Race Car Tech Discuss anything related to road racing and auto X.

Rev limiter

Old 05-29-04, 11:13 AM
  #1  
Senior Member
10 Year Member
Thread Starter
 
EProdRx7's Avatar
 
Join Date: Nov 2001
Location: Rochester NY
Posts: 576
Likes: 0
Received 0 Likes on 0 Posts
Rev limiter

Anyone know how to disable the rev limiter in a stock S4 ecu?
EProdRx7 is offline  
Old 05-29-04, 12:00 PM
  #2  
www.lms-efi.com
iTrader: (27)
 
C. Ludwig's Avatar
 
Join Date: Mar 2001
Location: Floyds Knobs. IN
Posts: 5,106
Received 30 Likes on 23 Posts
There's someone that advertises in the back of Sports Car. Other than that, no.
C. Ludwig is offline  
Old 05-31-04, 07:34 AM
  #3  
Rotary Freak
 
23Racer's Avatar
 
Join Date: Jul 2003
Location: Oakville, Ontario
Posts: 2,192
Likes: 0
Received 3 Likes on 3 Posts
I've been looking for 3 months and still no luck. If you find out, please let me know.
23Racer is offline  
Old 05-31-04, 07:37 AM
  #4  
Senior Member
10 Year Member
Thread Starter
 
EProdRx7's Avatar
 
Join Date: Nov 2001
Location: Rochester NY
Posts: 576
Likes: 0
Received 0 Likes on 0 Posts
The ECU in my car was reprogramed by Speed Source, but we were under the impression that there was a single component on the board that could be disabled to get around it. Looks like that is not the case
EProdRx7 is offline  
Old 06-01-04, 05:34 AM
  #5  
Full Member
10 Year Member
 
PaulyDee's Avatar
 
Join Date: Mar 2001
Location: Indianapolis
Posts: 245
Likes: 0
Received 0 Likes on 0 Posts
Here is the ad in the back of SportsCar verbatim:

RAISE THE REV LIMITER IN YOUR CAR'S COMPUTER FOR ONLY $100. Why pay more? RX7, Miata and most foreign cars. This is the most power that you can gain for only $100.00. Contact Keith (305) 232-0460.
PaulyDee is offline  
Old 06-01-04, 08:18 AM
  #6  
Rotary Freak
 
23Racer's Avatar
 
Join Date: Jul 2003
Location: Oakville, Ontario
Posts: 2,192
Likes: 0
Received 3 Likes on 3 Posts
Thanks, I had seen that ad a number of months ago and didn't think of trying them as I can't believe that the mod is that difficult and wanted to see if I could do it myself. I will call him a little later today and after I talk to him I will let everyone know.
23Racer is offline  
Old 06-16-04, 12:26 AM
  #7  
No need to post. Search.
5 Year Member
 
HyRisk's Avatar
 
Join Date: Oct 2003
Location: Bay Area
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
???soo...
HyRisk is offline  
Old 06-16-04, 01:17 AM
  #8  
Lives on the Forum
10 Year Member
 
Join Date: Feb 2001
Location: n
Posts: 26,664
Likes: 0
Received 4 Likes on 4 Posts
You cannot disable the rev limiter in the stock ECU without reprogramming it or replacing it with an stand-alone EMS.


-Ted
RETed is offline  
Old 06-28-04, 02:08 PM
  #9  
Rotary Freak
5 Year Member
 
Join Date: Jun 2004
Location: Ames, IA
Posts: 2,718
Likes: 0
Received 0 Likes on 0 Posts
I suppose a good question would be "Why do you want to disable the rev limiter?"

Stock intake/exhaust sort of falls flat around 8k, if you go much above 8k you need a clutch/flywheel blanket or shield, and if you go much higher you'll start running into eshaft flex & such.

If you've done the intake/exhaust & fuel system work and are running a race vehicle, then yes, disabling it makes sense. By this point, most people have replaced the stock ECU though.

