OCG35

iTrader: (2)

I'm getting JWT S2 cams for first gen G35... I plan to upgrade valve springs - not because of the cam, the lift is quite mild - but for increased rev limit (currently 7200, might go to 7500)...

I'm hoping the cams will allow gains past 6700 (which is where it plateaus now) - and I need the higher limit to make it through 1/4 mile in third because I have shorter than OEM gears...

Anyway, the question is - should I bother getting upgraded rods? I figure if I go to 7500 I probably should... but not certain if its necessary.

This is in this forum becasue I know I'll get the best answers here.

Thanks.

Z1 Performance

iTrader: (564)

if you do rods, you mind as well do pistons...and at that point you mind as well do heads to go with it all, if budget/time allows. While it technically can be done, changing rods in the car ain't fun, or clean, or easy, and you're far better off just building the motor to go around it

As far as the stock rpm limit of a stock bottom end, I can't answer that. I ran my car with a redline at 7200 for years and didn't have any issues. But I can't speak on going higher than that

KA24DE

No. Oil pump yes.

OCG35

iTrader: (2)

thanks for the response... I toyed with the idea of full build, but it’s not the plan at this time... I'm determined to see what good cams & headers will do with Osiris tweak... I just want to error on the side of caution with the springs (and possibly rods) with the increased rev limiter... I'll probably stay at 7200 and forgo the rods

With that, I probably don’t even need heavy duty springs - do I? Or is it better to swap 'em anyway?

OCG35

iTrader: (2)

please expound...

KA24DE

No. Just more wear and friction on the cams. If JWT doesn't recommend it, it's usually not worth it.

OCG35

iTrader: (2)

no chance of valve float with the stockers?... at 7200?...

KA24DE

I'm taking it you have a Pre Revup motor? A friend of mine built a Twin Turbo 350Z in his garage, and rebuilt...and rebuilt..and one of the failures was the Stock oil pump. I believe the revup one is better suited for higher RPM use.

KA24DE

Not that I have seen.

OCG35

iTrader: (2)

yes, non-revup... so your recommendation for oil pump is if I go to 7500? Staying at 7200 stock should suffice - no?

OCG35

iTrader: (2)

hmmm... this is getting cheaper

KA24DE

You should really call Ben/Clark at JWT, they are open now.
Don't spend money on things you don't need, and I don't think you'll need new Rods, nor will you need Valve springs. A good oil pump will go a long way though.

OCG35

iTrader: (2)

the rods and springs were only if I was going to 7500... and I definitely would do them in that case... I think even JWT would agree... I'll talk with them though.

Thanks for the feedback.

KA24DE

Looking on The website just now, not until you get to the aggressive C series cams are Valve springs recommended. JWT's cam Secret guide goes into detail and basically says that a lot of other cams out there cover up shoddy R&D by using Stiffer valvesprings, instead of designing the cams right in the first place.

At 7500rpm, $250 for the spring and retainer kit doesn't sound so bad, but if your around 7100 like Adam was, I'd say don't bother.

KA24DE

I'm calling for you now as we speak.

Eh,it took to long, you can try:
619-442-0680

OCG35

iTrader: (2)

Just a follow-up (in case anyone is interested)...

I spoke to JWT - they recommend springs at anything over OEM rev limiter (I'm non rev-up OEM 6700, currently running to 7200)... as for rods, the only thing they suggest is heavier duty rod bolts from rev-up (even for existing 7200) and Nismo or ??? for 7500rpm...

no aftermarket oil pump recommended - which I didn’t think would be since there are many high HP boosted VQs running OEM oil pump.

Techosquare also suggested rod bolts if I rev to 7500...

So the shopping list is JWT S2 (will have this weekend), JWT springs and shims, rev-up or Nismo rod bolts (rods not necessary but might do 'em anyway) and Crawford headers... then Osiris re-tune and we'll see if it’s worthwhile...

OCG35

iTrader: (2)

didn’t see your post until my recent one... thanks for taking the time... I've talked with them several times, very helpful - I just didn’t have time today until a few minutes ago...

KA24DE

As soon as I logged off and left, I remembered what I heard about the revup. Besides Cam phasing on the exhaust side, it did have stonger rod bolts. JWT's site does recommend using using valves spring above stock revlimit (on both rev up, and non rev) A few people on here have raised the rev limit higher than stock and had no ill effects (though I believe most were on stock cams)

DandyMax on Maxima.org used VQ35HR valve springs instead of JWT.

As for the oil pump, I'm pretty sure its RPM driven, and not from power. My friends was shattered, but then again his Z is TT. (and it was a non revup. I believe the revup one is better)

I don't see anything wrong with the rods, or why they would need to be changed.

KA24DE

here you go
http://forums.maxima.org/6402301-post20.html

OCG35

iTrader: (2)

thanks for all the feedback KA24DE and Z1