Ralliart Cat-back exhaust systems.
Dec 30, 2004, 04:50 PM
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Ralliart Cat-back exhaust systems.
I have yet to see any cat-back exhaust systems made by any company for the ralliart. I know about the axle-back from RRM but was wondering if anyone out there makes cat-backs for these cars. Any input is appreciated.
Dec 30, 2004, 04:55 PM
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Ultimate Racing has a cat-back. DC Sports is rumored to be making one too.
The thing is, the flow is actually pretty optimal through the existing piping from the cat-back (mandrel-bent, 2 1/8" ID, 2.25" OD). So all you'd probably gain from a bigger exhaust is noise. The real source of restriction in the exhaust is at the downpipe.
Really, the only reason you'd replace the cat-back piping is if you went forced induction.
The thing is, the flow is actually pretty optimal through the existing piping from the cat-back (mandrel-bent, 2 1/8" ID, 2.25" OD). So all you'd probably gain from a bigger exhaust is noise. The real source of restriction in the exhaust is at the downpipe.
Really, the only reason you'd replace the cat-back piping is if you went forced induction.
Dec 30, 2004, 05:17 PM
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we can make a catback system, but as stated above thedownpipe is restrictive and the only other part is the cat converter in the midpipe which would be eliminated by a catback system. Might throw a CEL.
Tory
Tory
Jan 9, 2005, 07:53 AM
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I personally think that even if we were to go turbo the stock piping would be sufficient enough. Reason I say that is because on my dad's supercharged tahoe, and VERY highly modified engine, hes still using the stock piping and even the stock muffler and the thing runs great. I would imagine the same concept goes for our cars.
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Jan 9, 2005, 09:30 AM
#8
Originally Posted by BLKRalliArt04
I personally think that even if we were to go turbo the stock piping would be sufficient enough. Reason I say that is because on my dad's supercharged tahoe, and VERY highly modified engine, hes still using the stock piping and even the stock muffler and the thing runs great. I would imagine the same concept goes for our cars.
Jan 9, 2005, 01:08 PM
#9
i think the evo is 2.5" stock, but lots of ppl up it to 3" after light modification. i could be wrong, but still....a turbo RA should shoot for similar pipeing that the evo or srt-4 or other comparable size engines use in the 250-300HP range.
but back to the topic at hand: a catback system.
THis wont be very useful until someone makes a header->cat downpipe and high-flow cat for the RA. Either in 2.25" or 2.5", it wont matter (one for NA, one for turbo). The downpipe is restrictive because of the flow angle. if u look under the car, its almost a kink! a new one using this design would be desirable as an emmisions legal alternative for many people. i am trying to persue a local vendor that does lots of evo and porsche work to get this done, but they are soooo busy, we havnt made much progress. also seeing if a better header design would be worth it, but the stock looks good as is. anyone else who would wana offer this could prob grab a decent market pretty fast.
but back to the topic at hand: a catback system.
THis wont be very useful until someone makes a header->cat downpipe and high-flow cat for the RA. Either in 2.25" or 2.5", it wont matter (one for NA, one for turbo). The downpipe is restrictive because of the flow angle. if u look under the car, its almost a kink! a new one using this design would be desirable as an emmisions legal alternative for many people. i am trying to persue a local vendor that does lots of evo and porsche work to get this done, but they are soooo busy, we havnt made much progress. also seeing if a better header design would be worth it, but the stock looks good as is. anyone else who would wana offer this could prob grab a decent market pretty fast.
Jan 9, 2005, 02:02 PM
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Alittle off topic, but has any one taken a look at the mating of the stock exhaust manifold to the header? How do the ports line up real nice? Is their a need for it to be re-ported? I have seen some horrid stock porting in the past. Just a little curious if this would free up some desired HP.
Jan 9, 2005, 04:49 PM
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Originally Posted by otter
However, I believe that Tahoes have stock 3" piping. We have 2.25". Doesn't the Evo run 3" stock? I would thing as you approach the same power level as an Evo, it'd be time to widen the pipe.
Correct, however this tahoe has a the engine blueprinted, puts out over 500 hp on the dyno. I am not saying you are wrong, simply that hes only using stock exhaust on that beast.
Jan 12, 2005, 08:15 AM
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Originally Posted by Rallilanc
rrm said they are going to use the stock piping on the ralliart with the turbo. i'm pretty sure they know what they are talking about.
RRM doesn't seem the type to take shortcuts, so if they were going to need it they'd make a cat-back I'd believe...
Jan 12, 2005, 09:51 AM
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they wanted there kit to be bolt on it starts taking awaay from the bolt on aspect when they haev to give u an exhaust, with turbo basically the smoohter bends and less restriction the better, the turbo itsself creates all your backpressure needed. thats why evo's gain lots of power when u just switch to a nice flowing 3" exhaust.
In about 3 weeks ill be starting construction on a downpipe that includes a high flow cat, it will be 2.5" and mate to the stock exhaust system. It will bolt up to your factory header, i just moved shops and thigns are a little bit hecktic right now.
Thanks
Tory
In about 3 weeks ill be starting construction on a downpipe that includes a high flow cat, it will be 2.5" and mate to the stock exhaust system. It will bolt up to your factory header, i just moved shops and thigns are a little bit hecktic right now.
Thanks
Tory
