RPM max sustainability

Subject: RPM max sustainability Wed Jul 28, 2010 12:26 am

just a quick question. how safe is it to run above 4000 rpms for any length of time? possible damage?

Subject: Re: RPM max sustainability Wed Jul 28, 2010 12:37 am

robotennis61 wrote:: just a quick question. how safe is it to run above 4000 rpms for any length of time?

Quick answer: safe.

Subject: Re: RPM max sustainability Wed Jul 28, 2010 12:39 am

no kiddin? my new chip is set at 6000 rpm. top speed limiter set at 255mph lol!

Subject: Re: RPM max sustainability Wed Jul 28, 2010 12:47 am

robotennis61 wrote:: no kiddin? my new chip is set at 6000 rpm. top speed limiter set at 255mph lol!

That's good, that's the factory redline... but I don't think you'll go more than 140 MPH.

Subject: Re: RPM max sustainability Wed Jul 28, 2010 12:57 am

thanks ! good to know. even to make it to 130 i will have to get off my ass and finally get her aligned and all quirks taken care of. including maxed up suspension. ive had her up the the previous max of 110.it felt like i was doing 75 mph super smooth and planted. thanks E

Subject: Re: RPM max sustainability Wed Jul 28, 2010 8:53 am

5500 RPM = caution
6000 RPM = not safe

But with Series I you don't really get much in the upper RPMs unless you modify the valvetrain. Stay in low RPMs and enjoy your torque band.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch
^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown

Subject: Re: RPM max sustainability Wed Jul 28, 2010 9:05 am

yeah, right around 6000 rpms on the stock valve train is when the valves start floating lol. Yes, I know from experience. suspect

Subject: Re: RPM max sustainability Wed Jul 28, 2010 10:20 am

AA wrote:: 5500 RPM = caution
6000 RPM = not safe

But with Series I you don't really get much in the upper RPMs unless you modify the valvetrain. Stay in low RPMs and enjoy your torque band.

im not sure how different the series I and series II in that aspect, but my torque curve has seemed to move north after the FWI and exhaust. i find that my car has a lot more torque above 3000rpm than it used to and pulls really hard at that point.

Subject: Re: RPM max sustainability Wed Jul 28, 2010 10:36 am

They are different from what I've read. Series II peaks horsepower at 5200 RPM (peak torque 3600), Series I peaks at 5000 RPM (peak torque at 3200). Exhaust helps some, but cam/rockers will move the power band to above 4000 RPM.

Even with 1.9:1 rockers and headers, I found that my shift points were too high at 6000. Lowering them to 5700-5900 gave me better power and acceleration during shifts, and less risk to the valvetrain. The numbers were confirmed on a dyno power graph.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch
^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown

Subject: Re: RPM max sustainability Wed Jul 28, 2010 10:45 am

i cant wait to finish this top swap with rockers or a cam. i cant even imagine what it will feel like when its done...

Subject: Re: RPM max sustainability Wed Jul 28, 2010 10:48 am

Oddly, it's similar to VTEC in a Honda (except we have low end torque, too!). The tach needle picks up extra speed right around 4k RPM and sweeps to 5500 much faster than before. Doesn't feel faster, but you really are. Imo, Series I SC engines would benefit even more from valvetrain mods than Series II SC.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch
^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown

Subject: Re: RPM max sustainability Wed Jul 28, 2010 11:04 am

AA wrote:: Oddly, it's similar to VTEC in a Honda

it feels exactly like that ever since the exhaust. i used to be able to spin the tires on a launch (cant with the 20s now unless its really smooth pavement). now i usually just roll into the throttle and then stomp it at about 3-3500rpms and it pulls like crazy. when i worked at a dealership and got to take an ssei out i wasnt very impressed, obviously it was all stock and i understand that but my heavier NA park avenue felt WAY faster than that car and that makes me want to top swap that much more. there were a lot of factors that told me that ssei shouldve been faster except that it was stock, but mine was heavier, bigger wheels, no supercharger, etc.

Subject: Re: RPM max sustainability Wed Jul 28, 2010 11:22 am

Seems like a similar result, except with rockers you can keep the engine sounding stock. wink

Wait... your PA is NA? That's entirely different. Our OEM exhausts are much better from the factory.

_________________
'05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26

'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes

'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch
^^^ SOLD ^^^ frown

'70 Ninety-Eight Holiday Coupe 455cid • 116k miles
^^^ SOLD ^^^ frown

Subject: Re: RPM max sustainability Wed Jul 28, 2010 12:48 pm

AA wrote:: Seems like a similar result, except with rockers you can keep the engine sounding stock.

Wait... your PA is NA? That's entirely different. Our OEM exhausts are much better from the factory.

haha yea, not for long though. i always knew the G/C/H body exhaust were much better than the W bodies even if they delete the u-bend. but it just seemed to me that a newer, supercharged, lighter bonneville would be faster than my car and it was anything but that when all i have is exhaust and an intake. from my butt dyno it felt like my car wouldve walked that bonneville hard from any speed, and i still dont understand why it seemed so slow. maybe my car is a factory freak, all i know is i can murder any other NA 3800 car that ive raced, the stock ssei felt way slow, and i can hang with my buddies (poorly modded) gtp.
i say poorly modded because he has a 3.4 with no supporting mods other than a K&N, magnaflow muffs, msd coils rolleyes

, and im pretty sure thats it...