hi guys. I recently installed downpipes and I'm getting a new exhaust made. I was wanting to hear some opinions about what I should do. I've heard that a Y-pipe off the DP's that splits out to an x-pipe then ends with tips sounds pretty good. I also wanted to know what setup would be optimal for torque output. thanks in advance. (my current pipe is 2.5" id like to stay that size, 3" tops. I'd probably make the y-pipe 3" and the rest 2.5")

Z1 PG exhaust - if you want all out power.

I'm not in love with the PG. I'm also more interested in my torque output than horsepower. I was talking to a Z owner in Canada who has a 3" DP and test pipe, followed by a 2.5 x pipe, finished with a 2.25" axle-back. he said this greatly improves exhaust scavenging. my only concern is hurting the flow. my car only has about 350whp. is this something I should worry about if I go this route?

1. You do know the PG stands for Power Getter.
2. The guy you talked to has the right idea THEORETICALLY. To put theory into practice you would need to do a bunch of flow modeling and build a full custom exhaust with precision (done with a micrometer) bends, reduction in diameter, and internally polished pipe and welds to combat the turbulence that is created by pretty much anything in a gas flow's path.
3. In practice: If you want more torque get higher gearing, custom intake and exhaust manifolds, and switch to e85.
4. In practice: If you're worried about getting max power out of your current setup get a 3" exhaust.
5. In practice: If you're after scavenging install an x-pipe right before the rear diff (this would be the estimated sweet spot for the Z32).

This is a very oversimplified explanation:
Torque and Horespower are directly related, or rather horsepower is a function of torque.

"Mathematically, horsepower equals torque multiplied by rpm. H = T x rpm/5252, where H is horsepower, T is pound-feet, rpm is how fast the engine is spinning, and 5252 is a constant that makes the units jibe."

So you cant have one without the other. Torque peak is affected mostly by the intake runner length and exhaust runner length. Once the exhaust hits the collector or intake air hits the combustion chamber you are no longer affecting torque directly.

Further, turbos work on the principle of gas expansion. The best environment for a turbocharger is one where the gasses exiting the turbine are allowed to expand and dissipate as quickly as possible thus, technically running with just downpipes would provide the largest potential for power. Because the law frowns upon running such setups and the human brain doesn't function too well when the lungs are full of NOx we must install an exhaust. The theory that your Canadian compadre subscribes to is one where as the exhaust gasses cool down when travelling down the pipe they contract and if provided the same volume as when they were hot they begin to loose velocity thus slowing the gasses behind them and not allowing the turbo to operate as efficiently and decreasing potential for production of power. By reducing the diameter of the exhaust you force the cooler "smaller" gasses to maintain velocity. This theory though based in absolute fact is only applicable if the pipe is gradually reduced like a cone not stepped down at certain locations. The step down creates turbulence which causes the gasses to slow down or worse travel back up the pipe.

If all of this isn't enough and you want even more torque then sell your Z32 and buy something with a big engine and a blower because turbo engines by their nature aren't very good at low end torque.

Thank you very much! that was a great explanation. Does the length of the x-pipe matter?

Not in practical terms, there's a reason the off the shelf exhausts sell so well.

I agree with no limit 100% go with the PG exhaust downpipes testpipes 3inch all the way just know that you will be blowing your eardrums out and the drone on the highway is loud if that doesn't matter to you go with that setup..... I am personally running 2.5 downpipes test pipes and hks hi power back and I absolutely LOVE the setup not loud when cruising but absolutely tips when you get on it I get compliments ALL the time

I do like the sound of the HKS exhaust, I don't love the way it looks. IMO fat quad tips look best on a Z32. My car is currently running 2.5" downpipes and test pipes w/o resonators. It is friggin loud to say the least and I'm kinda sick of the tractor sound which is why I don't really want the PG. I was going to put some cherry bombs in the test pipes, put an X pipe in, then put small mufflers before my tips. How do you guys think that would sound?

