I have an evo 9, and I am planning on keeping the stock turbo for awhile, but in terms of the parts that are going into the car(Cosworth 272 cams, deciding on either BR Race or Street IC, BR IC piping, TBE w/ test pipe, ARP headstuds/rod bolts, Walbro 255), do I need springs and retainers? I know putting them in wouldn't hurt, and especially since the head will be open anyways, just don't know if its needed at this point? Also, are ppl upgrading injectors at this point? I am running 91 octane btw. so would I need to upgrade to like 1000cc? (maybe for future e-85)

 

Depends on the cams. Check the recommendations from the manufacturer.

 

How high do you want to rev?

If you go anything and I mean anything above a HKS 280/280 you need to do springs and retainers.

I had a 7200 rpm limit with HKS 280/280 on stock valvetrain and they worked out fine.

 

I have the Cosi 272s (M2s, right?), everything else you listed, meth, a Magnus, an FPRed and I didn't do springs/retainers. I probably should have now that I am where I am though.

BTW - I wanted to go with 1200cc injectors to future proof for e85 but I am only running 850s (1200s weren't in stock). When I was at your setup level (bolt-ons + cams) I was on stock injectors.

 

Yea they are the M2s. With your mods I can see where springs/retainers may come into play, but I guess I can keep the stock injectors for now. Kind of on a budget so I just don't want to shell out any more cash than needed.

 

^I hear ya, buddy! I say stick with the stock injectors for now.

I'll probably move to different cams at some point and will do springs/retainers then. Maybe Cosi M3s, or Kelford/GSC. I have heard the FP cams work well with the red, but that could be a nice little line of tripe marketing. :P

 

with springs and retainers on a stock 8 motor what can u rev out to? kelford 272

 

mellon has tuned many cars with stock valve train to rev to 8k, what happens when you get a bigger cam duration isnt as important as the AMOUNT OF VALVE LIFT, HKS cams all use stock lift, the 264's the 272's and the 280's all push the valves in the same distance as stock(although increasing the time(duration) that they are open, now the cosi M2's are different they have a much bigger lift (and duration)and for that reason make more horsepower with big turbo setups where the additional lift is needed for the additional air being forced through the engine...what happens is the only way to have a cam lobe profile that still closes and opens on time is to have a higher ramp angle ***this is where the springs and retainers come in****now the springs on the stock valvetrain do not produce enough force over 7000rpm's to actually pull the valve back out of the cylinder fast enough...basically your cam spins faster then your springs can handle and the results can be bad including but not limited to bending valves and cracking pistons

thats why you want/need valvesprings and retainers(aftermarket retainers usually carry the benefit of being made of a lighter metal and occasionally a stronger one)

 

On point with this one BUT if your on stock turbo whats the point of reving past
7/k anyway! It falls on its face after 6,000 rpm. If your gonna upgrade the turbo which you will I guarantee, put them in.

 

These kelfords http://www.extremepsi.com/store/cust...at=1574&page=1 and the GSC s1's look like the best of the "drop in" cams for the IX. I am on the fence between the 2. Any option with more LIFT then these cams recommend a valve spring upgrade.

 

Well put, this should be a sticky in the cam section!

Josh

 

i have a twin scroll gt35r with cosworth m2 cams stock springs reving to 8k and have seen a bunch of people not using springs but if you wanna rev higher you need to take out the balance shaft anyway so no worth buying them and the labor of installation unless you are going to upgrade the turbo and build the motor but then youy have to take the head off anyway and its much easier to do springs with the head off the car

 

While HKS cams are known to be more mild than others with similar duration, they do have more lift than stock.

Cam specs

 

my mistake, i will also add that rpms are what kill motors running the ragged edge, if your car doesnt make power up-top then its pointless to run it that high, its a high risk for little or no gains unless a good turbo setup is matched to the cams

 

The M2 are 11mm of lift! Springs and retainers wouldn't be a bad idea, better to be safe than sorry I always say. It does also depend how high you'll be reving! S & R's are just insurance!