3.9L and 4.6L Throttle Body match??

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1BADLS

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I've been looking closely at the throttle body on my LS V8 lately, it looks like it matches that of the 4.6L stang?? Anyone else noticed this?? I am just going by pictures, also the 3.8L TB looks close to, does anyone know for sure if it will interchange?? Im looking to run a Dry Nitrous set-up and using a stang plate would be awesome!!! thanks. :steering :nos:
 
Be careful of using larger throttle bodies. Experience on a Chebby site was that unmodified LT1 engines did not perform better with larger throttle bodies, in fact they performed worse. This may not exactly translate to the 3.9 in the LS, but almost 100 years of hot rodding experience tells rodders that bigger is not always better. You need to match components for best results.

Unless your engine has mods that will require additional air intake, you will drop the velocity thru the intake which will drop your performance, you will bog.

Since Nitrous supplies additional O2, I am not sure that that kind of mod will increase the airflow requirements of the engine or even need more flow. Maybe a blower, hotter cam, traditional mods will increase the need for a bigger TB. But then I have read that the LS V8 is pretty well optimized now for our applications, and there are not enough aftermarket parts to take advantage of better flow.

Good Luck, think about what you want to do and why and how things interact, before swapping parts.

Jim Henderson
 
I'll look and compare the throttle bodies from the LS and Crown Vic (same as mustang). However, the only time you will see a gain with a larger TB is if you go forced induction. I'm not sure about on a NO2 application, but I don't think the TB will make a gain there either.
 
1BADLS said:
I've been looking closely at the throttle body on my LS V8 lately, it looks like it matches that of the 4.6L stang?? Anyone else noticed this?? I am just going by pictures, also the 3.8L TB looks close to, does anyone know for sure if it will interchange?? Im looking to run a Dry Nitrous set-up and using a stang plate would be awesome!!! thanks. :steering :nos:
Click to expand...
I believe the single-port 3.8 Mustangs ('94-'98) can use the older 4.6 throttle bodies ('96-'98) as an upgrade. It doesn't gain you anything unless you have other mods, though. On 3.8 Mustangs, upgrading the throttle body is really far down the mod list, after you do serious stuff like porting intakes, heads, and a cam swap.
 
are you also upgrading the fuel system?

NOS, Zex and NX all recommend a 'wet' kit be used with the factory fuel pump.
 
You don't need to increase your air intake for NOS...just fuel. NOS contains it's own oxygen molecules.

TB's are funny items. Some cars just love a larger TB with no other mods. Others they do nothing for. Since you may be able to find what you want to try for very cheap, it may be worth the experiment! Cars that like a larger TB usually show gains under the curve as well as peak. That's where you spend most of your time driving, so that's what I would look for. You can use the ol' SOP test...or check it on a chassis dyno.
 
If you need to get your hands on a higher flow fuel pump, I may be able to help you out. Does anyone know what the Flow/pressure specs on the fuel system are?

I'd like to know if any gains can be had!!
 
Okay, I measured, studied, and compared the throttle bodies in the Vic and the LS. As far as I can tell, they are the same. All the dimensions, bolt holes, tp sensor, all look the same. There was one minor difference, the throttle return spring settup is a bit different; that can be fixed easily by swapping the throttle bracket out though.

I know for a fact that the Mustang uses the same throttle body as the Crown Vic so any aftermarket Mustang throttle body should fit on an LS.

So, if anyone would like to buy a new throttle body and send it too me I will serve as the guinea pig and make sure it fits. There is a catch though, as other members and myself have said we won't see any gains unless we go forced induction, so I'm gonna need someone to send me a centrifugal supercharger as well. (All in the name of hotrodding of course.) :steering :N
 
JohnnyB said:
Okay, I measured, studied, and compared the throttle bodies in the Vic and the LS. As far as I can tell, they are the same. All the dimensions, bolt holes, tp sensor, all look the same. There was one minor difference, the throttle return spring settup is a bit different; that can be fixed easily by swapping the throttle bracket out though.

I know for a fact that the Mustang uses the same throttle body as the Crown Vic so any aftermarket Mustang throttle body should fit on an LS.

So, if anyone would like to buy a new throttle body and send it too me I will serve as the guinea pig and make sure it fits. There is a catch though, as other members and myself have said we won't see any gains unless we go forced induction, so I'm gonna need someone to send me a centrifugal supercharger as well. (All in the name of hotrodding of course.) :steering :N
Click to expand...

