# 280zx throttle body upgrade



## Guest (Jul 13, 2003)

I've heard that if I put a 240sx throttle body onto my 
280zx turbo and make a few adjustments, I will get 20% more power. Is this true?


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## 240ZT (May 9, 2003)

20% more power is doubtful. 280ZXT is about 180hp stock so a 20% would be an increase of 36hp. Now if you combine the 240sx throttle body and match port the intake, add a 3" downpipe and exhaust and lose the cat, then you will be looking at a 20% increase.


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## Engloid (Jul 7, 2002)

20% from a TB is total BS.

Somebody at z31.com put one on and dynoed a whopping .4hp I thin it was.

I put the TB on my z31 long ago when it wasn't well known how worthless it is. If I had it to do over again, I'd not bother. It is the sorriest mod I've ever done, taking into consideration time, money and effort vs gain.


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## TEAM REDLINE (Dec 7, 2003)

Turbogasm said:


> I've heard that if I put a 240sx throttle body onto my
> 280zx turbo and make a few adjustments, I will get 20% more power. Is this true?


I HAVE A 86 Z31 AND THE FIRST MOD I DID WAS THE THROTTLE BODY I PORTED AND POLISHED IT MY SELF IT REALLY DOESNT GIVE U ALOT OF HORSEPOWER IT HELPS UR RESPONSE TIME U GO THROUGH THE GEARS ALOT FASTER S I RECOMMEND DOING IT


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## ldsolja4 (Mar 1, 2003)

I think its a total waste to be honest with you... 200 bucks for 4 hp IMO is a waste. Id rather spend that money on injectors or a new fuel pump to get some real hp. I guess its all personal preferance.


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## Engloid (Jul 7, 2002)

ldsolja4 said:


> I think its a total waste to be honest with you... 200 bucks for 4 hp IMO is a waste. Id rather spend that money on injectors or a new fuel pump to get some real hp. I guess its all personal preferance.


It was .4 hp....as in four tenths of one hp. Sad!!


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## ldsolja4 (Mar 1, 2003)

me no likey pointless mods... i pitty the fool who spends money on these wastes.


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## duckyz (Dec 1, 2003)

The throttle body mod is a good idea if...

You are doing a total intake and exhaust overhaul/upgrade. .4hp is .4hp.

In conjunction with a BMW ('84 - '86 320i) AFM as well as larger injectors (500cc), fuel pump, POC intake, at least 2 1/4" exhaust that .4hp adds up.


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## PrOxLaMuS© (Aug 11, 2002)

Well.. the 240SX has a 60mm throttle body compared to the 44mm L28 throttle body.

More air equalls more power.

With a well tuned engine.. and a 240SX throttle body, there has been reports of


> Tests have shown increases in horsepower by as much as 9% at the rear wheels, and cuts in 0-60 times by .5 seconds


 There is a *40%* increase in airflow and 10% bigger than stock.

*9% from a bigger throttle body in a 170 HP engine.. equalls.. a grand total of 17 EXTRA HORSEPOWER*
Now you can get a 240SX throttle body or get an performance throttle body from MSA for $259.
http://www.zcarparts.com/store/merchant.mvc?Screen=PROD&Product_Code=11-3021-2&Category_Code=PFFC14










PS - guys please research before you post shit...


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## Minagera (Oct 25, 2004)

I say screw the 60mm BS. Get a 80mm from a Q45.


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## Zen31ZR (Mar 24, 2004)

PrOxLaMuS© said:


> Well.. the 240SX has a 60mm throttle body compared to the 44mm L28 throttle body.
> 
> More air equalls more power.
> 
> ...


 Did you read the section rules?


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## Engloid (Jul 7, 2002)

PrOxLaMuS© said:


> 9% from a bigger throttle body in a 170 HP engine.. equalls.. a grand total of 17 EXTRA HORSEPOWER


Thats fawkin' awesome!!! So if your math holds true, I can double the size of the throttle body, I will double the horsepower to: 170 x 2 = 340 !!!!! 

