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Engine Specific Info and Questions => IDI Engine => Topic started by: subsonic on January 08, 2008, 06:37:13 am

Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 08, 2008, 06:37:13 am
If I install a OEM tach and run my engine into the 6k range, what will happen to the tach?  Will the needle just keep moving, or will it peg out and cause damage to the tach?
Title: OEM tach, what happens if I spin past redline?
Post by: carrizog60 on January 08, 2008, 06:39:06 am
i guess that it will just keep moving...
i have seen many vw and other brands rev way past redline and it still works...
Title: OEM tach, what happens if I spin past redline?
Post by: Baselyne on January 08, 2008, 08:13:48 am
Not that anyone wants to hear about hondas but a freind of mine used to have a turbo'd Delsol and when he got his MSD 6AL ignition box he used to run the stock tach two or three thousand rpm past redline

I couldnt see any problem there provided there isnt a visable peg to stop the needle

How are you running a diesel over 6G anyways?
Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 08, 2008, 09:23:52 am
I have been gathering parts for about a year now for my build.  I think with what I have I should be able to get up there.

1.6TD hydro block-2nd over
New Kolbenschmidt pistons (getting ceramic coated)
New 1.9AAZ head with PP stage 2 porting
3 hole gasket
ATP turbo exhaust manifold matched to head
Stock 1.9 intake matched to head( will go with a PP intake if I can swing it)
Rebuilt Merc turbo with the 360 bearing upgrade and the stepped gap ring
Giles 9mm pump build for 2x fuel with no rpm cut off.
Rebuilt AAZ injectors with new Merc 300TD nozzles.
PP 3" DP as soon as I get my stuff up to Dave for the fab work.
ARP head studs, main studs, connecting rod bolts.
New bearings through out.
New 350hp rated precision intercooler( same as on Daves BW prodject)
new 36mm oil pump.
new water pump
etc, etc.....still need more parts, but getting there :)
Title: OEM tach, what happens if I spin past redline?
Post by: 935racer on January 08, 2008, 09:44:53 am
Some of them you can wrap around, some stop pretty quick after redline, not sure which models though, likely between ce1 and ce2. Mine in my jetta seams to stop right after redline, this weekend I might get around to installing the autometer one with a dakota digital box.
Title: OEM tach, what happens if I spin past redline?
Post by: jtanguay on January 08, 2008, 10:29:57 am
no rpm cutoff???  :shock:  crazy
Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 08, 2008, 03:43:12 pm
I have a line on a good oem unit for cheap.  I was just wondering if the tach would start to go to *** if you pushed it past its stops more than a couple times.   I had a old speedo in a diff car that only went to 85mph.  Car went faster than 85.  Soon the speedo needle started bouncing and would not hold steady at constant speed.  Thing made noise and pissed me off while I drove.  Dont want to go through that on this one if I can help it.  This is out of a 87 I believe, going into a 85.
Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 08, 2008, 03:44:27 pm
Quote from: "jtanguay"
no rpm cutoff???  :shock:  crazy


Thats what the man said.  I still have it all wrapped up sitting on the shelf.
Title: OEM tach, what happens if I spin past redline?
Post by: flapjack on January 08, 2008, 06:52:37 pm
(http://smellslikefries.com/vwpics/posts/redlinetach.jpg)
Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 08, 2008, 07:41:22 pm
Quote from: "flapjack"
(http://smellslikefries.com/vwpics/posts/redlinetach.jpg)


"One hundred twenty one Jigawatts!!!"

That was just classic Flapjack. :lol:  :lol:   *** like that is why I love this site. :D
Title: OEM tach, what happens if I spin past redline?
Post by: RabbitJockey on January 08, 2008, 08:39:08 pm
my modded cabriolet tach revs to 6, i assume it could go to 7 which i think is where it stops. i only know cause i down shifted on accident or something i forget what happened
Title: OEM tach, what happens if I spin past redline?
Post by: Mark(The Miser)UK on January 09, 2008, 11:46:59 am
Remember the needle is not physically attached in the speedo. In the tach it a pulse count. Thus neither will be 'hurt' :roll:
Title: OEM tach, what happens if I spin past redline?
Post by: malone on January 09, 2008, 03:11:32 pm
Quote from: "flapjack"
(http://smellslikefries.com/vwpics/posts/redlinetach.jpg)


