I was wondering if the JDM valvetrain is good enough to handle skunk2 stage 1 cams? My redline with the new ecu will be 9100 rpm and i need to know if my valvetrain can handle it with no problem. I will also be getting titanium retainers. thanks.

 

I don't think so.

 

itr valvetrain should be fine to run skunk2 stage 1 or stage 2 cams.......my friend's itr even has jun type2's on his stock itr valvetrain for months now and it works fine!

 

But does he rev to 9100!?!

 

9100 that pushing it. but for the lift the springs will be ok the lift is only a little more on the skunk2's

 

From the preliminary dynos the skunk stage 2's look almost identical to the JUN Type-3's. I dunno if I'd run them with just ITR valvetrain....

Stage 1's are fine though with the ITR stuff.

 

Yeah i know for sure that if i get the jun3's i'm going to have to upgrade my valvetrain cause they're 12mm lift cams. The skunk2 stage 1 is only 11.58 which is .08mm more lift than the ITR and has more duration. Since skunk2 stage 2's are almost identical to jun3's its going to be the same case with those.

Does .08mm more lift make that much difference?? Everyone says that with the JDM intake valve springs you can run to 9100 rpm no problem since its a little more stiff than the usdm ones. Thats what i have on order right now but i'm not sure if i should cancel my order and order something else. Do portflow inners work good with skunk2 cams? I remember reading a post that they break Jun cams.

 

Sure the JDM's you can run at 9100 on stock cams!

But, with the lift and duration at the speed you are going you are going to need some serious rebound to get the fricken valves out of the way in time.
I say no.

 

I hear from a reliable source that the Skunk stage 1 cams are safe with stock valvesprings/valvetrain. Upgrading to R v.springs wouldn't hurt at all though.

9100rpm reving issues.
You'll have to go dyno tune and see if you're making power all the way up to 9100. There's no sense in reving aimlessly up to 9100 if you car isn't even making power up there. Even though your car may 'feel' like it's making power up to 9100, it might not be. A dyno will tell you what's up with your powerband. Having someone who knows how to tune camsprockets, fuel settings, etc is suggested.


[Modified by Katman, 1:45 PM 2/25/2002]

 

ah i see...good point you have there. Its just that alot of people with spec B's will shift at 9000 rpm, but spec B's make peak power at around 8200 rpm. Especially with the GSR tranny, i want to land in the highest possible rpm for my upshift. I was told that skunk2 stage 1makes peak power at 8400 rpm.

 

8400 rpm eh?
then your stock rev limiter should suffice.

Speaking of transmission.
Gearing doesn't add power to the powerband. It adds acceleration. So, if you decided to upgrade to a B16A or ITR/CTR transmission, your revs would increase more rapidly than with a GSR trans, especially with a lightened flywheel.

This is why people w/ a B16A or 'R' tranny think they can be so damn rev happy and rip out to 9500 and think they 'feel' the motor is making power all the way up there; when they're actually kidding themselves and damaging they're engines in the long run. Again, the dyno will tell you where the powerband dies off at and where your shift points should be...

I do suggest upgrading to a B16A or ITR/CTR LSD equipped transmission. Don't forget this though, not all B16A tranny's are LSD equipped, but all 'R' tranny's are LSD equipped.


[Modified by Katman, 2:05 PM 2/25/2002]

 

he actually revs the car to 9500rpm

 

Silly......what does the Dyno look like?

I just don't want to trust a "stock" item going at such speeds when it was built for lower rpm's and smaller lift. But, I don't knwo what the spring rate is on those suckers.

 

I THINK jdm itr intake valve springs were built to go up to 9000 rpm. If youe ver watch those best motoring movies, it always shows the itr guy shifting at 9000 rpm.

 

You can just run ITR Intake outer valvesprings on the intake and exhuast side, and then use portflow inner valvesprings. I hear alot of people talk about that setup. It seems to hold up. I might run it when i get my jun3's.

 

I heard of portflow springs breaking Jun cams. I hope this is not the same case with skunk2 =/