Just wandering if anyone has destroked the VQ and given it a larger bore to increase rev potential. I searched this and only found people talking about stroking. I was wandering If you could safely spin 9k RPM with a destroked VQ?
I think the trade off with a ST kit and a large turbo would be phenominal!! Just a thought!

 

There are race setups running 10, 11, 12k+ rpm with 3.5+L VQ's. The bigger concern is getting a setup that can breathe there.

 

What would it take to get the VQ to reliably turn 9k? Is a destroke necessary or is just rods and headwork needed?

 

Wasn't there a member from Australia who did this a year or so back?

 

Maybe? Im not sure, and I do alot more reading than posting.

 

I think you are talking about Z350Lover. Here is his build thread.

https://my350z.com/forum/na-builds/159519-photos-on-engine-rebuild-n-a.html

His motor revved to 8200 RPMs.

 

If you read the GTM 3.8L high-rev stroker kit thread, you will see there is a whole bunch of info on this. The stock rod length and stroke are more than capable for 9k rpm from a dynamics standpoint. Getting stronger rods and wristpins to survive at that rpm are needed, not to mention cams and intake work to breathe well at that rpm.

Will

 

With the stock rod length it can consistantly be taken to 9K. There the pistons are moving at about 4500 ft/sec. A race motor with lower expected life span can do 10K or 11K. Higher compression, lots of head work, a cam controller and lots of intake manifold work are needed to make any power up there.

 

my motor would easily go to 9k now...I just have it currently set at a redline of 8200 till we do some more tuning - click my sig for the details

I am eager to try the Cossie intake manifold to see if will make more power upstairs than my current setup

I would not say you need a cam controller by any means...just the right combo of cams/header/port work

 

Neither is all the other stuff I mentioned if we are talking about what the OP asked concerning 9K RPMs but to make optimized power a cam controller can't hurt.

 

we'll agree to disagree then - a cam controller is really needed at the low rpms, not the high rpms

 

speaking of the variable cam crap on these cars, does anyone know exactly what they do? in terms relative to where the cams are degreed, does the ecu retard the cams at low rpms to get better low rpm drivability, or does it advance them in the higher rpms, or does it do both?

 

I can't confirm that these dynos are from a 350Z as the OP mentions in this thread, but with HKS cams and the HKS VALCON controller HKS seems to be getting more then ordinary power in the higher RPM range.

https://my350z.com/forum/showthread....ghlight=valcon

 

why would you want to rev to 9000 rpms? i think you should buy an S2000

 

simple physics really - as you increase duration and lift, as the HKS cams do, you increase the ability of the engine to make power in the upper rpm range (the valves staying open, for longer, allowing more air and fuel in the combustion chamber). However, you also run the risk of decreasing the amount of torque you have in the lower rpm range - this is where something like the Valcon, or any other method of advancing the intake cam timing, can be advantegeous. I have no doubt that with my setup for example, VTC mapping would result in a broader torque band. To me though, its not worth hacking up my ecu harness for the this net gain (and it would be relatively small on an NA setup - the differences would likely be greater on an FI setup). It's also not worth it, to me, to switch engine mgmt. just for the sake of being able to remap VTC angles. My setup is not really in need of this feature.

Doug - I think I know what you're saying- it would be a fairly unique setup to make 9000 rpm on forced induction VQ35 motor truly worthwhile - it certainly runs the risk of being very peaky. I think it would take a very, very aggressive cam profile, the ability to fully reconfigure the VTC, and considerably "playing" with AR ratios to really achieve such a zen-like setup (that is, a VQ that makes torque early enough to be a street animal, and holds it as flat as possible to redline, while making progressively more power the higher it revs). Ideally, a my estimation is a twin setup would be best suited for this

 

its one thing i love about the VQ .. it gives a great power band like a V8 ..

sure on a 4 cyl like this MR2 dyno you need 9000+ rpms



but we make so much good power.. why?

I was also kinda annoyed by his other thread about staggered turbo's.. seems he is just posting a bunch of BS for the sake of posting

 

staggered? like the Supra and RX7 had? On a big V6? I hear ya....utterly pointless

Properly doing a FI VQ35 has alot of potential things to worry about - where it makes power is not one of them

 

Well, Excuse me for asking questions and sharing Ideas on a FORUM!! I didnt realize page space was so precious that we need to save it for the SAME topics over and over and over!!!!!!! So Ill do what I do best and just sit back and read. That way I wont inconvenience you with what I write and you can go back to discussing the same things! GOOD DAY TO YOU

 

do some research and come up with some intelligent questions..

just because my toaster using electricity and my car has an electrical system, i am not going to come here and ask if using my toaster in my car is going to drain my battery faster and do i need a high output altenator..

your questions are stupid and un-intelligent

 

Wow, for this to be a stupid question, there certainly was alot of intelligent answers and conversation regarding the matter. Like stated above about Cams and plenum volume etcetera. So, Im sorry if the question went above your head and capability to understand it but different people like different things. By your statement, we should all have the same setups and that be that. Why do you think people do NA builds or builds for Nitrous only? Because its different. Just stay main stream and do what everyone else is doing!