Rev limit...7000RPM or 7200RPM
05-24-2005, 04:41 PM
#1
Supporting Maxima.org Member
Thread Starter
iTrader: (89)
Join Date: Mar 2004
Location: Quincy, MA
Posts: 6,255
Rev limit...7000RPM or 7200RPM
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?
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?
05-24-2005, 11:10 PM
#5
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 
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
05-25-2005, 05:31 AM
#6
Supporting Maxima.org Member
iTrader: (17)
Join Date: Aug 2004
Location: Montreal, Qc, Canada
Posts: 5,437
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.
05-25-2005, 08:16 AM
#7
Originally Posted by JClaw
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.
05-25-2005, 08:40 AM
#8
Supporting Maxima.org Member
Thread Starter
iTrader: (89)
Join Date: Mar 2004
Location: Quincy, MA
Posts: 6,255
Originally Posted by JClaw
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.
ok? thanks i guess
05-25-2005, 09:07 AM
#9
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
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
Originally Posted by deezo
Are the rod bolts stronger on the 3.0 than the 3.5?
05-25-2005, 01:53 PM
#10
Supporting Maxima.org Member
Thread Starter
iTrader: (89)
Join Date: Mar 2004
Location: Quincy, MA
Posts: 6,255
Originally Posted by IceY2K1
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
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
05-25-2005, 03:10 PM
#12
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.
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.
Originally Posted by zack342
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.
05-25-2005, 03:34 PM
#13
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.
05-25-2005, 03:37 PM
#14
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.
If you've got the coin, you can get forged rods that can take it.
05-25-2005, 05:45 PM
#15
Originally Posted by IceY2K1
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.
05-26-2005, 04:53 AM
#18
Supporting Maxima.org Member
iTrader: (17)
Join Date: Aug 2004
Location: Montreal, Qc, Canada
Posts: 5,437
35
Originally Posted by NmexMAX
Random question ... what's the safest the stock 3.5L could go safely?
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?
05-26-2005, 06:37 AM
#19
Originally Posted by JClaw
Same here.SR20DEN got the 7500 rpm rev limiter instead of 7100,
But w/o an IM or cams that will see gains past 6600, it's useless, but still nice to know ...
05-26-2005, 06:39 AM
#20
Supporting Maxima.org Member
iTrader: (17)
Join Date: Aug 2004
Location: Montreal, Qc, Canada
Posts: 5,437
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.
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.
05-26-2005, 06:53 AM
#21
Originally Posted by JClaw
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.
05-26-2005, 07:29 AM
#24
Originally Posted by JClaw
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.
If detonation is a concern, it is more effective to retard timing a bit.
05-26-2005, 07:46 AM
#26
Originally Posted by JClaw
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.
He's the only N/A max in the 12s, must know what he's doing.
05-26-2005, 07:51 AM
#27
Supporting Maxima.org Member
iTrader: (17)
Join Date: Aug 2004
Location: Montreal, Qc, Canada
Posts: 5,437
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.
05-26-2005, 08:05 AM
#28
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.
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.
05-26-2005, 08:20 AM
#29
Supporting Maxima.org Member
iTrader: (17)
Join Date: Aug 2004
Location: Montreal, Qc, Canada
Posts: 5,437
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.
Originally Posted by NmexMAX
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.
, and 7200 is fine for your engine, your biggest enemy now is valve float .. nothing a set of valve springs can't cure. We certainly did ruin his thread.Everybody and their grandmother has the 7200 rev cut. It'll be fine.
05-26-2005, 10:19 AM
#31
Originally Posted by JClaw
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?
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?
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.
05-26-2005, 10:28 AM
#32
Originally Posted by JClaw
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.
We certainly did ruin his thread.Everybody and their grandmother has the 7200 rev cut. It'll be fine.
05-26-2005, 10:47 AM
#35
Supporting Maxima.org Member
iTrader: (17)
Join Date: Aug 2004
Location: Montreal, Qc, Canada
Posts: 5,437
Originally Posted by krismax
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.
Redline comes so fast in first.
05-26-2005, 02:35 PM
#39
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.
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.