I was looking at inline4's in house made valvetrain for my spring build and wanted some opinions. Im going to be running pro2's and my biggest concern is these might be too soft. The combo price for springs and retainers is $250, which I must say kicks all other manufacturer prices out of the water. The Skunk2 Springs alone are about $330. Dont get me wrong, I dont cheap out on parts, at this point im just shopping around, and maybe im just buying into there advertising, but this seems like a killer deal from a company I would trust more than most. When I asked about specs on the springs this is the response I got . . .

"Our valve springs are about 205 over the nose. With supertech being approx 215-220 and Skunk2 Pro_Series around 230ish, I wanted these to be soft to where you would not get any premature valvetrain or camshaft wear. You would not lose any hp, since it will not take so much power to compress the spring. They are good to 11krpm and a camshaft with 13.5mm lift, which is plenty. This is designed to be an all motor spring, for use in auto-x and roadrace type of racing, which can trickle down into daily driving for the spirited driver. The closest thing I can compare them to are “Yellow” Integra Type-R outer valve springs with “stiffened” inner springs from Isky cams. That setup was about 200 over the nose and I wanted just a hair more stiffness. That old itr outer/isky inner setup was proven time and time again with my Puerto Rican clients, who would use that exact setup with their JUN stage III cams, and not even run the suggested JUN valvetrain. I am very proud of these valve springs and our ability to achieve what we have with them and for the cost."

Just curious to see what people think about them and if anybody has used them what there experiences have been.

 

Interesting.

I would be a bit weary about going much lighter on the sprig pressure at max lift compared to Skunks own springs.

I am running the Supertech h1002d spring with my Pro2s, and the pressure at max lift according to published specs is about 198 lb.

http://www.ipg-supertech.com/cart.ph...ategory_id=520

70 lb + (12.8 mm * 10 lb/mm) = 198 lb

Skunk2 published specs for the Pro Series valve springs is 210 lb at .820".

http://store.skunk2.com/engine-tunin...e-springs.html

Do the math with the an installed height of 1.320" and you get a height of about .868" at max lift for Pro2s. This means that pressure at max lift is less than that 210 figure.

Do some more math to figure out the linear spring rate, and you get 300 lb/in.

(210 lb - 60 lb) / (1.320" - .820") = 300 lb/in

For a max lift of 12.8 mm or about .452" lift for Pro2s, you get a pressure of about 195.6 lb at max lift.

60 lb + (300 lb/in * 0.452") = 195.6 lb

Just some info to chew on.

I will admit that I do not know my exact installed height, unfortunately. I was more concerned with clearance issues when I put it together.

 

Don't do it. You can buy proven and safe supertech springs for $140 from streetrays and titanium retainers are only like $150 (average price) on ebay from all kinds of proven manufacturers on ebay; including Brian Crower, Supertech, BLOX, etc. Personally, I put KMS's Chromoly retainers in my b20vtec. I have alot of miles on them too cuz I drive to Cali from Austin TX a couple times a year. Those were only like $80 or $90 shipped.
Dont do it risk it. "Softer Springs..." ? I dont know man.