S14 VTC Camshafts

[kernel]

I'm looking to buy camshafts for my SR20 S14 and willing to keep the VTC working

What cams you guys use or should I look at?

I think tomei and TODA make camshaft that retains the VTC ?

I'll run HKS GT-RS turbo to about 400whp max

if you have any suggestion, let me know

[Black240Ct]

greddy easy cams. i like them alot. still no modification needed with VTC

[Leetfade]

You can get the JWT S3 cams and have them fix the intake cam to accept the VTC. I believe it's a $48 additional cost where they will add the deeper (and thinner) bolt sleeve in the intake cam and add the longer dowel pin in the exhaust cam.

As strong as these cams are, it's worth considering. They are, however, a good bit more expensive (just under $600 for the S3s new). But if you're looking at Tomei and TODA it sounds like you're looking for a quality cam too.

[jr_ss]

You can get the JWT S3 cams and have them fix the intake cam to accept the VTC. I believe it's a $48 additional cost where they will add the deeper (and thinner) bolt sleeve in the intake cam and add the longer dowel pin in the exhaust cam.

As strong as these cams are, it's worth considering. They are, however, a good bit more expensive (just under $600 for the S3s new). But if you're looking at Tomei and TODA it sounds like you're looking for a quality cam too.

There's also a oil supply hole to feed the VTC cam gear. I don't believe JWT offers VTC compliant cams. And the only cam that has VTC is in the intake side.

[MADE]

I installed the Tomei 260 on mine and retained the VTC.

[dwadia]

I don't mean to hijack the thread but i was also reviewing different kinds of cams that would retain VTC just now (i have an s15)... looks like there are MANY options, including the ones already mentioned, HKS and some others.

Black240Ct, it sounds like you are using Greddy easy cams, right? Do you have any idea how much hp you gained? Can you tell us any more about them, like where in the powerband did you gain power, did you lose bottom end, and are you using stock valve springs? Did you have any kind of tune (or re-tune) done when they were installed? Any other changes at the same time?

kernel, the one thing i have decided from my reading thus far is i will NOT buy Brian Crower cams. They do have some specific for the VTC engines, and the price is very attractive, but i've read many mixed reviews about them. The problem i have heard of (several times) is that some of the cams, i assume due to a manufacturing flaw, need a slight adjustment with adjustable cam sprockets or they will not work right. In which case you would have lost your VTC, bought another part, and went through loads of hassles getting them adjusted properly.

I have basically narrowed my search down to Greddy easy, HKS step 2, or Tomei (they have loads of options). The Greddy's are the only ones that i think might be ok without stiffer springs.

[jr_ss]

The Greddy Easy cams were designed to be run without upgrading VS. With that said, they will have alot lower cam lift then the others... I run Toda's and made very good power, with a very broad powerband.

[Black240Ct]

Black240Ct, it sounds like you are using Greddy easy cams, right? Do you have any idea how much hp you gained? Can you tell us any more about them, like where in the powerband did you gain power, did you lose bottom end, and are you using stock valve springs? Did you have any kind of tune (or re-tune) done when they were installed? Any other changes at the same time?




I swapped them in two years ago with no Valve train upgrades or tune. I took the car out (trying to remember back a few years ago) and the car pulled harder from say 3k to redline. Not anything super crazy at higher rpm, but it felt great for mid range, no idea how much hp or tq, i have never dyno'd my car.
and i also did not notice any loss from my low rpm power band.

[TFD]

Im in the same situation right now.
Cams that will match my 2871 .86 turbo all need uprated valvesprings when retaining VCT (thinking about HKS step 2's)

Most cams that retain vct dont have huge duration or lift, or both With oem springs)

Easy cams are 256/11.5 lift in/out
HKS step 1's 256/10.5 in / 264/10 out.

Is a 256 in / 264 out gonna do justice on a 2871 .86 turbo? Good topend powergains?

