What size turbo would you use to make 400 - 450 WHP (max) with a 1JZ...

[JZA70 R]

Trying to put together a turbo kit on paper that will make 400 to 450 wHP (300 - 335 wKW) on a high boost setting of say 20 to 25 PSI.

I have two goals, first is obviously a peak power figure of 450 wHP and the second is to do it with the smallest turbo possible in an effort to enjoy a responsive turbo/engine package.

With the following mods what turbo would you recommend to make the aforementioned power?...
internally standard 1JZ
HKS 264' Cams (in/ex)
800cc sard side feed injectors
FMIC
high flowing exhaust
6boost manifold and appropriate external wastegate
power fc
bosch 040 fuel pump

Im pretty clueless when it comes to turbos and there are so many conflicting opinions and stories i thought id ask some people with a better idea than me.

other factors to consider would be... id like to have the turbo working at the end of its efficiency to go 450 HP, as opposed to wringing its neck to get that power.

a turbo ive been eyeing off is a Garrett GT3082R (GT3040) externally gated. with something like a .82 a/r rear. From what ive read a 3076R would be really struggling to hit 450.

Thanks

-Todd.

[The Real Roadrunner]

auto or manual?

3076r could do it with say 30psi and a 1.06 ex housing but 3582r would be a better choice with a .82 ex housing on about 20psi depending on the tuner and dyno used.

i havn't heard many good reports about the 3082r and there is probly fair reason as to why garret stopped producing it, it can only be ordered as a custom unit. kinda like the 2876r it is only good in "unique" applications.

cheers
linden

[jfallen]

Spins the engine calculating program... computing (note this model is very conservative, so likley power figure are higher.)

Assuming 25% drive train loss (thus looking for around 400crank kW,) and a Rev limit of 8,500RPM you'll need 62lbs/min of air (which is alot,) fed at 25psi.

now there are plenty of ways to do this, a very cheap way is to buy 2, nissan S15 silvia GT2560R (T28BB) turbochargers and put them on a custom manifold. this set up will give you a max of 70lbs/min.

A GT3582R will get you there, but a better option would be a 88mm 52 or 54 trim front wheel matted to the 0.86 T3 exhaust section. If you buy new from garrett (MTQ Systems or GCG) this can be organised. With this front wheel you'll be in the much more juicy section of the compressor map as opposed to the choke line on the 82mm 56trim wheel used in the GT3582R. That said people have been known to make 300RWkW on a GT3076R 56trim on their 1JZ's so there are other factors at play here. (mostly my conservative model which is gennerally down by 15-20%.)

A super cheap option that has apperaed to work is an ebay T70, ebay manifold, 550cc injectors, a genuine TaiL wastegate and a stock 2JZGTE and about 20PSI of boost. I calculate max power at 8500 with 20PSI, but it's likely generated lower around 7500 (can jzk25 confirm where max power is?) With a metal head gasket, 550 cc injectors in your stock 1JZ, this would be by far the easyest way to make 400RW banannas.

Cheers
Jordan

[cptsideways]

I'm running a Gt3076 on mine, with an Ebay manifold (XS Power) 550 injectors/emanage/040. This turbo is rated at just over 500bhp but 450 is well with its efficiency range.

It is super responsive & would make an excellent streetable combo, I'm running 1.5bar (21psi) all day long. Its a drift car & has been 100% reliable all season with this set up.

Will be off to the dyno in a few days for more mapping & more boost going for the full 500 for 2008

[1JZ.747]

to4r, to4z easily with the other items you mention. it will be realiable with those items and with kyles manifold it will spool just fine with a 1.00 rear.

if its manual you will shit it in if its auto the dyno reading might not quite get there but you will run trap speeds for that sort of power.

[JZA70 R]

its a manual... and im not interested in twin turbos or 2JZ's but thanks for the info!

shane you dont think a t4 sized turbo like the to4r or to4z is overkill for mid 400's?

I cant justify unneccessary lag for turbo headroom that i will never use.

The car will only ever be run on u98 and not on exotic race fuels that would let me make use of the 30 or so PSI one of those suckers will only start operating at.

[1JZ.747]

man, i had a to4r on my first setup, they are great from 14psi onwards. that was with a 1.00 rear housing. with a 6 boost manifold it will be fine i reckon.

a to4r/to4z in my opionion and experience is out of puff at 25-27psi.

i have never ran more than 18psi through any of my setups on pump fuel. i dont think the fuel is good enough for it. its probably why i havent fried engines where many others have.

any seriously, 1j or 2j anything over about 350 rwhp on the street is plain dumb. you wont get it to the ground in the first 2 gears at least unless you run drag radials.

i know with all my setups, first gear has been a waste of time, second gear is ok if you feed it on, third is the best fun.

you could try a 35/40 but they are only a poofteinth smaller than a to4r/z

[JZA70 R]

hmm kinda annoys me i missed out on that hks to4r kit on importbitz. i think hes had 2 on there for the 1JZ now, and both went for good prices...

[1JZ.747]

old jap manifolds are no good now mate. they are cracking and turning to shite.

my old manifold was a trust manifold and its was just about buggered.

get a steam pipe one from kyle and you will never have to worry

people will soon see these ebay manifolds will be leaking like a russian sub within a couple of years.

[MR 1JZ]

people will soon see these ebay manifolds will be leaking like a russian sub within a couple of years.

yeah but at $250 a pop who gives a shit

id be shitty if I paid $1200 + for a jap manifold

but seriously

if you get a $250 ebay one that leaks after a few years you fork out $250 for another and get over it

[1JZ.747]

a $250 wont get the spool happening anywhere near as quick as a 6boost manifold. so if you want the best result, you cant expect to get it with a 2.50 manifold.

same as using a 2.50 turbo instead of a garret. these chinese things spool shithouse and their boost control is shit house

so after 5 years of $250 manifolds i am ahead financially, plus i havent had to fugg around takign shit on and off, and every chinese manifold car i run i smoke. so its a win win situation.

i understand some people are happy to do stuff on the cheap. but if you want the best driveability and the best repeatable results, you spend the money on the right shit once and you dont have to do it again and again and again which costs you more in the long run.

[JZA70 R]

lol we need norbie in here to run the china manifold flag. puts up a good arguement that guy.

but yeah ill most probably be going 6boost, heard lots of good things.

[Norbie]

LOL

My China manifold is great for what I paid ($200) but I won't pretend it's as good as a properly designed big dollar custom manifold. I'm not a drag racer though so it fits my needs perfectly. I basically wanted something which attaches a big turbo to my 2JZ, and it does exactly that.

1JZ747 is right though, if you want big power and quick spool without any fuss a 6BOOST manifold is the better option. It's up to you if it's worth paying 6x the money for it though. For me, it wasn't.

[JustenGT8]

i have never ran more than 18psi through any of my setups on pump fuel. i dont think the fuel is good enough for it. its probably why i havent fried engines where many others have.

any seriously, 1j or 2j anything over about 350 rwhp on the street is plain dumb. you wont get it to the ground in the first 2 gears at least unless you run drag radials.

i know with all my setups, first gear has been a waste of time, second gear is ok if you feed it on, third is the best fun.

It's challenging, but fun and totally doable. Selecting the correct diff ratio helps alot and the GT8 will throw you down the road no probs with 450rwhp using the legs of the 2.92:1. Pretty spritely out of the gates as well with a 3.7 0-100kph on 235 Nankangs

[Ribfeast]

Get a 3037 or 3076R, 300rwkw and plenty responsive. If it's manual then you might get away with the GT35R series.
Flatmate had a GT35R 1JZ cressida (manual) and the lag didn't seem too bad.