NmexMAX

iTrader: (3)

Not 'internals'. More like rod bolts and possibly valve springs, but again, as was stated earlier, if you're not making power in that area, there's not really a point to it.

rcdash

iTrader: (18)

As mentioned without valve springs and perhaps a better rated oil pump, probably not safe to go beyond spec that far... There's a reason many choose to put in valve springs and the revup oil pump for their non-revup motor builds.

On the topic of making power, you gotta keep in mind that the torque to the wheels is much higher in a lower gear so crank TQ has to drop off A LOT to actually make less wheel TQ high in the rpm band in a lower gear vs midrange in the rpm band for the next higher gear. Even though crank TQ drops precipitously after 6200 rpms, there are reasons when it would be advantageous to raise the redline (such as for a short ratio final drive swap).

NmexMAX

iTrader: (3)

Valve springs should be thought of after rod bolts.

rcdash

iTrader: (18)

No one changes just rod bolts so that is irrelevant. If the engine is coming apart, rods, rod bolts, pistons, etc are all part of a standard shortblock.

Beyond a basic shortblock, to go for a slightly higher redline, valve springs and revup oil pump are next on the list. And of course, to actually make better power up in that range, cams round out the build. A truly high rev build (8k+) requires a redesign from the ground up in terms of component selection.

OCG35

iTrader: (2)

The only reason to bump rev limiter would be to have a little cushion for extended revs when shifting in the high 6Ks and/or if you need a little bump to make it through ¼ mile with shorter gears (so you don’t need an extra shift)…

You stop making power with stock cams in the low to mid 6K range… anything above 7200 shouldn’t be needed.

I have 3.692 FD with AT – my rev limiter is 7200 (without 7200 I would have to shift into 4th before finish line)… with an MT I’m sure you can make it in 4th with 7200 even with 4.0 FD (I’m not positive, but I’m pretty sure)

I will be getting after market cams soon and will have re-tune with Osiris – the plan is to make power beyond typical low 6K rmp and not lose too much (hopefully no) bottom end… I will upgrade valve springs and depending on peak hp might bump rev limit to 7500…

OP hasn’t given any real explanation or reason for going beyond 7200… just take it there and leave it (unless you do internals)… it is a relatively safe limit and should suite any needs you have.

h2kSPiG

iTrader: (2)

I am. There have actually been quite a few people (maybe not on this board or the Z platform) I know that just put in the ARP rod bolt kit, and NOT change the pistons, rods, etc. It is harder to do on the Z/G since you can't drop the upper oil pan without holding the engine up somehow, but still a lot simpler than a full short block build.

It is a lot cheaper while still allowing you to rev higher with some level of safety. Rod bolts are the most stressed fastener in the engine and for the $200 or less I sleep better at night, especially with the engine not in the car yet. If the engine pops later, then I will build it.

If you are going for a 8k+ rpm build then yes, of course rod bolts are not going to cut it for long, but to rev a VQ35 to 7.2k or 7.5k then rod bolts, valve springs, and oil pump are the three main safety concerns. Rods are the next thing to go, and you might as well change the pistons, and you probably need cams and a lot of other things to get power up there, and it goes on and on from there.

rcdash

iTrader: (18)

^^ That is insane , unless you're doing the work yourself. Even then, if you're dropping the motor and taking it apart, your halfway, labor-wise, to a fully built shortblock. I guess I have seen someone prop up the motor from above with a railroad tie to fix the upper oil pan with the motor still in the car.

That's still nuts though to go to all that effort for just that upgrade.

NmexMAX

iTrader: (3)

True, on an FWDVQ35, RB's can be changed while the engine is still in the car.

I've also seen a bolt on DE make peak power @ 6500 RPM.

h2kSPiG

iTrader: (2)

As Nmex said, most of the people that I know that do it have FWD VQs. Thus they have an extra motor mount and can lower the oil pan without much additional support. Realize they also normally have MUCH smaller budgets than the RWD Z/G crowd.

I never took the VQ35 out of this car since it never came in it . it will be going into an S13. I don't need to rev to 8000 rpm or have 600whp since my car will be about 700-800lbs lighter than a Z33 and already comes with a 4.083 FD.

For my goals, I had to draw a line. We all do. Project creep is all too common in automotive builds, and some people's budgets aren't unlimited. I believe small things go a long way. I am also doing the vast majority of the work myself, and I want to minimize machine work and custom fabrication as it is, so ripping apart the block and building up a short block is not what I want to do right now.

As far as the OP goes, he needs to decide what his goals are and what he really wants to spend getting there.