[B18C1Tnr]

I have a '98 GS-R and am planning on a cam upgrade (with VAFC, upgraded injectors, cam gears, and proper tuning). I am planning on using Skunk2 Stage 1 cams. I have a few questions:

1. Are the Skunk2 valve springs and retainers optimal and/or necessary for use in this application rather than ITR valve springs?

2. Seeing that it is necessary to increase CR, what is the optimal CR using 92 octane and what is the best/cost-minimizing CR for this application?

3. Is there any other information I am missing?

 

[MichaelDelaney]

you can use itr springs but they "suggest" using theirs instead...I would get their springs and not fart around.

they can run on stock GSR CR but like 10.6-11:1 CR better.

you will need cam gears and a VTEC controller to tune the most out of them.

 

[B18C1Tnr]

would it be possible to raise CR to around 11:1 through the use of aftermarket gaskets alone (stock gsr pistons)

what is a head resurface?

is it necessary to purchase aftermaket retainers, or will the stock GSR retainers run with the Skunk2 valve springs? Thanx MD

 

[MichaelDelaney]

No it is not abslutely necessary to purchase aftermarket retainers. They are stronger and are lighter than stock retainers allowing you to withstand more heat at higher revs and allows for 300 rpm more on the redline. In fact, I am running on stock retainers.

To ensure the cylinder head deck is perfectly flat a machine shop will mill off about 5 thousandths of an inch off the deck surface. That is resurfacing. It does not affect your CR significantly.

No you cannot go to 11:1. Some people use a single layer head gasket and copper spray to get 10.8:1 but you must have a perfectly flat clean deck on the head and block and use ARP head studs to prevent head gasket failure. Failure does occur quite easily with 1 layer gaskets though...I don't recommend it. A 2 layer gasket gets you to around 10.4:1.