of benefit. I'm not looking to go crazy with it and just hoping to find a practical solution. Does anybody have any suggestions?

 

-I have read good things about adding LCE Headers but am unsure of the cost/benefit of such a thing. I have also heard of people adding an RV Cam but the reviews appear to mixed.

 

All input is welcome and very appreciated! Thanks!

 

Edited by lucidawake
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I don't know about the gears, but I have a 1976 Chinook.  Also from Colorado - although I'm mostly in AZ now.  But...with a 20R it is definitely a challenge with the hills (mts).  Mine is so old that I have to re-adjust the timing and idle each season when I go to high altitude.  Don't know if you do that on yours, but it REALLY helps.  I also put big, god-awful 15" tires on the rear, which helped with the stability tremendously!  Wish I could have done the front to, but not enough room.

 

Good luck and enjoy!

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if you go to the bigger tires, you better change the rear gear too or you will be even lower on power

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Gypsy, what size 15" tires did you change to?

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Hill's mostly, lower gears definitely! Won't help your MPG but it will get you up the hills. Under the best conditions these things are not blazing performers! The 22RE is a outstanding little engine but the key word is"little" the 22RE engine like to spin so the higher rev's won't bother it.

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17 hours ago, WME said:

Gypsy, what size 15" tires did you change to?

30 x 9.5 x 15   They make it so much more stable than the little narrow 14's.

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Yikes that's a huge (tall) tire!!

OK I hope you can follow this, it makes perfect sense to me.😁 4th gear in your transmission is 1:1, the engine makes one revolution for each revolution of the drive shaft in 4th gear. The standard Toy House rear axle ratio is 4.1:1, the tire makes one revolution and the drive shaft (engine) goes around 4.1 times. Deep Breath. The standard MH 14" tire makes 816 revolutions per mile. So your engine is turning 3345 revs per mile. It's perfectly happy to do that.

With the 15" tire you have your engine is turns 2861 revs per mile. Which could make for better MPG, but sucks rocks in a drag race. Actually your rpm is almost the same as you having a 5 sp transmission. But you don't have enough HP to drag a house through the air at 2800 rpm so you have to press the throttle harder and burn more gas.

To restore your engine revs per mile to original (3345) you would need to change the rear axle ratio to 4.88. Your noise level would go up a bit, your MPG would be close to the same and your performance, like hill climbing, would be much better.

Your engine made 97hp when new and 127 lb ft of torque. Torque = acceleration and HP = speed. At 2800 rpm your engine is making less than 60hp and at 3350 it's making almost 80hp.

Now that your totally confused, I rest my case. 

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lucidawake, there is a simple proven path many on here have taken, and it works.  Three steps:

 

1)  Set your timing correctly.  These engines will run on a VERY WIDE range of incorrect timings and are really forgiving.  But they wake up a good bit when it is correct.  This extends to other obvious things, make sure the maintenance is up.  Plugs, wires, cap, rotor, the rest of the engine....  With time, youtube, and some basic skills and tools this is easily a DIY evening kinda job.  

 

2)  Once general maintenance is done the BIGGEST upgrade you can do is change out the rear end ratio to 4.88.  If you do this yourself, the parts aren't that expensive.  I probably could have but I pulled my pumpkin out and handed it to a coworker and watched him do it...  This is a labor intensive job.

 

3)  Get the engine breathing.  Mostly this means getting a header on there and a better flowing exhaust.  There are cheaper headers easily avalibe on Amazon and ebay.  If you order an exhaust for the 6cyl, it is slightly bigger than the 4cly and you can put a Walker exhaust on the back somewhat easily.  The exhaust will need some tweaking though to make it fit.  This is still driveway DIY-able.  

 

After these, there is plenty more that can get your engine up to snuff.  But they are mostly smaller gains for bigger money.  Or huge gains, but massive amounts of skill required...

 

Turbocharging is commonly suggested, but the factory setups are hard to find and utilize a CT20 turbo.  For our rigs, this turbo is sized in such a way it will be borderline between just right, and uselessly sitting in boost the whole time.  An aftermarket T3 setup can be put together, but this is NOT a simple job.  Non-factory setups also don't have the reliability of the thousands of hours of development for things like where to use studs vs bolts, mounting points to survive vibration, and a ton of other little details that are SUPER critical to longevity.  And for any turbo setup to be useful on these rigs, full programability of the engine management would be needed.  This is a whole separate discussion for a dedicated thread though.  

 

But there are plenty of us on here that have seen HUGE improvements from these 3 steps.  I haven't driven mine very far or fully loaded since I did these to it, but the acceleration is already NIGHT AND DAY difference.  I also have a programmable standalone ECU for mine and some other upgrades to go in that will take it MUCH further, but these are not cheap or easy.  

 

There is actualy a Plug and Play MegaSquirt ECU that pops right in and isn't too expensive (for what it is)...  Between that, a couple random installation parts and a wideband oxygen sensor you would be $1000-1200.  Installing it all can easily be done over a weekend.  But tuning it is a learning curve.  At the moment there are no "toyota RV tuning files" out there to just pop in it either.     

 

Anyways, the locals here roll their eyes at me when I get going on fuel economy, performance, and MegaSquirts...  LOL!    

Edited by thewanderlustking
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