Posted By: Moparmal
K&N substacks... - 12/31/14 03:34 AM
Anyone tried these?
results? What carbs and application eg fresh air or sealed scoop etc.....?
results? What carbs and application eg fresh air or sealed scoop etc.....?
K&N substacks...
Posted By: BradH
Re: K&N substacks... - 12/31/14 03:39 AM
I tried the version that fits over the standard Holley 4150 main body that still has a choke tower (NOT milled down).
Did it make a difference? You bet... caused a bog right off the line that went away as soon as I pulled it back off.
I didn't have the patience to go through a whole 'nother tuning routine simply because the stub-stack changed something so significantly.
Did it make a difference? You bet... caused a bog right off the line that went away as soon as I pulled it back off.
I didn't have the patience to go through a whole 'nother tuning routine simply because the stub-stack changed something so significantly.
Posted By: Moparmal
Re: K&N substacks... - 12/31/14 03:44 AM
If it did that to a Holley....I hate to think how an AFB would behave! 
Posted By: MR_P_BODY
Re: K&N substacks... - 12/31/14 03:49 AM
I run a stack thats mounted to the bottom of my scoop
pan...thats on a 1050 dom.. its been on there a long
time.. it smooths out the air due to the radius...
if you looked at the air filter on race car thread you
can see what that radius does
pan...thats on a 1050 dom.. its been on there a long
time.. it smooths out the air due to the radius...
if you looked at the air filter on race car thread you
can see what that radius does
Posted By: Locomotion
Re: K&N substacks... - 12/31/14 04:03 AM
It increases airflow so it leans out your carb set up. If it bogs and/or runs slower, you were close to optimum or a little on the lean side. If the car picks up, you were on the rich side without it. If I remember correctly, at least a couple of jet sizes richer helped me when I installed one on my bracket car. One size bigger squirters may also be helpful.
Posted By: joes68340s
Re: K&N substacks... - 12/31/14 04:15 AM
I have had one sitting in my garage for years and never tried it. I thought they were placebos and never gave it a chance.
Posted By: AndyF
Re: K&N substacks... - 12/31/14 04:22 AM
I did some dyno testing with a stubstack on an AFB carb years ago. The stubstack messed up the carb metering so bad we couldn't figure out how to fix it. Ended up just throwing the stubstack away.
Posted By: Thumperdart
Re: K&N substacks... - 12/31/14 07:05 AM
Bought one used on here years ago and it to screwed up the signal and it lost power............ 
Posted By: ademon
Re: K&N substacks... - 12/31/14 07:35 AM
Not to wander off too far but what's the consensus with removing the choke plate? Will the small holes in the choke tower where the choke shaft went through cause turbulence?
Posted By: Moparmal
Re: K&N substacks... - 12/31/14 08:25 AM
Thanks for the input.
Its interesting that these dont seem to work...but the factory used air bells on the race Hemi motors....
Its interesting that these dont seem to work...but the factory used air bells on the race Hemi motors....
Posted By: Thumperdart
Re: K&N substacks... - 12/31/14 05:29 PM
The bell`s have a generous taper to em the stub stack has an abrupt 1" wall to go over before it enters the carb.
Posted By: D_C
Re: K&N substacks... - 01/01/15 11:34 AM
I've been very happy with mine. Use it on 4150 and 4160 Holleys. Improved the performance wherever I have used them, but then again, I've been likely running rich before installation, so the additional smoothed out airflow seems a benefit, at least to an unmodified, intact choke carb.
Posted By: Rob C
Re: K&N substacks... - 01/01/15 04:35 PM
It seems to be a bit and miss with these things.
Posted By: Chris2581
Re: K&N substacks... - 01/01/15 04:57 PM
I have one that I use to hold the Moroso air pan on the carb.I dont remember if it helped or not,it's been on over 20 years.
Posted By: Just-a-dart
Re: K&N substacks... - 01/01/15 05:32 PM
The style that works on a milled choke horn 750 4150 Holley has been good for a .03 gain on 2 cars. But a HP main body is better
Posted By: MR_P_BODY
Re: K&N substacks... - 01/01/15 05:41 PM
This is the style I use... its mounted to the bottom
of my scoop and sits on the carb so the scoop is sealed...
I know they work for what they are suppose
to do(smooth out the air) because I had to use one
on all the carbs and filters that I flowed... with and
without you could see the difference.. its been on
the car since day one when I built it
of my scoop and sits on the carb so the scoop is sealed...
I know they work for what they are suppose
to do(smooth out the air) because I had to use one
on all the carbs and filters that I flowed... with and
without you could see the difference.. its been on
the car since day one when I built it
Posted By: BradH
Re: K&N substacks... - 01/01/15 06:35 PM
Quote:
It increases airflow so it leans out your carb set up. If it bogs and/or runs slower, you were close to optimum or a little on the lean side. If the car picks up, you were on the rich side without it.
No doubt my 850 would have appreciated my taking the time to re-tune it for the stubstack. However, at the time I was like "WTH?" when I did the A-B-A test vs. w/o it and decided it wasn't worth the trouble.
Posted By: AndyF
Re: K&N substacks... - 01/01/15 10:44 PM
You might not have been able to find a quick fix. I had a chat with one of the dyno engineers at Edelbrock a few years ago about the stubstacks and he said that they can really distort the metering system. Evidently the signal across the air bleeds gets disturbed enough that the carb can't properly meter the fuel. I think a person would need to run one on a dyno with a smoke wand to see what is happening.