New type Engine Rev Limiter

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
econo racer
Expert
Expert
Posts: 775
Joined: Mon Nov 26, 2007 11:44 pm
Location:

New type Engine Rev Limiter

Post by econo racer »

What is the new type of rev limiter that I am starting to hear? It is real loud and does not seem to break up much. I have heard it several times on those small tire no prep races. #-o
User avatar
mt-engines
Expert
Expert
Posts: 857
Joined: Fri Sep 27, 2019 12:35 pm
Location: MN

Re: New type Engine Rev Limiter

Post by mt-engines »

Not sure what you are talking about.. some are throttle stop. So all cylinders are still firing.. some are your basic 2 step, spark cut.
Zing
New Member
New Member
Posts: 28
Joined: Thu May 12, 2022 5:23 am
Location: Kilcoy Australia

Re: New type Engine Rev Limiter

Post by Zing »

Probably a type of traction control, timing retard through the ecu.
You can hear it, but depending on the tune how aggressive it works and sounds.
Maybe 🤔
Warp Speed
Guru
Guru
Posts: 3279
Joined: Wed Jun 25, 2008 1:46 pm
Location: NC

Re: New type Engine Rev Limiter

Post by Warp Speed »

econo racer wrote: Tue Aug 09, 2022 5:13 pm What is the new type of rev limiter that I am starting to hear? It is real loud and does not seem to break up much. I have heard it several times on those small tire no prep races. #-o
You may be referring to a lower rpm 2 or 3 step limiter to spool the turbo?
User avatar
Tom68
HotPass
HotPass
Posts: 2541
Joined: Mon Feb 07, 2022 3:43 am
Location: VIC OZ

Re: New type Engine Rev Limiter

Post by Tom68 »

econo racer wrote: Tue Aug 09, 2022 5:13 pm What is the new type of rev limiter that I am starting to hear? It is real loud and does not seem to break up much. I have heard it several times on those small tire no prep races. #-o
Pumped up exhaust valve lifters ?
Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
mag2555
Guru
Guru
Posts: 4585
Joined: Sun Sep 18, 2011 11:31 am
Location: Heading for a bang up with Andromeda as we all are.

Re: New type Engine Rev Limiter

Post by mag2555 »

Do you folks know how bad the added loading of a crank is when a rev limiter system is employed that drops out cylinders!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
User avatar
ptuomov
Guru
Guru
Posts: 3587
Joined: Fri Aug 07, 2009 3:52 am
Location:

Re: New type Engine Rev Limiter

Post by ptuomov »

Retarding ignition would work and sound loud in normally aspirated engines. Although many for bangers seem to cut off the fuel to the outside cylinders as the soft revlimiter.
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
RNorton84
New Member
New Member
Posts: 9
Joined: Fri Nov 06, 2020 8:51 pm
Location:

Re: New type Engine Rev Limiter

Post by RNorton84 »

In a turbo application there has been a trend of retarding timing to build more exhaust heat thus spooling turbo quicker.
User avatar
ptuomov
Guru
Guru
Posts: 3587
Joined: Fri Aug 07, 2009 3:52 am
Location:

Re: New type Engine Rev Limiter

Post by ptuomov »

RNorton84 wrote: Fri Aug 12, 2022 8:10 am In a turbo application there has been a trend of retarding timing to build more exhaust heat thus spooling turbo quicker.
That makes sense, but I think the way those calibrations work is by pulling timing temporarily after the gas pedal has been floored.

In turbo car and by my thinking, regarding timing alone is not the best way to create a soft revlimiter. It may spin up the turbine even more, trigger a boost spike, and preignition. I think that in a turbo car, either fuel or air has to be cut off (closing the throttle and/or opening the wastegate) to limit the revs.
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
User avatar
CamKing
Guru
Guru
Posts: 10709
Joined: Wed Aug 08, 2007 4:05 pm
Location: Denver, NC
Contact:

Re: New type Engine Rev Limiter

Post by CamKing »

mag2555 wrote: Wed Aug 10, 2022 6:47 am Do you folks know how bad the added loading of a crank is when a rev limiter system is employed that drops out cylinders!
It was so bad on the Indy IRL engines, it caused valve float/bounce. They had to add a soft limiter to keep the engine from hitting the mandated hard limiter.
Mike Jones
Jones Cam Designs

Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Orr89rocz
HotPass
HotPass
Posts: 2123
Joined: Sun Sep 28, 2008 9:25 pm
Location:

Re: New type Engine Rev Limiter

Post by Orr89rocz »

Might just be a soft limiter with timing retard and the rpm on off times set close together?

Thats how i do my turbo car. Holley efi soft limiter. The timing table around the limiter rpm starts dropping as boost starts building, further lighting up the turbo. Want full timing to get on converter to get to the limiter and dont wanna pull too much timing too quickly so engine doesnt fall off the limiter. I go from 34-36 deg down to 15-16 deg as i get up to 8 psi
Post Reply