Everyone got me wrong, I dont want to swap TB's, I was going to buy a nitrous kit, and most EFI kits are universal, you have to plumb them into the intake tube, but it the TB was the same as a stang, be it v-6 or v-8, I could buy a kit that comes with a TB Plate system, making it lots less work plumbing, see where Im comming from?? Thats my idea, if i can buy a kit with plate, less install time and more reliability. As far as Dry vs. Wet and efi, actually Dry is reccomended for EFI applications, not wet because the stock fuel pump provides enough fuel for dry, a wet kit would require a upgraded fuel pump.
 
I did get it - you wanted to upgrade the TB to use the matching plate.

on the fuel pump - it's the other way around -
- you have to go with a 'wet' system which adds more fuel into the intake charge since the stock fuel pump and injectors may be inadequate to supply enough fuel to the engine. Your adding much more 'oxygen' to the intake charge so you have to add more fuel. This is why most 'stock' applications are 'wet'.
- 'dry' systems are safer - since n2o is not flammable by itself - any pooling you'll get in the intake has a less chance of igniting if detonation occurs. Since a 'wet' mixes the fuel into the n20 in the intake you can have a massive 'hood removing' explosion if detonation occurs, the intake valve is still open, and the mix in the intake is lit.




from the ZEX web-site:
"Q: What is better, a "wet" or "dry" kit?
A: It all depends on the application. A "wet" kit is ideal for both normally aspirated applications as well as forced induction applications. It can require a little bit more installation time than a "dry" kit, but is easier to tune if greater than stock HP settings are to be experimented with. A "dry" kit is excellent for normally aspirated combinations that have a return style fuel system. They are very easy to install and are a great "first time" nitrous system. It is not recommended that "dry" systems be used on forced induction engines."

The LS uses a returnless fuel system.
 
Everyone got me wrong, I dont want to swap TB's, I was going to buy a nitrous kit, and most EFI kits are universal, you have to plumb them into the intake tube, but it the TB was the same as a stang, be it v-6 or v-8,
Click to expand...

:slam Oh. In that case, a mustang plate should bolt right in.
 
Quik LS said:
from the ZEX web-site:
"Q: What is better, a "wet" or "dry" kit?
A: It all depends on the application. A "wet" kit is ideal for both normally aspirated applications as well as forced induction applications. It can require a little bit more installation time than a "dry" kit, but is easier to tune if greater than stock HP settings are to be experimented with. A "dry" kit is excellent for normally aspirated combinations that have a return style fuel system. They are very easy to install and are a great "first time" nitrous system. It is not recommended that "dry" systems be used on forced induction engines."

The LS uses a returnless fuel system.
Click to expand...


Again, i dont want to upgrade my TB, just bolt a mustang nitrous plate in if the bolts lined up, thats all. I was looking at the venom Stang 4.6 kit, it comes with a computer, which surges the fuel injectors when the kits in use, adding more fuel. im not sure though, Quick LS, didnt you use a kit?? Do you rember which one exactly?? thanks.

From Venom Website:

Nitrous made simple.
Venom VCN-1000 Computer Controlled nitrous oxide kits practically run themselves. All you have to do is set the nitrous flow by choosing one of the four nitrous nozzles supplied with the kit (25, 50, 75, or 100 additional horsepower). Kits are designed to cut off nitrous flow automatically if the air/fuel mixture becomes too lean. Plus, they adjust fuel flow through the injectors, so you don't have to modify the vehicle's fuel pressure. Ideal for return-less fuel systems, they come complete with the bottle and mounting brackets, a control module, nitrous nozzles, wiring harness, solenoid, switch, hoses, rich/lean display, mounting hardware, and an installation manual.
 
Yes - I work with ZEX and NX technical departments:
Nitrous Express recommends kit # 20922 - Ford Stage 1 EFI Wet kit
ZEX recommends kit #82023 - V8 EFI Wet kit

I believe you cannot use the Venom kit - it needs to tap into your car - (could be wrong here) but the Venom kit monitors your O2 sensor and determines your A/F ratio - if lean - then it 'holds' your injector open longer (past the pulse width that the PCM does) - the issue is that the PCM may try to adjust by shortening the pulse width -and a loop effect begins. I have three friends that ended up pulling off the Venom kit - two went back to NOS and one to Zex.

I like the Zex kit - has the n2o and fuel pressure monitoring all in one.
 
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