1jz questions

[skin]

Hey all

Decided that im going to stick with the stock twins on my jzx81 for drifting for just a while.
What im wondering is, why using the twins what is the best way to draw a reasonable amount of power out of these why still using, stock injectors, turbo, and auto ecu (apparently they run a manual fine)

Is it just a matter of a boost controller? if so how much boost? If not what fuel mods are needed?

200rwk would be nice if possible.


Cheers (yes i searched)

[Gavatron]

Cheap:
Bleed valve boost controller
DIY Fuel Cut defender

More exxy:
SAFC/Emanage or the like
EBC

Boost on stock twins is sort of pot luck. Some run a fair bit while others die running standard boost. I'd say 14psi max if you want some sort of life out of them.

[big_zop]

Best to leave it stock and see how it is first. A more powerful car than you can handle will make things harder and less fun to learn.

But to increase power, certain things need to be done in order to get the most out of them - but quite simple really.

Two most important would be to have proper dumps fitted (quite expensive since many consider it custom due to clearance/conversion issues with the steering shaft) and removing the stock ecu restrictions. I cant say whether going to a programmable ecu will be best but would be the prefferred option and not cheap, at least FCD/SCD.

With a manual trans 250rwkW is possible with an ecu, fuel pump, exhaust, dumps, intercooler and the right amount of boost (will depend on condition of everyhting but if stop making power, then its time to stop increasing boost). At this point, you will also be nearing the limit of the stock injectors.

Dont go increasing the boost till you have done these but you are going to be a better driver if you learn with less power. Its probably better to concentrate on suspension, diff and durability items (upgraded cooling for oil/water, better clutch) - but i would be doing the dumps as your first 'power' mod.

The information is here, or on the net, so dont forget to search.

[skin]

Thanks fellas

Yea i been drifting ae86's for 4 years now, 3 4ac's 1 4age and a 4agte so i think im ready for some half decent power

The car already has coilovers and before i start i want some adj castor arms and sort the rear camber issue out.

Medwin off these forums is going to be helping me make dump pipes so thats that sorted

What is involved with removing stock ecu limits? Remember its a auto ecu on a manual, there is not problem with that right?

[skin]

any one know?

[big_zop]

At a minimum -
FCD (Fuel Cut Defender) - removes fuel cut in place when map sensor reads above the boost limit - not sure what the limit is
SCD (Speed Cut Defender) - removes the 180km/h speed limit - while you may not reach this speed, the wheels might when spinning

Not sure how to wire these up as i never have but essentially these intercept the signals and clamp them at the limit so fooling the ecu to think that it hasnt exceeded these limitations. Search.

You may run into issues with fuel mixtures so always get this checked before 'thrashing' it.

[skin]

cheers man

Intresting, looks like you can also use a jza80 map sensor instead of FCD

[Gavatron]

Nope. Search again. Has been disproved at least twice.

[xman]

You could try a jza80 map but I doubt it will work.
Look up diy FCD in google and you can get the plans good one. It costs less than $10 to make and works great.
I've had one on my 1jz for a year or so, no sign of a fuel cut at 15+psi.

[Gavatron]

IT WILL NOT WORK!

1JZ > 2JZ Map Sensor Upgrade Myth Burried.

[wiseco7mgt]

The jza70 of mine had a fuel cut defender on it which is normally fitted near the ecu.It has a few basic wires like power and earth and just two others which intercept the map voltage signal.I can pm you a pinout for the jza70 if you like that will show you where to cut and add in the fuel cut defender.The defender i have is made by jaycar so im guessing its a cheapo basic unit.

[wiseco7mgt]

in my opinion get a y pipe made up first for the turbos to help them live a bit longer at the higher boost.The stocko ones are uglier inside than my nana..

[skin]

The jza70 of mine had a fuel cut defender on it which is normally fitted near the ecu.It has a few basic wires like power and earth and just two others which intercept the map voltage signal.I can pm you a pinout for the jza70 if you like that will show you where to cut and add in the fuel cut defender.The defender i have is made by jaycar so im guessing its a cheapo basic unit.

Cheers man, yea its actually for a jzx81, not sure if thats goign to make a difference, but yea if you could shoot me that info that would be great, cheers.

Also the dump pipes are going to be under construction soon enough

Thanks all

[big_zop]

JZX81 and JZA70 ecu pinouts are the same.

[Smokey228]

Any linky to this DIY FCD?

I learnt the other night, that these dont like to go beyond 15psi without one...

Cheers,
Jase