Hi All,
Haven't really been active for a long time on here. Asked some questions on the R33 Owners page on Facebook and got some unhelpful responses so I thought I would try this community again (always been good).
I haven't driven my 33 much at all lately since I bought my fourby but I like to take it out for a bit of a spirited drive on weekends when I get a chance. The last couple of times I've gone out I noticed that for the first 10 minutes or so my 33 makes full boost no worries but progressively over time it struggles to make 1 bar of boost (typically 1.3).
I understand that heat soak is an issue but it has never been this bad since I've owned it.
Car is a R33 with RB25, ATR45SAT Hyper Gear Turbo, Apexi AVCR boost controller, 3" exhaust with Venom cat, Pod filter in an enclosure, Blitz SE return Flow, Haltech ecu, Nismo 740CC injectors.
Things I've checked
- Exhaust manifold studs - 6th cylinder was loose, done them up
- Turbo to manifold studs - one or two were loose, done them up
- Changed all main vacuum lines
- Boost leak tested, no noticeable leaks, sprayed joins etc
- Checked over silicone joiners - no noticeable leaks or splits
I do notice however that the upper section of the intake manifold has what looks like oil on the surface. I checked this when i used the boost leak tester and didn't hear or see anything. When I got back from the last test drive after I thought I fixed the issue, I boost leak tested it just to be sure and didn't hear anything obvious
I always thought that it might be the intake manifold expanding as the engine bay heats up or the exhaust manifold leaking as it heats up.
I thought I would ask here if anyone has any suggestions or personal experience on what I should be looking for with regards to this issue. Any help would be greatly appreciated.
Apologies if this is in the wrong section, please let me know and I can have it moved.
Thanks in advance for helping!