I was wondering what your thoughts were on a ported TB? I measured mine and the dia. where the blade sits is 75mm and the smallest dia. is 72mm. I just don't see where the 3mm is going to make a difference! I am not smart enough to figure out the cross sectional area and the flow rate differences.Will it make a difference on a completely stock 5.3?

Second question,if I jb weld the location for the IAC and deleate it,how will it run? I live in Michigan so the car is put up for the winter but I drive it from first good rain until first snow.How will this effect daily driving?

 

It's usually not for a ton of power, although it does give you some. It gives better throttle response and every little bit helps!

 

Not a bad idea to port it. You can typically pick up a little power and better throttle response like mentioned above. I would run a ported TB over most of the aftermarket 80-85mm stuff if it were my car. Also, I wouldn't JB Weld the IAC hole. The car uses that to make it idle properly and not die every time you chop the throttle.

Jon

 

Usually when people use JB Weld over the IAC inlet, they only do so to remove the big indentation there. Then, they drill a small hole in the JBW to allow the IAC to still draw air and function.

I've heard of people deleting the IAC totally, but you'd really have to tune the setup well for that (plus have the proper sized hole in the TB blade, and/or have the TB cracked open enough to flow idle air). At this point it'd be like a carb which can be a pain at times, like when snapping the throttle shut quick at low speeds the motor will want to die sometimes, etc. The IAC prevents this. Also, the combo of an IAC motor and IAT sensor allow the idle to remain unchanged even under drastic temp changes. On a carbed setup (or a TB without idle air control), you'll have minor idle speed changes based on outside temp changes.

 

Best 50 dollars I ever spent on my car...noticed a nice gain when I ran one.

 

What is the recommended dimension of the drill whole into the IAC after being filling with JB Weld?

I have and A4 and of course do not want idle issues.

Regards,

 

I had New Era do mine for about $80, very happy with the results.

 

I have access to a bridgeport at work so I am doing the porting myself so it won't cost me anything,but I don't know how big the hole would need to be.

I will have to look at the stock porting and see what the smallest dia. is for the IAC passages and that should tell me what size the hole will have to be.

 

Myself and a friend (with access to a machine shop) did a couple of these about 8 years ago. I honestly don't remember what size we drilled for the IAC, maybe a 1/4"? It's been a long time.....

 

i just had the tb ported on my H/C/I car, and it made a huge differance in the throttle response. i run the f14 and it made the driveability alittle worse. but the sotp feeling is up there.