1JZ engine build +parts recommended

[celica77]

hey guys,
just wanted to pick everyone's brains who know way more about this stuff than i do..
i currently have a 1ggte ra23 but am building a 1JZ ra28. Just wanted to pick ppls brains about what i should run for the goals ive set. All help and suggestions are greatly appreciated.
I want to run a non -VVTI 1JZ and convert it from twin turbo to a single turbo conversion, with a goal of 400-450HP in mind. Ive got all the other stuff sussed like diffs, brakes, mounts etc just need help on the engine specs as i know little on the 1J's capabilities.
i was thinking of running the following.

6Boost manifold with external gate
HKS 264 degree cams 9mm lift intake and exhaust cams
Greddy 5 key adjustable cam gears
Performance valve springs
get the head ported etc, new valve seats etc.
PWR water air barrel intercooler
3 inch exhaust,highflow cat etc

*either Haltech ECU or wolf V500 like i run on my 1ggte

now i know ppl have made big HP from 1JZ's with next to no head modifications and just a big turbo, but just thought id do the lot and not rely purely on boost. what i need help with is the following..;..
1.what size external wastegate should i run? was thinking turbosmart and what size spring etc?
2. what turbo selection should i go? i was again thinking of running a garret BB turbo as a few ppl have on here. i just need help with housing size selections etc. but i was thinking a T4 flange. with the 6boost manifold.cams, and porting response should be ok... remembering the car will be street driven and i dont want rediculous lag.
3 What size injectors will i need for this kind of HP? im guessing 700cc + and any suggestions for fuel rails etc... or are there direct replacment injectors of this cc capacity.





thanks alot any oppinions suggested are greatly appreciated. ive never really delt with custom single turbo set ups so all the help i can get is ausome.

[Dieseltrain]

1) 50mm progate would be nice . Running a 14.7psi wastegate spring.

2)Might be better off with a larger housing T3 sized housing, than a smaller T4, even with the 6boost manifold and other work . SOmething like a GT3540 would be pretty gnarly with a 0.8 rear housing .

3) for 400-450rwhp you could run some 550cc injectors but may as well go 650's in case you want to up the ante down the track .

[celica77]

hahaha thanks for your help so far man,
hahaha see there you go you learn somthing new everyday. i always thought the T3 flange was smaller than a T4. is 50mm a tad big? should a 38mm or something be ok?
dont know much about external gates.
cheers andy

[Pimpin_1JZ]

The sizing of the wastegate all depends on what boost your planning to run.

[celica77]

well im unsure of the 1JZs full potential. but im guessing with the mods i have planned i wont purely need to rely on boost to achieve my 400-450 HP goal. im guessing 20PSI plus these mods would be more than enough.... any one guess how much id need to run? and does anyone else recommend the GT3540 with a 0.8 rear housing .

[jeffro ra28]

Im going to be different and list the things you probably dont need to make your 450rwhp easily with the 1jz.

Adjustable cam gears (most cams make max power when dialled in at zero, cam gears are generally only used to modify the power curve and look pretty)

Valve Springs (only needed when high revs or larger cams are used)
HKS cams
Head porting
New valve seats (unless the engine has a few 100 000km's why bother?)


At 20psi with the 6boost and a 3582r or similar turbo you should see between 400-450hp.

I suggest you take a good look at this thread aswell http://www.toymods.net/forums/showth...jz+power+turbo

[celica77]

ok so far the 3582r seems viable and ill still stick the cams and cam gears in to alter the power and torque curves to the optimum for the street. All out HP is not what im after. I know 450HP is gonna be more or less usless on the street. but i plan on running dual stage electronic boost. so i can have a more sensible street mode. and a more all out HP setting also. More help and advice is much appreciated... should really update both my RA23 and 28 projects and post some pics

[Dieseltrain]

The T3 IS smaller than the T4, which is why im pointing you towards it instead of the T4 . You say you want response ans streetability

[celica77]

thanks for your help so far dieseltrain much appreciated
so is a 38mm external gate gonna be enough for around the 20psi mark?
diesel im also confused in your first post u were saying the T3 and T4 flange sizes in reverse. u said T3 is bigger in first and T4 is bigger in 2nd.
i always thought the T4 was bigger??

