external wastegate

[sin-city_turbo]

hey people

im wondering if anyone here has strapped an external wastegate on their citys or civics?

for it to work effectivly would the internal wastegate on the turbo have to be welded closed?

[James]

Colza had one on my car when we had the T04. To make it go on a standard city turbo you would have to weld/wire the wastegate flap shut and get someone to weld a flange onto the factory manifold. Need someone good to do it cause cast iron welding isn't the easiest I dont think.

Why do you want one? You can get very good boost control by porting out the factory wastegate, I can turn my boost down to about 8psi possibly lower.

[sin-city_turbo]

yeh i know it would have no power increase, but i love the sound of an external when full boost.

although come to think of it, my city sounds pretty mean, guess im just wanting to amplify the sound

[turbo11]

Hi Guys, had to jump in here and say that there is always a slight power gain by using a external gate even on a normal turbo with the factory gate closed due to the lack of turbulent exhaust gas flowing into the system. Have seen this on many cars on the dyno mostly mazda's but should be the same on all cars especially ones running high boost. I have a TD04 with HKS external gate with adapter for city turbo manifold that im going to sell soon.

[sin-city_turbo]

that sounds like an awsome upgrade, wish i could afford to buy it off you ( im unemployed until wednesday ) but ive gotta get the t1 running properly again haha.


so did you ever have that setup on your city?

[Hyperblade]

The racing T2's from what i read ran a external wastegate on a the standard turbo, might be worth trying to get some pics of one out of kazzaa

[James]

If you want to avoid the turbulence from the re-entry then you can build a split dump, a lot cheaper than an external. Colza had one on my car at one stage too, just sold it to Mike_NZ hes now got it on his T2. You can also make it a screamer pipe using this method.

Mugen made an aftermarket exhaust for the T2 that piped the wastegate all the way to the back of the car seperately.

I did a lot of research into dump pipe theory and actually a lot of the point in having a dump pipe is to get turbulent flow. Fast turbulent flow creates low back pressure compared to slower laminar cork-screw like flow that comes out of the turbo. Thats why sticking a huge pipe on the turbo works well because it creates a hard step from the outlet of the turbo to the inlet of the dump which creates good turbulence.

[Colza]

Looks like ive tried just about everything at some point doesnt it

If its just the sound you are after you can build a dump pipe that seperates the wastegate flow, and then you can put it whereever you like. Either plumb it back in nicely further down the line or dump it to ground to get that angry wastegste scream going on.

Having a your wastegate dumping to the ground is illegal in NZ at least as it is considered an exhuast leak, however on my car I had a fake plumb back that looked like it rejoined the main exhaust however it wasnt actually plumbed in. It looked legal for warrants and then you can remove a section of the wastegate pipe and it goes straight to the ground.

The car will overboost when you have the fake plumb back connected so youll have to hope the warrant guy doesnt thrash it. VTNZ dont take the car into boost so you would be fine there.

[James]

On road dont even take it for a road test so youd be sweet there too.