bellmouth design.

if 2" wide, how long would i need, or what wrap/width would you recomend?

thanks
ian

 

i did my headers up-pipe & downpipe used a roll & half 50m roll 50mm wide, half a roll would easily do downpipe

 

and if it was 2 inch wide wrap, what would you think i would need with a 50% over lap

 

I wrapped my de-cat down pipe the other day before fitting it and I used 3" wide roll and 5 meter length, it covered just the right amount, covered it just underneith the car, I would of liked it to be a bit longer tho, maybe 7 meter length or something, if you want to wrap the whole pipe them I think you'll need around 10 meter length.

 

so would a 2" wide wrap with 50% overlaping,
would 30ft be enough? for 3" decat downpipe?

need to know asap

 

wot exactly does the wrap do? is it just to shield the heat???

 

yes keeps the heat in the exhaust, and out of the engine bay, and if you keep the down pipe gasses hotter, they will flow faster, this will help with power, and turbo spool up etc.


worth doing i think

 

Is there any benefit wrapping down / up pipes with cats still in or is it not worth it?

 

3" open neck D/P will take over three quarters of a 2" x 50' roll of wrap with the recommended overlap. DO NOT go for a 50% overlap.
I use DEI wrap which I have in stock here and it has a stitching about 6mm in along the edge and that is the target overlap.
Excess overlap is not necessary and you will use more material.
Excess overlap closer to the cylinders will result in excess heat retention and on tubular headers this will greatly reduce service life.

 

hi harvey, when you say 2" x 50' is that 50 ft?

so would 30 ft be enough or would i need more?

thanks
ian

 

or does anyone know how long the decat down pipe is?

 

50 feet. 30 feet is not enough even with only trying to follow a 6mm overlap.
You would be as well to get a 50 foot roll of DEI wrap. It is relatively easy to use because of the stitch guide and from the roll you will have 10' (10 feet) or just a fraction more left over if the job is done properly and kept tight.
Alternatively, use what you have but do not wrap the first 18" from the end that couples to the exhaust.