Performance with Secondary down pipes???

[Stiletto]

Any time you alter the exhaust, you need a new tune! The exhaust is factory tuned to scavenge the cylinders optimally.... You'll be reducing back pressure thus altering the exhaust velocity for the factory setup. This is the main reason most people actually have no performance gain, or make it worse because the exhaust isn't being scavenged properly... If you open it up too much, the velocity of the gases will slow down unless you increase the density which means more air & fuel . RETUNE! Anyone who's an expert with cars will tell you this. I know from doing it all myself and learning over the years.... You might see a gain on some cars ... but sometimes you'll lose bottom end torque because the back pressure has been altered in some manner. Again... mileage varies

Most folks aren't pro-tuned or running custom maps. Thus, a "new" tune isn't a commonly viable option. The OEM ECM will learn the new parameters, and the piggy backs available will adjust accordingly.

You can't really open a turbo exhaust too much. This has been known for years. The snails themselves are the focal point of the exhaust. Therefore, everything after is simply done for emissions and noise reduction...and odor relocation. You don't need back pressure in an forced induction set up.

 

[Pearl]

There are minimal gains if anything with installing aftermarket secondary downpipes. However, they do change the sound and tone of the exhaust and for that alone, they could be the right mod for the right person. For example a lot of people run the Ark Performance Downipipe and the Borla Turbocharged cars do gain significant performance from changing or eliminating the cats. For the Stinger GT you would want to swap the primary and secondary cats in order to get maximum horsepower ability pre-catback. We sell the Ultimate Performance HFC Combo Kit here at the K8 Stinger Store. This combo kit is the only option to my knowledge that offers both primary and secondary HFC that throws no CEL and does not require a tune.

Running into the over boost/ turbo cut out when JB4 is not connected. Are you saying I can run these ultimate performance downpipes and not get this issue without a tune ?

 

[Dillon]

The primary cat is the restriction when it comes to generating boost, which is why there's all the discussions about overboost codes and limp mode when deleting the primary cat. The secondary cat has little impact because you're waaaaay down the pipe at that point.

2 years and and almost 4 months later. I have the 22' GT2 Scorpion Edition AWD. Amazing car. Ark Grip Cat Back and Secondary Downpipes, HKS Sparkplugs, JB4 Tuning, Injen CAI, WMI Kit, Mishimoto Intercooler, Velossa Tech Air Ducts with the "Lit Kit". This car is insane!

 

[Striker's Stinger]

2 years and and almost 4 months later. I have the 22' GT2 Scorpion Edition AWD. Amazing car. Ark Grip Cat Back and Secondary Downpipes, HKS Sparkplugs, JB4 Tuning, Injen CAI, WMI Kit, Mishimoto Intercooler, Velossa Tech Air Ducts with the "Lit Kit". This car is insane!

Now you gotta get the EK-1 Lite BEF to pair with your JB4 to run pure E85!