Jump to content
View in the app

A better way to browse. Learn more.

300ZX Owners Club

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.
  • Replies 28
  • Views 877
  • Created
  • Last Reply

Top Posters In This Topic

Featured Replies

did they make as big a difference over stock ones as he makes out they do?

 

doubt it.

if the smaller of the 2 wasn't routed back into the exhaust it would make more of a difference, i.e. it was venting right to atmosphere, then i could see the point in this, the wastegate gases would be venting right out, giving less pressure in the exhaust system, turbos would prop spool up quicker as well :)

if the smaller of the 2 wasn't routed back into the exhaust it would make more of a difference, i.e. it was venting right to atmosphere, then i could see the point in this, the wastegate gases would be venting right out, giving less pressure in the exhaust system, turbos would prop spool up quicker as well :)

 

 

having them routed right back into the exhaust system kinda defeats the purpose of divorced downpipes in my opinion :)

Which do you mean Dave - Self-gutting the stock pre-cats , or Aftermarket Divorced wastegate Downpipes,.

 

If its the latter then its an extremely popular mod.

gutting or doing away with the cats would make a huge difference, divorced downpipes even more so, although looking at these ones, i can't see the benefit of them being routed back into the exhaust :(

The reroute is perfectly fine. Its about removing the increase in turbulant flow caused by the wastegate at the exit from the Turbo.

The reroute is perfectly fine. Its about removing the increase in turbulant flow caused by the wastegate at the exit from the Turbo.

 

surely the wastgate gasses being vented out from the system would be better though?? would make a hell of a racket mind you :)

The trouble with anyone giving direct feedback on the difference the downpipes alone make would be difficult as Divorced wastegate downpipes are typically fitted alongside a decat at the same time.

I was going to buy the japspeed downpipes and decats but they were out of stock for so long I ended up settling for the standard decats instead :(

if the smaller of the 2 wasn't routed back into the exhaust it would make more of a difference, i.e. it was venting right to atmosphere, then i could see the point in this, the wastegate gases would be venting right out, giving less pressure in the exhaust system, turbos would prop spool up quicker as well :)

 

Divorced waist gate gets its extra benefit from the air inside the divorced pipe as its still, when the waist gate opens the release gas encounters less resistance.

 

where as the non divorced waist gate, it opens straight into the stream of exhaust gas's coming from the exit turbine of the turbos, thus the gas has to force its way into the exhaust system.

 

There would be no benefit to dumping to atoms, and even if it did, you would never pass emissions and it would sound bloody horrible.

 

the reason the pipes are so long before they join is to allow maximum flow of release pressure from the wastegate before it gets to the exhaust flow.

 

thus increasing the speed at which spool up can occur once the waist gate closes. hope that helps explain it.

 

so in short yes you can get an extra BHP boost, dunno what the correct BHP gain figures are, but they do work.

ah i see, i was under the impression that the 2 pressures would meet in the exhaust regardless?? if the wastegate gasses were vented to atmos, then would this not keep the backpressure down as well??? not arguing here, i'm just curious, as i don't fully know the ins and outs :)

ah i see, i was under the impression that the 2 pressures would meet in the exhaust regardless?? if the wastegate gasses were vented to atmos, then would this not keep the backpressure down as well??? not arguing here, i'm just curious, as i don't fully know the ins and outs :)

 

It's all like black magic to me mate :lol:

yeah it would be fully unrestricted, but as its needed only at high boost when the waist gate opens, it would be pointless and very noisy for a split second lol

yeah it would be fully unrestricted, but as its needed only at high boost when the waist gate opens, it would be pointless and very noisy for a split second lol

 

 

would be the same as a screamer pipe on an external wastegate i would have thought :)

 

 

 

like this :)

would be the same as a screamer pipe on an external wastegate i would have thought :)

 

 

 

like this :)

 

that sound fookin horrible.

oooooh, i do like that, had a HKS on my mr2 for a while, they do sound good, i assume both valves open right at the same time???

oooooh, i do like that, had a HKS on my mr2 for a while, they do sound good, i assume both valves open right at the same time???

 

if they're plumbed in correctly

  • Author

The basics are its flow rate, instead of gases coming out and hitting a 90 degree wall they can escape easier.

If a car can breath easy and also exit easy your halfway there...

 

I think its a great mod as no more stress on engine for good power increase, like weight loss is a good way to increase bhp per ton.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

Recently Browsing 0

  • No registered users viewing this page.

Important Information

Terms of Use

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.