2JZ VVTi Questions (turbo and injection).

[Mickp]

Hi guys, hope this is in the right place, seems to be the only place I can see tech stuff..

I had a coupple of questions re the 2Jvvti
I have a 98 JZA80 Auto 2JZGTvvti motor, running in a project car, we couldn't get it working properly on the factory ecu so I went for the new autronic sm4.
Current mods are cooler/piping, exhaust, lightened flywheel and not much else.
I am considering a turbo upgrade and am wondering whether the best option is to keep the twin sequntials and upgrade the wheels or to go for new bb twins and go for a regular twin (split type) manifold. My aim is a nice driveable 450 to 500 rwhp (this is road registered track car).
I like the idea of the sequential factory setup, but have no idea about how practical it is to upgrade and whether it will support 450-500 rwhp.

I am also wondering what the upper end limit of the factory injectors is. I want to push the engine as far as it will safely go on the factory injectors. The engine is in a 1150 Kg car and as such shouldn't be under as much load as it would in a heavier car.

I also have an unlikely question that may sound silly but hey I honestly would like to know the answer if anyone does.

The alloy underdrive crank pulleys (that seem to have no harmonic balancer) that I see all over ebay, are these worth getting? I dont need powerful psteer, aircon or lots of accessory power from the alternator so it seems like a good idea, is it?
And the other alloy pulleys I am also considering purchasing.

Thanks much in advance guys.
all the best - Mick

[The Real Roadrunner]

forget the factory twins for that kind of power, they just wont cut it.

get a GT3582r and you will have a nice drivable combo with more power than you would ever need, besides it will cost less than upgrading the factory twins.

factory injectors will be out of puff before 400rwhp, mine are close to maxed at 280rwkw.

the underdrive crank pulley may be fine but i wouldn't change the others as i have nothing but annoying dramas with them (non anodised ebay specials) a set of trust ones may be the go but i doubt you would actually "need" them on a street/track car.

cheers
linden

PS what version SM4 do you have? only the 1.09 will support the vactory trigger arrangement for the VVTi, or you can snap a lobe or 2 off the cam and it will run with the earlier versions.

[Mickp]

Thanks much for that advice,
Re the single turbo, does the vvti 2JGT have the same exhast port config as the non vvti 2J? as I could easily adjust an ebay manifold for the turbo if the exhaust side is the same.


Does the weight of the car have much to do with injector load? ie would an 800kg car pushin 280rwkw use less fuel than a 1400kg car doing the same? my idea seems to be that it would, what size are the factory injectors in the vvt?

I will go ahead and get the crank pulley, and leave the alloy pulleys then, One wonders though does the lack of harmonic balancer effect things?

thanks again -Mick

[Mickp]

I purchased the Autronic about 4 months ago, it had only just been released, I got some kind of an introductory special on it because it was the newest one, unfortunately I don't know what version it is, I am leaving wiring/tuning to a professional.

[The Real Roadrunner]

Ebay mani's will fit but they aren't the best in my opinion.

the balancer issue scares me abit so probly better off sticking with the stocker till it breaks then get a good SFI aproved balancer or a SH good condition one.

fuel requirements are the same regardless of vehicle weight, the onlyu thing that does make a difference is the AFR that its tuned to. factory injectors are 440cc from memory but i havn't flowed any as yet. just go bigger when you can afford it as the retune won't be stupidly expensive with the Autronic's built in injector size configs.

introductory special? thats kinda weird but hey every saving is a saving.
4 months ago might be a V1.09 and if that is the case should run the VVTi no probs but if its an earlier series there is a simple mod to get it running, or see if you can change it for the latest chipset.

cheers
linden

[Mickp]

SFI aproved ? any chance you could fill me in on this?

Ebay manifolds aren't that good but with a few minor adjustments they can be strengthened up a bit. they are a good option if you dont have time for alot of maths and measuring. As long as the exhaust ports and bolt pattern are the same as the non vvti 2jzgte it will be the best way to go for me atm.

I may pick up some 480's or 510's for the injectors.

thanks again for all your advice.

[The Real Roadrunner]

SFI is a US motorsport standard that a particular item must meet before it can be used in drag/circuit racing.

the balancers from the states have a harmo in them and are built for motorsport use, there are a few brands to chose from over their and would probly be cheaper than a locally built part.

you could try ROSS balancers in Blacktown NSW but im not sure if they do a JZ version (probly do) price may be exxy but could be cheap, i havn't checked in a while.

just go straight for some 650cc's as the Autronic will run them with ease and you wont need to ugrade later.

have you had a look at Draven's rides thread? he has the same combo im suggesting and is making plenty of grunt.

exhaust bolt pattern is the same, maths and measuring? just by a decent off the shelf aussie built 1, it will make more power, have less lag and save you money in the long run when you dont have to remove it monthly if racing regularly.

cheers

[Mickp]

Great info!
I will pick up a crank pulley up in the sates later this year then.

Good to hear that Draven's car is runing the setup you suggest, I'll check out his thread and I'll ask Greg if perhaps he can hook me up with a ride to see how it all goes.

Any suggestions on where to buy an Aussie item?

I will check out the bigger injectors too.

thanks again

[The Real Roadrunner]

I'll ask Greg if perhaps he can hook me up with a ride to see how it all goes.

be sure to mention car in that question as you may find yourself in a compromised position if you don't

Any suggestions on where to buy an Aussie item?

I will check out the bigger injectors too.

thanks again

only Ross Balancers as per the last post, they're located in forge st blacktown but i dont have their number on hand.

cheers

[Mickp]

Its ok, Ive been in compromising positions with greg before, I can handle it,
(its not such a bad thing )

lol, sorry for being non specific, I meant an Aussie made manifold.

[The Real Roadrunner]

there are probly 2 places id suggest trying, myself being one and 6BOOST being the other.
both of us build quality manifolds and Kyle has a lifetime warranty on his which im happy to match also.

supose it comes down to price and how quickly it could be built, im snowed under at this current time but should be fine in a month, if you need it sooner search for Kyle's website 6boost.com i think it is.

cheers
linden