[RAWZE]

what mods are needed to put a 300 tb on a 79 zx?

rick

 

[RAWZE]

anyone, anyone at all

rick

 

[DylanZ]

From what I hear ya gotta grind out the opening of the manifold to match the bigger opening, and that is best done with the intake off the car to avoid getting grindings through your baby. Mabee you'd get away with stuffing a rag down the hole. As for the throttle linkage, I dunno, I gotta find that out myself, I want to do this mod too. Other things like vaccume lines and those other tubes coming off of the thing, I don't know what is kept and tossed!! If you do get any info, E-mail me, [email protected] seeing as I'll be trying to find one of these in a week or two. I don't know if it will help much, unless you get the other bottle necks out - the tb and filter. Good luck man.

Dylan

 

[DylanZ]

There is a fair bit on this topic in the archives, but nothing specific. By the sounds of it, you gotta keep the linkage in some instances, but is not all that difficult, besides the reaming out your intake to the bigger size. Check these options out:

TB sizes ---
78-83 280z/280zx………………………..50mm
300zx……………………………………..55mm
89-91 240sx ka24e………………………60mm
Webber big throttle body……...............60mm
90-91 Stanza ka24e……………………..60mm

 

[yo2001]

I got it done. here is what you need:
1 inch spacer with 55mm hole
300zxt TB 55mm
280Z TB linkage
Longer TB bolts
300zxt TPS
Extra 280Z airbox to AFM boot
Spacer to hook up the airbox (I relocated my AFM and I needed to extend a boot to reach the airbox) I used 3 inch rubber boot
Valvecover breather

Stuff I took off:
air regulator
valve cover return line
EGR

Pros
power gain
cleaner looking intake
better idle

Cons
I can figure out where I should hook up the vacuum advance line (300zxt TB has two hook up)
No more high idle during warm-up ( I think you can make a place for air regulator on the 1 inch spacer. I've not yet try.)
No more idle screw

It's a money worth upgrade. I paid $50 for spacer and TB. But little tricky. I got bug right now. my car likes to nose dive during half throttle load. (????) I think my AFM is shutting close cutting the fuel pump off. Or may be a wrong vacuum advance. Other then that, I can feel the power gain. I messed with AFM air screw and enrichment circuit (aftermarket) to get a good mixture. I won't recommend this swap for someone who don't know what thier during kind of like me. Need Voltmeter check all the components like TPS. If I find the solution for my nose dive problem, I'll post again.

 

[yo2001]

For N/A L28 55mm 300zxt TB is big enough I think. remember the bigger isn't always better. The intake is velocity vs flow. bigger will give more flow but also looses velocity at sametime

 

[DylanZ]

Yo,

Why do ya need the spacer between the intake and the tb?, and do you think I should go with the 60mm 240sx tb if I have a turbo afm, 2.5" exhaust, header, ported intake and head, 480/274 cam, compression around 9.5 or 10-1??

Dylan