Does a cat back exhaust actually add power?

[FSUZ33]

Outlet on the LDPs is ony 1.68 inches, it's a major chokepoint.

Pipe is a garden hose, but fortunately they made the flanges adult sized so you can replace individual exhaust pieces rather than having to to replace everything together due to undersized connections.

Upper with a 600 cell core and slightly over 2” exit is nothing to brag about either.

 

[sarge]

When I don't see the dyno report in SAE Or the smoothing I suspect they r showing the results in standard. IMHO not a fair representation.


My wife and I installed the Nismo Street exhaust in about 3 hours in our garage with the car on jackstands. It sounds MUCH better than the videos. 3 weeks and an 800 mi trip it seems to have gotten louder. Killer exhaust, the cops won’t run me down but everyone around me (and the ones that end up behind me definitely know I’m there.

[/QUOTE]
We have a Stillen Trucontrol that add a noticeable, push you back in the seat, performance improvement using the #7 setting. The main thing the exhaust has done is make it loud enough to give shifting feedback, I cant say there's a performance boost.

 

[robin]

I have always used a dyno sheet to c when to shift into TQ.

 

[Hernandooo]

Pipe is a garden hose, but fortunately they made the flanges adult sized so you can replace individual exhaust pieces rather than having to to replace everything together due to undersized connections.

Upper with a 600 cell core and slightly over 2” exit is nothing to brag about either.

This is why I recommend full downpipes (Catted, Resonated or straight) for the bang for your buck. Paired with 3" exhaust all the way to the rear. End it off with a proper tune. Your looking at conservative 30-50hp gain (depending on how spicy you want to push the psi) with a drastic jump to torque

 

[Lvckv99]

This is why I recommend full downpipes (Catted, Resonated or straight) for the bang for your buck. Paired with 3" exhaust all the way to the rear. End it off with a proper tune. Your looking at conservative 30-50hp gain (depending on how spicy you want to push the psi) with a drastic jump to torque

I wouldn't do full dp's unless you are upgrading your stock turbos. With full downpipes, it is hard to control the wastegate especially with how quick and fast the turbo spins. Running a turbo passed it operating limits will cause wear further down. And it can happen at any time. First symptoms will be a white smoke, and lack of acceleration.

 

[Hernandooo]

I wouldn't do full dp's unless you are upgrading your stock turbos. With full downpipes, it is hard to control the wastegate especially with how quick and fast the turbo spins. Running a turbo passed it operating limits will cause wear further down. And it can happen at any time. First symptoms will be a white smoke, and lack of acceleration.

I'm running fdp's (catted) at over 30000km and haven't run into that issue. A proper tune will prevent that

Edit

There are 4 Zs here in Melbourne (as far as I'm tracking) also running fdps, 3 of them are catless. All of which haven't had that issue as mentioned

 

[Lvckv99]

I'm running fdp's (catted) at over 30000km and haven't run into that issue. A proper tune will prevent that

Edit

There are 4 Zs here in Melbourne (as far as I'm tracking) also running fdps, 3 of them are catless. All of which haven't had that issue as mentioned

I know know someone from FL with a Red Sport who had his turbos replaced at 73k. Full dp's and tuned. A tune could prevent that but it is not guaranteed.

 

[Tranzor Z]

We have a Stillen Trucontrol that add a noticeable, push you back in the seat, performance improvement using the #7 setting. The main thing the exhaust has done is make it loud enough to give shifting feedback, I cant say there's a performance boost.
[/QUOTE]
I have the stillen harness as well. Honestly I just wanted some sound so it's easier to drive the 6mt. And not worry about clutch grab. The car is plenty fast and as advertised the stillen harness should make the car 470 bhp and 440 brake torque. Has anyone dynoed these cars with the trucontrol harness?

 

[Hernandooo]

I know know someone from FL with a Red Sport who had his turbos replaced at 73k. Full dp's and tuned. A tune could prevent that but it is not guaranteed.

Experiences may vary, but I wouldn't necessarily blame it on the downpipes.

Other factors may include. Was he doing pulls all day everyday, how was is oil change and maintenance intervals, was the engine warm enough, did his tuner not set safe parameters and set him up to +24psi boost.

Again, there are plenty of Zs running fdps, maybe your friends redsport was just unlucky, our being beat on constantly

 

[VR30Infection]

Someone else said it earlier in the thread but, lower down pipes are the biggest issue. The biggest gain on the VR30 is lower down pipes and a tune. This is according to more than one tuner. Weather or not the upper down pipes or the cat back are the next in line I’m not sure of. I do know that the difference between lower DP’s vs Full DP’s catless or high flow cats is 15-20 more HP. This is according to a tuner as well. I would be willing to bet that uppers are more important than the cat back because as the gasses cool down the volume decreases so the diameter of the piping is less important the further back you go. As far as cat back exhaust size is concerned, any high quality mandrel bent exhaust is going to be a win just to get rid of the pea shooters. As far as sizing is concerned, Z1 makes over 600 wheel with large turbos through a duel 2.5” to a single 3” section and then back to duel 2.5”. With the stock turbos there is no power to be found going to full true duel 3”. Full duel 2.5” or single 3” is fine. Is there anything wrong with full duel 3”? No. It’s personal preference based on design, looks, sound volume and quality.

 

[Xylander]

Not, in any way, saying you're wrong; but it's not uncommon for Ass Dyno's to report higher than actual power gains that trace directly with increased noise/volume.

"...higher than actual power gains that trace directly with increased noise volume and COST."