VVT-i V-8 Super Charger
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The reason Toyota doesn't make superchargers for the 2UZ-FE (4.7 L V8) anymore is because they were becoming a liability. The problem is that the conrods in the 2UZ-FE are pencil thin and under boost have had a tendancy to snap and cause catastrophic engine failure. See examples here: (Note: 2UZ-FE rods are identical to 3UZ-FE rods).
http://www.lextreme.com/rods.html
I think TRD cleared the original superchargers for something like 6 lbs of boost (non-intercooled) for about a 50-80 HP gain. The problem is after a while, this wouldn't be enough for people and then they would start adding boost (smaller pulleys) and adding fuel (more injectors & more pressure) resulting in more power that grenaded the engines. I have come across (in my online quest to research) many cases where the TRD blower granaded an engine, most of them were Tundras. While most of them had upped boost and fuel, I did run across a few that blew up under normal driving conditions but had many miles on them with the supercharger installed. This suggests that even under normal (and warrantied) boost, the fatigue stress limit of the conrods (at max load) was well within the operating range (in cycles) of the engine. After a couple of these hit the books, TRD pulled the unit, and that was that.
Of course, every engine is different, but to an engineer, you treat them all the same. Once they had normal engines blowing up under normal conditions, they realized they had overestimated the fatigue strength limit of the conrods and concluded that if it could happen to a couple, it could happen to a couple (thousand) more, which would be expensive. Toyota turned a corner with the 2UZ-FE which came in the form of VVT-i, which was long overdue anyway and the rest is history.
I'm not saying not to supercharge. In fact, I plan on supercharging myself. Just be smart about it. You're not going to get a safe 400 HP out of the stock 2UZ-FE engine just by supercharging it. Stick to 6 lbs max boost and premium fuel and you *shouldn't* have any problems. We'll go ahead and call the grenaded stock TRD blowers that I mentioned above anomolies (bad metal in the conrods? poor engine maintenence? un-corrected knocking, there is so much that could factor in here). I trust the 2UZ-FE, and with proper installation and tuning, 6 lbs should be a breeze (pardon the pun).
http://www.lextreme.com/rods.html
I think TRD cleared the original superchargers for something like 6 lbs of boost (non-intercooled) for about a 50-80 HP gain. The problem is after a while, this wouldn't be enough for people and then they would start adding boost (smaller pulleys) and adding fuel (more injectors & more pressure) resulting in more power that grenaded the engines. I have come across (in my online quest to research) many cases where the TRD blower granaded an engine, most of them were Tundras. While most of them had upped boost and fuel, I did run across a few that blew up under normal driving conditions but had many miles on them with the supercharger installed. This suggests that even under normal (and warrantied) boost, the fatigue stress limit of the conrods (at max load) was well within the operating range (in cycles) of the engine. After a couple of these hit the books, TRD pulled the unit, and that was that.
Of course, every engine is different, but to an engineer, you treat them all the same. Once they had normal engines blowing up under normal conditions, they realized they had overestimated the fatigue strength limit of the conrods and concluded that if it could happen to a couple, it could happen to a couple (thousand) more, which would be expensive. Toyota turned a corner with the 2UZ-FE which came in the form of VVT-i, which was long overdue anyway and the rest is history.
I'm not saying not to supercharge. In fact, I plan on supercharging myself. Just be smart about it. You're not going to get a safe 400 HP out of the stock 2UZ-FE engine just by supercharging it. Stick to 6 lbs max boost and premium fuel and you *shouldn't* have any problems. We'll go ahead and call the grenaded stock TRD blowers that I mentioned above anomolies (bad metal in the conrods? poor engine maintenence? un-corrected knocking, there is so much that could factor in here). I trust the 2UZ-FE, and with proper installation and tuning, 6 lbs should be a breeze (pardon the pun).
Paulmessen
New member
are you still planning on superchargering? And if you get it installed at the dealer will they still waranty it or is no waranty with the kit no matter what? Oh and if the sc kit in tampa also have one for the V8?
