Notices
MEGAsquirt A place to collectively sort out this megasquirt gizmo

Rev Limit- How high can you go?

Thread Tools
 
Search this Thread
 
Old Aug 27, 2012 | 07:27 AM
  #21  
Reverant's Avatar
Elite Member
iTrader: (10)
 
Joined: Jun 2006
Posts: 6,019
Total Cats: 368
From: Athens, Greece
Default

Necro thread alert, lol.
Old Aug 27, 2012 | 10:34 AM
  #22  
concealer404's Avatar
Elite Member
iTrader: (3)
 
Joined: Aug 2011
Posts: 10,917
Total Cats: 2,206
Default

Originally Posted by BARMY
My '04 MX5 SE (aka Mazdaspeed Miata) now spends a lot of time on the track, I've been killing brakes and tyres, so I'm going to go with the 201rwhp map instead of the 233rwhp one and aim to become a better cornerer. The ECU presently stops the action at 6500rpm, which seemed a good thing with the high power map, but was a bit intrusive in several places on the tracks I drive at. So when I finally work out how to play around with the Haltech, can I go with a higher rev limit with less boost?
You can go a higher rev limit with the same amount of boost = more awesome.

I spin my Mazdaspeed to 7600.


Also: Toasting in a 7 year old thread!!!
Old Aug 27, 2012 | 07:45 PM
  #23  
BARMY's Avatar
Junior Member
 
Joined: Mar 2012
Posts: 72
Total Cats: -2
From: Blackpool, England
Default

Originally Posted by concealer404
Also: Toasting in a 7 year old thread!!!
Jeez! I obviously hadn't noticed. Sorry 'bout that and thanks for the answer. I'll wind it up to 7250.
Old Aug 27, 2012 | 09:45 PM
  #24  
Savington's Avatar
Former Vendor
iTrader: (31)
 
Joined: Nov 2006
Posts: 15,442
Total Cats: 2,106
From: Sunnyvale, CA
Default

7600rpm is outside of my comfort zone for a factory motor. The rods aren't going to like that for long. 7250 is a much safer number.
Old Sep 25, 2012 | 11:07 AM
  #25  
BARMY's Avatar
Junior Member
 
Joined: Mar 2012
Posts: 72
Total Cats: -2
From: Blackpool, England
Default

Again, sorry for the necro. But reading more about these motors makes me feel happier leaving mine at 6750 bearing in mind it hits 16psi at those revs - because apparently revs kill rods?
Old Sep 25, 2012 | 11:22 AM
  #26  
Braineack's Avatar
Boost Czar
iTrader: (62)
 
Joined: May 2005
Posts: 80,541
Total Cats: 4,364
From: Chantilly, VA
Default

torque/pressure kills rods.
Old Sep 25, 2012 | 11:26 AM
  #27  
BARMY's Avatar
Junior Member
 
Joined: Mar 2012
Posts: 72
Total Cats: -2
From: Blackpool, England
Default

So what rpm can I safely go to?
Old Sep 25, 2012 | 11:32 AM
  #28  
shuiend's Avatar
mkturbo.com
iTrader: (24)
 
Joined: May 2006
Posts: 15,235
Total Cats: 1,700
From: Charleston SC
Default

Originally Posted by BARMY
So what rpm can I safely go to?
What is done to your motor? The stock redline of 7200 should be more then safe.
Old Sep 25, 2012 | 03:14 PM
  #29  
Savington's Avatar
Former Vendor
iTrader: (31)
 
Joined: Nov 2006
Posts: 15,442
Total Cats: 2,106
From: Sunnyvale, CA
Default

Stock redline is 7000. 7200 is safe forever (i.e. endurance cars). 7400 for HPDE/normal track cars. 7600 for street cars that might see that figure once a day for a moment.

Run an HPDE car at 7600 and it will blow up eventually. Run an endurance car at 7600 and it will blow up fast.
Old Sep 25, 2012 | 07:28 PM
  #30  
hustler's Avatar
Tour de Franzia
iTrader: (6)
 
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
Default

Originally Posted by Savington
Stock redline is 7000. 7200 is safe forever (i.e. endurance cars). 7400 for HPDE/normal track cars. 7600 for street cars that might see that figure once a day for a moment.

Run an HPDE car at 7600 and it will blow up eventually. Run an endurance car at 7600 and it will blow up fast.
What breaks? Eventually I'd like to get a Supermiata crank gear and wheel, Skunk t-body, and then rev higher...but that's a lot of scratch.
Old Sep 25, 2012 | 08:30 PM
  #31  
pusha's Avatar
Elite Member
iTrader: (5)
 
Joined: Nov 2009
Posts: 7,330
Total Cats: -29
From: Miami, FL
Default

idk about you **** but I rev my car to 12k all day every day because the sounds of det make my **** swell
Old Sep 25, 2012 | 08:32 PM
  #32  
shuiend's Avatar
mkturbo.com
iTrader: (24)
 
Joined: May 2006
Posts: 15,235
Total Cats: 1,700
From: Charleston SC
Default

Originally Posted by hustler
What breaks? Eventually I'd like to get a Supermiata crank gear and wheel, Skunk t-body, and then rev higher...but that's a lot of scratch.
I think it depends on which head you have and what is done to the head.
Old Sep 25, 2012 | 09:24 PM
  #33  
hustler's Avatar
Tour de Franzia
iTrader: (6)
 
