silent1

iTrader: (3)

I've just finished installing my new Darton 427, but due to some unexpected delays, I won't have the new exhaust system installed before the dyno tune. My current exhaust setup is Dynatech LT's, 2 high flow cats on a 2.5" y-pipe, and no mufflers. The new setup will be with the same LT's, 3" mandrel bent pipes all the way back with a 3" x-pipe. Any guesses as to how much I'll be losing with the y-pipe setup?

LS1LT1

iTrader: (16)

No cats on the new dual set up?
If so I'd say less than 15rwhp and maybe even none at all at certain rpms IMO.

silent1

iTrader: (3)

Actually I do plan on running cats, just not sure which ones to go with. 15rwhp huh? Thanks for the input.

LS1LT1

iTrader: (16)

If high flow cats on both set ups then maybe only a 10rwhp (or less) loss.

EviLS1

iTrader: (8)

I don't think the 10 hp is really going to matter anyways 427s are scaaaaaary