[The Real Roadrunner]

Not quite,

He was saying you would be better off with a .82 T3 flanged housing than say a .6# T4 flanged housing as it would be more streetable.

If you want a fast street car with good response then why are you considering a GT3582r? you could get 400rwhp out of a GT3076r and have a much more streetable package with a heck of alot more midrange grunt. The GT3582r will make more peak power but it will also come on about 6-900rpm later depending on the tune, cams and manifold.

Cheers
Linden

[celica77]

thats why im asking questions, as i know bugger all about the garrett range, and single turbo selections. have only delt with factory CT12's before. so all the help i can get is much appreciated. So Linden you would recommend a GT3076r with a T3 flange and .82? yea i do want streetability and midrange torque rather than end of the Rpm power...
Linden would u say a 38mm external gate will be plenty? and if say in the future i wanted more power for whatever reason, when and what HP do you think the GT3076r would run out of puff??
cheers andy

[lexsmaz]

As Jeffro said i would Not be looking at getting the Head ported, unless the person has had Proven success with 1J heads, otherwise it will cost you money with little to possibly even poor gain, big does not mean better !! .. also cam wise if you want mid range type of power just leave the cams standard .. My 1J RA28 runs cams, & 2 x GT28's, ( not my ideal choice, came as purchased ).. Comes on very strong up high, but far from ideal in the bottom to midrange power range, which for me is really where you need the power on the street ..

[celica77]

thanks for your help lexsmaz, yeah no respose and midrange is definatly what im chasing cause it will be for the street. I was just unsure if id require the mods i was talking to achieve my 400-450 HP goal. ok then the less i have to do to the engine the better really. but i thought maybe it might take some stress of the motor and not purely rely almost entirely on boost to achieve the HP im after. But if everyone agrees that 400HP for the 1J with no internal work what so ever is a breeze for it all day every day then thats great
So with the GT3076r with a T3 .82 and no other internal mods what boost would ppl guess this would need to run to achieve the power goal? so just the turbo, 6 boost manifold, external gate, zorst and cooler...and also is the GT3076r capable of more? or is this about its threshold.

cheers guys,
andy

[lexsmaz]

Also you are probably aware but you will need to run a strong rear end, mines running a 9'' maybe over kill but then ? Also body strengthening will be required for the chassis & you will also need to run a R154 gear box, plus possibly a twin plate clutch set up as well, also you will need to run some very soft comp tyres for the street otherwise you will be sideways when it comes on boost every time & in most gears !!! I run 255's semi comp tyres & it just kicks out sideways in 2nd at around 4,000 with out even trying, fun but not good for the Hoon factor ...

Hope you have a few spare dollars lying around cause its going to cost you quite a bit ... Less power = less cost but with more power everything then needs upgrading ...

Mines putting out 321 rwkw at 19 pounds of boost ...

[jak]

Head porting does help. but if you go to the trouble of doing it, i would recomend getting oversize valves as it dramatically increse the effect of the headwork. I know for a fact 2j inlet valves are 1mm oversize for a 1j if you dont want to spend loads of money.

If you are planning on running this sort of power with a standard bottom end i have one piece fo advice. GET ARP ROD BOLTS!! the rod bolts will be the first thing to let go unless there is something wrong with any of the other parts. I have lost 2 1j's because of rod bolt bolt failure (given one had a dry bearing) the rod bolts failed first. Now running ARP2000 rod bolts im confident we can push the motor alot further. Its a good investment for any 1j build in my opinion as it doesnt require much work, just flip the motor over and replace some bolts. The 1j should handle 30psi comfortably with stock internals.

The gt3540 with the .80 rear housnig is a common choice fir single turbo 1j conversions and seems to come on boost reasonably early and is good for boost you will need for that sort of power.

Good luck with the build.

Cheers
Jak