[dwadia]

Im in the same situation right now.
Cams that will match my 2871 .86 turbo all need uprated valvesprings when retaining VCT (thinking about HKS step 2's)

Most cams that retain vct dont have huge duration or lift, or both With oem springs)

Easy cams are 256/11.5 lift in/out
HKS step 1's 256/10.5 in / 264/10 out.

Is a 256 in / 264 out gonna do justice on a 2871 .86 turbo? Good topend powergains?

IIRC (and i'm 99% sure), the Easy cams were 256 in, 264 out, and 10.5 mm for both.

There was some thread here on zilvia (idk the link) that said those durations are perfect for the stock s15's T28. I think for your 2871, it said those or 264/264 were good. Wish i could find that link...

Anyway the Easy's look like the way to go without changing valve springs, otherwise i'd probably go for an 11.5 lift (i believe HKS has that option, among several).

[codyace]

There's also a oil supply hole to feed the VTC cam gear. I don't believe JWT offers VTC compliant cams. And the only cam that has VTC is in the intake side.

JWT does offer VTC compliant cams, call them.

JWT S3's would be your best bet in regard to cam choice.

[TFD]

Yeah, I know whats really good for my turbo, but still havnt made up my mind.
Sgonna be step 2's in the end but still not to keen on changing the springs myself without taking the head off haha...

.. gonna get some beer and gain confidence ;)

[s15specR]

I have a pair of SR20 Tomei 270s for the NVCS (VTC) if your interested.

Has been working great.

[codyace]

Yeah, I know whats really good for my turbo, but still havnt made up my mind.
Sgonna be step 2's in the end but still not to keen on changing the springs myself without taking the head off haha...

.. gonna get some beer and gain confidence ;)

JWT S3's don't require spring changes FTW :D :D


It's an easy job tho, just need the right tool.

[dwadia]

Can some of you more experienced/knowledgable guys explain for me (and everyone) what the deal is with needing stiffer valve springs? I mean, why does Greddy say you need new VS for their pro cams at an 11.5 lift (256,264 or whatever duration), but HKS Step 1's and Tomei Poncams both have 11.5 mm lift with 256* and/or 264*, and those manufacturers claim those are drop-in cams :tweak: What am i missing here?

Also, does higher lift cause rougher idle, or only duration affects idle? Any other drawbacks to 11.5 vs. 10.5 mm?

I'd look into Step 1's or Poncams but i really don't wanna change the VS and i'm leery of the 11.5 lift...

[codyace]

Can some of you more experienced/knowledgable guys explain for me (and everyone) what the deal is with needing stiffer valve springs? I mean, why does Greddy say you need new VS for their pro cams at an 11.5 lift (256,264 or whatever duration), but HKS Step 1's and Tomei Poncams both have 11.5 mm lift with 256* and/or 264*, and those manufacturers claim those are drop-in cams :tweak: What am i missing here?

Also, does higher lift cause rougher idle, or only duration affects idle? Any other drawbacks to 11.5 vs. 10.5 mm?

I'd look into Step 1's or Poncams but i really don't wanna change the VS and i'm leery of the 11.5 lift...

The answer is really multi fold

-Lift doesn't so much effect sound or idle, as duration and LSA do.

-The big reason behid cams requiring springs at different lifts is all do do with ramp rate and lobe profile.

-Duration and Lift are not always measured 'fairly' or as advertised. There are standards, and the information should be available on a cam card, but many JDM companies do not provide this, like American based cam companies

Persay again JWT S3's...they are 260* with 11.2" lift...no springs needed. They spend a ton of time designing the cams, revising your lobe profiles, and doign actual research on valvetrain harmnoics...where I'm sure Greddy does not spend as much....and we can all agree that BC does very little.

Ultimatly cams can not truley be 'compared' directly by duration and lift...sure they provide a starting point, and a generic ground...but a 260* 11.2 lift S3 is not the same cam at all, a Tomei 260* Poncom 12mm lift...

[dwadia]

Codyace, all the points you made completely make sense. I understand about "ramp-up" which is why i considered the duration together with the lift (they are all 256 or 254). Unfortunately this is limited, at best, because as you said there is no way to tell about how they measured the lift or duration, and how it compares to another company's "identical" measurements. And they don't even provide a spec for lobe separation angle! Which sucks because i can't determine overlap.

