Pete1122 Posted March 2, 2015 Share Posted March 2, 2015 When it comes to the 3.0 V6 in our Toyota Motorhomes, I have learned that it’s the little things that can make a big difference. Here is a quick list of modifications I have done, in order from first to last. Each modification was done separately and not at the same time. (Keep in mind that my Warrior was running stock exhaust and was in excellent mechanical shape) While I feel that this makes it an excellent baseline, your results may vary. 1. Rear Differential change: I swapped my stock differential to 4.56 gears. This had an immediate and profound impact on the drive ability of the RV. The differential change keeps the engine in a higher RPM range making the Overdrive useful. I noticed less downshifting and better usable power around town. This did not seem to impact MPG. 2. New O2 Sensor, New Spark Plugs, New Cap, New Wires and rotor: I saw no change in performance or drive ability, a smoother idle and small MPG improvement. 3. Airbox modification with K&N filter: Slightly better high end power, very slight. This however increased the intake noise by a substantial amount. 4. New 2.25 Exhaust, new Muffler and new Catalytic converter: This made a huge difference in top end power, up to this point I could only keep a speed of 61 mph driving up a hill close to my house. With the exhaust change I hit 67mph and was still accelerating by the time the hill leveled off. (keep in mind, it’s a small incline) 5. Increase timing to 13 degrees: I saw an improvement in throttle response and a slight increase in power through low-mid-high power band range. 6. New upgraded 4 hole injectors: (Pending install) Overall impressions: The combination of all of these modifications has greatly improved the drive ability of the RV. When I first bought my 1989 Toyota V6 Warrior I immediately took it on several trips and noticed a few things about the power/drive ability of the RV. It seemed to down shift a ton, at almost every incline the RV would shift out of overdrive and into 3rd gear. Overall my Warrior really seemed to be struggling to maintain 60-65 mph without downshifting every few minutes. I found the constant downshifting to be annoying due to the engine noise and just the constant reminder that the engine was struggling. I then did what I do best, research. I hit all the popular websites including the Yahoo Toyota RV group, Pirate4x4, YotaTech, and of course this site. Most of my research told me that doing any modification on the 3.0 engine would be a waste of time. However I started to realize that those people who advised against modifying the 3.0 did not have the same goals or objectives that I have. My goal were to increase the drive ability of the Warrior so it could stay in overdrive longer, reduce the downshifting and climb hills faster. Basically, increase the drive ability and reduce the stress on long trips, for both me and the engine. Over at the regular Toyota Forums people are running 33” tires and wanting some serious low torque for four wheeling, or crave pure HP numbers. With that goal in mind most people just recommend swapping the 3.0 for a 3.4. For me I found that the little modifications make a big difference. Increasing your speed climbing a hill by 7 mph does not seem like a ton, but cruising down the freeway in Overdrive without down shifting as you start to hit an incline is a big deal for me. I keep her in OD, put the cruise control on and just relax. Quote Link to comment Share on other sites More sharing options...
Vanman Posted March 2, 2015 Share Posted March 2, 2015 How much did #1 cost?? I've been considering this as I live in a steep hilly area. Quote Link to comment Share on other sites More sharing options...
Pete1122 Posted March 2, 2015 Author Share Posted March 2, 2015 I purchased the entire differential, not just the gears, I found them on craigslist for $120.00. I had a backyard mechanic do the swap for another $100.00. The only thing to note is your speedometer will be off once you install the gears. You can buy an adapter to fix that, or do what I did and buy a cheap GPS Heads Up Speedometer that displays your accurate speed on the window. Quote Link to comment Share on other sites More sharing options...
zero Posted March 2, 2015 Share Posted March 2, 2015 How much did #1 cost?? I've been considering this as I live in a steep hilly area. The new parts come to around $225. Obviously if you don't install yourself and have someone else take your OEM gears out, and properly setup the new gears - you're talking a lot more money. If fact, some places don't even have the know-how to set-up new gears and want to install a complete, pre-assembled Hotchkiss center-section. I'd guess at 3-4 hours shop-labor to remove your existing center-section and bolt in a complete, pre-assembled replacement. That pre-assembled unit (if you can actually find a known-to-be-good-one) with the correct ratio can be $150 from a junkyard and often $700 from a shop somewhere with new gears and all checked over. Having your center-section removed, new gears installed along with new crush-collar and pinion seal - probably around 6-8 hours total shop labor and $225 in parts if you shop around. One warning: Ring and pinion gears need to be perfect in the way they are made and the way they are set up. Off-roaders often use "factory seconds" that are not suited for highway use. They have slight imperfections and will howl at high speeds. Not an issue for an off-roader, but not something you'd want in a motorhome. Gear makers like Yukon Gear sell ring & pinion sets in two price levels. The "less then perfect" for off-roaders and the higher priced "perfect" for what you'd want in an RV. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted March 2, 2015 Share Posted March 2, 2015 Thanks for the write-up. A couple of comments:- - Your change of gearing is ~10%. Just be advised that some later V6s were supplied with a 4.30:1 (vs 4.10:1) so the change will be less noticeable; - Do you think the air filter mod is worth the extra noise? Quote Link to comment Share on other sites More sharing options...
