Joining wastegate 'screamer' to the rest of the exhaust

[cat007]

Hey all

Previously I had my wastegate venting to atmosphere - because that's what all the cool kids did.

Now I want to plumb it into my exhaust but not sure where to.
The shortest trip would be about 12 inches behind the turbo, but that would be at about a 60-70 degree turn that the gasses would have to make to follow the rest of the flow. I could put it right at the bottom of the down-pipe just before it turns towards the back of the car - which would mean it would have a nicer flow - but I'm wondering, does it really matter?

What has everyone else with an external wastegate done?

This is on my supra with the turbo etc on the drivers side. My wastegate sits pretty much between my turbo's exhaust housing and my strut tower. The exit of the turbo and the wastegate point in the direction of the passenger seat.

[CAMB01]

Not a toyota but this is what i have done with my wastegate on the evo. Dont have any problems with boost spiking or anything like that.

[Mr Ree]

Yes it does matter what angle you merge the dump tube into the DP at.

You ideally want to have it merging with the least angle possible so there is no abrupt collision of exhuast gasses when the gate is open.

Joining it where the DP bends to go under the car is good as you can get a great merging angle there, you will just need to cut a nice oval hole in your DP and sculpt the dumptube to fit perfectly.

Heres a pic of what I did with mine



P.S Good on you for getting rid of the external gate too

[Bazda]

What is done above is not ideal.
Seen ones like that crack too many times.

Make sure you use flexi joints or slip joints before joining it to the exhaust.

[cat007]

What is done above is not ideal.
Seen ones like that crack too many times.

Make sure you use flexi joints or slip joints before joining it to the exhaust.

Suggestions where to buy flexi joints? Are they something the local exhaust shop would stock and sell?

[Bazda]

Need to be quite small like 40-45mm id. Try trademe first.

[cat007]

Need to be quite small like 40-45mm id. Try trademe first.

Do you mean put a flexi on both the main exhaust and the wastegate pipe? Or just the main exhaust?

[Bazda]

Need to be quite small like 40-45mm id. Try trademe first.

Do you mean put a flexi on both the main exhaust and the wastegate pipe? Or just the main exhaust?

Your main exhaust should already have a flexi on it :S

If not then you should def be putting one on!

And also a flexi in between the wastegate pipe to the exhaust (small one) - If its a short section then you prob dont need a flexi.

[Mr Ree]

What is done above is not ideal.
Seen ones like that crack too many times.

Make sure you use flexi joints or slip joints before joining it to the exhaust.

You are right, it isnt ideal without the flexi on the dump pipe. I tried to find a small flexi at the time I was getting it fabricated, but couldnt get the right diameter on the day so decided to have it done anyway.

Luckily, 3 years, 10,000km, and many track days later, its still fine. I think the fact that the metal is the same grade, and the amount of surface area there is welded helps alot as its sculptured in a very large oval, rather than just having a circle the same diameter as the pipe on a 90 deg angle.

Fingers crossed it holds up until I finally pony up and buy a well designed manifold, and new WG. Although truth be told, the only reason I will upgrade is when my current set up needs to be repaired, or I win lotto

[gt4dude]

is it all good to be so far from the o2 sensor aswell??

[Trls250s]

Distance from O2 sensor will not change the AFR, or fuel levels in the exhaust gas.

Dyno tuners often put O2's in the absolute end of the exhaust with a g clamp if there are no o2 bungs free.

[Mr Ree]

As above, unless there is a leak between the turbo and the o2 sensor, then AFRs will be accurate.

For my wideband, I have installed it at the front of the mid pipe, just after the downpipe flange, facing down from the 11 oclock position.

Its not recommended to have it mounted super close to the turbos outlet.

[iOnic]

Yes it does matter what angle you merge the dump tube into the DP at.

You ideally want to have it merging with the least angle possible so there is no abrupt collision of exhuast gasses when the gate is open.

Is there any actual evidence of this? Just curious because my Evo has the EWG dump tube plumbed at a 90deg angle to the downpipe via a removable adaptor to change it from atmo venting to plumb back. It accelerates much quicker with the pipe in place than venting to atmo.

[Grrrrrrr!]

Yes it does matter what angle you merge the dump tube into the DP at.

You ideally want to have it merging with the least angle possible so there is no abrupt collision of exhuast gasses when the gate is open.

Is there any actual evidence of this? Just curious because my Evo has the EWG dump tube plumbed at a 90deg angle to the downpipe via a removable adaptor to change it from atmo venting to plumb back. It accelerates much quicker with the pipe in place than venting to atmo.

Does it also overboost when pipe is in place? Would be consistent with restricted flow due to shit plumbing forcing more flow thru turbo than without pipe in place.

[iOnic]

Nope rock solid boost all day everyday. Has the EWG controlled by a Turbosmart eBoost Street.

[CAMB01]

Same here with my wastegate setup, boost is rock solid and stable as ive had it on STM's dyno. I run a Turbosmart 2 stage boost controller.

[QikStarlie]

probably doesn't make any difference if the pipe is big enough. maybe if you were restricted for room and were using smaller diameter pipes, you'd wanna get the merge nice. as for gaining power plumb back vs atmo, cant see how, other than if it was having some kind of scavenging effect. probably just sounds faster.


small flexi can be found on standard cars. i use one of a gt starlet, is correct diameter and short.

[iOnic]

Pretty sure it's actually quicker based on accelerometer and GPS timer measuring speed vs distance vs time. Doesn't make sense to me either as my thoughts were always the same as what's been said here but what I'm seeing first hand is the complete opposite. Car runs the same 13psi boost in both situations.

It sounds much faster venting to atmosphere than plumbed back. Just sounds like stock with it plumbed back. Going to STM for a retune on 23psi in a week or two so if I get the chance I'll see where the difference is.

[KwS]

My old turbo integra lost about 20-30WHP when the wastegate was plumbed in at 90 degrees to downpipe. That was the only thing changed, both runs were on the same dyno (about 6 months or so apart).

I was also getting boost spiking issues afterwards. Needed it plumbed for a WOF (and it sounded retarded vented to atmo) so quickly got pitstop to do it.

[Bazda]

There are many stories where people lost power or cant control boost well after plumbing it in.

I guess it all depends on where you plumbed it in and what size pipe your running. Also depends on what boost and power levels your engine is gona run as that will determine how much pressure is in the exhaust.