I've got an Edelbrock 52mm TB that has the notorious whistle/sucking sound at idle and part throttle. I'm probably going to replace it with a 58mm and port my intake while I've got everything apart. Are there any 58mm that people could recommend that don't have the whistle without having to drill out or mess with the IAC opening? I'll probably end up with an LE2 383 so it'll be sucking even more air that it is now.

Thanks!

 

My holley does not whistle at all, but it does need to be drilled. I have yet to drill it and mine idles just fine, but my motor it is not that "wild". I believe that all aftermarket TB need to be drilled, or modified in some way, but I could be wrong.

 

I don't get why everyone keeps drilling their throttle bodies. I guess no one got the idea that more air gets past the blades with the huge increase of surface area around the edges and thats why they didn't drill the hole in the IAC hole. As far as the whistling, my 58mm edelbrock whistled, but if you spend 30 seconds and sand the edge of the IAC it will sound as quiet as stock.

 

speed,

with my current setup, not only does it whistle badly, it seems to struggle to idle and gets even worse when i turn on the A/C. i assumed that most likely meant the more healthy 383 setup wasn't able to pass enough air thru the IAC opening and that drilling it out a bit (and sanding of course) would help. do you not think this is the case?

 

The BBK is known for the whistle, and generally its due to casting flash left in the IAC passage. Did you ever try cleaning it out?

My 58mm Holley doesn't whistle, and I never had to drill a hole in it. It had other problems though.

 

my 58mm summit works great, no noise at all,

 

Injuneer,

Just curious about what other problems you had with the Holly 58mm TB....that was the one I am leaning towards.

Thanks

 

Where exactly should we sand, any pics would be useful.

IF you dont drill the TB, you get poor cold starting and MAY get high IAC counts and an unsteady idle. Its important to remember that its not JUST to bypass the IAC. That hole leads to a separate pathway which routes the air to the cylinders invidiually, unlike the intake plenum which will favor the pistons at the front (i.e. closes to the throttle body blades).

 

I have the BBK 58mm and had no problems either. I did have to adjust the IAC though, and I used my Scanmaster for the correct setting.

No whistling, and simple install.

I heard people had more problems w/ the Holley, that is why I didn't go w/ that brand.

 

Who tuned it?

 

My IAC counts are ~20 at idle....

 

my holley is great didn't have to drill anyholes ,no whistle

 

I drilled an IAC bypass hole in my BBK TB the same size as my old stocker and that really helped out a lot. I also made a small piece out of aluminum to isolate the IAC passage on the BBK from the plenium. If i had it to do all over again i'd probably just get a nicely ported stocker.

 

For those who have drilled out your IAC's and had good results, can you tell me what drill bit you used? I'm not sure if the needs of a healthy 383 would require a bigger hole than a lightly modded 350 or not but just looking to get an idea of how much bigger to go if i do any drilling.

 

I'd use the stock size to start out, its much easier to go bigger than to try to make the hole smaller.