1JZ inlet manifold design?

[HIZOKU]

Alright well coming to the last parts of my engine build. was going to keep the stock manifold. i have 850cc sard injectors a modded twin entry fuel rail but now i have been thinking of selling them off and running ITB and a custom plenum or just a full custom manifold the reason for this is to maybe go top feed injectors to so in the long run it is easier.


Anyway ideas worth it? should i forget about it? currently running a GT30 so the response is already awesome but with a nice inlet manifold design this should help with top end power?

[JZA70 R]

so you currently have a GT30, stock manifold, 850cc injectors and a stock rail modded for duel feed?...

sounds like a decent setup, the injectors will supply more fuel than your GT30 will ever demand so why would you want to change?

you do know the stock intake manifold is very well designed and many people in australia and in the states are making 600, 700, 800+ hp with them...

Todd

[HIZOKU]

My setup


HKS Cam Gears
Pulley kit
Valve springs
Ross engernerring Engine dampner
Night page water bypass kit
2JZ Water pump
Sard Injectors 850CC
Twin Entry modded Fuel Rail with Dash fittings
Sard Fuel Regulator
Aquamist Meth injection Setup HFS-6
1/2 Fuel line
HKS stainless exhaust manifold
HKS 3037S turbo
HKS 50mm External Waste gate
HKS 264 degree Cams
HKS 1.6mm head gasket
Custom HKS Intake Pipe
Custom HKS cooler kit
Custom HKS catch can
HPI torque dampener
3 ½” straight through exhaust to a custom HKS Muffler
screamer pipe from external waste gate
Custom HKS front pipe
HKS thermostat



my engine is almost ready to be put back together ( well add the couple things i need to add ) like it currently has 550cc in it so im putting the 850cc in and so on and i thought maybe while im doing this i should sell all the stuff off (fuel injector wise) get a custom manifold made put in a top fuel rail and go from there. as if i want to go E85 later i can sort of feel a bit like im stuck maxed everything else out and have hit a wall that being my fuel system/inletmanifold

just a question if it is worth it would it change response or top end power better or even spool up better. or not worth it unless i go something bigger like a GT35 or bigger

[JZA70 R]

i dont see a fuel pump on that list... but anyway the 850's will probably still be enough to feed the 3037 even on e85. sounds like you are trying to find excuses to spend money. can I send you my bank details?

[Duk]

My setup
Custom HKS Intake Pipe
Custom HKS cooler kit
Custom HKS catch can

HKS made custom parts for you??? That must have cost plenty

[fixeruperer]

im in the same boat, im still rocking a stock inlet manifold and dont know if i should get a custom one (different motor). what power are you making now ?, you say its already responsive, so i take that as its already running and tuned. ? if the motor is apart, you can save your time later and just put a custom manifold on now ?, or see how well your stock one does ?, you might be happy with it.
as said, toyota must make some pretty good inlet manifolds, cause im happy with mine, if i can sqeeze ~20hp from a new manifold ill be stoked !!!!!!!!!!!

[HIZOKU]

Sorry got a Sard intake pump. 280 one

As for custom HKS parts whole car was built by HKS and Kidsheart. im just given it a freshen up you could say. the car is aussies old jzx81 yamaha edition.

At the moment car makes 300rwkw and has 200rwkw by 4000rpm so response is good. as for spending money for no reason i would rather pay for labor once then have the inlet manifold taken off again and injectors and try and sell them later on. the guy i was going to get to build the inlet manifold said he can put RB26 ITB on it if i wanted to. or he said i can use the stock lower manifold so i can use the stock injectors still but im un decided. and as above back in the evo the HKS inletmanifold i had just that with a tune added another 40hp with a tad more lag but a fair bit more top end out of a TD05 turbo

[JZA70 R]

Ok well Ive pretty much said it already, but ill say it one more time. IMO unless you are planning on developing the car to make in excess of 600 rwhp, then I think you are wasting your time upgrading the factory intake manifold. You already have big injectors and a modified fuel rail to support big horsepower, to throw that all away to upgrade the intake manifold for an insignificant power increase is borderline insane.

If you want to talk to people that are making twice the horsepower you currently are with a stock intake manifold, PM 1JZ.747, sleepercorty, 1.5jzmx83‎

[mr1jz]

Yeah as above mate I wouldn't bother. Most aftermarket inlets are designed to increase top end power due to the shortened runners. The factory manifold will make enough grunt and will probably outflow that turbo anyway. It seems needless considering you already have the fuel rail modified and objectors to suit.

[HIZOKU]

Alright i will stick with stock manifold. just give it a clean up.


BTW 1JZ747,1.5jzmx83 are not using a stock manifold. both have custom ones. but do see what you mean with sleepercorty but also reading he has gone to top fuel rail. to run E85 and 1000+CC injectors. This is where im stuck biggest injectors i could get for stock rail is what i have the 850CC and that is why im worried.

just want to be safe then have to take it all apart again to do it again.

Thanks for help guys. looks like im using stock manifold and just went out and picked up another one so i could get it all cleaned up and read for the swap.

[1JZ.747]

until you got to a gt51`r or bigger turbo, dont bother changing from the stock intake manifold, maybe put a xf throttle body on it as its slightly bigger dia but still worth 2/5's of fuck all in gain.

i had the stock intake and tb with my gt51R and it was fine.

[1JZ.747]

and as for running ITB's form a rb26, thats a dumb idea, everyone makign power with a rb26 head pisses them off and runs a big single throttle body anyway

[JZA70 R]

BTW 1JZ747,1.5jzmx83 are not using a stock manifold. both have custom ones.

Yes they were using a stock intake manifold... And making shitloads of horsepower with them. If thats not enough proof for you Darin Dichara in the states ran 8's in a supra, on a modified factory 2J intake manifold (essentially the same) and I think even a modified throttle body. That thing was making over 800hp at the wheels at the time. Do you plan on making 800hp at the wheels?

[HIZOKU]

Well other 1JZ might have over that.

Twin TD06s will be going on that got the kit just got to change the pissy TD05s

As for RB26s guys run huge power on stock inlet manifold guess it same as JZ some people change some dont. anyway keeping stock like i said i got another one now to clean up and get it ready to put on

[Toy77]

i thought the rb26 problem was the crappy vaccuum signal. Big cams and individual throttles make it very hard to tune - most the big HP ones i have seen also have single throttle bodies.

As for the factory manifold, you could modify the stocker if you like - add a little volume.. but as has been shown not really required for making power, asthetics is another reason all together

Cheers
Stew