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
Default

Originally Posted by shuiend
I think it depends on which head you have and what is done to the head.
The head on my turbo car has supertech springs so that's nice.
Old Sep 25, 2012 | 10:19 PM
  #34  
Savington's Avatar
Former Vendor
iTrader: (31)
 
Joined: Nov 2006
Posts: 15,442
Total Cats: 2,106
From: Sunnyvale, CA
Default

Originally Posted by hustler
What breaks? Eventually I'd like to get a Supermiata crank gear and wheel, Skunk t-body, and then rev higher...but that's a lot of scratch.
Different stuff breaks depending on the application. Enduro/track cars will typically break the throttle shaft first, then break the crank pulley bolts, then damage the valvetrain (7500+), then stretch the stock rods (7600+). If you expect OEM reliability at 7500+, you need to address all of that.
Old Sep 26, 2012 | 03:05 AM
  #35  
BARMY's Avatar
Junior Member
 
Joined: Mar 2012
Posts: 72
Total Cats: -2
From: Blackpool, England
Default

Originally Posted by shuiend
What is done to your motor? The stock redline of 7200 should be more then safe.
Breathing, fueling and a piggy back ECU. No changes to the internals, which I guess is why the previous owner left the redline at 6500 as set at the factory. It's at 16psi at 6500. The 173.4kW = 232hp.
Attached Thumbnails Rev Limit- How high can you go?-blacksters-se-dyno.jpg  
Old Sep 26, 2012 | 12:28 PM
  #36  
hustler's Avatar
Tour de Franzia
iTrader: (6)
 
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
Default

Originally Posted by Savington
Different stuff breaks depending on the application. Enduro/track cars will typically break the throttle shaft first, then break the crank pulley bolts, then damage the valvetrain (7500+), then stretch the stock rods (7600+). If you expect OEM reliability at 7500+, you need to address all of that.
I will continue rolling with a spare throttle-body in the track trailer...one day that Skunk TB will join me in holy mantrimony.
Old Aug 22, 2014 | 12:05 PM
  #37  
t2couger's Avatar
Junior Member
iTrader: (1)
 
Joined: Jan 2012
Posts: 57
Total Cats: 6
From: College Station/Bryan
Default

Originally Posted by ecugrad
I have been pondering rev limits for my squirted N/A 1.6. AFAIK, the stock limit is 7,300 rpm.

Im thinking around 7,800 rpm. My car is tracked and autocrossed EXTENSIVELY in CSP with 13" Wheels. This translates into a bunch of time spent on or near the limiter for autox.

Lets not pretend all motors are equal. So here is what i have on my 1.6L.

Started off completely stock driven by grandma until 46K miles. Then i got it. drove it on the track for a little over 1K miles then. Full exhaust, Intake, Megasquirt 126WHP. Raised the RMP to 7,500 and have been driving it for the past Year and 1/2 for at least 2 track weekends a month. I bounce of the rev limiter almost religiously and beet the hell out of it. I change the oil very 2-3 events stock oil filter and Rotella T6. I have a coolant reroute 180 thermostat and ducting for rad. I never see temps over 185 on the track even when it is 100 gotta love Texas. I have no idea what my oil temps are and that has been on my mind so i'm installing a sensor as soon as i stop being lazy. I run 225 Nt01's 87oct and im waiting for the motor to fail so i can try a hot 1.8.

Last edited by t2couger; Aug 22, 2014 at 12:25 PM.
Old Aug 22, 2014 | 12:44 PM
  #38  
concealer404's Avatar
Elite Member
iTrader: (3)
 
Joined: Aug 2011
Posts: 10,917
Total Cats: 2,206
Default

Wonder if he'll log in for the first time in 4 years to see your reply.
Old Aug 22, 2014 | 01:53 PM
  #39  
t2couger's Avatar
Junior Member
iTrader: (1)
 
Joined: Jan 2012
Posts: 57
Total Cats: 6
From: College Station/Bryan
Default

Originally Posted by concealer404
Wonder if he'll log in for the first time in 4 years to see your reply.
lol how the hell did i bring this thread back form the dead?
Old Mar 31, 2017 | 10:30 PM
  #40  
Kinavo's Avatar
Junior Member
iTrader: (1)
 
Joined: Aug 2011
Posts: 150
Total Cats: 6
From: Queens, NYC
Talking

Not that I am into necro or anything but this thread is on point. I have done some reading on bumping up the rev limit and this helped me out.

I autocross very competitively quite often (20-30 events/year) and attend 1-3 HPDE's/year. I am looking to increase my rev limit because when I autocross I am too often at the limiter and I end up losing ground/time. Switching to 3rd and then rev matching down is fun but that also loses me time. I am planning on bumping up my limit to 7,500 this season (lower for track days). I think I should be safe. What do you guys think?

Here are my specs:
95 bottom w/ 99 factory head. ~5k miles since it was built.
MS2
210 - 240 whp
Forged rods and ARP hardware all around
FM lightened flywheel
4.1 diff (switching to a 3.9 this season)
225/50-15 tires

According to the FM gearing calculator, with the new rev limit and the 3.9 diff, I can take 2nd to 72 mph!! I can smell a few more FTD's this season.

Thanks in advance.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
Apr 12, 2021 04:21 PM
Zaphod
MEGAsquirt
47
Oct 26, 2018 11:00 PM
StratoBlue1109
Miata parts for sale/trade
21
Sep 30, 2018 01:09 PM
FrankB
Miata parts for sale/trade
6
Sep 30, 2015 11:48 AM
ihiryu
General Miata Chat
9
Sep 28, 2015 10:22 AM




All times are GMT -4. The time now is 07:33 AM.