1UZ Intake Manifold
#1
Pole Position
Thread Starter
1UZ Intake Manifold
Are there any alternatives to the manifold on the earlier 1uz's? Will the 98-2000 manifold fit with modifications? Im just wondering whether or not it would be possible to get a different manifold thats not custom made.
#5
Pole Position
Just out of curiosity, what is driving you to want a different intake manifold?
There is a recent thread in the LS400 UCF10/20 forum where a member had his vvti 1uz intake manifold extrude honed. Interesting results for sure..
There is a recent thread in the LS400 UCF10/20 forum where a member had his vvti 1uz intake manifold extrude honed. Interesting results for sure..
#6
Intermediate
I think the runner layout is better in the VVTI intake. I'm a Ford guy for the most part and have extrude honed my intakes with good result, especially my blower motors (centrifugal)
#7
TL;DR: It should bolt to the heads, but the sensors and actuators won't bolt up, and it probably won't actually help you.
The VVTi intake has dual length runners with butterflies that open the shorter air path above 4400 RPM. Without the capability in the stock non-VVTi computer, those won't open. You might get a bit more torque from idle to 4400, but you lower your breathing somewhere above that, possibly before you even get to 5K. So you took your peak of 250-260-ish HP at 5400RPM, lowered it to somewhere around 4500-4800, and probably didn't gain any torque somewhere above 4400. Where is the WOT shift point on a A340E? If it's quite a bit above the peak, you're certainly not doing yourself any favors, depending on how fast it drops off. Or you keep them open (or remove them altogether) and possibly get some more higher RPM horsepower, but at the loss of idle to 4400RPM torque (no idea the difference between the short runner and a non-VVTi intake.)
Of course, this is all theory. I don't know the actual measurements of runner differences; most of the gains in the 98+ could be from VVTi or other means. We can look at pictures of the differences and say "Oh, neat", but without anything to directly compare them, I don't know. I've had the 98+ open, but not with a non-VVTi intake to compare it to. Plus, while I can figure out a lot, I'm not an engine builder, so I couldn't tell you anything concrete with those measurements, anyway.
Although, if someone was willing to disable their secondary runner butterflies, they could test at least part of that for you (for completeness, might as well test locked open and locked closed.) I'm sure that'd pop some CEL codes and might even retard the timing or something else non-helpful, though, so it might not be a particularly helpful test.
It really seems like the top end of these engines were system-built for the power they were going to put out; although the lower end is very stout (the rods got smaller in 95, though.) All the way from the valve sizes, valve spring rates, cams, intake, exhaust, and computer. Even more so with the computer on the VVTi engines. So changing any one thing doesn't seem to do much if the others are left alone, assuming it's kept naturally aspirated (and even then boost doesn't do much in 98+.)
From everything that I've read it's mainly sounded like the easiest source for more power from these is a simple nitrous oxide fogger. But careful with your transmission (and rods after '95.)
Also, the 2UZ intakes should fit, as well. So the Tundra stuff probably bolts on. Not to say any of your sensors or even your throttle body bolts to those intakes, but the head pattern should be the same. So if you were going to go all out and replace the computer with a stand-alone engine management system and do something crazy, those exist. The stock 2uz intake is meant for lower RPMs, it might give you a bit more torque, but probably also not breathe very high. With the larger reciprocal mass of the 4.7, the engines don't turn as high RPMs, so the aftermarket intakes are also likely tuned for that unless they're built for forced induction, at which point they're just going for sheer flow.
But, like a lot of things, if you were going that direction you would likely already know that. In which case, since you're asking, you're probably not at a level to do such a thing. (Don't take that bad, I'm not, either.)
The VVTi intake has dual length runners with butterflies that open the shorter air path above 4400 RPM. Without the capability in the stock non-VVTi computer, those won't open. You might get a bit more torque from idle to 4400, but you lower your breathing somewhere above that, possibly before you even get to 5K. So you took your peak of 250-260-ish HP at 5400RPM, lowered it to somewhere around 4500-4800, and probably didn't gain any torque somewhere above 4400. Where is the WOT shift point on a A340E? If it's quite a bit above the peak, you're certainly not doing yourself any favors, depending on how fast it drops off. Or you keep them open (or remove them altogether) and possibly get some more higher RPM horsepower, but at the loss of idle to 4400RPM torque (no idea the difference between the short runner and a non-VVTi intake.)
Of course, this is all theory. I don't know the actual measurements of runner differences; most of the gains in the 98+ could be from VVTi or other means. We can look at pictures of the differences and say "Oh, neat", but without anything to directly compare them, I don't know. I've had the 98+ open, but not with a non-VVTi intake to compare it to. Plus, while I can figure out a lot, I'm not an engine builder, so I couldn't tell you anything concrete with those measurements, anyway.
