I have been trying to tune my exhaust a little bit to squeze some torque out of it. After I went to Hot Rod Scotts and got my exhaust built I lost a lot of torque. There is a couple issues .. that I know I need to change. But Cory at scotts just told me that a guy recently had the same issue with Highflow cats on an SRT8 Charger .. claiming that eventually the guy with the charger put the stock mids with cats back in and put an X pipe after the cats and gained 30+rwhp after the fact.
Anyway ... if you are this person can you send me a pm or chime in .. I would really like to hear about this. I was about to go with high flow cats .. but looking at my stock ones they are already 2.1/2 " and I dont see other then the actually cats how they would be very restrictive. Seeing that you went stock changed a couple things and saw large gains id like to verify it if possible.
Charger R/T R&T: Halffast Performance built/Overkill Motorsports tuned
Inertia Spartan Cam 214/218 114LSA/Predator/Edge 3200/3.91 Getrag upgraded clutch pack/RDP True CAI/170*/MTCMJBA Headers/JBA mids/SOLO Exhaust/BC Coilovers/Hotchkis Sways/SPC camber arms/Mopar Strut brace
ET: 13.44 @ 108 with a 2.191 60 ft. Nov 15/2012
(full street trim/20" rims tires/Half tank of gas/stock tcm/2.82 gears)
Ive been looking into this as well, i believe the cats and down pipes are 2.5 inches but the rest of the stock RT exhaust and the R&T exhaust is 2.25 inches.. Correct me if im wrong... you might be too big with no cam or heads to help fill the 2.5 inch diameter..
Brilliant Black 08 Charger RT /w Road And Track
Burnt Orange 09 Ram Sport
Mods: I'm not telling
Well interesting enough .. all of the pipes on my R&T were 2.25 .. however the stock R&T mid pipes are 2.50 ..with a 3.50 collector .. so though I upgrade to 2.50 exhaust the issue wouldnt be the actual exhaust ...it would be the lack of the X pipe and lack of cats. So thinking of puting my stock mids back in I think will still be better then puting in a set of 2.50 JBA's with high flow cats..on a fairly stock engine. Im sure if I was runing heads and cam and other things that the 2.50 JBA's with HFC's would work great .. but for the small amount that I plan on doing to my car .. small cam .. stock heads .. should work better with my stock mids. Im wondering though if the stock mids on a regular R/T is 2.25 ... and that the R&T has the 2.50 .. SRT with 2.75.
1 odd thing I noticed is that I have a marker on my stock mids .. that say 6.1 from the factory !!
Last edited by leeban; 06-02-2010 at 02:38 PM.
its not a 6.1 mid pipe....
they're 2.75" pipe, and have both the upstream and downstream o2 sensor in them
every 5.7 RWD cat that ive ever replaced has been exactly the same. every manifold has been exactly the same. cat backs differ between R/T, R&T, and daytona. all have the same pipes. the suitcase differs.
Really .. so they all have 2.50 mids. Except for the SRT 2.75 ..
Looks like ill be getting a hold of you at some point for a cam install !!
Eventually a TC .. maybe before next year I hope.
Ill let you know .. once I have everything !!
Im 99% sure on putting the stock mids back in and putting in a 2.50 X pipe.
Also .. possibly banging in the fire wall a bit for the clearance on the JBA headers as thats what looks to be rubbing.