:thumbup: :thumbup: 

And to think...all these people are spending big money on turbos, injectors, intercoolers and all that stuff....when all they need is a bigger throttle body!!


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## Crowbar60 (Jan 22, 2005)

I have sold dozens of these 60mm TB's (KA24e). My own vehicle is a VG30e 200sxse converted to a 88 300zx ecu/mfu. The stock vg30e is 51mm and the KA24e is 60mm.

The goal is not HP but throttle response and torque. The car feels and drives much better.

The best ones are NOT 240sx but rather KA24e stanzas. They have the bottom hose connections, vg30e compatible linkage (no swapping), usually cruise control and throttle potentiometer as well as a throttle position switch.

Any pull n save type junkyard will have vg30e maximas/300zx with the 51mm throttle body. This can usually be had for 20-25 bucks. This would be a cheap upgrade from the stock 44mm unit.

I usually sell the 60mm KA24e's for 60 bucks.


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## Engloid (Jul 7, 2002)

I'll agree with the VERY SLIGHT throttle response. The reason is this: If you have one butterfly valve that's 3" diameter and one that's 1" diameter, and both are open the same angle, the 3" valve will flow more. So yes, it basically means you don't have to push the pedal as far to get the same "response" as with a smallet TB. 

However, 40% more flow is simply not true. Half a second off a 0-60 time is also not true. It doesn't take half a second to push the pedal to the floor, no matter how far you have to push it. A few degrees in ambient temperature will make more difference than this. The TB is NOT the bottleneck of the intake system. The difference in the TB's is about .290" on the diameter, if I remember correctly. 

The plenum is the big bottleneck of the system on a z31. The second worst is the heads. 

And $250 for one of thest throttle bodies is an absolute scam!! People should be ashamed to sell for that much..but if somebody's STUPID enough to pay that for it, they've got to have a mental impairment. (BTW, Crowbar doesn't sell for near that money, so if you want one, skip the link above and get with him for one.)


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## Crowbar60 (Jan 22, 2005)

My latest creation is a use for the throttle position potentiometer that is on the TBs.

I use this to fake out the ecu into believing the cyl head is getting colder as a function of throttle position opening. This enriches the fuel and advances the timing.


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## Crowbar60 (Jan 22, 2005)

The 60mm TB needs a much better air filter than seen on most nissan cars. Most 200sxse owners use a cone filter (especially if using the larger 300zx mfu on the car).

For smaller TBs like on the 280Z or other nissan cars, a vg30e 51mm is probably the way to go. They are very cheap since they are often left over from guys that have gone to a 60mm TB.


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## Engloid (Jul 7, 2002)

Crowbar60 said:


> My latest creation is a use for the throttle position potentiometer that is on the TBs.
> 
> I use this to fake out the ecu into believing the cyl head is getting colder as a function of throttle position opening. This enriches the fuel and advances the timing.


You can actually richen the fuel mix by putting a resistor in the loop for the CHTS...and with a potentiometer, you can run wires into the car and richen fuel mix on the fly. If you wanted, you could wire in a relay with a couple different resistors and have a couple presets also....even have one that allows you to flick the switch and go back to stock for emissions purposes.

I used the potentiometer on my car, and it worked well. I successfully ran 12psi and 125hp (wet) of nitrous on stock block, stock injectors, fuel pump, etc... ran great.


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## Crowbar60 (Jan 22, 2005)

Actually I run the pot in parrallel with the CHTS. At small throttle openings, this barely effects the real value of the CH temp reading. But as the throttle opens, it increases the 'seen' resistance that the ecu A to D processes. The CHTS is a negative resistance transducer with temp increase.

If you just put a resistor in series with the chts, the O2 signal feedback loop will null it out eventually.

The CHTS has many effects on the car (in a 88 300zx anyway). It even effects the injection mode the car uses. 

My ecu reports a 5-5 red-green LED error code so as far as the ecu is concerned, everything is OK.


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