1uz fe vvti good or not

[gloverman]

Why remove the VVti. I always make more torque and power with less cam with VVti working than with a bigger cam with it removed. Early non VVti 2uz have a taller intake to make a torquey engine.


My supplier does weld and regrind with lifetime warranty even in race engines.

 

[cribbj]

Justen just to satisfy my curiousity, can the VVTi motor be run with the VVti system disabled without fear of kissing pistons, as long as the timing belt is on there correctly to begin with?

For example, let's say you just want to get the beast started/running on an aftermarket ECU, then get the VVTi system tuned. Is that possible?

It's probably a very basic question, but I've never played with one of these VVTi motors.

 

[gloverman]

Yes John. The solenoids can be unplugged and the engine will run fine without the VVti operating. One the dyno the other night playing with a 3uz I dropped the VVti table to zero advance and gave it a run. Net lose was 10% torque below 5K and similar figure for the power. Above 5/5500 the VVti is in the most retarded position anyway.

 

[JustenGT8]

As glove said, no dramas.

As to why disable...only because my ECU won't run it Just one of those things that, on balance, the cost to upgrade the ECU to get the VVTi running just isn't worth it. I'll make over 500kw at the treads so I can live with being 10% down

 

[cribbj]

Kelvin / Justen, thanks for the clarification.

Do you know if Kevin over at Kelford's has come up with aftermarket VVTi cams? Years ago he was looking for sets to reverse engineer, but I'm sure he's found them by now?

I wonder if there's much to be gained with aftermarket VVTi cams, considering the tuneability you already have with the stock ones? I assume having more lift would be nice, but then you might get yourself into trouble with valves/pistons at certain points on the VVTi curves?

 

[JustenGT8]

Kelfords will do them but my quote was over $2k. Def gains as they are still a pretty mild cam duration wise and still some lift you could add.....some careful measuring required before adding lift though

 

[alfablack]

ok thanks chaps i know i am late to the party but over here they are not used very often especially in n/a applications and parts are scarce also expensive,

i think the standard cams are going to be enough for where i am going
perhaps a rethink of expectations

headers what size pipework 1"7/8ths

with my other mods more like 330-350 flywheel
standard bottom end with arp studs and bolts what should i be capping the revs to around the 7000-7500 or have the standard cams gone by then

i have got to keep reminding myself that normaly these and most of the conversions end up in a vehicle nearer 2 tons i need to consider getting and keeping traction with what i have and keep it usable

 

[krayn]

With a standard set up they start falling over past 5500. so not a ot gained by reving a standard set up past 6..

 

[JustenGT8]

With a standard set up they start falling over past 5500. so not a ot gained by reving a standard set up past 6..

Not the VVTi mate....run these out to 7000rpm at least, more with decent headers. Gloverman probably has some dyno plots he can post?

 

[krayn]

Sorry. My bad. Getting confused with a non vvti.

 

[alfablack]

Well it was all coming along nicely.
got my
exhaust flanges cut as per the gasket so large 1"7/8 headers being made
billet flywheel ordered
just about to order the itb and this very minute been offered a supercharger

an eaton m122 gen 5 complete cannot turn it downfor the money nearly brand new the customer swapped it for a lysholme at a 1000 miles

so it looks as though a gentle blow job is on the cards as i don't want to change to much inside at the moment ?