You need to look at the units that BBE offers, they have two full 3" cat back systems with X-pipe but they aren't cheap. Its going to be the best mix of performance and sound.

https://www.bbexhaust.com/exhaust/nissa ... turbo-3in/

All that said, what is your setup? Because unless you're really making use of the extra exhaust potential you wont be able to tell a difference. If you're on stock turbos and are trying to squeeze every last HP out of them you'll end up spending more on the ancillaries than you would getting upgraded turbos and less expensive bolt on bits. Also if you're on stock turbos you're limiting spool and efficiency because they are journal bearing and any BB unit will out-spool them.

I'm on stock turbos, single intake, 12psi jets, z1 smic (not BA's), the exhaust bits mentioned previously, upgraded clutch pressure plate, and a lightweight flywheel. I'd guess I'm at ~350whp? I really doubt I need a 3" exhaust for where I'm at currently, I just want it to sound good. My end goal for the car is probably 500whp.

Bfish wrote: ↑

Thu Jun 11, 2020 12:01 pm

I agree with no limit 100% go with the PG exhaust downpipes testpipes 3inch all the way just know that you will be blowing your eardrums out and the drone on the highway is loud if that doesn't matter to you go with that setup..... I am personally running 2.5 downpipes test pipes and hks hi power back and I absolutely LOVE the setup not loud when cruising but absolutely tips when you get on it I get compliments ALL the time

Well, I found a guy selling a Hiper exhaust for $140. problem is its only the axle back portion. $140 is far cheaper than what it would cost me to get a custom set up so I'm going with that option. what type of crossover pipe would you recommend for sound/performance, X or H pipe?

I have 2.5 split dp, 2.5 hpipe, and a custom resonated cat back; a local shop did up, I just brought them the tips and resonators.

I think it sounds good, doesn't drone much on the highway. I highly recommend at least having some part resonated, it'll save your head.

zxFarside wrote: ↑

Thu Jun 18, 2020 2:49 pm

I have 2.5 split dp, 2.5 hpipe, and a custom resonated cat back; a local shop did up, I just brought them the tips and resonators.

I think it sounds good, doesn't drone much on the highway. I highly recommend at least having some part resonated, it'll save your head.

That's what I was originally going to do, but I think I'm going to just buy an HKS catback from a friend. less of a gamble in quality in sound. I still have the exhaust tips that I planned on using, so ill use them for my final exhaust setup after I get new turbos.

I feel ya. My car sounds a little different because my heads are decked and the upped compression makes it sharper sounding. I would like to swap in a xpipe at some point to see what that does.

zxFarside wrote: ↑

Thu Jun 18, 2020 8:20 pm

I feel ya. My car sounds a little different because my heads are decked and the upped compression makes it sharper sounding. I would like to swap in a xpipe at some point to see what that does.

What's your compression ratio?

Not sure the exact numbers, not up by much, I do know if the heads ever have to come off they go in the trash because there is no more material to remove lol. There is a lot of weird custom stuff done to the car, I don't buy pre-made kits; just fab crap myself, and wing it. It makes good power, that's all I care about.

zxFarside wrote: ↑

Fri Jun 19, 2020 1:13 pm

Not sure the exact numbers, not up by much, I do know if the heads ever have to come off they go in the trash because there is no more material to remove lol. There is a lot of weird custom stuff done to the car, I don't buy pre-made kits; just fab crap myself, and wing it. It makes good power, that's all I care about.

Heck yeah! whatever works

unreliableZ32 wrote: ↑

Sat Jun 20, 2020 8:17 am

zxFarside wrote: ↑

Fri Jun 19, 2020 1:13 pm

Not sure the exact numbers, not up by much, I do know if the heads ever have to come off they go in the trash because there is no more material to remove lol. There is a lot of weird custom stuff done to the car, I don't buy pre-made kits; just fab crap myself, and wing it. It makes good power, that's all I care about.

Heck yeah! whatever works

That's my motto.

Here's a clip of the exhaust. The car has its share of issues... I'm convinced that on the day this car was built it was possessed by something that crawled up from the depths of hell.

"I'm convinced that on the day this car was built it was possessed by something that crawled up from the depths of hell."

That line made me laugh for a solid 2 mins, thank you. Your car sounds really good at the higher RPM's.
I think all Z32's have inner demons. Heck, my car doesn't even turn off with the key!