[Chuck29]

I’ve got a 2018 q60 3.0T luxe and I’m running a JB4 on map 6. Is there any benefit to adding full downpipes without tune and just a JB4? What about if the downpipes were catted? Is it worth the cost to upgrade to a FDP and tune for the added HP gains? How much HP is to be gained over just a JB4 and my catback exhaust?
I also have BMS inlets with drop in filters, BMS Heat exchanger in tandem with stock heat exchanger and HKS blow off valves.

 

[Joe_Can]

I read somewhere in this forum from IridiumRS400 saying that if you add LDP you should not expect anything without investing in CBE too.

 

[Chuck29]

I read somewhere in this forum from IridiumRS400 saying that if you add LDP you should not expect anything without investing in CBE too.

Forgot to mention I do already have one

 

[IridiumRS400]

If you already have an aftermarket CBE, going for full downpipes (catted or not) vs just lower downpipes depends are what your ultimate power goals are. I started out with FI LDPs & CBE, then added the JB4, and then a year later got Full Catted DPs installed along with an Ecutek tune. I went that far to realize the most gains, where my Q dyno'd at 437 WHP & 502 WTQ on 93 pump gas w/1.3 bar (~19 psi) map.

To realize those same gains with LDPs, you'll need to turn up the boost levels to 21-22 psi, something I wasn't comfortable doing, as higher boost levels can compromise turbo longevity. Therefore, I went with 3" Full Catted DPs, which also provide more low-end torque than running with the stock primary cats + LDPs.

As mentioned, I wouldn't do Full DPs or LDPs with the stock CBE, because the downstream restriction of the OEM CBE will create more heat/backpressure in the turbos, which is not good operating conditions.

 

[Stunt_101]

I'm currently running FI non-resonated 10" sport CBE setup with stock cats. Would going FULL DP vs LDP cause a lot of drone?

 

[IridiumRS400]

I'm currently running FI non-resonated 10" sport CBE setup with stock cats. Would going FULL DP vs LDP cause a lot of drone?

No, not with a resonated CBE. Since you are non-resonated, you could try installing the resonated LDPs, which will get you a majority of the power gains:

PPE Engineering PPE Stainless Steel Lower Downpipes, 2.5" Resonated - Nissan Z / Infiniti Q50, Q60 3.0t VR30DDTT PPE-VR30-01-R 33006-BN001 400Z CZP-20691-19U0A-VR30 CZP-20813-5CA0A CZP-2BLT-250 ppePPE-VR30-03 EXH-HRDW - Concept Z Performance

 

[Stunt_101]

No, not with a resonated CBE. Since you are non-resonated, you could try installing the resonated LDPs, which will get you a majority of the power gains:

PPE Engineering PPE Stainless Steel Lower Downpipes, 2.5" Resonated - Nissan Z / Infiniti Q50, Q60 3.0t VR30DDTT PPE-VR30-01-R 33006-BN001 400Z CZP-20691-19U0A-VR30 CZP-20813-5CA0A CZP-2BLT-250 ppePPE-VR30-03 EXH-HRDW - Concept Z Performance

Thanks for the link to the PPE. I am thinking of going Full catted DP like the PLM below. Would this cause more drone than the catted LDP?

PLM Infiniti Q50 Q60 2016-2021 Full Downpipes Kit - Catted

PLM Infiniti Q50 Q60 2016-2021 Full Downpipes Kit - Catted Vehicle Application: 2015+ Infiniti Q50 Sedan VR30 2017+ Infiniti Q60 Coupe VR30 Fits both RWD and AWD models Fits all trim models For VR30DDTT engines only Proven to yield 50-60+ HP on the 300hp models, and 25-35+ HP on the 400hp...

privatelabelmfg.com

 

[IridiumRS400]

The Full Catted DPs are fine, but having them (or any other DP for that matter) paired with the non-resonated CBE could be drone-inducing. That's why FI sells the CBE with resonators as an option.

 

[Stunt_101]

The Full Catted DPs are fine, but having them (or any other DP for that matter) paired with the non-resonated CBE could be drone-inducing. That's why FI sells the CBE with resonators as an option.

I thought installing catted DP (full or lower) would mitigate the drone issue caused by not having resonators. I might have to add 2 vibrant resonators on the x-pipe if I decide to go the DP route. Thanks!