Volkszone Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
15,754 Posts
Discussion Starter · #1 ·
I'm putting twin Dells into my camper. I've run them in my beetle with 'stacks and no filters but, now I'm running filters- do i need short stacks too?

Shane
 

·
Registered
Joined
·
1,238 Posts
No not really, the general idea of the stacks is to straighten the air as it goes into the carb, how much actual effect it has is questionable, few horsey's. It obviously makes a little difference but in general terms not having them isn't going to make any significant difference. Personally I wouldn't worry if you haven't got them.
 

·
Registered
Joined
·
6,422 Posts
They do make a small difference, even with filters. make sure you have a minimum of 35mm clearance between the top of the Stack and the underside of the filter top plate.
 

·
Registered
Joined
·
15,754 Posts
Discussion Starter · #4 ·
Thanks chaps

Obviously I want to squeeze every bit of power I can, or I wouldn't be bothering with the Dells in the first place. I'll see if I can source some short stacks. Anyone know of a supplier? I've tried the usual suspects and none seem to do them for 36's.

Shane
 

·
Registered
Joined
·
4,872 Posts
Stacks can helep with another problem. When you lift off the throttle to change gear, the mist of air and fuel can (hard to explain properly) suddenly slow down, build up, and come out of the top of the carb. If you've got a stack it can be contained in the stack, ready for when you've finished changing gear and hit the throttle again. Without them you sometimes get a flat spot as the fuel/air mixture has gone out the top of the carb. I've noticed this on cars on the dragstrip that don't run stacks, just open carbs with no filters. Of course, if you have a filter, then any fuel/air mixture will be contained within it, so the need for stacks isn't there, or not so great.
 

·
Registered
Joined
·
1,238 Posts
Mr_Wobble said:
Stacks can helep with another problem. When you lift off the throttle to change gear, the mist of air and fuel can (hard to explain properly) suddenly slow down, build up, and come out of the top of the carb. .
Very simply you can a surge and blow back. Due to differential pressure differences, the air mixture always wants to go from a high pressure to a low pressure, When you close the throttle the pressure builds up in the carb throat, and you get a high pressure in the carb and a relative low pressure (atmospheric/static pressure)outside the carb, the mixture then wants to travel back up the carb to equalise.. True the stack helps this as it keeps the mixture contained but wont actually prevent it...
 

·
Registered
Joined
·
15,754 Posts
Discussion Starter · #8 ·
I spoke to James at Stateside Tuning this morning. He said 'Yep, you still need the stacks- 42mm in height'. I think that's case closed for me. Thanks for all the tech info...

Shane
 
1 - 8 of 8 Posts
Top