Given those limitations, would you tend to believe when a given manufacturer (i.e. HKS or Tomei... not BC haha) claims their cams are safe to use with stock springs?

I know Tomei makes many internal parts for SR's (and even complete built engines) so my gut feeling is that they have good R & D time, and HKS and Greddy may be a step below them with R & D but hopefully still decent... but that's just a surface impression.

[TFD]

To give this one a kick: 99% Im going for Toda's 264/10.5 since:
-Retaining vct
-264 in/out to deal with the 2871 .86
-10.5 lift is not optimal compared to S-cams but hey... there's allways a downside.

Best thing actualy is that this is the only cam with 264 intake that retains vct without changing valvesprings.

Greddy Intake and the way we go.

[codyace]

And they don't even provide a spec for lobe separation angle! Which sucks because i can't determine overlap.

Trust me, it's quite annoying. However (and I will go against the norm here)...I do actually prefer some overlap with these smaller high strung turbos...they spool fast enough down low that keeping overlap at a minimum really isn't helping or hurting it...but using some on the top end really helps them make power (persay the JWT S3's have a healthy amount of overlap)

Given those limitations, would you tend to believe when a given manufacturer (i.e. HKS or Tomei... not BC haha) claims their cams are safe to use with stock springs?

I would most certainly trust Tomei, or HKS, or JWT when it comes to cams and their reccomendation. IN the same respect if BC is calling for a spring, it probably needs it.

The big issue then is harmonics in the valvetrain...and comparing seat pressures across all of the springs etc etc etc. Cam and valvetrain stuff is fairly technical...it's a shame so many just throw a heavy spring at a cam and just deal with it. (although 90% of the time it's really limited by option)


To give this one a kick: 99% Im going for Toda's 264/10.5 since:
-Retaining vct
-264 in/out to deal with the 2871 .86
-10.5 lift is not optimal compared to S-cams but hey... there's allways a downside.

Best thing actualy is that this is the only cam with 264 intake that retains vct without changing valvesprings.

Greddy Intake and the way we go.

Why would you keep VTC, but want a .86 housing 2871r and a greddy intake?

I'd not concern myself with a 'lesser' cam to retain VTC, as trutfhully speaking, running the proper cam will yield much better average power.

The minimal(at best) gains VTC will allow you to have to me are not worth sacrificing the top end power ability.

With that said, I'd ditch VTC, buy the 264 cams, and change the springs to use them. You want everythign to match ...running a big housing, and big intake (which needs bigger rpm to make the most power), but using a dinky cam doesn't work out.

[tricky_ab]

Im in the same situation right now.
Cams that will match my 2871 .86 turbo all need uprated valvesprings when retaining VCT (thinking about HKS step 2's)

Most cams that retain vct dont have huge duration or lift, or both With oem springs)

Easy cams are 256/11.5 lift in/out
HKS step 1's 256/10.5 in / 264/10 out.

Is a 256 in / 264 out gonna do justice on a 2871 .86 turbo? Good topend powergains?


I believe the Greddy Easy cams are IN 256 10.5mm lift/ EX 264deg 10.5mm lift. I've been looking into it before I had placed my order now that they are discontinued and going to great prices over in J-Land...

[codyace]

I believe the Greddy Easy cams are IN 256 10.5mm lift/ EX 264deg 10.5mm lift. I've been looking into it before I had placed my order now that they are discontinued and going to great prices over in J-Land...

FWIW: Mixed duration cams never make good power, or strong powerbands.

[tricky_ab]

Really? Well that sucks. From what I've read on other forum, they were recommended. I still plan to run them. Now to find a turbo to use...decisions decisions...

[codyace]

Really? Well that sucks. From what I've read on other forum, they were recommended. I still plan to run them. Now to find a turbo to use...decisions decisions...

Not that I doubt your research, but having been around this now for quite some time I can promise you that split duration is never suggested.