Dodge Challenger Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
82 Posts
Discussion Starter #1 (Edited)
Many thanks Speedlogix for the posts, great supplier, sure wish he was in Canada,,

Corsa XTREME catback exhaust for the 392 (6.4L) Challenger AUTOMATIC

Ordered full kit today from my Local Speed shop in Stratford, his distribitor in Toronto
already had a set coming in for stock so I guess I may be getting the first set
in the Great White North....


Will ket you know how I like em...

Thanks again

Al
 

·
Premium Member
Joined
·
456 Posts
Did you get them installed OK? How is the sound when on the HWY?
 

·
Premium Member
Joined
·
456 Posts
Did you install them yourself? if so is there any cutting on the old exhaust where you mate the new exhaust? Sounds like a no brainer if there is no Fab work to do. I am thinking of going with the sport Corsa? This will be my daily driver for half of year. :pimp:

I did and they sound awesome, really not much change in the level inside the car...

Well worth the wait...

Al
 

·
Registered
Joined
·
1,456 Posts
I think the bolt-ons being proposed are pretty safe/standard.

The Hennessy CAI only added 5 HP (and we don't even know at what RPM band since there is not a separate dyno for that mod alone). I would suspect the gain is primarily at the top-end and probably related to better filter flow rather than any reduction in intake temps - in fact the opposite will probably be true with the hood closed. The CAI would be my least favorite mod of the bunch.

The factory exhaust from the cat-back is probably fine from a flow standpoint and will surely get louder with the additional of LTs and high flow cats anyway.

I think the biggest gains to be had will be with the LTs and high flow cats. These look like American Racing units on the website. Notice how the dyno shows 20-25 HP gain across the entire operating band and not just up-high. This is definitely an attribute/characteristic of LTs.

Expect the system to throw rear O2 sensor cat-efficiency codes after a bit of time, because all high flow cats (any brand) don't scrub the air as well and wear out over time. Once that happens, it will throw a cat-efficiency code. The fix is to install stainless steel rear O2 sensor spacers at the time of install and I recommend the 304 stainless units from Big Daddies Garage. These will space the rear 02 sensors out of the exhaust stream and the sensor will 'think' that the cat is doing a better job than it really is. You don't want to be installing these a year later when the cats start throwing codes - do it at the time of install and be done with it.

The tune has already been mentioned and I think that will be where you will get the most gains if you go for a DS CMR tune on a dyno using a wide-band upstream O2 sensor to get the most accurate information on open loop (part-throttle) and closed loop (full-throttle) operation. The factory adaptives are clearly struggling on the dyno to 'keep up' with the additional air flow and the TQ curve looks a bit ragged. A DS CMR tune will add a bunch more power and driveability, and make sure your spark/fuel trims are as close to optimal as possible at all throttle positions.

I don't think you will hurt the engine by going too lean at WOT, but with that said Hennessey did not include the AFR data with the dyno run and it would be nice if they shared that information on the website or at least to prospective customers concerned about a lean condition with these mods in place without a DS CMR tune.

DS says to expect another 40 HP/TQ on top of the existing Henessey gains after the CMR tune is done. That would be a hella nice gain overall and will really wake-up the 392 without going inside the engine.
 

·
Premium Member
Joined
·
456 Posts
Wow thankyou for all the info
 

·
Registered
Joined
·
1,456 Posts
The short answer is - if it was my money - I would install LTs and high flow cats and a CMR tune first, and then evaluate the performance and sound. I would skip the CAI and you'll probably find the stock exhaust is a bunch louder with LTs and high flow cats anyway.

Not that I don't like the Corsa X-treme - it's bad a$$. But that's with the stock manifolds and cats. It will probably be very loud with LTs and high flow cats - maybe too loud. So do the LTs and cats first and then evaluate the sound level and decide if you want even more.
 
1 - 7 of 7 Posts
Top