:lol: nice chop. That tachometer picture is from 935racer's red MK2 Jetta when it had a stock 1.6TD and a slightly removed RPM governor. I don't recall if the needle can physically swing further than that.
Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 09, 2008, 04:37:17 pm
This is a vid from the french section.  The tach looks like it goes up to 7 grand?  Is it a gasser converted to the w signal?

http://www.dailymotion.com/group/26519/video/x2im2l_golf-mk1-16-td-portugal_auto
Title: OEM tach, what happens if I spin past redline?
Post by: foxracer1 on January 09, 2008, 05:47:56 pm
Quote from: "subsonic"
This is a vid from the french section.  The tach looks like it goes up to 7 grand?  Is it a gasser converted to the w signal?

http://www.dailymotion.com/group/26519/video/x2im2l_golf-mk1-16-td-portugal_auto


That doesn't sound like 5K. My car sounds like its gonna come apart and according to my calculations i'm only turnin 4100rpm @ 60mph in third
Title: OEM tach, what happens if I spin past redline?
Post by: jtanguay on January 09, 2008, 08:56:46 pm
Quote from: "foxracer1"
Quote from: "subsonic"
This is a vid from the french section.  The tach looks like it goes up to 7 grand?  Is it a gasser converted to the w signal?

http://www.dailymotion.com/group/26519/video/x2im2l_golf-mk1-16-td-portugal_auto


That doesn't sound like 5K. My car sounds like its gonna come apart and according to my calculations i'm only turnin 4100rpm @ 60mph in third


if the spedometer is working correctly i'd say the tach is right on... damn thats one fast car.

creepy music though... i pictured some dude walking out with a cape ready to do battle with some honda guy... then race him and pwn him.   :lol:
Title: OEM tach, what happens if I spin past redline?
Post by: Diesel Fumes on January 09, 2008, 10:05:36 pm
Im not about to tell you to over rev your VW, but heres a pic of my old diesel maxed out in 4th gear.

(http://img145.imageshack.us/img145/9682/img19925ih.th.jpg) (http://img145.imageshack.us/my.php?image=img19925ih.jpg)
Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 10, 2008, 05:03:04 am
Did the needle peg out there and get stopped, or did the engine climb past that point?
Title: OEM tach, what happens if I spin past redline?
Post by: burn_your_money on January 10, 2008, 09:00:35 am
I find it concerning that you were traveling that fast and were able to take the time away from driving to take that picture :shock:
Title: OEM tach, what happens if I spin past redline?
Post by: MJF on January 10, 2008, 09:33:57 am
Quote from: "foxracer1"
Quote from: "subsonic"
This is a vid from the french section.  The tach looks like it goes up to 7 grand?  Is it a gasser converted to the w signal?

http://www.dailymotion.com/group/26519/video/x2im2l_golf-mk1-16-td-portugal_auto


That doesn't sound like 5K. My car sounds like its gonna come apart and according to my calculations i'm only turnin 4100rpm @ 60mph in third

This (http://s13.photobucket.com/albums/a297/mattif/?action=view&current=MVI_2086.flv) is how my 1,7 sounds @5800&180kmh :lol:
Title: OEM tach, what happens if I spin past redline?
Post by: Diesel Fumes on January 10, 2008, 05:32:37 pm
Quote from: "subsonic"
Did the needle peg out there and get stopped, or did the engine climb past that point?
It just wouldn't go any higher  :lol:
Title: OEM tach, what happens if I spin past redline?
Post by: 935racer on January 10, 2008, 07:37:27 pm
Quote from: "burn_your_money"
I find it concerning that you were traveling that fast and were able to take the time away from driving to take that picture :shock:


Thats nothing I'll have to get you a picture of my jetta with the tach wrapped past 5500rpm and the speedo wrapped past 200 :twisted:

I won't take the picture though.
Title: OEM tach, what happens if I spin past redline?
Post by: subsonic on January 11, 2008, 10:48:11 am
So no one has experienced any damage to the actual tach from pushing the rpm's past the stop?