I do plan on supercharging still, but it will have to be a pretty custom setup utilizing a centrifugal supercharger from someone like URD or Procharger.Paulmessen said:
If you can get your hands on the roots type TRD one, I *think* the dealer will still install/warranty it for you. This is only for the '03-'04 V8 though. The important thing to know is that TRD stopped building the supercharger units so they becoming increasingly scarse.
ThatsRicci
New member
OUTRNNR said:
You can -never- compare the strengths of different metals just by looking at the size and weight of them.
Purities, impurities, forged strengths, forged methods, forged at all, compounds..etc.
I know this can go for a lot of things. I've seen hollow steel cranks on mountain bikes bear 5x the stress has their solid counterparts.. construction and materials have so much to do with it. He needs to test their break/bend limits by applying some serious amounts of torque to them. Also need to test break/bend limits under heat (300F-400F sounds fair) as impurities will start to rear their heads when you heat up metals.
This is a completely inconclusive report.
I think you're outstepping your bounds a little here dude. Everything you just read came from a graduated and licensed mechanical engineer.ThatsRicci said:
You're right, you can't compare just by looking at them because they could be different materials. One could be titanium and one could be lead for all we know. That would lead to drastic differences in compressive and tensile fatigue strenghts due to the axial loading (not torque), which is the predominant loading condition applied to the conrod. You also can't look at a piece of metal and judge its strength either. The good news is that we have a pretty good idea of what the conrods are made of. That information combined with other engineering factors yields what is called a "Safety Factor" which takes into account material properties & strenghts, loading conditions, fatigue limits, etc. It is safe to assume that each rod is made neither of an extremely strong or weak material.
Here's where my report is conclusive. Toyota doesn't make their conrods out of titanium nor do they make them out of lead. They make them out of powdered metal casting. Now what percent alloy/steel content, I don't know, but I guarantee you a TON of research has gone into optimizing the lightest, strongest and cheapest alloy powder mix. Furthermore, once the mix was optimized through R&D, the forging process developed is very, very repeatable yielding conrods that are of consistant strength time after time. Worried about heat effects, or what we call annealing? Don't. The hot casting process takes care of this. All intra-molecular stresses are quelled during the casting process, another reason they do it.
My point is that the conrods you see in the picture are at the very least made of very similar compounds. Even if they're alloy content differed significantly (which they likely wouldn't), this difference would have a very, VERY small effect on the fatigue loading regime. If you would like to know how much, I would be happy to write you up a report on how many cycles difference would result from different alloys; I don't really feel like breaking the equations out right here; better yet, read a little "Machine Design" by Robert Norton (the bible for ME's) and you'll figure it out.
Bottom line, Toyota doesn't make their rods out of significantly different materials. So my post above is valid. Besides, I don't think the people who put that website up would overlook that *minor* detail anyways...
Paulmessen
New member
wow dude that was impressive! My sisters a BME, trust me dont doubt Engineers. So why did they take it off the market? I've heard the super charger only works on the 03/04?
ThatsRicci
New member
Still not convinced these break under only 6psi in normal conditions. licensed engineer or whatever. I took plenty of those engineering courses too from an accredited program (just graduated with something other than mechanical) i am no backalley mechanic.
This is literally a visual inspection and by no means is a complete analysis. There are a dozen major factors that go into rod design, and 3 times that in environment variables (rpm, temp, oils, load, endurance)
I wouldn't mind seeing some of these broken rods to analyze where/how they are breaking and the conditions they broke under. And a lot of "This is why toyota stopped making the supercharger" statements by non-toyota people, and no official statements by toyota... it's heresay.
