should i get an external wastegate?

[NJgsx]

i have a 97 gsx with a jdm 6 bolt, slow boy 20g turbo,660 injectors,afc,intake and other mods , im deciding if i should do an external, like a 38mm, do u think i should do it ?

 

[GVR4592]

Are you having problems with your internal wastegate?

 

[rjennings]

If you have already ported out the internal flapper and are still experiencing boost creep, go with an external waste gate. TiAL WG (and BOV) are the best you can get and a 38mm can control the boost on a GT35R, so that would work great for your application.

You have two options on where to mount the WG:

(A) Weld the internal flapper shut and mount the 38mm WG on the manifold (stock 2G) or if you have or get a manifold with a location already fabricated on it for a 38mm WG.

(B) Port-out the internal wastegate and mount the 38mm WG off the O2 (aftermarket of course, not the stock O2).

Mounting the wastegate on the manifold would probably do a better job of controlling the boost, depending on how it is mounted (how well it vents all four cylinders).

Either way will work, just make sure there are no restrictions to the flow of exhaust to the wastegate.

Randy

 

[shleppy]

Have you read the slowboy turbo test thread yet? They posted some very interesting dyno results on internally gated turbos including the 20g that you have. Once you read it I'm sure you'll want to go external.

 

[gr8popp]

Have you read the slowboy turbo test thread yet? They posted some very interesting dyno results on internally gated turbos including the 20g that you have. Once you read it I'm sure you'll want to go external.

i have not seen the test, where can it be found??
Thanks

 

[shleppy]

right here in tuners in the tech section under turbocharger tech. Basically it showed how all internally gated turbos boost spiked, then the boost came down alot for around 1000 rpms, which killed up to 60 hp for that range. Then the boost came right back up almost to where it should be, and then steadily came down 5-10psi since the internal gate couldn't hold the pressure. It looked to me like the internal gates lost alot of potential power, and that was the conclusion that the guys at slowboy came to.

 

[GVR4592]

My internaly gated turbo has no boost spike, not even 1 psi. It climbs to 24 psi and holds rock solid until redline.

 

[shleppy]

Slowboy claimed that you could only really see these results on a dyno. My internally gated turbos seemed to hold boost as well, but after seeing so many dyno's I didn't want to take the chance.

 

[Tom N]

i have a 97 gsx with a jdm 6 bolt, slow boy 20g turbo,660 injectors,afc,intake and other mods , im deciding if i should do an external, like a 38mm, do u think i should do it ?

Clear your PM box so I can replay to your question.
$300 shipped

 

[GVR4592]

Slowboy claimed that you could only really see these results on a dyno. My internally gated turbos seemed to hold boost as well, but after seeing so many dyno's I didn't want to take the chance.

Slowboy is full of shit. I have AEM, with internal logging I can see 250 samples per second, my boost doesn't spike more than .3 psi.