Jump to content


lulululululul

3.5 inch turbo back exhaust to stock rear muffler

Recommended Posts

Hi guys,

 

New to the forum, usually a lurker but I have a question which I have done some research about but I'm not 100% sure about. 

 

I have a fg xr6t with supporting mods making 470rwhp. However the car drones way too much at highway speeds even though I have a cat, mid muffler and rear muffler. Recently I replaced the rear muffler with the stock 3 inch muffler. I assume ive lost power but would this be a substantial loss?. Doing some research suggests that it shouldn't harm the engine. 

 

I prefer the quiet sound while cruising around. I have a varex on the way which ill probably install but if the stock muffler does the job is it worth putting a 3.5inch varex rear muffler?. 

 

Tl;dr - Is it okay to have an exhaust go from 3.5inch turbo back to 3 inch even with power upgrades. 

Share this post


Link to post
Share on other sites

It's fine to have it like that. You've probably lost a few ponies, though. Only one way to find out - before and after dyno runs in the same conditions.

 

:Welcome2FordXR6t:

Share this post


Link to post
Share on other sites

Hmm that is a good point. Might have to do that. I usually read that getting a turbo back exhaust would require a retune. But if im replacing the rear muffler to a 3 inch would that require a retune?. 

 

If I use the varex which is a 3.5 inch muffler I assume that I wouldnt need a tune again at all as its back to what it originally was?. 

Share this post


Link to post
Share on other sites

changing the rear muffler (or the middle muffler) does NOT require a retune.

 

It's the cat that is the most restrictive part and if you free up that restriction it can overboost with the stock turbo setup.

 

A varex is totally fine to just install.

Share this post


Link to post
Share on other sites

Sorry for reviving this thread but hopefully someone answers. I just had a 3.5 inch varex installed onto my 3.5 inch exhaust with 4 inch dump. The exhaust shop however added some tips to the rear muffler that is only 3 inch in diameter. I am wondering will this hinder performance or be bad for the car?. The guy at the shop reckons it wouldnt make a difference but I am looking at getting more power soon.

 

Thanks in advance

Share this post


Link to post
Share on other sites
42 minutes ago, lulululululul said:

The exhaust shop however added some tips to the rear muffler that is only 3 inch in diameter.

 

The grammar says muffler but the context says tips. Which is it?

Share this post


Link to post
Share on other sites

The rear muffler is 3.5 inch but I had another tip installed to this 3.5 inch rear muffler. I wanted the tip to be minimum 3.5 inches but they installed a 3 inch tip. Hopefully that makes sense. Cheers

Share this post


Link to post
Share on other sites

Yep it makes sense. 

 

After the exhaust gas goes through the cat and various exhaust bends I doubt a 3 inch tip will be a restriction.

 

As hamster balls said the only way to know for sure will be a dyno comparison but that's a waste of money. 

 

If it bothers you then swap it.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Donation Box

    Please donate to support the community.
    We appreciate all donations!


FordXR6Turbo.com Powered by Invision Community

×