Jump to content
SAU Community

Recommended Posts

Had a good look at my exhaust the other day and noted that the exit from the first cats is 70mm OD narrowing down to 54 mm at the bellows/flex joints and into the resonator and then emerging from the resonator back at 70mm OD. My question is this, if you have no intention of changing the rear system what is the point of going to, (say), a 76mm primaries midpipe exiting at 90mm when the following pipe is just 70mm? Ive seen some pipes advertised at 76mm at both ends which is closer but still not a match for the stock system. If I bought a 90mm exit midpipe would it pay for me to taper the outlet down to 70mm internally or grind the rear flange out so I don't have a 10 mm step/edge in my system to cause turbulence etc? Are all these 76mm/90mm midpipes really designed for a big bore aftermarket system and would I be better off just making the midpipe 70mm all the way through if I plan on leaving all else stock?

Also other than weight saving. What are the advantages/disadvantages of titanium over stainless? Im concerned about things like durability, heat radiation etc. And why doesn't anyone ceramic coat the titanium pipes for durability/heat insulation purposes? Weight being the primary reason I imagine? I'm not that fussed about 3 kgs but I would be if my pipe falls apart after 50,000 kms....

Edited by fungoolie
Link to comment
https://www.sau.com.au/forums/topic/346034-question-on-midpipes/
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


  • Similar Content

  • Latest Posts

    • Oh, also, forgot to add these photos I believe.
    • Thought i'd update on this. I was able to get in contact with Craig Lieberman and later on Darryl Alison (owner of Kaizo Industries). Darryl was able to help me verify that my car was in fact one of theirs and is helping me find more info on mine !
    • There's restrictor pills in the stock boost control hoses. That's how they set the amount that was bled off and hence the "high" boost setting. The usual mod in the day was to remove it and send the "high" boost setting up to about 14 psi.
    • Thanks Duncan, that's the best info I've read. Furthermore after learning about the PCM programming side controlling the factory boost solenoid, the purpose of the solenoid is to "bleed" boost when pin 25 is earthed, thus allowing spring pressure in the wastegate actuator to overcome diaphragm boost pressure, thus closing or reducing the position of the wastegate flap creating more boost as the turbo is able to spin faster. It's pretty cool to see a designated Pill to do exactly this, would have liked to have seen it with a tiny filter over the end for those moments in vacuum.  The constant bleed pill has now been removed completely from the system and solenoid boost control has been restored once again.   Case closed 😂
    • The wideband reading is meaningless if it's not running. Why are you using shitty old sidefeeds on any engine, let alone a Neo? What manifold and fuel rail are you using to achieve that? Beyond that, can't help you with AEM stuff as I've never been their ECU/CAS combo.
×
×
  • Create New...