4.7 liter V-8 with VVT-i

[jp213a]

I'm interested in any negative experiences with the 4.7 liter V-8 with VVT-i that's used in the late model Tundra, 4 Runner, and Sequoia. Posting a page out of a FSM showing the VVT-i design would also be appreciated. I've got a generic schematic but no detail on what Toyota uses to move the cams to get the advance or retard (is it hydraulic cylinders ?).

[firetruck41]

Probably won't get much feedback, as its only been out for a few months. I wish I had one

[bkg]

Think of a 4.7 i-Force...


but better.

Haven't driven one, but I was VERY happy with the 4.7 in my '03 Tundra.

[FirstToy]

Not worth the hassle- that's an entire valvetrain/ecu swap. You have a 100 and that is so nice, why bother with a little valvetrain bling? It's nice but not worth all that trouble and $, imo.
I think an SC will give you more bang for the $

[jp213a]

I'm not planning on adding the VVT-i to my 100. You're right, way to much hassle and cost for a few HP and a little better fuel economy (supposedly). I am interested in Toyota's design details and any negitive experiences from VVT-i owners. There is one unconfirmed report it will be introduced on the LC's in mid 2005. I have toyed with the idea of adding a TRD supercharger to my 100. I can't justify all that extra HP and the $5k price tag but I would like to experience a SC'd engine.

[jjbodean1970]

toyota has pulled the trd s/c off the market for the v8, iirc

[jp213a]

I appreciate you posting that bit of information. I new I'd seen the 4.7 liter SC on the TRD web site several months ago but yesterday I couldn't find it. I spent at least an hour searching. Do you know why they pulled it? Someone was selling a used 4.7 liter SC on the 100 forum a week or so ago and it got my interest up again.

[bkg]

TRD never made an SC for the 03+ models. Lots of information on TundraSolutions.com about the ECU's not being able to handle the SC. TRD was rumored to be coming out with one late last year, but pulled it off the market instead.

I think you'll see TRD getting out of the SC business shortly. With all of the fuel problems and cracked heads on the 3.4's, I doubt you'll see an SC for the 4.7 or the new 4.0 V6.

[Jetboy]

I haven't seen any diagrams of toyotas setup but This is how the honda variable timing works. there are two lobes on the cam for each set of intake valves. exhaust stays the same. under low power only one intake valve opens on the standard lift and duration lobe. (swirls air to better atomize= better mileage) then when more power is needed a pin connects both intake valves and they both are actuated by the standard lobe. under high power needs there is a second "wild" (high duration high lift) lobe that is between where the two rockers sit for the intake. an aditional pin moves that connects the two rockers and the center rocker and lobe thus giving both intake valve "wild" valve rise and duration.

The system has been very dependable in honda. it is the best of both worlds, high horsepower and good mileage.

this combined with the S/C was probably gining too much HP for the drive train, or they didn't have enough fuel for the massive air flow.

HTH

[fj55-100]

P/M me your e-mail i will send you toyotas book on how it works

55-100

[Bear80]

Originally Posted by jp213a

I appreciate you posting that bit of information. I new I'd seen the 4.7 liter SC on the TRD web site several months ago but yesterday I couldn't find it. I spent at least an hour searching. Do you know why they pulled it? Someone was selling a used 4.7 liter SC on the 100 forum a week or so ago and it got my interest up again.

I belive that alot of TRD's products where halted because they are being absorbed into toyota or else the motorsports division...it's somthing like that from what I hear. Oh and some dealers online have the sc in stock, my dad's thinking of gettin one for his '05 vvti.