Why would toyota take out their own aftermarket by making less quality rods? If the size is only... 7.5% less than the 1uz's i'd imagine the cost of 7.5% of material (30grams or so) is miniscule compared to the costs of operating the machines that prepare the materials and molds. there's probably some other place to save 3 cents on the production line... ah, the headliner ;d
This is literally a visual inspection and by no means is a complete analysis. There are a dozen major factors that go into rod design, and 3 times that in environment variables (rpm, temp, oils, load, endurance)
I wouldn't mind seeing some of these broken rods to analyze where/how they are breaking and the conditions they broke under. And a lot of "This is why toyota stopped making the supercharger" statements by non-toyota people, and no official statements by toyota... it's heresay.
Why would toyota take out their own aftermarket by making less quality rods? If the size is only... 7.5% less than the 1uz's i'd imagine the cost of 7.5% of material (30grams or so) is miniscule compared to the costs of operating the machines that prepare the materials and molds. there's probably some other place to save 3 cents on the production line... ah, the headliner ;d
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Well, unfortunately for us, you don't have to be convinced, and neither do I. In fact, I'm not convinced that 6 psi alone is what started blowing up engines. But someone in a pretty reputable position does, and in this case, that's all that matters...ThatsRicci said:
Its not that they're making less quality rods, its that its not worth it for them to re-engineer the entire engine to push maybe a 1000 superchargers/year, the numbers just don't work out.
Damn It !!!!!!!!!!
Looks like I will wait untill my 4.7 gets some miles on it. And then maybe beef up the internals. I should have maybe got the V-6 and supercharged it. They got a V-6 Tacoma making 400 horses with a supercharger. 400 horses would be nice in the 4runner. I guess I will just have to suck it up for now and spend the supercharger money somewhere else.
Looks like I will wait untill my 4.7 gets some miles on it. And then maybe beef up the internals. I should have maybe got the V-6 and supercharged it. They got a V-6 Tacoma making 400 horses with a supercharger. 400 horses would be nice in the 4runner. I guess I will just have to suck it up for now and spend the supercharger money somewhere else.
?
Is there anyone out there that has or knows someone that has a supercharger on the new V-8. Or one on the older V-8. Have you had any problems? Is it worth the $? What kind of differance does it make when you push the accelerator to the floor? Does it feel like a huge gain in power.
Is there anyone out there that has or knows someone that has a supercharger on the new V-8. Or one on the older V-8. Have you had any problems? Is it worth the $? What kind of differance does it make when you push the accelerator to the floor? Does it feel like a huge gain in power.
Thai
Elite Member
Re: Damn It !!!!!!!!!!
Time will tell if those V6 would hold up. Why would you think a V6 be any stronger than the V8?? From the article above (credible or not), it does not seem like the new engines from Toyota is any stronger...it seems to go in the opposite direction...new engines have weaker internals??
timf said:
Time will tell if those V6 would hold up. Why would you think a V6 be any stronger than the V8?? From the article above (credible or not), it does not seem like the new engines from Toyota is any stronger...it seems to go in the opposite direction...new engines have weaker internals??
ovrrdrive
New member
timf said:
Don't the TRD units only kick in at like 3/4 throttle and above?
If so, that could be one reason you could get alot more useable power with less stress from an aftermarket unit.
Seems like being able to enjoy a full 6psi of boost in normal driving wouldn't stress the internals as much and would also allow you to feel and hear the boost during everyday driving.
If I'm not mistaken, having boost off the bottom could actually improve gas milage too by making the engine more efficient... Well that, or by cramming all that fuel and air in might cut milage in half. Whatever, boost would be cool.
rolla_dink
New member
Re: ?
03-4Runner SC'ed - 3000 miles no mechanical problems. Just tapping the gas and putting the engine under load flips the bypass close and the boost starts right away. Power gain over stock is huge 100+ hp and 100+ torque at the crank.
25mph roll to 100mph 75% throttle.
Sorry for not posting in awhile. Been working on the corolla.
timf said:
03-4Runner SC'ed - 3000 miles no mechanical problems. Just tapping the gas and putting the engine under load flips the bypass close and the boost starts right away. Power gain over stock is huge 100+ hp and 100+ torque at the crank.
25mph roll to 100mph 75% throttle.
Sorry for not posting in awhile. Been working on the corolla.
