FJ20 with Bike Carbs

[tss240zg]

Thinking of putting bike carbs on my dad's Fj20.
Does anyone know if these would be anygood... Bogg Bros said they are very good for 2.0ltr engine but i am also after a nice sound aswell?
Any advice would be appreciated!

The carbs also have throttle position centre, what is that and what does it do?

http://www.ebay.co.uk/itm/Kawasaki-Z...60999568779%26

[Nattman82]

Throttle possition sensor?? This is wired to the ecu to help controll fuel. tells the ecu what possition the throttle butterfly is at. on the bike it would help control ignition timing and other related systems. Im assuming the carbs run a traditional setup i.e no electronics involved in opening fuel valves etc. If so you should be good to go. The TPS should be redundant as its not needed on the FJ20. However you may have issues if the FJ20 lump uses a TPS as well, you may end up needing a stand alone management system to run the ignition.

[tss240zg]

trying to avoid use of ecu as may as well go for efi
so i am now thinking of webers.

Do you think weber 40's rejetted wouldbe fine... thats what bogg bros have said anyway.

[s13eater]

Originally Posted by tss240zg

trying to avoid use of ecu as may as well go for efi
so i am now thinking of webers.

Do you think weber 40's rejetted wouldbe fine... thats what bogg bros have said anyway.

who's bogg bros ?, where are you situated ? and why carbs matey ? and do bogg bros know anything about fj 20's ?

[nedge2k]

Bogg brothers are well known in the NA world for fabricating manifolds for bike carbs and bodies. you see it a lot on the C20XE and the like. Its not the proper way to do it but it works.

Not sure on the FJ setup but the dizzy on the CA is not a "proper" dizzy - it has what is essentially a crank sensor in it which the factory ECU uses to fire the coil so if you were hoping to ditch the factory ECU and run carbs, you'll still need something like a DTA S40i to control the ignition timing. The C20XE has a similar setup but uses a proper crank sensor - people often replace the XE 16v dizzy with a "proper" 8v points dizzy when converting to bike carbs.

Throttle position sensors are usually used for calculating engine load in an EFI setup but to be honest it can be left disconnected in an ignition-only ECU.

So in short, you need an ECU or a proper dizzy from another Nissan that will fit the FJ. Either way you'd need it all setup on a dyno / RR and using a "proper" dizzy from another engine may have mixed results as the ignition curve will be different - but this is usually just controlled by weights and springs or vacuum.

If you want to do it properly, get some jenvey SF ITBs, a DTA S40, a fabricated manifold and mount a 138mm trigger disc and ford type crank sensor to the front of the engine (or get the flywheel "toothed" and mount a sensor in the bellhousing).

[s13eater]

kameari do a proper manifold for carbs on the fj20.

[nedge2k]

wow, that's horrendously expensive at $640!! the C20XE is obviously a more widely used engine but a DCOE manifold for them is like £160!

maybe you could build the first XE S12? 150bhp stock, will push 200bhp with milds cams and carbs. only problem would be mating it to gearbox but i'm sure a Ford Type 9 XE bellhousing could be modified to suit.

[tss240zg]

Originally Posted by s13eater

who's bogg bros ?, where are you situated ? and why carbs matey ? and do bogg bros know anything about fj 20's ?

Im in Amersham Bucks, you see i would have left the engine standard with standard intake, my fj20 is from dr30 skyline so the intake is a lot larger so hence it wont fit. so i was gonna go for carbs to make it fit, it would be slightly cheaper.

What will i need to do for an efi set up, with regards to cost, dizzy (i have got standard dizzy), ecu and stuff i will need?

[tss240zg]

And the other thing putting me off using jenveys is the high price. you are looking at around 3700 dollars and its near impossible to find used ones.

[s13eater]

Originally Posted by tss240zg

Im in Amersham Bucks, you see i would have left the engine standard with standard intake, my fj20 is from dr30 skyline so the intake is a lot larger so hence it wont fit. so i was gonna go for carbs to make it fit, it would be slightly cheaper.

What will i need to do for an efi set up, with regards to cost, dizzy (i have got standard dizzy), ecu and stuff i will need?

ben diggles in aus uses the dr30 inlet manifold on a s12 matey.