Where should wastegate dump enter downpipe/dump?
Thread Starter
Joined: Apr 2006
Posts: 3,889
Likes: 1,137
From: Grand Rapids, Michigan
Where should wastegate dump enter downpipe/dump? I'm having a custom exhaust built, and I'm wondering if there's any design specifications to follow when routing a pipe for the wastegate dump. I have a Huronspeed V1 truck manifold kit, and my dump pipe goes right above the wastegate. It would be super easy to have a V-band welded to the dump so the wastegate could feed into it, but I'm concerned that dumping it into the pipe right next to the turbine outlet ( within 6" ) might disrupt turbo operation. I'm not venting it to atmosphere, as this car is supposed to be sleeper-ish, so can I route it there? Or should I have a length of pipe added and route it into the exhaust system?
I don't think even at full tilt, there would be any problems caused from putting it there, unless the downpipe was dramatically undersized. I have a twin turbo setup, and mine are also dumped in that same kind of position. I would recommend using a bellows on it so it has some room to move around with the heat difference.
I'm having a custom exhaust built, and I'm wondering if there's any design specifications to follow when routing a pipe for the wastegate dump. I have a Huronspeed V1 truck manifold kit, and my dump pipe goes right above the wastegate. It would be super easy to have a V-band welded to the dump so the wastegate could feed into it, but I'm concerned that dumping it into the pipe right next to the turbine outlet ( within 6" ) might disrupt turbo operation. I'm not venting it to atmosphere, as this car is supposed to be sleeper-ish, so can I route it there? Or should I have a length of pipe added and route it into the exhaust system?
Thread Starter
Joined: Apr 2006
Posts: 3,889
Likes: 1,137
From: Grand Rapids, Michigan
That makes sense. However, my exhaust set-up is going to be pretty odd, so I may have to figure something else out. Basically, I want this car to be stealthy at idle and cruising around. My fab guy is building me a 4" dump that is going to exit adjacent to my passenger front tire, as stuffing it out the fender/bumper will ruin the sleeper effect. The dump will have a boost activated flapper valve that will open at 5-7 lbs. of boost. Fishmouthed into the dump is going to be a 2.25" pipe that will turn and travel back on the same path as the Huronspeed downpipe did. It will then attach to a stock style exhaust. So at low speeds and cruising, the flapper stays shut and all the exhaust is routed into the stock size tubing. This should make it as quiet as it was factory. Then when I get on it, the valve opens up and I get all the benefits of a 4" pipe with none of the annoyances. It almost seems like the best routing path for the wastegate would be into the stock size exhaust tubing running out the back of the car, but I'm not sure if it would cause any flow problems. RPTurbo, your point on the bellows is well taken, and I'm realizing that routing it directly into the pipe would be a no-go, as the distance between the wastegate exit and the dump is around an inch. Setting it up that way is bound to crack something. And if I did route it into the dump further down, it's going to have to backflow when the flapper is shut - not an ideal situation.
As i get older the boost activated cutout with quiet exhaust is way more appealing to me than something that is constantly loud. The only downside is weight, unless you make it out of titanium then you can have your cake and eat it too!
yes but having the wg routed through the cat back really cleans up the sound compared to it just blasting into the ground or wherever its vented to. I hate that wg sound, some people like it but to each his own.
As i get older the boost activated cutout with quiet exhaust is way more appealing to me than something that is constantly loud. The only downside is weight, unless you make it out of titanium then you can have your cake and eat it too!
As i get older the boost activated cutout with quiet exhaust is way more appealing to me than something that is constantly loud. The only downside is weight, unless you make it out of titanium then you can have your cake and eat it too!
I also didn't care for it but everyone I talked to said you get better/more accurate boost control when venting to atmosphere so that's what I did.
My fascia exit isn't that loud really imo so I guess it just depends on what you want to live with.
Trending Topics
Thread Starter
Joined: Apr 2006
Posts: 3,889
Likes: 1,137
From: Grand Rapids, Michigan
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote Every time I drove the car the cutout was open because the turbo spooled way faster, made noticeably more power and well, turbo noises.
You could sometimes hear the waste gate venting when the cutout was open if there were walls or a car next to me and it did sound funny, like a straight pipe lawnmower at high rpm, you could definitely hear it when the cutout was closed.
The only time it was closed was on fire up or after I did a burnout to hide from the fuzz, but they've been defunded so the cops are a rarity.
For me, I want all the power, all the time, so my current car has a passenger side 4'' fascia exit and its marvelous.
It's kinda loud but totally enjoyable at cruise and best of all I get all benefits of a large, free flowing exhaust plus all the turbo noises, now with the passenger window down its pretty loud but not obnoxiously so.
When I drop the hammer its very, very loud, like my wife could hear me from blocks away goofing off so no hiding from the fuzz.
Just lending my experience and opinion from both sides.
On The Tree
Joined: Feb 2022
Posts: 196
Likes: 72
From: Grand Rapids, MI
With a 4" fender dump DP, routing wastegate discharge into the DP it will not restrict wastegate/turbine activity at all.
As far as stealth goes, I don't think you will blow your sleeper status regardless of where wastegate is plumbed because wastegate will only open once you reach your desired boost. For sound quality once in boost you may want it routed into the DP.
My wastegate is dumped to atmosphere under the car and you can sort of hear it, but only when I'm up higher into boost and it is bypassing and im going over a bridge or by a wall,
The 3.5" open fender dump basically drowns out everything. It is wayyyyy loud. My Dad has said he has heard me pull away from the gas station 3 miles from his place.
As far as stealth goes, I don't think you will blow your sleeper status regardless of where wastegate is plumbed because wastegate will only open once you reach your desired boost. For sound quality once in boost you may want it routed into the DP.
My wastegate is dumped to atmosphere under the car and you can sort of hear it, but only when I'm up higher into boost and it is bypassing and im going over a bridge or by a wall,
The 3.5" open fender dump basically drowns out everything. It is wayyyyy loud. My Dad has said he has heard me pull away from the gas station 3 miles from his place.
I know what you mean, my last car vented to atmosphere but had the cutout farther back so you could hear the wastegate when it opened.
I also didn't care for it but everyone I talked to said you get better/more accurate boost control when venting to atmosphere so that's what I did.
My fascia exit isn't that loud really imo so I guess it just depends on what you want to live with.
I also didn't care for it but everyone I talked to said you get better/more accurate boost control when venting to atmosphere so that's what I did.
My fascia exit isn't that loud really imo so I guess it just depends on what you want to live with.
you bring up a great point about boost control, most of the guys that recirculate the wg and run the exhaust all the way out the back (no dump) run 2 wg’s in order to overcome the pressure in the downpipe. When you vta you have zero pressure so you can get away with less wg.
I didn't want a loud wastegate and heard about potential issues routing it back into the down stream exhaust, so I just added a 2" muffler to the wastegate discharge piping. The muffler is open tube with perforations and packing material, similar to the other Magnaflow mufflers I using, so it doesn't create much of a restriction.