Pete1122 Posted March 2, 2015 Author Share Posted March 2, 2015 I don't think the air filter modification was worth the noise, however I'm going to go with a full K&N kit and see how that works out. Quote Link to comment Share on other sites More sharing options...
shibs Posted March 4, 2015 Share Posted March 4, 2015 Pete, Good information, I am glad you took the time to confirm the end result of each change. #3: FYI: k&n is not good for you engine in the long run, tests have confirmed that it lets more dust through, pls search google to confirm. factory air boxes are fine with factory air filters. #4 My 90 runs bit rich, that over time I am sure it will clog the cat converter. what OD pipe did you use for the exhaust, cat part# and muffler details pls, Quote Link to comment Share on other sites More sharing options...
zero Posted March 4, 2015 Share Posted March 4, 2015 Other then the gear change, there's no way to use those results and apply to another rig. That because any reported gains might be based on poor conditions to start with. E.g., replacing plugs, wires, cap, rotor, etc. will have NO effect on an engine that had good parts to start with. Same with exhaust. Any reported gains don't mean much unless we know how restrictive the system was that was replaced. An OEM system will have adequate flow unless you drive at 5000 RPM a lot. As to timing? I'm assuming it was the "static" timing that was changed and not the timing-advance curve? If so, it's usually a bad thing to do. It "robs Peter to pay Paul." But I don't know exactly what was done. For best running, the timing is supposed to be retarded at low RPMs and advanced at high RPM. Cranking up the "static" timing makes the timing wrong at all RPMs. Some people "tweak" their rigs with custom timing advance-curves but it does not sound like that's what was done here. From what I've seen, the custom air-cleaner kits are just about always a bad idea unless you have high RPMs in mind and are willing to sacrifice longevity. Obviously, putting in a new oxygen sensor also will have no effect if the one being replaced was working properly. I'm not trying to be a wet-blanket here. Just trying to stick to reality. What gives a gain to one person might not do anything for another. Quote Link to comment Share on other sites More sharing options...
Pete1122 Posted March 4, 2015 Author Share Posted March 4, 2015 I think it's pretty clear that changing the exhaust from OEM like I did will have a positive impact on any other Toyota Motorhome with OEM exhaust. The question has always been "is it worth it?" Same with the gears. You will notice that I stated that there was no performance impact for me by changing out spark plugs and other regular maintained items. I would consider my Warrior to be a great baseline to start with, in great mechanical condition. While every vehicle will react differently to different modifications, there is no denying that by opening up the exhaust and intake, and changing gears, you will net gains. Again, the point of my post was to help answer the "is it worth it" question. Quote Link to comment Share on other sites More sharing options...
RVdaytrader Posted March 4, 2015 Share Posted March 4, 2015 On my 89 seabreeze the exhaust pipe was extended about 8 feet with 2 90 degree bends to exhaust it out the back. I am sure that puts more restriction on the exhaust. As soon as the muffler needs to be replaced I will do what you did and exhaust it out the side behind rear wheels Quote Link to comment Share on other sites More sharing options...
RVdaytrader Posted March 4, 2015 Share Posted March 4, 2015 And quite a few have put in 4.56 rears and every one liked the results...that is on my to-do list when I get some spare $$ to play with. Quote Link to comment Share on other sites More sharing options...
Pete1122 Posted March 4, 2015 Author Share Posted March 4, 2015 Jdemaris makes some good points, I will edit my post to help establish the "baseline" and put a disclaimer "results may vary" Quote Link to comment Share on other sites More sharing options...
Derek up North Posted March 4, 2015 Share Posted March 4, 2015 And quite a few have put in 4.56 rears and every one liked the results...that is on my to-do list when I get some spare $$ to play with. I can safely say that I don't recall a single case of someone saying they regretted done the swap. Quote Link to comment Share on other sites More sharing options...
zero Posted March 4, 2015 Share Posted March 4, 2015 4.56 made a nice difference in my 1988 Minicruiser. OD/4th was useless with the 4.10 to 1 rear unless I was on a purely flat road. Now I can cruise most places in OD, have less revs then I used to have in 3rd, and have more pulling power in 1st. Cost me $80 for the speedo adapter though. Just watch out when buying new gears. Sellers advertising new gears for Toyota as "standard" are full of it. "Standard" means "factory defect" meant for off-roading. The Yukon 4.56 gear set for my four-cylinder Toyota in "standard" from is $160. Part # ZG-T8-456. The gear-set actually meant for highway use is part # YG-T8-456. Defective gears are $162 new. Perfect gears are $225 new. Quote Link to comment Share on other sites More sharing options...
Totem Posted March 4, 2015 Share Posted March 4, 2015 I would love to see someone do an identical write up for the 22re, where gains are even more necessary. Quote Link to comment Share on other sites More sharing options...
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