Exhaust Fitting Help!!

[grayfox]

So my sportex 421 blew a massive hole and I first ordered a FRP ebay special which didn't fit, now I've had a 2nd hand Pumabuild Piper 421 turn up today (guy said it was pumaspeed :roll: ) so I badly need to get the car ready to rock for the weekend as I have a track day booked but I don't know how to go about piecing it together??! (especially as a milltek would have a flex built it and now I need to fix one in)

I've got the bits below:

Piper 421 - 53mm inside bore (would need 56mm+ connecting pipe to fit over the lip)

standard flex repair pipe (flange at one end) - 45mm bore at both end which widens massively before the flex itself begins

Hoffman centre standard size (outside 53mm / inside 45mm bore at flange)

 

[zinc2000]

Just a suggestion not sure how helpful....

Could you maybe weld an short extension/ reducing tube onto the pipe from the 421, which would then sleeve into the flexi and onwards to join the flange on the hoofman?.

As I said not sure how helpful but not sure how else you can do it :-(

 

[grayfox]

Cheers for the suggestion bud, certainly won't be easy. I have another powerflow centre section on the car but again that mated direct to the sportex I had on which was long enough to fit directly and had a smaller bore to match up properly.

 

[DOH]

Well it looks like you've purchased a larger bore Piper manifold than used on the FRP? That is good , in view of the other performance mods you've made It may well produce power or at least cause the engine to spin up faster. With that in mind, it would be best to continue with a larger bore exhaust to suit fabricated specifically for your Puma. There is no point trying to reduce it's size.
PowerSpeed in Ashford, Kent are very good , Maniflow, Salisbury is another. You can sell on your old exhaust on Fleebay to recover some of the outlay.

If it is found to lack torque low down, (an extra silencer can be added to recover back pressure) , which will assist with track day noise testing.

 

[grayfox]

Not sure if it's larger bore than the FRP, Thought the pumabuild piper was affectively a FRP copy, like miltek and janspeed? agreed that ideally I don't want to be running a standard sized centre pipe but just need it to come together for now! may well get my hands on a janspeed centre (no silencer) from FRP tooling (but likely not before the weekend) and already run a piper straight through 3" backbox.

 

[ElDude at Allison Automotive]

[post]352058[/post] Not sure if it's larger bore than the FRP, Thought the pumabuild piper was affectively a FRP copy, .

unfortunately, none of the copies are very accurate copies... partly because they've tried to 'copy' the original mild steel system with Stainless which is difficult to shape... also because copying the flanges joints at the correct angle very time is also very difficult...

Even the 2nd batch that Janspeed made up was a very different fit to the original... I bought one of the 2nd gen systems.. Stevie Wonder welded my manifold!.. was very cheesed off with it...

Am going to get some complete systems made up next week (hopefully)..



Chris