[Kitch428m21]

Looking for someone who's been in this situation. Has anyone spliced in their own down pipes to their current pipes?
I'm switching from log manifolds to RA. Are the collector locations the same measurment back ? I know the RA manifolds are lower at the collector.
I want to make the cut right in my pipes I have now, so the supplied 2.5 down pipes will slide nicely over my 2-1/4's.
I have the motor out now so I was thinking just putting the new pipes next to the old and make my marks 2" up. Is this what you would do?

[b-man]

Originally Posted by Kitch428m21

Looking for someone who's been in this situation. Has anyone spliced in their own down pipes to their current pipes?
I'm switching from log manifolds to RA. Are the collector locations the same measurment back ? I know the RA manifolds are lower at the collector.
I want to make the cut right in my pipes I have now, so the supplied 2.5 down pipes will slide nicely over my 2-1/4's.
I have the motor out now so I was thinking just putting the new pipes next to the old and make my marks 2" up. Is this what you would do?

Put the new RA manifolds next to the old logs and check the difference in outlet location, they're probably not a lot different.

In this case you will end up with a not-so-ideal situation as far as exhaust gas flow is concerned, the 2-1/2" pipe with the 2-1/4" slipped inside is a no-no when building an exhaust. It's not a deal-breaker, but a smoother transition from large to small would be best.

A 2-1/2" pipe all the way to the muffler would really be the way to go, although more trouble and expense. This will allow you to reap the maximum performance benefit from your $300+ investment in the manifolds.

Even when using a slip-fit connection with pipes of the same size it's best to put the expanded pipe (expanded to facilitate the slip-fit) at the rear of the connection with the straight section at the front (the source of the exhaust gasses).

I built my own 2-1/2" downpipes when I put RA manifolds on my car, so I could tailor them for maximum ground clearance. Then I mated them up to an existing aftermarket 2-1/2" exhaust that had the slip fit at the rear.

[Kitch428m21]

Thanks, this is good information, and I agree 100%. However, somewhere you have to draw the line and set priority's. In my case, I just want the new motor in, and with the best manifolds. This alone has been a big setback financially.
For now, I just want the pipes connected and sealed tight. Further down the road will be 'the best' exhaust system. And of course, it will be 2.5".
Rare did give my down pipes a little squeeze with a inner rounded dimple all the way around about 2" from the end opening.
This will give the transition to the old pipe 'a little' better flow.

My God, you should see what I've been driving with for 10 years! With the motor out, and looking straight down the collector openings, the pipe installer left a huge restriction with his welding of the collector to the curve of the original down pipes. (2 pieces) I don't know what he was thinking.

Thanks, again.