DASHOCKER

iTrader: (2)

Hey guys. I was curious if there is a company out there that makes larger throttle bodies for the GS400. Where can I get it if they make it at all? I want one as a part of my project for this car.

AZDesertGS

iTrader: (4)

Don't think a company makes a larger Throttle Body for our cars. Rod Millen built a N/A roadster with our motor and did a custom job in which it had a seperate throttle body for each cylinder.....but I also think they had to build a custom intake manifold as well. Don't bother with a TB spacer either....big waste of $$$

GSteg

iTrader: (15)

http://www.maxbore.com/

this guy can bore out your stock throttle body. He also makes new throttle plate and cleans up the whole thing for you.

There is a 30+ page thread on honda tech on this subject. I dont think i have seen a negative feedback.

100 shipped is for the 4-cylinder TB. I received a quote of $150 shipped for my old V6 throttle body, so I'm guessing the V8 is $150 shipped also. Or...you can just tell him you want to bore out the V8 TB and hope he forgets about the extra cost, and only charge you $100 shipped.

It's beneficial if you already have intake and exhaust already. THat's when the most gain will occur.

DASHOCKER

iTrader: (2)

Suprising there isn't one for this motor. LS1, LS2 have them available, the Porshe GT3 has a bigger TB available. Those guys can upgrade from the old 76mm to the new 82mm. It would be great to have it for the 1uzfe.

AZDesertGS

iTrader: (4)

You could probably get it polished or "honed" out. This would allow smoother airflow. That might give you some extra hp

DASHOCKER

iTrader: (2)

Oh just saw this. That is great thanks for the info . I will check this out. Some guys are not aware about the advantages of a bigger bore throttle body. Gotta know your stuff when it comes to upgrading your vehicle.

GSteg

iTrader: (15)

I think RM's car has Individual Throttle Bodies (ITBs). It basically is the intake manifold

V8_Aristo

Is the factory TB restricted? Maybe someone should do a flow bench test on a the factory TB to see how much it flows. It's just that I could not believe that RMM, SRT or LMS would pass up a simple mod like this if it will make their force induction systems more efficient.

SoCalSC4

I'm not buying it either. Unless somebody can show me dyno proof that a larger TB helps the newer 1-UZ, I think it is a waste of money. On a forced induction application, there are some gains, but for a naturally aspirated car I think you're barking up the wrong tree.

A torque converter, SRT intake, headers or gears would offer a much better bang for the buck.

AZDesertGS

iTrader: (4)

It's been proven that larger, ported/polished TB do increase HP.....There is dyno charts all over the internet. It may be only 3-5 HP....but it is an increase. Since there is no options out there for bigger TB for us....I think a port/polish for the right price would be worth it....(plus it would look pretty)

DASHOCKER

iTrader: (2)

The Porshe GT3 is a N/A car and makes415 horse at the crank from 3.6 litres. More than the last gen Turbo 911. They bored the throttle body form 76mm to 82 mm to increase power. Of course it will not give the car 60 horses, more in the neighborhood of 10-12 horses at the wheels just by that mod alone. The 10-12 horsepower is also gained on LS1 motors with that mod.

SoCalSC4

That's what I'm saying... I suppose 3-5 horsepower is relatively 'big' on a 100 whp 2300 lb. Civic. Not so much on a 300hp Lexus that weighs 3700 lbs.

You can 'free up' 3-5 horsepower by using lightweight wheels (as opposed to heavy cast wheels).
It's all about priorities.... and diminishing returns.
For the amount of money and labor to install an aftermarket TB, I wouldn't even bother.

$350 larger TB... +5hp. = $70/hp.
$600 SRT intake... +24hp. = $25/hp.
$6000 RMM Supercharger... +100hp. = $60/hp.

Forced induction starts to look relatively good (compared with the TB mod).

Edit; On the Porsche, most of those gains came from software changes. The GT3 is a beast... there's other stuff going on with that engine far above the standard 996 flat-6

On the LS1 engine... an old pushrod V8, the OE TB is quite restrictive. Toyota overengineers their engines, the stock TB on the 1-UV is not as restrictive. Remember, this car is only 4.0 liter and has sophisticated equipment like VVt-i.

But hey, if you want to experiment and spend the dough, go for it. Just be sure to post the before & after dyno sheets. No bench racing allowed!

Dx3

iTrader: (13)

I wonder what type of gains you could expect from this??

Jonny

DASHOCKER

iTrader: (2)

Lol bench racing.. good one. Yeah of course the Porshe GT3 gets its power from upgrades other than a bigger TB, one wicked ride. But, to have it bored out for 100 bucks is not a bad. Boring out a TB does give you some gain. How much for the 1uz-fe is the million dollar question.

svt5150

A larger TB will not always give you better gains. Especially on a mild modded motor. Even if you get 1-3hp you might lose some torque.