Although, if someone was willing to disable their secondary runner butterflies, they could test at least part of that for you (for completeness, might as well test locked open and locked closed.) I'm sure that'd pop some CEL codes and might even retard the timing or something else non-helpful, though, so it might not be a particularly helpful test.
It really seems like the top end of these engines were system-built for the power they were going to put out; although the lower end is very stout (the rods got smaller in 95, though.) All the way from the valve sizes, valve spring rates, cams, intake, exhaust, and computer. Even more so with the computer on the VVTi engines. So changing any one thing doesn't seem to do much if the others are left alone, assuming it's kept naturally aspirated (and even then boost doesn't do much in 98+.)
From everything that I've read it's mainly sounded like the easiest source for more power from these is a simple nitrous oxide fogger. But careful with your transmission (and rods after '95.)
Also, the 2UZ intakes should fit, as well. So the Tundra stuff probably bolts on. Not to say any of your sensors or even your throttle body bolts to those intakes, but the head pattern should be the same. So if you were going to go all out and replace the computer with a stand-alone engine management system and do something crazy, those exist. The stock 2uz intake is meant for lower RPMs, it might give you a bit more torque, but probably also not breathe very high. With the larger reciprocal mass of the 4.7, the engines don't turn as high RPMs, so the aftermarket intakes are also likely tuned for that unless they're built for forced induction, at which point they're just going for sheer flow.
But, like a lot of things, if you were going that direction you would likely already know that. In which case, since you're asking, you're probably not at a level to do such a thing. (Don't take that bad, I'm not, either.)
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#8
Lexus Champion
iTrader: (10)
you can hook up the butterfly on the vvti manifold to straight vacuum and it will operate like stock except it wont give you short runners in cruise, which is what the vac tank and vsv/ecu accomplish.
you will still get long runners down low and short runners when you punch the throttle without the vac tank and vsv/ecu.
you will still get long runners down low and short runners when you punch the throttle without the vac tank and vsv/ecu.
#9
you can hook up the butterfly on the vvti manifold to straight vacuum and it will operate like stock except it wont give you short runners in cruise, which is what the vac tank and vsv/ecu accomplish.
you will still get long runners down low and short runners when you punch the throttle without the vac tank and vsv/ecu.
you will still get long runners down low and short runners when you punch the throttle without the vac tank and vsv/ecu.
That was the trade-off on the old GM TPI engines (or really anything with longer runners, but this is a decent example I have experience with), they had these great, long runners that gave amazing torque, but couldn't breath much above about 5500RPM to 6000RPM in the 305 and more like 5000RPM to 5500RPM on the 350 they eventually put them on (I had a Firebird with a TPI 350; great torque, wouldn't rev too well, still fun.) With the dual runners in our VVTi intakes you get the ram effect in the long tubes up through 4400RPM, with the short runners opening after that you don't get the problem the TPI engines had, but still getting the long tube benefit at lower RPMs. Again, if you open those short tubes based on vacuum (or lack of), then you likely negate those benefits below 4400 RPM.
A less restrictive air path isn't always a good thing, even at WOT.
#10
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This complete something different but I've not seen any one put a 1uz to the test so im going to do it I will see how much nitrous the 1uz will take until it blows up right now I'm in the process of swapping na 1uz into my mk3 Supra so soon I will put the nitrous kit and see how much of a shot it takes then after that I'm going to rebuild it with cp pistons x beam rods kelford cams and valves and springs then I'll get e85 injectors and fuel pump and then start adding nos
#11
Lexus Champion
iTrader: (10)
matguy, I get what you are saying it can go to "open" before 4400 rpm's if you have the pedal slammed off the line, but you still get the initial effect off the line and for however many rpm's it takes for it to drop off. The vacuum tank system and the vsv's make the system perfect, but if you don't have the ecu to control the vsv's and the tank installed, then having it connected to vacuum is better than leaving it "open" all the time. that way you still get that off the line air velocity of the long runner even if it is less efficient in the middle rpm range.
Usually you would use the vsv's and tank to have the best setup, but if you are retrofitting intakes to use with ecu's that don't control it (like in this case an older 1uz ecu wont control the vsv's that the vvti ecu does), or you are on a standalone and don't have them setup.. its better to connect it to a vacuum source then to disable it.
One thing to note is that if you are running a turbo with higher boost pressures like over 18psi, then you would want to remove it as they have been known to come apart and make its way through the intake and then the motor itself. this happens on the 2jzge sometimes.
Usually you would use the vsv's and tank to have the best setup, but if you are retrofitting intakes to use with ecu's that don't control it (like in this case an older 1uz ecu wont control the vsv's that the vvti ecu does), or you are on a standalone and don't have them setup.. its better to connect it to a vacuum source then to disable it.
One thing to note is that if you are running a turbo with higher boost pressures like over 18psi, then you would want to remove it as they have been known to come apart and make its way through the intake and then the motor itself. this happens on the 2jzge sometimes.
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