JWT has my ECU and i noticed some guys on here have 7200RPM limits with MEVI. The normal N/A JWT program has a 7000RPM limit.
I called Ben and he said they can do a 7200RPM limit if i would like one but they would have to do a disclaimer because they don't want to be held liable for valvetrain float with stock cams.
My question is can a stock 3.0 VQ handle 7200rpm safely and repeatedly?
I told ben i would get back to him about changing it from 7000 to 7200? would the extra 200 rpm help setup for the next gear?
I will have MEVI by the time the ECU goes in?
Also i have thought about it and i know even though i get 7200rpm doesn't mean i have to rev it to 7200rpm i could stop i 7000 but i just find it fishy they have a disclaimer for this change.

So do i want 7200rpm?

 

Go for 7200rpm.

 

What is a MEVi and what year do you have because i have a 2k and i cant find anytihng to help with rev limiting

 

Go with 7200, I have 7000 on mine and I wished I had the extra 200 rpm to play with.

 

On cartest the 200 extra did not do anything different. I did mine 7.2k b/c I have an auto and needed a little bit of tolerance I shifted a little later and the auto lagged. It's free of charge if you go with JWT and would hope too with TS, so why not go with it.

For clarification my 95 with 228k sees 7k on a daily basis, and sometimes 7.2k, I'd be more worried if it was a 3.5L. Stop being and sack up a little bit

 

I've got the same question about the 3.5. My VQ35 is internally stock. The guy can do however high I want it. 6800, 7000, 7100, 7300. Not sure yet. Since I may get the ARP rod bolts and an intake manifold with power higher up (00 VI or Z plenum). I was thinking of putting it at 7300 RPM, but it seems 7100 (like the TS ECU for 02-03) would be enough.

 

Are the rod bolts stronger on the 3.0 than the 3.5?

 

ok? thanks i guess

 

Yes, since the 3L uses bolt/nut vs. VQ35 bolt. The 2005 Annivesary/Track 350Z w/7100rpm limiter that just came out went back to the bolt/nut setup.

The biggest reason for concern for overrevving a VQ35 is because of its long stroke, which induces large tensile stress on the rods. VQ30s are short stroked, so they can get away with a lot higher RPM.

For example...
VQ35@6600rpm stock redline has an average piston speed of 3511fpm.
VQ30@6400rpm stock redline has an average piston speed of 3066fpm.

Overrev example....
VQ35@7200rpm = 3830fpm
VQ30@8000rpm = 3832fpm

 

thank you some actual factual engineering.. i will let BEn know i want 7200rpm after all assuming that the piston speed on a stock 3.0 VQ at 7200rpm is safe.

 

Should be knocking on 200 FWHP's door....

 

Just plug the stroke/rpm into any online calculator = piece of cake.

7200rpm isn't a concern for VQ30 connecting rods, however 7300+ is in risk of valve float per others experiences/stories, which is unsafe and kills power.

Personally, I'm going with 7250rpm, however I'll have my shift light set at 7000rpm and the extra 250rpm is just for padding to keep from bouncing the rev-limiter since I'm a slow shifter.

 

Knowing that the 3.5l is not good for over reving. Is there any way to correct that? By any way I mean production aftermarket parts nothing custom. I apologize for not doing a great deal of research on this, but I have been cruising this forum a lot lately trying to learn as fast as I can.

 

ARP or NISMO rod bolts allow beyond 6600rpm on VQ35s...not sure how high is "safe", but Tilley/SR20DEN have said they hit 7300-7500rpm occasionally.

If you've got the coin, you can get forged rods that can take it.

 

Thanks for the reply. I don't think I'll be taking it all the way to 7100 either but I'll be shifting at around 6500 because in the auto I seem to drop back to the sweet spot.

 

Random question ... what's the safest the stock 3.5L could go safely?

 

whats the safest or what the...? Huh?

 

Same here.

Everyone seems to disagree about how high we should rev our VQ35's. Crawford z doesn't "recommend" going above 6800 RPM, Technosquare says 7100 Rpm is a safe rev limit, I heard the valvetrain doesn't fall apart until 7400 rpm, SR20DEN got the 7500 rpm rev limiter instead of 7100, the race 350z reportedly sees 7800 rpms with just rod bolts, and Krismax takes his to 7700-7900.

Personally I would get 7300 rpm and granny shift it at 7 grand flat, but this is really confusing. I understand the whole piston speed issue, about how the VQ35 at 7200 rpm sees as much stress as a VQ30 at 8000, but Kris reved his VQ30 at 8000 for a LONG time and its death wasn't a rod, piston, valvetrain and what not that failed, it was a headgasket.

