SC30096

so i was on the highway testing out my lights and I thought I mine as well have a few pulls so dropped down into 3rd and floored it. now I dont think i use to go 100% throttle because as I was gunning it my SAFC told me I was only at around 95% throttle, so i picked up my heel and drove my toe down going up to 100% and for the first time I noticed that at 4400 rpm there is a noticeable change in tone and a little harder of pull as if it were like VVTi or Vtec (I use to drive a GSR). This only happens at 100% anything less and it isnt there. do we have valve lift?

5spdSC300

iTrader: (1)

no vvti in 96

hateshino

well, if you wot anything at 4400rpm your supposed to feel a stronger pull anyway right?

SC30096

no no... i would WOT starting from around 3000 RPM and when It would reach 4400 it would change. I'll try and get a video clip of it.

hateshino

sorry, im a bit noob, but does it have to do with how its max/optimum torque is around 4000 something rpm?

1sxyrxy

maybe its just the secondary butterflys opening in the y section

Gunnar

There is a butterfly in the main intake manifold, not the y-section. And yes, that's most likely what you're feeling.

SC30096

huh well i learned something new... guess i'll search to learn more about this.

5spdSC300

iTrader: (1)

What butterfly are you guys talking about ? The only one im aware of is the traction control butterfly but it is directly inline with the throttle butterfly. What you feel might just be mental .

qksl2

That butterfly is vac operated, not electronic, so its not opening at a certain RPM but vac based.

Ian

5sp_jzz30

iTrader: (2)

its all in your head

what do you have done to your motor? if you have a 2jz-ge...without mentioning na-t, why the need for safc2 or wideband. unless you will use them later when going turbo its a waste of money.

Ali SC3

iTrader: (10)

I think your hearing the infamous whistle. My last SC had it, almost sounded like a tiny turbo starting to spool exactly at 4400 rpms and only at full throttle.
The Air control valve in the intake starts to open at WOT only above 4400 rpm to change the effective intake length or resonance or something in order to achieve maximum torque, and when it is gunky around the opening it makes a whistle depending on how bad its gunked i believe. you should be noticing a stronger pull when you hit 4400 rpm at WOT, this is normal and how Toyota designed the engine

see: http://www.turbomr2.com/MR2/Reference/TVIS/TVIS.htm "Acoustic Control Induction System"
and i believe a discussion somewhere on SF. i believe the solution is to open it up and clean it