Small vs Large throat precups

[Guardian2433]

So I have some precups I'm about to use for an engine build. Would a small or large throat make the engine louder?

Like Square vs Diamond. Can anyone tell the difference in noise? and I mean same timing (No Advance or Retard)

 

[WarWagon]

Precups are all about power OR MPG. Choose one. Small precups limit the amount of fuel you can throw at the engine before it just turns to smoke but get the best MPG with the lower maximum fuel setting. Larger precups allow you to make more smoke free power, but, at the expense of MPG when you don't need full power all the time. A small turbo hides this difference some by hiding the smoke and limiting top end power.

More fuel = more noise... I doubt it would make a noticeable difference. Exhaust type, muffler or lack of, and exit point make a bigger difference in noise.

 

[JayTheCPA]

First: :welcome2:

Not the best expert, but I know that tuning (IP timing?) plays a role in noise. Do not recall reading where one style of pre-cup makes different noise than another (everything else remaining equal). Am sure the better experts will chime-in with the correct science of this.

 

[Guardian2433]

Precups are all about power OR MPG. Choose one. Small precups limit the amount of fuel you can throw at the engine before it just turns to smoke but get the best MPG with the lower maximum fuel setting. Larger precups allow you to make more smoke free power, but, at the expense of MPG when you don't need full power all the time. A small turbo hides this difference some by hiding the smoke and limiting top end power.

More fuel = more noise... I doubt it would make a noticeable difference. Exhaust type, muffler or lack of, and exit point make a bigger difference in noise.

I'm just wondering if a larger throat or smaller throat will make a different in noise.. Any difference at all? even if its just a little.

 

[6.2 turbo]

The small ones have a softer clatter,the big ones more of a knocking sound. I'm running the small ones currently, they work just fine,if not better than the big ones.

 

[Guardian2433]

The small ones have a softer clatter,the big ones more of a knocking sound. I'm running the small ones currently, they work just fine,if not better than the big ones.

So you've ran both? how much louder were the large throat cups over the small throat?

I want to make my 6.5 loud as a Cummins or close. Remember we're talking diesel clatter, not exhaust.

 

[Will L.]

Just loosen a couple rod caps...
:lol:

 

[tanman_2006]

Just loosen a couple rod caps...
:lol:

Hahaha! That sounds right!

The 6.5 already clatters plenty, the cummins is a loud engine though. If you want that noise then get one.

Most people say my straight piped 6.5's with aftermarket turbos are loader than most scummins or powerjokes.

source unknown

 

[6.2 turbo]

So you've ran both? how much louder were the large throat cups over the small throat?

I want to make my 6.5 loud as a Cummins or close. Remember we're talking diesel clatter, not exhaust.

About like rod knock at part throttle . The small ones just clatter,much better sound IMO.

 

[WarWagon]

My 1993 has the 6.5 NA precups in it now and the ATT. Was the same sound with 6.5 turbo precups, 6.2 NA precups, and 6.5 NA precups with the factory turbo. It has had a 4" exhaust with a straight through muffler with all the turbo's. It sounds like a big block with clatter. You hear it coming 2 blocks away and it rattles plates off the wall esp. when the cold advance is on. It is tiring after hours in the cab with a full load towing. So be careful how much noise you wish for.

The major difference I have noticed is with advance on the pumps for clatter esp. if the light load retard lever is late by adjustment to come on.