Ok, official report back to the massess:
I took my car for a drive as is with only a temporary boost gauge fitted to check pressures: max 9psi (with waterprayer on auto at 8psi) which replicates the Tenagah Dyno Day run and made 104.4 kw atw.
Went home, swapped this hose back to OE, with the 'olive' restrictor in place(i had all vacuum lines changed to silicone a couple of years back) and took it for another spin. Boost now back to 16/16.5psi and the car pulls harder than ever. all the way to 6500 rpm.
My 'official' and highly calibirated bum dyno shows a great improvement in performance.
To give you a brief run-down (sorry to high-jack the thread Tom).
My car originally made 102.9kw at the wheels with stock computer and a full 3" system.
I had a link
ecu fitted and tuned and added a watersprayer to the combo set at 8psi on. Car made 150 kw at the wheels.
A few months later, in the name of asthetics, I had all vacuum lines changed to silicone. This included the small ection (around 100mm) that has the olive restrictor fitted to it.
My car performed poorly (well, below my expectations anyway) (14-15's down the quarter) at the plex and felt rather sluggish at higher revs.
Recently ran the car at the REXPO dyno day @ Tenagah and the best she could manage was 104.4kw at the wheels (once again disappointing, but I am not playing the blame game as the guys at Tenagah were not to know, afterall it is a dyno comp, not a tuning session)
I read the post in this thread regarding a car making 8psi without the resitrcitor in place and decided to investigate.
I have had a look and what do you know, the olive restrictor was not moved over from the OE hose to the new silicone hose.
I did some testing (read above if you wnaty to know more) and fixed the problem.
We are now back in action and at full power again.
Who would have throught that by putting a restrictor in, you could make more power.
In the interest of safety, I will be taking my car back to Tenagah (when possible) to give it another run and check the AFR's. Will let you know what numbers it pulls next time.
Now Tim...... bring it.