I would rather see what the VQ35 valvetrain can handle since that would most likely fail first (and rod bolts), before making any claim of what it can and can't handle. I mean has any one blown an N/A VQ35 just from overeving? At what RPM? Anyone?

 

He has ARP rod bolts..

But w/o an IM or cams that will see gains past 6600, it's useless, but still nice to know ...

 

I'm trying to do it once and do it right. When I do get an IM that pulls to 7k I will be ready. Lets wait and see what kind of dyno curve the FWD Crawford Z plenum delivers on Altimas.

BTW, the 2k2 IM isn't a top end champ indeed, but simply adjusting the A/F will help somewhat. Nissan tuned the Altimas/Maxs to run at 10.5:1 or so A/F on the high end. Tune it to 13:1 and it's quite a bit better. Not to mention that I don't have the problem of having my TB closing by 10-20% after 6k since I don't need to put up with that E-Gas BS.

 

I still haven't seen any proof that the throttle closes, and indeed there are some that need tuning .. mines not that bad ...

 

Check the Technosquare website. Nissan tried to screw you guys over because they didn't want a grocery getter to kill a 350z.

 

What is the highest i can set my stock internals 3.0 VQ. 7200rpm ?

 

Really? That surprises me greatly. There is no need to go as low as 10.5:1 for a NA engine, and it's really too low for a boosted engine, too. And there are reasons you don't want to go that low.

If detonation is a concern, it is more effective to retard timing a bit.

 

That is what the A/F was at on SR20DEN's 263whp dyno. 13-13.5. He's the only N/A max in the 12s, must know what he's doing.

 

Sorry, I was expressing surprise that Nissan would tune as low as 10.5:1, not about SR's tune, which I fully agree with.

 

Ah I see. They deliberately set it that low. That, combined with the slowly closing TB and poor flow of the 2k2 manifold, is why top end power is so-so on stock cars. They should have kept the 00-01 VI instead.

 

But JClaw, have you any proof of the throttle closing? I know you don't have that problem due to your conventional throttle. I could tell you my product does this, but does it really? I still have yet to find outside proof of this.

My tune could use some work, but it's not terribly bad is ...

All my runs.




My runs w/ SR20 w/ respect to RPM.



Sam as above but with respect to speed.



zach sorry to troll on your thread... , and 7200 is fine for your engine, your biggest enemy now is valve float .. nothing a set of valve springs can't cure.

 

I couldn't put my finger on a specific source, but I didn't pull it out of my @ss.

We certainly did ruin his thread.

Everybody and their grandmother has the 7200 rev cut. It'll be fine.

 

It's posted on their website that's where I got it from ...

 

I have gone to around 7900 a few times ,wont do it anymore i stay around 7500-7600 now.

now with my 3.0 i did rev it to around 8k at least 700-1000 times and the engine did have 200k miles on it . Now my headgasket was bad way before my VI or ecu was put on . The thing that the high revs caused and made me switch to a 3.5 was that the oil pump exploded that and valve springs in my mind are the only things that limit a 3.0 from revving high all day long.


i say thou if you ever plan on getting cams or anything that would require the timing cover to come off ( then would be a good time to change oil pump )go with 7500rpm if you dont ever plan on going in there get the 7200.

 

I'm pretty sure Zach is not upset with this kind of whoring. At least we're learning something thru it all.

 

krismax ... Even on stock rod bolts?

 

krismaxs' VQ35 has ARP rod bolts.

 

I think I will settle for 7300. I will not use 7300 though. I plan to shift at 7 grand flat, maybe 7100. The extra 200 rpms are just in case... and also because I don't want to look like all the dumb@ss civic guys hitting their rev limiters at the track and/or bogging off the line Redline comes so fast in first.

 

Eliminate it at the track ...

 

...the f*ck?

 

Start in 2nd .. SR20 thought of it when he put the 6th gen (shorter F/D) tranny in there. That's the fukc

 

I went with 7200 specifically because cartest DID show a marked improvement vs 7000rpm limiter. I've still got the files if anyone wants to view them. I actually posted about this way back in the day, before I got my JWT ECU around Jan or Feb of 2003 I think? Maybe 2002? I can't remember but I know I ordered it in Jan or Feb. I tested this very carefully I might add, using existing dyno curves and then extrapolating the extra 200 rpm. I have my cartest models down to within hundredths of a second for every stage of modification my n/a car went through.

As far as JWT and that disclaimer BS... they are just blowing smoke. Even if you went with 7000rpm, they STILL wouldn't do anything for you if you broke your motor, so their stupid little spiel about signing a waiver to get te 7200rpm limiter is pointless.

 

Neal - What do you need to view the files?