In a few days I am going to drop by my friend who runs an exhaust shop.
We are going to chop the exhaust from the cats on back. Yes, there is no flange so we don't have a choice. I could change it out with high flow cats but I don't want problems with emissions on this car, especially when concerned that it might set off some error code.
We are probably going to go true duals all the way back to a set of Borla Mufflers with 2 1/2 " pipeing connected with an H- Pipe.
My question is how much horsepower can I expect from this modification? Any dyno graphs?
In a few days I am going to drop by my friend who runs an exhaust shop.
We are going to chop the exhaust from the cats on back. Yes, there is no flange so we don't have a choice. I could change it out with high flow cats but I don't want problems with emissions on this car, especially when concerned that it might set off some error code.
We are probably going to go true duals all the way back to a set of Borla Mufflers with 2 1/2 " pipeing connected with an H- Pipe.
My question is how much horsepower can I expect from this modification? Any dyno graphs?
If you are not going the FI route (which is doubtful since the IS is still so new), 2 1/2 " pipes might be a tad too big and you may end up losing power due to lack of sufficient backpressure.
In a few days I am going to drop by my friend who runs an exhaust shop.
We are going to chop the exhaust from the cats on back. Yes, there is no flange so we don't have a choice. I could change it out with high flow cats but I don't want problems with emissions on this car, especially when concerned that it might set off some error code.
We are probably going to go true duals all the way back to a set of Borla Mufflers with 2 1/2 " pipeing connected with an H- Pipe.
My question is how much horsepower can I expect from this modification? Any dyno graphs?
Unless you're running two cats, the exhaust won't be true dual. Along with this, you won't see much more of a performance gain. Keep in mind though, you'll need some back pressure so you don't want to open things up too much. The weight added by running a true dual and the cost, would negate most benefits, unless you have supporting mods. Depending on what you finally go with, I'd say you'd gain about 15hp +/-. Good luck though.
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93' Black on tan RX-7 ~353rwhp, 2,647lbs.
06' GFM on black IS 350, Park Assist, Pre-collision/Active cruise, Luxury pkg, Nav/ML, 18s. 30% tint, stock lip spoiler, LED city lights, and a JoeZ tube.
When I went to larger pipe and free flowing mufflers on my car(not and IS yet) I lost some low end torque. But with a supercharger I could get it back with a smaller pulley. Also, V6's don't sound that great when they are loud IMO.
Unless you're going to remove the cats, I don't see you losing enough back pressure to rob you of any power. While you do need some back pressure to maintain torque, the cats, especially if there are 4 of them should provide enough back pressure to keep your torque from dropping, even if you did go with 2.5" pipes. Other than changing the exhaust note a bit, the performance difference between 2.25 and 2.5" will be small. By the time the exhasut reaches the back of the car, it has cooled down enough not to need larger diamater pipes. There are of course exceptions, like if you've got significant mods and moving large amounts of air, then of course you'd wan't the larger diamater.
Exhaust Idea, what do you guys think?
Linear Mode
