Valve Springs Wtf

[dingah2]

Know what you mean .... those oh so simple days when Phase II meant perfromance and no issues and now we have moved on to Geeksville Edit no tuners and more 'apparent' issues than even Ford could poduce........

[FPV TRANNY]

Dont ask why but I ve managed 300 rwkw with stock springs.No dramas

[Guest fredwho]

Seems that many of the cars fitted with Nizpro stage 2 kits don't have springs with some producing 330 rwkw or more.

Might have something to do with intake back pressure, ala having mucho boost behind the valve to try and make reasonable power through the stock and very restrictive intercooler. The more boost pushing the valve open, the moe chance there is of bounce.

Reduce the boost with a quality intake and intercooler, and guess what. Valve spring problems are heavily reduced.

[ktford]

So to summarise, instead of spending $500 in having the springs replaced, spend $7,000 & replace everything else, when you say it like that it makes perfect sense.

[EnviTurbo]

Seems that many of the cars fitted with Nizpro stage 2 kits don't have springs with some producing 330 rwkw or more.

Might have something to do with intake back pressure, ala having mucho boost behind the valve to try and make reasonable power through the stock and very restrictive intercooler. The more boost pushing the valve open, the moe chance there is of bounce.

Reduce the boost with a quality intake and intercooler, and guess what. Valve spring problems are heavily reduced.

<{POST_SNAPBACK}>

This is taken from the Nizpro web site

"The Cobra valve spring is designed to work in almost every application with engines ranging from mildly modified to radical 800kW applications. They are also recommended for all 'boosted' engines whereby the factory intercooler results in significant backpressure on the back of the valve (a problem not associated with Cobra's Stage 2 kit due to the incredibly free intake design)."

Looks like the factory intake is to blame?

[ExAreSix]

The XR8 springs that I've done about 15,000k's with have 58 pound with the valve shut & about 160 with it open, the stock spring has about 62 when shut & about 125 when open. So there is a huge difference when opening/shutting.

I'd be careful shimming the OE springs, they aren't far off coil bind to start with.

24 of the XR8 springs will set you back about $220, fitment will be roughly between $300 to $500 depending

Thanks Scotty