Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
> Rev Limiter (123 Ignition)
Not_A_Six
post Dec 3 2019, 06:12 PM
Post #1


Member
**

Group: Members
Posts: 110
Joined: 28-November 18
From: North Idaho
Member No.: 22,682
Region Association: Pacific Northwest



The positive reviews here have me looking hard at a 123Ignition dizzy replacement on my '73 2.0 w/ stock D-Jet.

But, the version they offer for the 914 that's compatible w/ D-Jet (123\PORSCHE-4-R-V-IE) has a fixed 8000 rpm rev limiter.

The thought of my motor turning to shrapnel at 8000 rpm is a just tad bit worrisome. (IMG:style_emoticons/default/icon8.gif)

Ed at 123 Ignition said that the OEM rev-limiting rotor won't work in their dizzy, and suggested an aftermarket stand-alone rev limiter. But, I'm not too enthusiastic about adding an extra box at additional expense, just to limit revs.

Has anyone here used the 123Iginition w/ D-Jet? What did you do to limit rpm? Anyone just run without a rev limiter?

Thanks.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
BeatNavy
post Dec 3 2019, 06:26 PM
Post #2


Certified Professional Scapegoat
****

Group: Members
Posts: 2,921
Joined: 26-February 14
From: Easton, MD
Member No.: 17,042
Region Association: MidAtlantic Region



QUOTE(Not_A_Six @ Dec 3 2019, 07:12 PM) *

Has anyone here used the 123Iginition w/ D-Jet?

Yes, many of us have. Works really well.

QUOTE(Not_A_Six @ Dec 3 2019, 07:12 PM) *

What did you do to limit rpm?

Nothing. Just drove it, why? (IMG:style_emoticons/default/confused24.gif)

Seriously, is not having a rev limiter a real worry? I don't know that anybody here using the 123 is that worried about running too high on revs or has had a problem. I mean, I'm not racing or anything, but I rarely get too much above 5000.
User is online!Profile CardPM
Go to the top of the page
+Quote Post
Not_A_Six
post Dec 3 2019, 06:32 PM
Post #3


Member
**

Group: Members
Posts: 110
Joined: 28-November 18
From: North Idaho
Member No.: 22,682
Region Association: Pacific Northwest



QUOTE(BeatNavy @ Dec 3 2019, 04:26 PM) *

...Seriously, is not having a rev limiter a real worry?...


I dunno. (IMG:style_emoticons/default/confused24.gif)

Maybe I just shouldn't worry about it...
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
BeatNavy
post Dec 3 2019, 06:38 PM
Post #4


Certified Professional Scapegoat
****

Group: Members
Posts: 2,921
Joined: 26-February 14
From: Easton, MD
Member No.: 17,042
Region Association: MidAtlantic Region



Ok, then I wouldn't let that stop you if you're otherwise interested in buying one. It's pretty solid (IMG:style_emoticons/default/beer.gif)
User is online!Profile CardPM
Go to the top of the page
+Quote Post
porschetub
post Dec 3 2019, 06:53 PM
Post #5


Advanced Member
****

Group: Members
Posts: 4,695
Joined: 25-July 15
From: New Zealand
Member No.: 18,995
Region Association: None



QUOTE(Not_A_Six @ Dec 4 2019, 01:32 PM) *

QUOTE(BeatNavy @ Dec 3 2019, 04:26 PM) *

...Seriously, is not having a rev limiter a real worry?...


I dunno. (IMG:style_emoticons/default/confused24.gif)

Maybe I just shouldn't worry about it...


Not 100% but think the stock rev limiter creates a ground which to some electronic modules is instant death as it becomes a short,if the unit has no polarity protection.
T4's don't make huge rev's in the normal driving range and don't need to if stock,really they run out of puff under 5K,I wouldn't worry.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mark Henry
post Dec 4 2019, 09:36 AM
Post #6


that's what I do!
***************

Group: Members
Posts: 20,065
Joined: 27-December 02
From: Port Hope, Ontario
Member No.: 26
Region Association: Canada



You want no more than a 6K redline and never use a limiter as a shift indicator.
Depends on the cam but torque drops of at 5400 rpm with most cams, some hotter street cams it's about 5600.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Not_A_Six
post Dec 4 2019, 09:52 AM
Post #7


Member
**

Group: Members
Posts: 110
Joined: 28-November 18
From: North Idaho
Member No.: 22,682
Region Association: Pacific Northwest



QUOTE(Mark Henry @ Dec 4 2019, 07:36 AM) *

You want no more than a 6K redline and never use a limiter as a shift indicator.
Depends on the cam but torque drops of at 5400 rpm with most cams, some hotter street cams it's about 5600.



