'08 4runner 2UZ HP upgrades?

[zimm17]

I have an '08 4runner with the 2UZ VVTi. Did the K&N intake and magnaflow exhaust. What else can I do to boost power? 260-ish sounds awfully low...

 

[-Nemesis-]

Did you try looking around the forum? The 'How do I get more power' question has been asked about 7000 times

 

[JBrady]

Get some headers. I am not sure if you can tune your vehicle but that would help. From there things get expensive. Weak rods means any super/turbocharging option would be very low boost and even then somewhat of a concern.

Not sure why (haven't studied the overall details) the 2UZ is so low on power vs the VVTi 1UZ and 3UZ engines. At 260hp @ 5400rpm and 306tq @ 3400rpm this engine is definitely down on power vs its siblings.

The 1998-2000 1uz at 4.0 liters made (apx numbers adjusted for power rating change made in 2006) 288hp @ 6000rpm and 302tq @ 4000rpm.
Comp ratio 10.5 to 1
That gives 72hp/liter and 75tq/lt.

The 2001-2005 3uz at 4.3 liters made (apx numbers adjusted for power rating change made in 2006) 288hp @ 5600rpm and 317tq @ 3400rpm.
Comp ratio 10.5 to 1
That gives 67hp/liter and 74tq/lt.

The 2008 2uz at 4.7 liters makes 260hp @ 5400rpm and 306tq @ 3400rpm.
Comp ratio 10.0 to 1
That gives 55hp/liter and 65tq/lt.


This is a BIG difference. One half of a point of compression will make a little difference. The intake is different with longer runners and should make MORE torque. The engine is tuned for 87 octane (R+M/2) vs 91 octane for the 1 and 3UZ. What are the camshaft numbers? Are the heads that much worse?

Just getting the power up to the 288hp that we KNOW the 1 and 3UZ heads/cams/intake support would be a good start. There is NO reason I can think of that should prevent this engine from making the same relative torque/ltr as a 3UZ which would give 348tq.

Does the 2008 2UZ have the variable length intake? If so (or even without it) I would consider heads and intake off of a 3UZ. Depending on unknowns the compression may go up and the cam potential and port potential is known.

Have you searched the 4runner forums to see if anyone has successfully tuned this engine. By that I mean adjust the air/fuel ratio with some sort of piggyback controller like the Apex NEO while dyno tuning?

Like I said, the stock exhaust manifolds are terrible. I am thinking the cheapo chinese truck headers will fit. That with tuning (although it may be the timing curve that is the bigger issue and less likely to be adjustable) will give an idea of what is possible and if changing intake and heads would be worthwhile.

 

[dpf22]

The camshaft specs between all of the uz motors are nearly identical as far as lift and duration. The valvetrain will only breathe to a certain rpm given several things such as valve diameter, lift, and duration. After that its the flow of the head. Since the 2uz is larger displacement with the same cams as the vvti 1uz and the 3uz its pretty much hampered by the fact that it can't breathe. To a point a better flowing set of heads should help, but to make more power you will need it to rev, and thats going to mean a set of cams. I would assume that the 1uz vvti high lift cams would fit in the 2uz heads but thats just a hunch. The shorter runner intake from a 3u will lessen torque, but let it breathe up top. Getting a dyno chart of the vehicle for a base run and seeing where the curves are strongest, then finding out weather the power curve holds to where the cams lose their breathing capacity (given the stock valvetrain components) will tell you if the 3uz intake will really make you much more hp. My assumption is that the bulk of the power will be gained by cams and a remap of the computer (if possible) Use of a good set of headers will be necessary as I'm sure the stock ones flow like crap just like every other uz exhaust manifold does. compared to even a half decent set of headers that is.
If easy power is what you're looking for, then there's always superchargers. Either way, cams really are the main restriction in the stock running gear.

 

[JBrady]

The camshaft specs between all of the uz motors are nearly identical as far as lift and duration. The valvetrain will only breathe to a certain rpm given several things such as valve diameter, lift, and duration. After that its the flow of the head. Since the 2uz is larger displacement with the same cams as the vvti 1uz and the 3uz its pretty much hampered by the fact that it can't breathe. To a point a better flowing set of heads should help, but to make more power you will need it to rev, and thats going to mean a set of cams. I would assume that the 1uz vvti high lift cams would fit in the 2uz heads but thats just a hunch. The shorter runner intake from a 3u will lessen torque, but let it breathe up top. Getting a dyno chart of the vehicle for a base run and seeing where the curves are strongest, then finding out weather the power curve holds to where the cams lose their breathing capacity (given the stock valvetrain components) will tell you if the 3uz intake will really make you much more hp. My assumption is that the bulk of the power will be gained by cams and a remap of the computer (if possible) Use of a good set of headers will be necessary as I'm sure the stock ones flow like crap just like every other uz exhaust manifold does. compared to even a half decent set of headers that is.
If easy power is what you're looking for, then there's always superchargers. Either way, cams really are the main restriction in the stock running gear.

Well, the 95 LS400 cams had a little more exhaust duration than the 90-94 and had roughly .300" of lift. I believe the VVTi camshafts starting in 98 had closer to .350" lift but I am having a hard time finding accurate VVTi lift numbers. The variable control should mean more potential peak power on the VVTi engines. Not sure about the non VVTi early 2UZ vs the VVTi 2UZ.

The above indicate that there is definitely a difference in cam profiles through the years and the RMS engine made peak HP at 6500rpm on the mildest cam option. At 260hp the stock VVTi 2UZ that is the subject here either has much less agressive cams than the other engines or it should able to make at least 300hp on the VVTi cam profile for either the 1UZ or 3UZ.

 

[spf_lexus]

Headers + exhaust + piggyback should add a grip of torque w/o ripping the block apart for the 4.7L. Unichip is a proven piggyback and should run around $600 tuned from what I have read and can improve a UZ motor by 10-11% due to the added timing and fuel trim.

I have no idea if the header companies offer products for the new 4runners but its worth a look.