New to turbo upgrades (T28 to HKS GT-RS)

[S14_AP1]

Hello all,

I've had my 95' s14 for a few years now and have been content with the stock T28 in my s14 notchtop SR20. However, I'm going to be giving my T28 to a good friend as an upgrade to his T25 and I have an HKS GT-RS .64 (basically modified GT2871r) sitting around for a while now. I was hoping someone on this board is running the same turbo on the same motor and could provide recommendations when it comes to exhaust manifold, lines/fittings and external waste gate setups.

Focusing on the turbo itself for the upgrade, I don't have an actuator for it and do not fully understand how actuators work. If the turbo has an internal wastegate and I weld it shut to go external, would I still need it? Also, I was planning to just use the stock manifold since it's a direct fit but would anyone recommend against this?

Thanks for any help!

[2_Liter_Turbo]

If the turbo fits, the stock manifold works fine. It's very, very durable. If you want an external WG, there are some people who even offer services to modify the factory manifold by welding on an EWG flange. A good quality manifold will give you a performance gain, but they are pretty spendy (expect around $1,000 +/- $200 or so). There are cheap manifolds out there, but they won't be very reliable and they were just made to fit, not with any engineering or exhaust specialty knowledge/experience applied to the design. If you run EWG, you do need to weld the flapper door shut and you can ditch the actuator. The actuator is just a boost actuated diaphragm that will move the rod (and in tern the flapper arm/door) to control boost levels. If you're planning to run low levels of boost, you should upgrade to the EWG. If you are planning on maxing the turbo out, you can use the internal, but technically speaking, the EWG is still better.

[S14_AP1]

2_Liter_Turbo,

Thank you for taking the time to reply! I did some additional research and asking around after I posted this and learned a lot. I'm definitely going external and will be sticking with the stock manifold, I'll most likely send it to CodyAce or seeing if I can buy one from him. Boost creep is what I wish to avoid and I hear with these turbos it can be very apparent in higher RPMS. I couldn't find any answers concerning if I could ditch the actuator. I thought about ditching it all together and going with an s15 Spec-R T28 but after even more research, it doesn't seem worth it for my goals especially since I have the s14 T28.

Anyway, you helped me make the decision so I really appreciate the response!