Jump to content
SAU Community

What Size Dumppipe For 500Hp

nick81xd

By nick81xd,
in Engines & Forced Induction

 Share

Recommended Posts

nick81xd Community Regular

nick81xd

Posted
Posted

Tried searching but must be hopeless at using it. Also the 25 thread is full of small turbo results.

Have a 25 with a 3582r plain wheel turbo.

I have a full 3 inch turbo back exhaust with a resonator and rear cannon on it but I'm struggling with small amount of exhaust backpressure pushing open gate under full noise.

I am thinking the dump pipe might be a tad small With the wastegate plumbed back in. I'm aiming for 500+ (currently at 471hp).

looking at what people's opinions/experirence are on What size exhaust they have.

I have enough room for 4 inch but don't want to go oversized if not necessary.

Go with posts.

Link to comment
https://www.sau.com.au/forums/topic/425650-what-size-dumppipe-for-500hp/
Share on other sites
scotty nm35 Grand Master

scotty nm35

Posted
Posted

A free flowing exhaust would just make it worse I think. You need to increase the wastegate actuator spring tension to help hold the manifold pressure in.

What is your base (minimum) actuator pressure?

XRATED Veteran

XRATED

Posted
Posted

4" = no restriction.

Saying that, plenty of people have made 500bhp on a proper 3" exhaust with open screamers.

Personally I'd go with a 3.5" dump to tip, magnafolw muffler and a free flowing rear can of choice... Here's the thing though, make the waste-gate dump pipe larger and longer than you might think. Run it right down and merge it just before the cat in a nice long, shallow angle transition.

nick81xd Community Regular

nick81xd

Posted
  • Author
Posted

i have 14psi actuator springs in. its a turbosmart 50mm gate.

I cant stand the sound of a screamer pipe so plumbback is a MUST..
the gate pipe is about 60cm long joining in just before the cat area so i think having a bigger diameter exhaust in a copy of current setup will do the trick.

I just dont want to go to hassle of doing 3.5inch only to need a 4 inch down the track

GTScotT Grand Master

GTScotT

Posted
Posted

There is no oversize with a dump pipe imho. 4" will work fine.

However I don't think that's your issue, you should be able to get away with a 3". Have you tried a heavier WG spring as mentioned above?

nick81xd Community Regular

nick81xd

Posted
  • Author
Posted

There is no oversize with a dump pipe imho. 4" will work fine.

However I don't think that's your issue, you should be able to get away with a 3". Have you tried a heavier WG spring as mentioned above?

i have changed the way the gate signal is being sent and it helped sort of. its either 16psi base and wont bleed past 21psi as a single connection onto wastegate or as a 2 port connection its 23psi minimum bleeding up to the 26psi wanted.

I would like to run 18psi low and 26psi high settings so changing the spring pressure up closer to higher settings is something im trying to avoid

scotty nm35 Grand Master

scotty nm35

Posted
Posted

At what boost? 7psi is fark all spring...

I am running 26psi of spring, and after a few track days the tension has dropped back, now it only runs 19 psi off the spring. If you plumb pressure onto the top of the gate also you should be ok either way, mine easily runs a flat 32psi now with the 5 port Mac.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

I have a 3 inch dump, and 2 inch off the 45mm gate. As long as they flow well and merge gradually into a 3.5 inch free flowing system you should crack 400kw with it fairly easily. Mine would be making that if I had a manual box...

abr33 Proficient

abr33

Posted
Posted (edited)

At what boost? 7psi is fark all spring...

I am running 26psi of spring, and after a few track days the tension has dropped back, now it only runs 19 psi off the spring. If you plumb pressure onto the top of the gate also you should be ok either way, mine easily runs a flat 32psi now with the 5 port Mac.

22 psi, barely falls over any more than half a pound at 7700. Im running e-boost and pressure to both sides of gate respectively

Edited by abr33
nick81xd Community Regular

nick81xd

Posted
  • Author
Posted (edited)

Is that no fit in a r32 with a 25 in it stao? What fouled?.

I want to run plumbed in no matter what so can't include screamer. I prefer to hear the engine while its making noises not finding out after when its brokent

Edited by nick81xd
34GeeTeeTee Grand Master

34GeeTeeTee

Posted
Posted

Is that no fit in a r32 with a 25 in it stao? What fouled?.

I want to run plumbed in no matter what so can't include screamer. I prefer to hear the engine while its making noises not finding out after when its brokent

It shouldn't make noises :/

Kurtis ran 500hp with the gate plumbed back and 3inch system....

Mine is a screamer so results are irrelevant I guess.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      Jacks that fit under GTR lips that can reach the subframe?

      By MBS206 · Posted

      You know how your car rolled through a fence in your last jacking escapade? Scissor jacks increase the likely hood of that sort of thing happening immensely!
    • Piggaz
      Jacks that fit under GTR lips that can reach the subframe?

      By Piggaz · Posted

      http://calfinn.com.au/product/1500kg-standard-trolley-jack-cj-2t-c/1500kg-standard-trolley-jack-cj-2t-c   I have this and fits under a S3 33 GTR with no issues. Purchased in 2009 and not one issue. It was $950 back then. Not cheap but something so important isn’t worth cheaping out on.
    • MBS206
      R32 GTST - 600KW+ RB28/CD009 Build

      By MBS206 · Posted

      Just trying to get my head around this. At 5psi of boost, you turn on your wmi pump, and then you're using a 3000cc injector, to allow flow upto the actual engine, where you have your 6x200cc injectors and a 500cc injector. If the above is correct, what advantage are you obtaining by having the 3000cc injector blocking flow, is this just incase a line breaks between that injector and the motor you can stop flow immediately? Or are the 6x200cc and 500cc less injectors and just spray nozzle?
    • f00stx
      Intro/R33 owner

      By f00stx · Posted

      Welcome! New member myself, but I had an R33 back in 2002. Best advice I could give, based on my experience: if you're running the factory turbo, be very conservative with boost. I made the mistake of just fiddling around with the boost controller and cranking the boost for fun, and the end result was my intake pipes popping off frequently from the constant deluge of oil that was being blown into the recirc by the stressed-out turbo, which itself was siphoning oil from the engine and farting it out both sides of its centre bearing (or something to that effect). If I could do it all again, I would have gotten a new turbo and had a tune dialled in professionally and then just left it alone! Funny you mention the metal shavings in the gearbox, as I had the same thing - the probe plug (magnetic drain plug, essentially) would come out caked with shavings. At least it was doing its job. Not sure if that's just sacrificial wear and part of the deal, or if my gearbox was shagged, but I wasn't abusing it. Enjoy the R33 - they're a dying breed, and if they weren't $35k+ on CarSales in Queensland, I might have picked up one of those again, instead of the 370GT I own now (though I'm loving the 370GT, that big 3.7L V6 just hits different).
    • f00stx
      Second time Skyline owner (R33 GTS-T and now a V36 370GT)

      By f00stx · Posted

      Howdy folks. I owned an R33 back in 2002, which was thoroughly beyond my capacity (financially speaking) to maintain/insure, so we parted ways in 2004. Fast forward 21 years (to literally yesterday, in fact) and I'm now the proud owner of a 2007 V36 370GT. I'm happily surprised by how much power the VQ37VHR makes, compared to the RB25DET, considering the latter is turbocharged. I had planned to add a turbo at some point but I'm on the fence about whether I'll even need it (though I do love the sudden onset of extra torque). Any other 370GT owners around the traps, I'd love to hear about your experiences with this car (good and bad).
×
×
  • Create New...