PDM or JWT cams
PDM or JWT cams
See above^ Currently the car is n/a, soon to have a greddy kit . Can any one familiar with these products give me an idea where the new powerband would be. It is currently between 3k-5.5k
I have PDM cams...
I really liked the cams N/A, they pulled real hard all the way to redline--and there was only negligible torque loss with a good increase in power all around, mostly up top.
I also am boosted, 9 psi. At first I thought these cams were killing my powerband, when indeed my restrictive exhaust was killing my top end. With an open, freer-flowing exhaust, my car pulls really nicely to 6000 rpm. I asked a question about this a while ago concerning my cams/the fact that I'm turbocharged, but WDRacing said the PDM cams are probably perfect for the amount of boost I'm running (and Don @ PDM said they were fine as well).
I'd say go with them if you have the extra $, otherwise, stay stock, you'll gain plenty of power from the GReddy kit.
I really liked the cams N/A, they pulled real hard all the way to redline--and there was only negligible torque loss with a good increase in power all around, mostly up top.
I also am boosted, 9 psi. At first I thought these cams were killing my powerband, when indeed my restrictive exhaust was killing my top end. With an open, freer-flowing exhaust, my car pulls really nicely to 6000 rpm. I asked a question about this a while ago concerning my cams/the fact that I'm turbocharged, but WDRacing said the PDM cams are probably perfect for the amount of boost I'm running (and Don @ PDM said they were fine as well).
I'd say go with them if you have the extra $, otherwise, stay stock, you'll gain plenty of power from the GReddy kit.
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klattr1
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hey
the Jim Wolf cams are alot more install friendly since all you have to do is correct valve clearance after the cams are installed. All I had to do was swap one shim from one location and put it in another lobe and the same goes with the shim in that location. That was it for my JWT cams install to have correct clearances and tolerances.With PDM cams, you have to document what shim to valve clearance is before and also what shim thickness is in each location. Then you have to send out your cams along with shims and wait another week or two for the cams to return with correct shimming. So you would have downtime and you have to pay a core charge if you dont ship out the original ones in your motor.Jim Wolf has no core charge and no downtime and discrete instructions on their website.I have Jim Wolf cams in my car but I was so close to buying PDM cams previously. I'm glad I went with the Jim Wolf cams. Power delivery after 4000 rpm was great when I implemented them in my naturally aspirated setup. A little low end torque was lost but upper gains were worth it. I was happy with them then and I'm happy with them now in my built KA turbo.
Yeah, the shims are a PIA--but PDM wants to make sure the valve clearances are EXACTLY like they were after the install...
And you always run into the problem of not having a shim you can just swap in from your existing valvetrain--if you don't, then you have to order them up from Nissan for like $11.50 a pop.
Oh well, I'm happy with them, and I was happy with the install. Good learning experience!
And you always run into the problem of not having a shim you can just swap in from your existing valvetrain--if you don't, then you have to order them up from Nissan for like $11.50 a pop.
Oh well, I'm happy with them, and I was happy with the install. Good learning experience!
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AkiraSkyEighty
- Posts: 47
- Joined: Wed Oct 22, 2003 7:29 pm
- Car: My Nissan Sky Eighty
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AkiraSkyEighty
- Posts: 47
- Joined: Wed Oct 22, 2003 7:29 pm
- Car: My Nissan Sky Eighty
I guess you don't need to shim any set of aftermarket cams--if you can live with valve-lash that may be quite a bit out of spec---
After changing the design/cut of the lobe, obviously the OEM shims used with the OEM formed lobes are not gonna produce the exact same valve lash for that location. I can't imagine changing cams and not changing shims. That's why PDM needs your valve-lash specs before--so they can make custom shims that keep the valve lash the same so when you put on your newly shaped lobes the clearance is the same.
I'd recommend re-shimming it no matter what cams you use-you may as well since the cams are off. (And trust me, it's VERY hard to replace shims with the cams on, even with the right tools--I bought a specially made tool just for doing that and it was such a PIA to do that I ended up just taking the cams off to re-shim it).
LT_Z: I recommend installing the cam, taking the valve-lash specs as outlined in the FSM, and then changing all the shims (you only have 12, I had 16 to do) so that they're on the tighter side of the allowable valve lash. (I believe the spread is 0.013 to 0.016 IIRC). To do this subtract the actual valve lash from the minimum valve lash (0.013) and then buy/find a shim that is the sum of the difference + the original thickness of the shim. You'll be able to reuse some of them by just swapping them around to different valves, I only needed to purchase like 9 of the 16 shims.
Anyway...hope that helped
After changing the design/cut of the lobe, obviously the OEM shims used with the OEM formed lobes are not gonna produce the exact same valve lash for that location. I can't imagine changing cams and not changing shims. That's why PDM needs your valve-lash specs before--so they can make custom shims that keep the valve lash the same so when you put on your newly shaped lobes the clearance is the same.
I'd recommend re-shimming it no matter what cams you use-you may as well since the cams are off. (And trust me, it's VERY hard to replace shims with the cams on, even with the right tools--I bought a specially made tool just for doing that and it was such a PIA to do that I ended up just taking the cams off to re-shim it).
LT_Z: I recommend installing the cam, taking the valve-lash specs as outlined in the FSM, and then changing all the shims (you only have 12, I had 16 to do) so that they're on the tighter side of the allowable valve lash. (I believe the spread is 0.013 to 0.016 IIRC). To do this subtract the actual valve lash from the minimum valve lash (0.013) and then buy/find a shim that is the sum of the difference + the original thickness of the shim. You'll be able to reuse some of them by just swapping them around to different valves, I only needed to purchase like 9 of the 16 shims.
Anyway...hope that helped