Exhaust tip change volume??

discopotato03 · Post by **discopotato03** » Thu Jul 10, 2008 9:47 am

Sorry may be confusing two cars/engines .

A 2" hole in the back of a 2.5" exhaust will work brillianty - not . Makes a waste of having the 2.5 " system in the first place .

I'd look at it like this .

2.5" in metric is 63.5mm , 2" is 50.8mm . If you subtract ~ 4mm for the approx wall thickness of the tube (2mm x 2) you get 59.5 and 46.8mm .
Then work the area of a circle formula which is Pi x radius squared to get 2780.5 and 1720.2 mm square area .
The smaller figure is ~ 62% of the larger one .

Your call .

AndrewT · Post by **AndrewT** » Thu Jul 10, 2008 10:51 am

The only way is to compromise.....but there is a way to avoid that.
I still say the best solution is to use a conical restrictor in the rear tip. Step it down to 2" or even further with a removable restrictor attached with a wing nut. When it's time to drive down somewhere for a camping trip bung it in there and drive down in quiet comfort. When it's time to go for a spirited blat around offroad take it out and scare all the wildlife with Hatchy's unrestricted fury

Best of both worlds and will probably cost about $5 to knock one up yourself with the Mig.

SuBaRiNo · Post by **SuBaRiNo** » Sat Jul 12, 2008 1:04 pm

Thank you for your sanity AndrewT... im not sure if i have discussed this with you yet but that is the avenue im now going down. I realise by reducing the tip im reducing the flow hence making it quieter... but the hatch aint much good to me with a yellow sticker and a head ache.

I guess it's hard for others to understand the sevear lack of space i have left in the hatch and how much shorter the exhaust system is compared to other EJ vehicles.

Dave

YouTube · Post by **El_Freddo** » Sat Jul 12, 2008 10:20 pm

AndrewT wrote:The only way is to compromise.....but there is a way to avoid that.
I still say the best solution is to use a conical restrictor in the rear tip. Step it down to 2" or even further with a removable restrictor attached with a wing nut. When it's time to drive down somewhere for a camping trip bung it in there and drive down in quiet comfort. When it's time to go for a spirited blat around offroad take it out and scare all the wildlife with Hatchy's unrestricted fury
Best of both worlds and will probably cost about $5 to knock one up yourself with the Mig.

This sounds like the go, I might use this trick one day

SuBaRiNo wrote:I guess it's hard for others to understand the sevear lack of space i have left in the hatch and how much shorter the exhaust system is compared to other EJ vehicles.

I agree with you on this dave. Hatchie is a real piece of work - in a good way. Hatchie and your work have my full respect as you'd probabily already know. Good luck with sorting out the canary. Bugger eh?

Cheers

Bennie

Subafury · Post by **Subafury** » Sun Jul 13, 2008 12:57 am

i dont think he actually has a yellow sticker el freddo- unless ive missed somthing. but the exhaust how it is would certainly attract one.

SuBaRiNo · Post by **SuBaRiNo** » Sun Jul 13, 2008 8:27 pm

Yeah no sticker. If it was i would be looking for an MY sedan i think.

Dave