Jump to content
The mkiv Supra Owners Club

GT28R turbos on stock manifold, value?


Swampy442

Recommended Posts

Bit of history on the HKS kit.

In the early part of 2000 HKS sold adapters to make the GT25 and GT28 turbos work with the stock manifold and stock piping. These turbos were standard upgrades and direct bolt-ins for the GT-R and 300ZX of the same time period. They are also internal wastegate turbos like the OEMs so there wasn't any need to modify the manifold. Small pipes were also fab'd up to route the exhaust gas back just as it does in the OEM setup.

The one thing HKS couldn't ever overcome was the "pre-spool" of the second turbo. When the valve opened up to allow the exhaust gas to pre spool the second turbo, there would be a "shock" to the turbine shaft of the second turbo. At transition there is a massive dip (loss of TQ & HP) then it builds back up. Over time this shock to the turbine shaft caused the second turbo to fail. The system/set-up always worked much better in TTC but made less power and and was no more responsive than a small single on a log-style cast iron manifold.

At the time these turbos were circa $1800 each. Once the turbo blew the cost of replacing it was so prohibitive people just went single and the kits were discontinued.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.