doubt you'll see more than 2bhp increase freeing up the exhaust though, not worth it for the work involved in changing
spitfiremk1uk
Active Member
If you get the chance, try and get a 4-2-1 exhaust header. These work a lot better for torque at the rpms of a 2.25 over the 4-1 headers often used. Ashley exhausts used to do them. Not chea but you wll find them on ebay.
A bigger exhaust pipe will help with power, yes, by only about 2 or 3 horspower but you wouldnt want to throw 3 horsepower away would you? Economy will also be helped.
The silencer is also a very restrictive section of the exhaust system. ACR do have a larger bore and free flowing silencer but at a cost. Check your exhaust back pressure if you want a more accurate estimate of the extra power you would get.
You can make your own exhaust up from parts and use pipe with 2- 2.5 inch diameter pipe and a free flowing exhaust silencer. I get mine from real steel. If you take a pattern into some places they will knock you one up but it always costs. Custom car workshops being favourite.
A bigger exhaust pipe will help with power, yes, by only about 2 or 3 horspower but you wouldnt want to throw 3 horsepower away would you? Economy will also be helped.
The silencer is also a very restrictive section of the exhaust system. ACR do have a larger bore and free flowing silencer but at a cost. Check your exhaust back pressure if you want a more accurate estimate of the extra power you would get.
You can make your own exhaust up from parts and use pipe with 2- 2.5 inch diameter pipe and a free flowing exhaust silencer. I get mine from real steel. If you take a pattern into some places they will knock you one up but it always costs. Custom car workshops being favourite.
