Custom Inlet Plenum

[Craig89 0]

I need to do a fabrication project for work and i also need some sort of filtration system for my twin weber TU with very limited space. So i thought i would make a custom inlet plenum from sheet aluminum. I have done these drawings:

 

 

 

There are 2 missing dimentions, it is 130mm deep and 70mm wide at its widest, also the 122mm dimention is actually 99mm (dont know how i made that mistake)

 

I basically just want to know if this will give me good airflow to my carbs or if there is anyway to change the design in order to get the best airflow?

 

Thanks, Craig

[Henry Yorke 270 3 Cars]

Is this a design that will take a nibble out of the bulkhead like they sometimes do on 106's? You will get an improvement on a TU with anything that feeds cold air into the back of the engine I reckon due to the ambient underbonnet temperatures

[Craig89 0]

Is this a design that will take a nibble out of the bulkhead like they sometimes do on 106's? You will get an improvement on a TU with anything that feeds cold air into the back of the engine I reckon due to the ambient underbonnet temperatures

 

With these dimensions it will fit and there will be no need to cut the bulkhead, which is good. I have had to angle the left hand corner for clearance of the brake master cylinder. This design should concentrate cooler are to the intakes. I am just wondering if i will get even amounts of air into each intake on the carburettors? Or if there are any other technicalities to consider?

 

Thanks

[Sandy 191]

In my experience the inlet air temp on TU engines out on the road is very close to ambient, unless the engine bay is panelled in! Once you're on the move there's plenty cool air about in there, it's only in rolling roads with the bonnet down that it looks bad.

 

I'm in favour of the easy filtration of an enclosed plenum, but it will impact the power delivery, what's gained in cool air is usually more than lost in undesirable pulse tuning and cross breathing effects. If you really know what you're doing and have lots of dyno time to test; you can all but erase such problems, sometimes even find a sweet spot, but without that luxury, the best way to avoid detrimental effects is to maximise the volume of the box and the intake pipe size. The induction noise will change.

[Craig89 0]

In my experience the inlet air temp on TU engines out on the road is very close to ambient, unless the engine bay is panelled in! Once you're on the move there's plenty cool air about in there, it's only in rolling roads with the bonnet down that it looks bad.

 

I'm in favour of the easy filtration of an enclosed plenum, but it will impact the power delivery, what's gained in cool air is usually more than lost in undesirable pulse tuning and cross breathing effects. If you really know what you're doing and have lots of dyno time to test; you can all but erase such problems, sometimes even find a sweet spot, but without that luxury, the best way to avoid detrimental effects is to maximise the volume of the box and the intake pipe size. The induction noise will change.

 

Ok, cheers for that Sandy, i will make it as large as i can and see how it goes.