10-18-2015, 04:51 PM
Join Date: Jan 2005
Location: Los Gatos, California
Total Cats: -1
turbo VVT, springs choice for stock redline
Please help me close on this dilemma.
Building a 0.5mm overbore 1.8 VVT, for turbo (3071 at 20psi on 91).
Will likely upgrade to SST +1 Supertech valves, because they fit Supertech pistons without additional machining.
Most run successfully stock valve springs, and I have a choice of 99/00 and 01-05 valve springs for that.
Other choices are Volvo Vs-855 and Eibach, and Supertech.
I rather not spend on Supertech, unless some special benefit is derived.
Stock are 46lb seat pressure.
Eibach 66lb, Volvo 66 I believe, Supertech single 56lb and double 75lb.
Another option is to shim OEM valves by adding 1 more stock shim, and it bumps from 46 to 62lb the pressure.
I feel like going from 46 to 66 or more is a big jump and with consequent increase in stress and wear on valve train.
So perhaps using custom 1/2 thickness OEM like shim would bump the OEM valve springs from 46 to 54lb (62-46=16, 16/2=8, 46+8=54), about right no the money additional seat pressure for stock redline.
Am I rightfully concerned, or should I just get really affordable Volvo valves and call it a day: I think $80 for set.