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71 mm throttle body


dohc v6

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i am getting plates made to do the throttle body upgrade. all i have to do is get my throttle body bored. is there any potential buyers if i can get it to work right. i am not doing the boring my self it is being done by a shop and the plates are cnc machined

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rsm racing made a throttle body up to 72 mm. any ways if you do everything right it will increase all around. if you get you plenum and lower intake manifold ported it will not kill your low end and will give you better gas milage

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If it makes it run extremely better let us know. I was simply going to put a TB on from a junked Venture, but if a 71mm throttle body makes a big (and positive all around) difference I'd like it.

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itll kill low end in the 3.4s. hell, the 3.4 intake setup is ALREADY too large hence the low end sucks like it does.

 

if GM was smart, they wouldve done a setup similar to the Yamaha motor in the SHOs. they have 12 intake runners with a butterfly that swaps between the two runners for each individual cylinder allowing less air for torque on pickup and then opening up for high end.

 

that is why an SHO is quicker than the LQ1.

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If it makes it run extremely better let us know. I was simply going to put a TB on from a junked Venture, but if a 71mm throttle body makes a big (and positive all around) difference I'd like it.

 

This is for a 3.4 DOHC engine, not a 3X00...71 is too big for a 3X00 :shock:

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71mm is also about the absolute upper limit for boring............there just isn't enough material to go bigger.

 

Be aware, that a large TB really isn't going to help very much....and as others have mentioned, it may just kill your low end a little.

 

You money is better spent elsewhere first (chip, UDP, a good CAI and a PROPERLY designed exhaust).

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Prove it kills low end.

 

it was proven by the guy who did short intake runners on his DOHC in his Fiero.

 

also, proven with numerous people who have gutted their airbox or added a cone.

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I didnt see anything about TB size vs plenum volume. I didnt see any dyno sheets for a larger TB on a 91-95 TB and barely even a mention of the 95 runner length at that.

 

I see a lot of talk about "the TB alone isn't worth it" yet I can read on another famous DOHC site that there is no reason to mess with the exhaust because there is very little backpressure stock. I know that is bullshit. I just want something concrete....but then again ill have my own tested soon enough that ill find out for myself.

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Im just doing street testing for now since john hasn't even gotten his stock dyno run. I havent seen anyone with a larger TB on their DOHC reply on their own results so something is better than talking at this point.

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Im just doing street testing for now since john hasn't even gotten his stock dyno run. I havent seen anyone with a larger TB on their DOHC reply on their own results so something is better than talking at this point.

 

im up for concrete results myself. im just going with what i noticed in letting more air in on a stock setup.

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This might not be applicable to anything.. but I was just reading on the Callaway "Supernatural" Corvette, TT LT1 that puts out over 780hp... and its only got a 52mm TB. Since its not n/a its probably a difference story, just thought I'd share :wink:

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This might not be applicable to anything.. but I was just reading on the Callaway "Supernatural" Corvette, TT LT1 that puts out over 780hp... and its only got a 52mm TB. Since its not n/a its probably a difference story, just thought I'd share :wink:

 

It's different in whats required for each individual application, my friend runs a 70mm throttle body on his NA/high compression 347 stroker in a mustang that runs 11's.

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Nothing :lol: you would need a 3400 top end for any kinda extra power for that 3100

 

-Jeff

I was gonna get that too (if I ever find a junked Venture)

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the 3.4 is not ment to go fast off the line, it is ment to be a car driven on the high way. thats why we get 27 mpg vs 17 in the city. the cams dont like to be drive hard at 10 it would be more like 50. the 3.4 is a car ment to take off at 50-70mph. who cares if it makes your low end slow because you are getting better gas milage.

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.. But if your making a fast car doesn't that negate the gas mileage anyways?

 

I was going to say that. I guess it depends on your driving habits. If you do mostly city driving its gonna suck even worse than stock. On the highway it might be better, but nobody here really seems to know for sure.

 

that callaway corvette runs a DUAL 52mm throttle body. big difference. 2 52mm blades.

 

I should have looked at the picture :oops:

 

435engine.jpg

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that callaway corvette runs a DUAL 52mm throttle body. big difference. 2 52mm blades.

 

That's approximately the same area as a single 74mm TB. Still not very large considering............

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