It's a nice move to upgrade the throttle body of my 81 N/A to a 60 mm? What could be the difference?

 

If you do the 240sx T/B swap??? It is alot more airflow.. See the PIC. I mean when the stock T/B fits in the other it has to be a good upgrade...

 

So you recomendation is to upgrade to a 24osx throttle body. It's a better upgrade than the 60 mm? Will I need to make any modifications to install it?

 

The 240SX throttle body IS 60mm.

And yes, you'll need a throttle body spacer and may need to modify the water lines and throttle linkage a bit depending on which one you get.

In order to get better performance, you will also need to bore out the input of your intake manifold to accept the volume of air.

Of course, you won't see very much improvement in power unless you also install the complimentary upgrades like headers, exhaust, cam and port matching your intake and exhaust ports on the head itself.

Then you'll get some nice power and torque. A lot of people don't realize that all the mods are necessary to achieve the full potential of even one upgrade.

If you're going to do it, it should be a small part of a bigger plan. A roadmap if you will, to your performance goal. Throttle body this month, Header next month, cold air intake the month after, new 2.5" mandrel bent exhaust the following month, cam/rockers/valve springs & port matching to finish it all off. By now, you'll probably need to upgrade to at least 280ZX Turbo injectors. While you're at it, get a nice Pallnet fuel rail and convert to O-Ring injectors instead of stock Nissan ones, might as well replace your 'head' hardware set too:

http://www.hammondsplains.com/z/zwor...lnet/index.htm

If you just want bragging rights, then all this isn't necessary, you can just bolt it right on and go about your merry way.

 

the 240sx (ka24de) throttle body IS the 60mm throttle body. MSA sells one that is the correct depth. If you get a 240sx tb, you will need a .5" or .75" adapter between the tb & manifold.

 

Damn... lww beat me to it.

 

how do I wire up my 240sx TB? i just got it and it has 2 3pin connectors whereas the stocker has one 4pin right?

 

the 240sx tb sensor should have 2 connections... one that looks just like the Z's, and one w/ a lighter gray plug. Use the one that looks just like the Z one.

 

Solid. the TB already has the ball stud on it. so it realls is a direct bolt on if you have a spacer? What about the intake boot?

 

With a spacer you should be able to squeeze the boot over the KA TB. I did it without too much trouble to see if the boot would fit. I didn't have spacer though so I had to make my own piping anyways but the boot should fit. If you're having trouble you can use a little hairspray on the inside of the boot. That'll make it easier to slide on and it helps it to not slip off in the future. A little trick I learned from my BMX days that works on cars

 

has anyone completely deleted the water/coolant lines from the TB? It never made sense to me to have hot coolant flowing where cold air should be. (even after the lecture from an engine builder, and automotive teacher, i still think its better without it! Only seems like it would cool with the stock airbox, if you have a custom cone filter sucking up cold air from outside the engine bay, you don't need it right?!).

 

yep... I re-routed the coolant from the air regulator directly back to the thermostat housing. No need to intercool the air, then heat it back up!

 

I re-routed the coolant on mine too. That heater is to keep the throttle body from freezing in cold weather. The air sucking through the throttle body can cool the throttle itself much colder than the air outside. If the throttle plate freezes, it can stick open. I haven't had any trouble this summer but I'll see how it goes through this coming winter, if I can even drive a car after gas hits $5 a gallon.

 

I went to a junk yard that specialize in nissan amd I asked for a 60 mm TB from 240sx . But then the guy working there came with too many info for me . He told me that he has a couple of TB"s , but all of them were different #'s but nissan 60mm . He first showed me the TB of a 1995 infinitti 60 mm; then came one with a # like this SR20DET. At this moment I was a little bit worried of my lack of knowledge. And the he brings one with # KA24E and a Ka24DE. Please can you tell me which one of them I can use in my 81 N/A?

 

You can use either one... Just gotta be from a KA24DE or an SR20DE. They look the same except for the throttle linkage & coolant ports.

EDIT: KA24DE (Nissan 240sx) SR20DE (Infinity G20)

 

Thanks NismoPick. So is there any difference in difficulty to make it fit? What about the difference in throttle linkage? If you can be a little more specific I would really appreciate it.

 

All you really need is the spacer and swap the linkage andit will bolt right in for the most part.. I got lazy and just swaped out half of the 240 linkage and grinded the intake manifold a little for clearance..

 

linkage diff... the 60mm throttle body will most likely be cable operated... the Z has a ball / rod linkage. Some 60mm throttle bodies have the same diameter butterfly shaft, and you can just swap over the z one. Might have to use ya imagination a lil.

 

Again I was lazy but this is how mine ended up at the end... You can see where I grinded the manifold for clearance..

 

Is there any difference between the sr20det and the sr20de TB's?

 

shouldn't be. If you find an actual SR20DET... buy the whole motor! I can't even imagine an SR20DET at a junk yard!

 

That reminds me why I had to trim mine (I trimmed the shaft though). The screws to the throttle shaft/butterfly) were striped so I couldn't get the shaft out. So I just used a cutoff wheel to cut down the shaft to make it fit.

 

It makes any difference if the TB has cruise control? My z's CC is not working. So I want to know if there is going to be any difference if it has or it has not CC?

 

nopers... the cc for the z is connected back @ the firewall. The 240sx @ the throttle body. That extra cable linkage on the tb can be removed.

 

The spacer that I need, how long it is? I've read different things. In some places they say .5", others .75, and others 1" For what sould I ask in the machine shop?