1985 Mustang GT Exhaust Replacement
 

Gooday All!

Well spring is coming! Not quick enough but it's coming.............

My exhaust system is the stock set-up which they had in 1985 with the exception of the mufflers disappearing....... :laughhard .......funny what a can happen when you get your hands on a cutting torch........anyhow.......I also have a leak in the stock headers...........YACK!

I want to replace this with a true dual exhaust. Here is the set-up I wanna go with......and I do have the 86 GT Dual Hump Tanny X member on the way........bought it yesterday......

Flowtech Equal length headers
Flowtech Off Road H-Pipe (2.5")
No cats
Cat-back exhaust.........American Thunder 40 Series from Flowmaster (2.5")..................

What do you guys think of this set-up????? :chacha:

i think it's too much....there's no back pressure there....say goodbye to your torque. i'm running in the low 13s now and should see hih 12s on my next track visit and still using the stock 4-cat H-pipe and stock headers....

It'll sound nice!! :tup
I did the same when i had my ol' '85 gt.
Except i used mac headers,and off road h pipe,along with the flowmasters.

Then much later i changed the set up again. :biggrin:

Did you notice a good difference in power?? I am looking for sound and power............. :tup

Well I was told that with the 2 chamber flows........I should be ok with no cats...........worst case I will just mod my set-up after...........put hi flow cats........but after doing much research and talking to many.........they recommended this............we will see...........

Throttle response seem to be better,and i guess she felt stronger,hard to remember as this was back in '96/'97.
She ran the best all bone stock of 15.1 @ 94 mph,after exhaust she ran the best of 14.5 @ 95 mph.So there is some gain.And i was a rookie at this drag thing at the time...well still am !!! :LOL:


Eventually after all the mods she ran the best 14 flat @ 101.something mph,on street tires :banghead: .

You will not be disappointed. :tup
And the back pressure lost do to having no cats,it will be little,you will not even notice the difference. :)
Actually,my '03 GT felt more torquie without cats then it does after putting cats back in. :confused:

Hey bud,

Thanks for the good feedback! When I took her to the track........I did 14.5 with her on the 1/4 mile @93mph.............she was stock except for 8.8 rear and 3.73 gears. Poor thing had a header leak too.........so I am anxious cause since then I put an Edelbrock intake and now the exhaust is going on soon with a fresh tune up...............accel plugs........9mm Ford Racing wires........so anxious to get her out ther again.............

Thanks :tup

No prob!! :cheers: :biggrin:

Sorry bro, but you're off base here. The 85's stock exhaust is much more restrictive than the 86 newer exhaust, and 1 5/8" shorty headers combined with 2.5" h pipe and 2.5" Flowmasters would give a very nice increase in power. I wouldnt be surprised to see 20 extra HP out of that setup over stock. It will really make a big difference, and I suggest not going with equal length headers... they're a pain in the ass.
SS

i don t know why you dont like equal lenth shorty , i had in my stang and yes there are a good job to install but i have more trouble to install my new long tube , i never had trouble to remove spark plug ,and never burn spark plug boot , the only problem whit Mac is the 4 separate flange ..