Thanks. I was more concerned with somebody over-revving the engine accidentally and thought the rev limiter would be a valuable (essential?) safety valve.

I do know how to drive, after all. (IMG:style_emoticons/default/wink.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
VaccaRabite
post Dec 5 2019, 08:16 AM
Post #8


En Garde!
**********

Group: Admin
Posts: 13,407
Joined: 15-December 03
From: Dallastown, PA
Member No.: 1,435
Region Association: MidAtlantic Region



QUOTE(Not_A_Six @ Dec 4 2019, 10:52 AM) *

Thanks. I was more concerned with somebody over-revving the engine accidentally and thought the rev limiter would be a valuable (essential?) safety valve.

I do know how to drive, after all. (IMG:style_emoticons/default/wink.gif)


How would you accidentally rev past 6K?
A rev limiter won't save the engine from a money shift (typically 5th to 2nd) since that is a mechanical over-rev and not caused by the gas pedal.

Only way I see this as possible is racing the car (AX or track) and not paying attention to the sounds your car is making.

Zach
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
GregAmy
post Dec 5 2019, 08:52 AM
Post #9


Advanced Member
****

Group: Members
Posts: 2,262
Joined: 22-February 13
From: Middletown CT
Member No.: 15,565
Region Association: North East States



QUOTE(VaccaRabite @ Dec 5 2019, 09:16 AM) *
How would you accidentally rev past 6K?

Mis-shift. Think you have it in gear and plant the right foot, ain't in gear.

I agree it would do exactly nuttin' for a money shift. Scattered the top-end of an SR20DE at Road Atlanta doing that...
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mark Henry
post Dec 5 2019, 01:42 PM
Post #10


that's what I do!
***************

Group: Members
Posts: 20,065
Joined: 27-December 02
From: Port Hope, Ontario
Member No.: 26
Region Association: Canada



QUOTE(VaccaRabite @ Dec 5 2019, 09:16 AM) *

QUOTE(Not_A_Six @ Dec 4 2019, 10:52 AM) *

Thanks. I was more concerned with somebody over-revving the engine accidentally and thought the rev limiter would be a valuable (essential?) safety valve.

I do know how to drive, after all. (IMG:style_emoticons/default/wink.gif)


How would you accidentally rev past 6K?
A rev limiter won't save the engine from a money shift (typically 5th to 2nd) since that is a mechanical over-rev and not caused by the gas pedal.

Only way I see this as possible is racing the car (AX or track) and not paying attention to the sounds your car is making.

Zach


Never say never, with a high performance balanced engine it's a lot easier than you think.
I hit my rev limiter a couple times on my 2600cc T4 bug this last season. I haven't hit it yet on my new 3.0 /6 but I came pretty damn close. I wouldn't drive a performance engine without one.

Mr. Hyde's engine, a 2.3 (80x96mm) balanced with healthy breathing from 44mm webers and a tangerine 1-7/8" header, he had one of the cable linkage carbs stick WOT and it went BOOM. Pete from RD has a vid of the mishap, it only took a second before it granaded.
Mike was so bummed he sold me the car, in his case a rev limiter would have likely saved the engine.

On a stock or stock-ish engine you are much less likely to ever hit a rev limiter, as the engine just can't breath enough to get one into trouble.

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Not_A_Six
post Dec 5 2019, 05:30 PM
Post #11


Member
**

Group: Members
Posts: 110
Joined: 28-November 18
From: North Idaho
Member No.: 22,682
Region Association: Pacific Northwest



QUOTE(VaccaRabite @ Dec 5 2019, 06:16 AM) *

How would you accidentally rev past 6K?
A rev limiter won't save the engine from a money shift (typically 5th to 2nd) since that is a mechanical over-rev and not caused by the gas pedal.

Only way I see this as possible is racing the car (AX or track) and not paying attention to the sounds your car is making.

Zach


I'm guessing that you don't have kids. (IMG:style_emoticons/default/biggrin.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 28th March 2024 - 08:32 PM