throttlebody upgrade 280zx

[s14280zx]

Last May, I bought a 1995 pathfinder with 105,000 miles, had it for two weeks, had the oil temp sensor blow out, and locked up the motor (vg30e). After having it sit at a garage for 5 months, they decided to tell me the warranty didn't cover it. I found a whole parts car for $500, with a good drivetrain (94000 miles), and changed motor, tranny, and trans.case. Now I have all these extra parts. My question is, will the throttlebody from the vg30e work as an upgrade for a 280z,or zx? I'm not sure of the size whether it's 60mm, or if it's the same as a 240sx TB. Would anything else from this motor be interchangable with the l-28e ?(Ex. ignition, etc.)Any advice would be appreciated.

[Vintage]

If its the same as the TB in the Z31 VG30E, then its 54mm compared to the stock L28s 50mm. It bolts straight to the L28E intake manifold, but needs a spacer to keep the stock linkage and to clear the EGR runner on the bottom of the manifold.

[BRAAP]

VG30E TB is smaller then 60mm, just a little larger than the OE L-28 TB. At any rate, a throttle body swap alone, even to 60mm or larger especially on stock or even mild L-28 will net you nothing you would ever notice. The stock intake manifold runners are the biggest hindrance to air flow as well as the stock exhaust system. There are SEVERAL other mods to perform that will net noticeable gains in performance before the OE throttle body becomes a restriction and should be considered at hindrance to performance. Here is great thread on larger throttle bodies;

 

Click me for Large throttle body discussion

 

 

For gains in performance, Start by advancing your ignition timing. OE is 10-12 degrees BTDC at idle. Bump that up to 15-17 at idle. There are many other easy mods that will deliver noticeable gains in performance, which can be found through the HybridZ search engine.

 

Good luck,

Paul

[s14280zx]

Thanks for the advice, I'm trying to figure out what my best options are. I have a 78 280z 2+2, and a 79 280zx which both have n47 blocks/heads. I also have two parts cars with f-54 blocks/ p-79 heads. I'm planning on building one with triple weber 40mm's(which I already have), and the other car will be either NA fuel injected, or turbocharged. What do you think would be my best route to choose?

[FlatBlack]

Yeah I just picked up as 240sx throttle body for my NA L28 so I could run cable linkage and have the option of megasquirt. I dont know why people would think a bigger TB would give gains without a new cam... kind of like the headers on my car that dont do anything but sound good.

[DuoWing]

I'd like to do a throttle body upgrade simply so I can adjust the idle with an idle bypass screw rather than having to mess with the stock 280ZXT throttle stop. I've removed the AAC, VCV, EGR, etc so now I need to actually adjust my idle and that would make it a little easier.

[BRAAP]

I'd like to do a throttle body upgrade simply so I can adjust the idle with an idle bypass screw rather than having to mess with the stock 280ZXT throttle stop. I've removed the AAC, VCV, EGR, etc so now I need to actually adjust my idle and that would make it a little easier.

 

Later '81-'83 N/A 280-ZX's came from the factory with a remote mounted idle bypass screw, attached to the side of the plenum, allowing idle speed adjustment by altering the air bypassing the throttle plate, i.e. no need to adjust throttle stop. I thought the Turbo cars did as well?

 

I didn't know the 240-SX throttle body even had the idle bypass built in? Do you have a picture of that?

 

In short, swapping to a 240-SX throttle body just to acquire idle speed control really doesn't make sense.

[DuoWing]

I could be wrong on the 240sx throttle body, although I believe the Z31 might work, but you'd still need the spacer. The turbos never had an idle adjustment screw on the throttle body. I guess Nissan figured the newer ECCS, VCM, and AAC would be good enough to not need to adjust the idle? When they got to the Z31 they must have realized that sometimes it doesn't always work as it's supposed to and gave the idle adjustment screw back.

[BRAAP]

The 240-SX throttle body, as far as I am aware, has no integral idle speed adjustment, same as the late ZX and ZX-T throttle body, like what you currently have, which means you’d still be in the same exact situation that you are in now, having to adjust idle speed using the throttle stop.

 

The Z-31 throttle body does NOT have integral idle air bypass either.

 

Now the early 280-Z, (’75 through at least ’78, possibly through early ’81, though I can’t confirm that), DID have an integral idle air bypass, (I’ve got early 280-Z, late 280-ZX and Z-31 throttle bodies here).

 

The N/A 280-ZX from ’81 on, (possibly earlier), utilized an external adjustable idle air bypass, functions just like the early 280-Z integral style, but is external/remote, not integral with the throttle body itself, (see pics below).

 

Due to the fact that you eliminated a lot the ZX-T intake manifold stuff, it seems like it would just be easier to incorporate the N/A ZX idle air bypass or the early 280-Z throttle body, than to install a throttle body that doesn’t offer any more idle speed adjustment than the throttle body you are currently using. This remote idle speed adjuster is dirt cheap at the wrecking yard, easy to plumb, can be located ANY where on/in the car, (with enough vacuum hose, even inside the cockpit if you wish).

 

Here is the N/A ZX idle speed controller as mounted in the car, on the side of the manifold itself.

 

 

 

Here is one of those OFF the car.

 

 

 

Here you can see the slotted adjuster, (flat blade screw driver to adjust idle speed via regulating air flow that bypass the throttle valve itself).