Top end upgrades - few questions

[Mastaflash]

im going to be rebuilding the top end of my sr(possibly along with a built bottom), and i have some questions about my parts selection. heres a little info on my setup. i have a good sized turbo that has lag. its a precision sc61. im not woried about making power below 4krpm, because my turbo wont even make full boost untill then. i would like my parts selection to be able to increase the redline, just to increase the length of my powerband, not just to rev higher.

springs. im not really sure here, are they all just about the same? as far asi can see comp springs are the cheapest, along with the greddy and hks. do they all funtion and perform about the same?

retainers. as far as i can see the only choice here is crower. do these come with spring keepers as well??

also im thinking about going with the apexi spring/retainers. would these yield the best results?

camshafts. i know the 264/264 setup is popular, but im unsure if that woudl be the best cam for my aplication. since im wanting to make more power up top, and the low end is not what im woried about would i be better off going with a 270/270? also as far as brand i was looking into TOMEI band camshafts, because they advertise that the use of adjustable gears is not required, as they are designed to be "maximized" already. any opinions on this?

along with these aftermarket parts i will be doing the head gasket, head studs, gaskets, valve job, and seal replacements.

is there anything else im laving out?

[Colton]

How much whp do you really want? I use an SC-61 with HKS step 2 cams, HKS valve springs, port and polished head, and a HKS 2.0mm headgasket.

we layed down 400 whp at 18-20 psi (crappy autometer boost gauge) this was at 7000rpms (intercooler pipe blew off), my ecu is tuned for a 7800 rev limit. we were seeing gains of 21-26 whp for every 500 rpms when it got past 6000 rpms. We figured it has a solid 425 whp with 20 psi of boost at 7500 rpms.

I would invest in a better intake manifold and maybe use the stock valves and cam gears to save some cash, but it all depends on your goals.

[Mastaflash]

well i dont really have a set HP goal, but really as much as possible. if im going to do a full build on the head and bottom end i would want at least 450WHP.

i think i have prety much decided what parts im going to get. i havent recieved too much input on this. i guess not many people do it, and those that do dont bother posting.

[Nismo_Freak]

Typically you match springs with the cam maker. The springs are designed to work with their own camshafts so they have an ideal rate for the lift profile.

You can mix and match but sometimes without knowing the specifics you can't accurately dictate valve float points, and / or gain accelerated cam wear.

For the cams I suggest Tomei 260's or the HKS high lift 264's. In my opinion 272's are massive overkill for 99% of the SR20DETs.

The retainers will be dictated in large part by your spring choice (ie. double valve springs = "double" retainers)

I personally think Tomei makes some of the highest quality components for the SR, and I stand by their product 100%.

[Mastaflash]

ah, deciding what parts to get is hard. hmm...

[s13sr20chris]

i agree with alan.

if you are having trouble deciding then check out jwt.

why not get jwt s3 cams with their spring and retainer set. you get dual springs with titanium retainers designed to hold back the super high lift c series cams. then you get slightly less agressive s3 cams and figure you have headroom for a high redline. if you have a little cash left over you can get the jwt sprockets (which cannot slip like some others) and spread that lobe separation angle just a hair for less overlap and therefore less reversion.

this setup will work really well with a good sized turbo. you can make more power with the really big cams but at the sacrifice of area under the curve. who wants a nissan with no midrange punch?

[matt240det]

I have jwt c2 cams springs and retainers, oh and cam gears, it isn't running yet so I dunno how well they work, they install nice and easy though well i'm sure they all do..lol

[Mastaflash]

i can get my hands on a set of s4 cams and gears for $400 from a friend of a friend. i have searched the jim wolf site, but i cant find any info on these cams. for that reason i wrote them off. if that website were better designed and easier to use, then he would probobly sell more stuff.

can anyone tell me the specs of the s4 cams??

[9240sx]

Jim wolf S4 cam(0.464" lift, 266* duration)