Do you need to upgrade the valve springs if you have hks 272 cams or would it be a waste of money? I am going for 400 to 450 hp. I will have a Fp red, Buschur fmic, and all the usual bolt on's. I don't want my springs to fail with that much hp. Thanks

 

any of the hks cams will be fine for factory valvetrain.

They only change the duration not the lift so it doesnt put any more strain on the valvetrain.

I run hks 280's on stock head . everything is A - OK!

 

just get head studs, but i bet you allready knew. im running hks cams for almost 60k miles...272/272

 

as long as you dont go passed like 8k rpms you should be ok with any aftermarket cam but the valve springs add insurance. i have stock springs with my kelford 272's and it is fine right now. my tuner said i will be fine as long as i dont go above 8k.

 

If your going to running a FP Red on an IX then you would suggest you go with cams bigger then HKS. I would suggest Kelford 272's, Cossi M2's, or GSC S2's to really wake that turbo up. If I would have kept my HKS 272's in the car I would have made about 30 less HP. I would suggest you red up on cams before committing to HKS's.

https://www.evolutionm.net/forums/ev...-cam-test.html

 

If you have the money get the buschur springs/ retainers, good price and reliability for high rpms

 

You probably wouldn't lose 30hp from the HKS'. They are a decent cam for the stock head.

 

They add power too. An aftermarket cam that specifies a valve spring upgrade stands to be down on power with the factory springs due to valvetrain deflection, and that is the least concern.

Advising someone to ignore a valve spring upgrade is like advising them to use non-speed rated tires and just keep it to under 100 mph. It isn't the smart thing to do.

FYI

 

Most camshaft companies recommend a valve spring and retainer upgrade to be
installed with the camshaft. However those HKS camshafts are relatively mild
compared to the offerings by other well known companies. So valve springs and retainers
are probably not required as long as the RPM usage does not go much past 8k.

 

Correct. The lobe profiles of all HKS grinds are mild, and are intended to be compatible with the factory valvetrain. The tradeoff is some degree of spool response and power. It's just the price of convenience.

 

The real problem with the factory valve springs is not just the rate at which they compress
which is relatively soft, but the much higher chance of coil blinding and float type conditions
that are associated with following aggressive camshaft lobe profiles. Then there are the spring retainers which are another subject altogether. So as you can notice its more of a continue
at your own risk kind of situation without doing the valve spring and retainer swap.

 

the reason that i want to go with the hks is on the ams cam test thread it showed the least amount of low end power loss. i no that no matter what i will loose some but i dont want to loose that much since it will be a dd. thanks for all the help.

 

Does anyone have a dyno sheet comparing the cossi m2 with the hks 272?

 

Well that is true cams are basically designed to more your power around the power band. My thing is I didn't want to keep my HKS in there and have the power come on hard down low and then fall flat in the upper RPM band. Plus you have to remember you have MIVEC so your tuner can adjust the MIVEC map to help spool the turbo faster so you shouldn't loose that much tq with the big cams and the car and turbo will just keep pulling like a freight train. I'm glad I decided to change the cams to something bigger then HKS's

 

Hks 272 w/out springs... Runs fine kelford are good cams... But i really like the driveability of the hks's