Randee of the Redwoods
11-22-2003, 16:15
Weather was nice today(can you say 70*F in DC) and I had permission to use my work parking lot. I set out to swap my GM4 for the GM8 I bought a few years ago. While at it, I drilled the downtube for an EGT probe. I took the upper intake that came with the GM8 turbo, drilled it for a boost gauge tap, and swapped it on. Alas, of all the went good, the turbo did not come off. Stripped off the back nut trying to loosen it in the wrong direction(insert extremely foul language here). I even went as far as removing the rear housing from the GM$ for better access. Came apart easily, but the back turbo nut was too far gone to recover. That one nut held up the entire operation. To recoup lost time, I removed the intake housing from the GM4 what was leaking and resealed it. We'll see how good a job I did. The silicone coupler w/clamps are also new. So now I ask: since it looks as if the exhaust manifold will have to come off to remove the damaged nut, would it REALLY be worth it? I ask because the upper intake I drilled and swapped on does not have the EGR boss cast into it. When I removed the stock part, I saw the tiny little openings the high velocity air charge has to clamor through. Well, the replacement part is totally open so, theoretically, I should see better performance in the upper rpms(smoother airflow, fewer restrictions). The impellor blades looked good, no eroding that I could tell. Just dirty and oily with clean leading edges(no scuff or scratch marks). Bearings seemed good. So am I missing much by not getting to put on the GM8? I'm assuming that new upper intake will show some improvement, but the turbos themselves don't differ that much, do they?(except for the location of the wastegates)