Tall Weber Velocity Stacks

[0396]

OK always wanted to install taller weber velocity stacks on my 3.2 with 46 webers..

Heres my questions for the experts here.
1) will this help and at which rpm?
2) where can I purschase a set- provided they help.
3) the stock ones are approx 2 1/2 inches tall- How about a 3-4 inch tall set or...?

Thank you!

[Don Plumley]

Moved to the main tech forum.

[mede8er]

CB Performance has them...and the socks....

[Steve@Rennsport]

Originally Posted by 0396

OK always wanted to install taller weber velocity stacks on my 3.2 with 46 webers..

Heres my questions for the experts here.
1) will this help and at which rpm?
2) where can I purschase a set- provided they help.
3) the stock ones are approx 2 1/2 inches tall- How about a 3-4 inch tall set or...?

Thank you!

What cams are you using?

[myfast911]

i was wondering the same thing. i am running elgin ge 60 cams with 97mm p/c s. thanks for any info in this.

[0396]

Originally Posted by Steve@Rennsport

What cams are you using?

The cams are early 's'.. thank you

[Mo_Gearhead]

Wanting to flirt with Bernoulli's Law 'ey? (IE: as gas speed drops, pressure rises and vice versa.)

On all out race cars (perhaps yours is?) you can tinker with short/long intake stacks and long/short header collectors to improve the "wider tuning band".
In other words ...the RPM range where the engine makes its best power.

Intake and exhaust runner lengths are changed to move that power band either up or down the RPM range and as such, it's a 'black art' which you can refine through experimentation ...or best done on an engine dyno.

Enjoy.

[HawgRyder]

I remember the stacks on the Can-Am cars in the past.
All the stacks were of slightly different lengths so that the charge to each cylinder was equal.
That must have been a lot of time on the engine dyno to come up with that system.
With my own drag car I was running, I found that plugs were the secret...3 heat ranges in 5 different manufacturers got me down the track about 2/10's faster.
Do whatever it takes....keep the secret...smile when you win...be gracious to the losers..LOL
Bob

[BK911]

A basic rule of thumb is taller intake stacks help the lower end, shorter stacks help the upper end.

[911st]

I thought the stagered length stacks were an atempt to widen the TQ/HP band.

[Steve@Rennsport]

Originally Posted by 0396

The cams are early 's'.. thank you

You will not see any gains with taller stacks using those cams.

FYI,.....Tall stacks help contain reversion on engines using cams with far more duration and narrower LC's such as 906/Sprint, GE-80/GE-100's, 171i/149, etc.

This is a grossly simplified answer as there is a lot more to this subject.

[jluetjen]

0396, you'll love this thread where I went down essentially this same tangent a while back.

[jluetjen]

Originally Posted by HawgRyder

I remember the stacks on the Can-Am cars in the past.
All the stacks were of slightly different lengths so that the charge to each cylinder was equal.
That must have been a lot of time on the engine dyno to come up with that system.

Hi Bob; actually those staggered stacks came about because the intake ports in the "porcupine" heads had different lengths (or at least volumes) on alternating cylinders. So the stack lengths were adjusted to keep the ports consistent from cylinder to cylinder.