Hi I am just trying to figure out what I should do about an exhaust system for my hotted up A15. It has a pair of DCOE 40 weber carbs, 54/86 cam, 11.0:1-11.5:1 compression ratio and a 1200GX exhaust manifold. I was thinking of heading down to the wreckers and just buying an old system from a 120Y since they had the twin outlet exhaust manifolds too....didn't they? or should I just tow it down to the exhaust shop and ask them to fit a single 2 1/4 inch system with a straight through muffler and a hot dog resonator at the end? I don't want it to sound too brapppy but want it to sound meaty if that makes any sense!

I Had Jeff Taylor 4-2-1 extractors and 2 1/2 inch exhaust single sports muffler and came out at the side for racing. Sounded nice looked good and was cheap Under $500 all up brand new. It was also below the 95dba limit so the only reason it was streetable was side pipe. Dont go below 2 1/2 inch as A series love to rev and need to beathe.

No 120Y I have ever seen had a dual outlet.

With a cam like that it would be advantageous to run a set of 4into1 extractors (branch) and 2 1/4" system.

I have run a system with a milder cam (42/72?) with 4into1, hotdog (12") and offset muffler in 2 1/4" and it wasn't loud unless you wanted it to be. Quite meaty at idle.

The only A-Series with dual outlet were the GX models. Unlike the 510 that used dual outlet on regular and SSS models.

Question is whether using a GX manifold on a hotted A15 is the best thing to do.

exactly. And 54/86 cam, and 11.0:1-11.5:1 CR is very hot. A factory exh manifold (even the GX one) would be a pretty big compromise on that engine.

alrighty I am leaning away from the manifold now which is a shame because I just installed new studs and cleaned all the old gasket and rust from the face with a flap disc on a grinder so it is perfectly flat. The studs took a hell of alot of work to get out all three broke off then I drilled them through the centre, broke 2 differnt easy out stud extractors, cut the studs off level with the flange, drilled the holes out to 6mm and bought a larger stud remover, which only got half of the stud out, the remainder then had to be retapped with an M8 tap ho hum that was pointless! so a set of extractors would be a better choice then into a 2 1/2 inch system would be ok. I wonder what it will sound like

the induction roar will be louder then the exhaust....i love a series
I still have one in the rally car.......

mmm I love A-series too.... even if they do have less than 200hp....

Quote:

holy crap really! I have got to get this thing into the coupe it sounds like it will be awesome compared to my clapped out rattling A12 currently getting me around! I actually think the standard A12 is pretty nippy so I actually can't even immagine what this A15 will go like, will be like driving a 6 cylinder falcon or commodore in acceleration terms?

Got a set of Hi-tech headers on my A-15 they sound good. dont know how much they were cos they were on it when I got the car, but they were available locally. 2 1/4" I think. Big step up from any of the cast manifolds, but not mandrel bent and wouldn't suit a wildly ported head.

Edit: Sounds like it should keep up with a local six- most of them pull about 10-12 kg/kw, so if you can find 70-80 kW you're in business