VVTI or not

[The Last Streetfighter]

If height is an issue, would 1UZFE VVTi or 3UZFE be a better option?

[Turdinator]

Just out of curiosity, whats wrong with the twin turbo 20b rotor the cosmo comes with? Or do you have the 13b version? My mate has one with a 20b and its torquey and an absolute weapon in a straight line for a car of its size and weight.

[dkabab]

Just out of curiosity, whats wrong with the twin turbo 20b rotor the cosmo comes with? Or do you have the 13b version? My mate has one with a 20b and its torquey and an absolute weapon in a straight line for a car of its size and weight.

nothings wrong with it... ive owned 2 cosmos already. a 13b and 20b, but the car i'm looking at doing the conversion to doesnt have an engine in it at the moment, and i dont really want another rotary. also the 20b used to average 25-30L/100km not too good.

i just love cosmos, so thought i would get the best of both worlds.. plus i now have the time, space and money to build something myself. (always wanted to)

[Esteban]

Whay wasn't vvti 2JZ an option? So what they're expensive...

[Norbie]

Give me a VVTi 1J any day over either twin turb 1J or non VVTi 2J.

It makes 373nm of torque by 2400rpm and a lazy 200rwkw with just an exhaust and cooler

If you don't want any more than 240 odd rwkw a boosted stock engine will get you there and it drives like a torquey NA engine with the standard CT15b turbo

While I've never driven a VVTi 1JZ, I'm having a hard time believing it will out-torque a 2JZ with 20% extra capacity and sequential twin turbos.

[Esteban]

The 1JZ vvti torque comes on strong and early for sure ... but I couldn't reliably compare them even having driven both :/

[dkabab]

i keep reading sequential twin turbos, but from looking at them, they arent, they are parallel twin turbos. can anyone confirm this?

[Joshstix]

2J is sequential 1J is not.

[dkabab]

do they have a lot of problems with them being sequential? i remember with the cosmos, they were really touchy... so many problems with them, when they worked they were FAST! but yeah they had lots of problems.

[whatthe?]

While I've never driven a VVTi 1JZ, I'm having a hard time believing it will out-torque a 2JZ with 20% extra capacity and sequential twin turbos.

The figures Ive quoted are from the Toyota specs for the engine. I don't know what sort of torque a 2J produces, but I'm willing to bet that it makes it's full torque later than 2400rpm. The non-vvti 1J makes slightly less torque than the VVTi 1J and doesnt peak until 4800rpm, so the newer engine is pretty damned impresive

And having driven a stock VVTi 1J with a cooler and exhaust and a 2J with a similar setup, both running stock turbos I know which one feels nicer down low in the rev range...

[JP]

I prefer the vvti 1J over the non-vvti engine for a daily driver. I had a manual JZX81 drivetrain in my chaser with FMIC and 3" exhaust from the turbo's, made 195kw atw on 10psi, my gx70 wagon has a jzx100 manual drivetrain installed also with FMIC and 3" exhaust and made 187kw atw on 10psi too.

I had both dyno'd on a Dyno Dynamics unit in shootout mode and compiled all the data into excel for comparison. On Paper the non-vvti looks better, but seat-of-the-pants I like driving the vvti engine.
http://users.tpg.com.au/adsl0uxv/dynoresults.xls

[The Real Roadrunner]

The figures Ive quoted are from the Toyota specs for the engine. I don't know what sort of torque a 2J produces, but I'm willing to bet that it makes it's full torque later than 2400rpm. The non-vvti 1J makes slightly less torque than the VVTi 1J and doesnt peak until 4800rpm, so the newer engine is pretty damned impresive

And having driven a stock VVTi 1J with a cooler and exhaust and a 2J with a similar setup, both running stock turbos I know which one feels nicer down low in the rev range...

2jz out torques a 1j everyday of the week, compare average torque and it will be higher for sure.

remember your comparison was also with 2 cars with a weight difference of 300kgs or so and 1 was manual vs the heavier cars auto so the comparison isn't really fair.
also was that before or after i fixed the exhaust valve soleniod on crystals?

2JZ tt auto Z20 soarer versus a 1JZ vvti manual A61 = comparing chalk and cheese

Dkabab, ive talked to rob many times while away at drift meets and he asked me to R/R the turbos on it once, was a tight fit in the bay so i had to decline as i couldn't be arsed working on it that day.

cheers
linden

[whatthe?]

I wasnt talking about the soarer, I was talking about an RZ JZA80 with 6spd manual and my old white MA61.

Like I said, I'm not saying that the vvti 1J makes more torque, just that it makes it's peak a shitload earlier which makes it a better drive at low rpm

Edit - Here are the torque figures for the JZ turbo engines

1jzgte - 363Nm @ 4800rpm
VVTi 1jzgte - 378Nm @ 2400rpm
2jzgte - 432Nm @ 3600rpm
VVTi 2jzgte - 451Nm @ 3600rpm

[The Real Roadrunner]

1jzgte - 363Nm @ 4800rpm
VVTi 1jzgte - 378Nm @ 2400rpm

Never disputed that fact.

2jzgte - 432Nm @ 3600rpm
VVTi 2jzgte - 451Nm @ 3600rpm

Just under 400Nm at 2000rpm and higher at 2400rpm.

Therefore the 2JZ-GTE makes more torque than the VVTi 1JZ-GTE EVERYWHERE.
Note that this is not the VVTi version of the 2JZ-GTE which I would expect would make more torque everywhere, further cementing its superiority over the 1JZ-GTE of any variant.

Mos (cbf relogging ).

PS. The above toyota published graph also dispells the myth that the 7M-GTE has more torque than a 2JZ-GTE

[Norbie]

pwned.