-=Russ=-
Syonyk is offline  
Old 06-28-04, 02:45 PM
  #10  
Full Member
10 Year Member
 
PaulyDee's Avatar
 
Join Date: Mar 2001
Location: Indianapolis
Posts: 245
Likes: 0
Received 0 Likes on 0 Posts
My ECU is on it's way back from getting reprogrammed. The explanation I received from several sources is that S4 and S5 ECU's start getting ignition break up about 7800 RPM (soft rev limit). I have been experiencing this phenomenom for quite some time. I have the dyno charts to prove it.

The other benefit of removing the rev limiter is for race applications. If you can rev to 8500 RPM, you may not make more power but if can save from having to shift up and then down at a particular part of the track. Best example would be between 10A/10B and 11 at Mid Ohio.

I am racing at Mid Ohio this weekend and I will let everyone know how it turns out.
PaulyDee is offline  
Old 07-04-04, 10:45 PM
  #11  
Full Member
10 Year Member
 
PaulyDee's Avatar
 
Join Date: Mar 2001
Location: Indianapolis
Posts: 245
Likes: 0
Received 0 Likes on 0 Posts
Just a follow up on the ECU mod I had done. I raced this weekend at Mid Ohio, and the rev limit removal worked wonders for my shift points. The car does not stutter above 7800 anymore either. In fact it revs all the way to 9000 without hessitation. I highly recommend it for those who track teir cars.


Pauly D
PaulyDee is offline  
Old 07-05-04, 06:18 AM
  #12  
www.lms-efi.com
iTrader: (27)
 
C. Ludwig's Avatar
 
Join Date: Mar 2001
Location: Floyds Knobs. IN
Posts: 5,106
Received 30 Likes on 23 Posts
Paul, can hitting the rev limiter induce the limp mode we were talking about?
C. Ludwig is offline  
Old 07-05-04, 07:46 AM
  #13  
Full Member
10 Year Member
 
PaulyDee's Avatar
 
Join Date: Mar 2001
Location: Indianapolis
Posts: 245
Likes: 0
Received 0 Likes on 0 Posts
I have not heard rev limit causing limp mode. I will look into it.
PaulyDee is offline  
Old 07-05-04, 08:55 AM
  #14  
Full Member
10 Year Member
 
PaulyDee's Avatar
 
Join Date: Mar 2001
Location: Indianapolis
Posts: 245
Likes: 0
Received 0 Likes on 0 Posts
Chris,

Looking at the control system trouble shooting chart, the only inputs that would cause limp mode symptoms ("basic fuel injection amount and ignition timing fixed")is a failed oil metering pump or pump sensor, or a bad airflow meter. There are quite a few other fail safe modes for failed input devices, but the ones I mentioned are the likely causes. Keep in mind you might have a short or open int he wiring harness as well, especially since the fault is intermittent.

Pauly D
PaulyDee is offline  
Old 07-05-04, 09:05 AM
  #15  
www.lms-efi.com
iTrader: (27)
 
C. Ludwig's Avatar
 
Join Date: Mar 2001
Location: Floyds Knobs. IN
Posts: 5,106
Received 30 Likes on 23 Posts
Well...I replaced the airflow meter with a new one last year, used two different OMPs, reshimmed the ones I have, tested the sensors, tried three different ECUs and two wiring harnesses. I'll keep flipping the switch I guess. Thanks!!!
C. Ludwig is offline  
Old 07-05-04, 10:36 PM
  #16  
13B N/A POWA!
10 Year Member
 
KiyoKix's Avatar
 
Join Date: Apr 2002
Location: Everywhere, WRLD
Posts: 1,013
Likes: 0
Received 0 Likes on 0 Posts
Hey pauly...what did you do to remove the limiter? I don't see where you actually said what you did? I don't really need 9k but still it'd be nice to be able to go a LITTLE further than 7700.

Kiyo

P.S.
PM me I'll prolly see it faster .
KiyoKix is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Prediict
2nd Generation Specific (1986-1992)
32
11-18-15 08:41 AM
LongDuck
1st Generation Specific (1979-1985)
12
10-07-15 08:12 PM
Rotafuzz
New Member RX-7 Technical
3
09-30-15 09:55 AM
dexter snoek
New Member RX-7 Technical
4
09-29-15 09:18 AM
baix2
Power FC Forum
1
09-28-15 09:40 AM


Thread Tools
Search this Thread
Quick Reply: Rev limiter


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: