Throttle body options
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- Mechanic
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Throttle body options
My next mod on the list is the throttle body!
I got couple options, hopefully you guys can help;
Enlarge the standard to 63mm.
Enlarge the standard to 65mm.
Get a 65mm 3.5L magna throttle body.
Get a 68 mm from a 380 ( too expenisve i think).
I know the 63mm will be the cheapest option but i have spent a lot of money the car and don't mind if its around 500 or a little bit more if i can get more power out of the engine.
Any tips would be highly appreciated.
I got couple options, hopefully you guys can help;
Enlarge the standard to 63mm.
Enlarge the standard to 65mm.
Get a 65mm 3.5L magna throttle body.
Get a 68 mm from a 380 ( too expenisve i think).
I know the 63mm will be the cheapest option but i have spent a lot of money the car and don't mind if its around 500 or a little bit more if i can get more power out of the engine.
Any tips would be highly appreciated.
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- Grease Monkey
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- FTO338
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My had bore out to 65mm, & the intake manifold & other stuff is half way through already, so hopefully i have them back in 2wks time.
But yeah the guy said, u won't able to safely bore out more then 65mm
But yeah the guy said, u won't able to safely bore out more then 65mm
DISCLAIMER: The above text is the personal opinion of the author and does not represent the indisputable truth. The author is not responsible for any deaths, injuries or mental illness caused by the above statments.
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I've got a 65mm Magna TB as well, but i like the idea of just plug & play instead of modifing to fit.
I have no idea about the cost yet.
I find out when I pay the bill.
I have no idea about the cost yet.

DISCLAIMER: The above text is the personal opinion of the author and does not represent the indisputable truth. The author is not responsible for any deaths, injuries or mental illness caused by the above statments.
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- Bennoz
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I've been down this road a dozen times. Will post pics up when I get home. Any good machine shop can whip you up a ported TB for around $100 bucks (including butterfly valve)
Remember - there are 2 measurements
1. The diametre of the inlet side
2. The diametre of the bore through the TB
The inlet side is generally flared out to a much larger diametre than the thru size as to cause the throttling effect - ie copressing the air, speeding it up & cooling it down.
Remember - there are 2 measurements
1. The diametre of the inlet side
2. The diametre of the bore through the TB
The inlet side is generally flared out to a much larger diametre than the thru size as to cause the throttling effect - ie copressing the air, speeding it up & cooling it down.
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I got it for free.
From memory the water pipe is backward, so you have to extend it & install the magna TB upside down. I can't remember now, so i could be wrong, all i know its, you have to modify it to fit.

From memory the water pipe is backward, so you have to extend it & install the magna TB upside down. I can't remember now, so i could be wrong, all i know its, you have to modify it to fit.
DISCLAIMER: The above text is the personal opinion of the author and does not represent the indisputable truth. The author is not responsible for any deaths, injuries or mental illness caused by the above statments.
- Bennoz
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Yeah the pre 96 ones are 60mm in the bore size, they are the same as FTO (just with reversed piping. Thing is - if you go to a wrecker & ask them for an FTO one that your gonna go bore out, they'll hit you for $200 bucks, if you ask for a Magna one you get hit for $60...
I went through this exercise: The best solution is to port out your own one if you can afford the time to have your car off the road for a day or 2. Mind you, if you know your machinist, they can turn them around in a few hours & they are only 5 bolts to pull off & put back on.
And btw - there is ablsoutely no point going for a whopper one unless youre gonna open up the mouth of the plenum as well. You'll just suck air into a big flat overlap & cause turbulence on the lip of the plenum.
I went through this exercise: The best solution is to port out your own one if you can afford the time to have your car off the road for a day or 2. Mind you, if you know your machinist, they can turn them around in a few hours & they are only 5 bolts to pull off & put back on.
And btw - there is ablsoutely no point going for a whopper one unless youre gonna open up the mouth of the plenum as well. You'll just suck air into a big flat overlap & cause turbulence on the lip of the plenum.
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the mods listed on rpw for the throttle body of the magnas lists a 65mm high-flow unit if u wanna go further.. "Stock unit exchange high flowed for approx 40% more flow. No manifold modifications required." so i take it its already bored to about max at ~65mm, and they just reduce some of the restrictions internally increase flow..
"exchange unit" means u give them a 65mm tb and they give you a completed one
though as benoz says u would still need to port-match the intake manifold for the larger tb anyway if u put the 65mm on,
which means you have unbolt that aswell...
"exchange unit" means u give them a 65mm tb and they give you a completed one
though as benoz says u would still need to port-match the intake manifold for the larger tb anyway if u put the 65mm on,
which means you have unbolt that aswell...