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HELP: TACH CONVERSION QUESTION???

Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
We are putting a tpi 350 (L98) into a 89 YJ and I'm looking for a tachometer conversion module.

Josh (who I'm paying to do the motor swap) from the Rad Jeeper says I need one to convert the v8 tach signal to a signal the stock YJ I6 tach can read.

We are running stock chevy ignition.

Brad at the Rad Jeeper says he gets a tach converter from advance adapters, but didn't have a part number or cost, so I called advance and Gino there says they don't carry anything like that and they even used an aftermarket autometer tach on their shop YJ that is running a 350 (of course he didn't have an autometer part #). They do have one to convert the signal for a 350 to a FJ40 that they order from a shop in Australia, but that's besides the point. He said, "don't you think if we sold something like that we would have it on our own vehicle?"
I laughed, "good point, thanks for your time :)."

I spent 45 mins on the line with Summit Racing and they don't have anything unless I was running a MSD ignition, and even then they couldn't say difinitively if it would work with the stock tach.

#1. Do I need a tach conversion module to make the stock tach work?
A. if so does anyone know where I can get one?

If it won't work without some sort of conversion module and there is no inexpensive way to convert the signal; I have no problem running an aftermarket tach.

#2 What tach should I use to fit in the stock dash that looks factory-ish?

#3. Not that I mind (because I like this stuff)... but why the heck am I doing all the leg work if I'm paying someone to do this swap for me???... lol :confused: :D

Thanks. I figured its not that uncommon to put a 350 in a wrangler, so maybe you guys can help me and this thread can help someone else down the line.
 
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DaveB

DaveB

Long Jeep Fan
Location
Holladay, Utah
The six cylinder tach wouldn't read correctly with the signals from the 350 so some conversion or aftermarket tach would be needed. I should hook up my oscilloscope to both and compare the waveforms to see what it would take to convert the signal.
 
L

larrybenny

larrybenny
Location
Salt Lake City area
go to www.dakotadigital.com they sell a module (150.00 or so) to convert the v8 to the stock 6 cyl. tach. Personally I chose to use a digital aftermarket tach mounted to the dash. In the install kit of the aftermarket tach, it comes with attachment to clip to any spark plug wire, or, in my case, there was a tag labeled on the painless harness for "tach" and I just clipped the other provided wire in the kit to It.
 
Rusted

Rusted

Let's Ride!
Supporting Member
Location
Sandy
I acutally stopped by Novak the other day to check out there shops. Call up there and see if you can talk with Ken. He knows that stuff inside and out, and if he can't give you the answers he can send you to the right direction.
 
R

rholbrook

Well-Known Member
Location
Kaysville, Ut
Rusted said:
I acutally stopped by Novak the other day to check out there shops. Call up there and see if you can talk with Ken. He knows that stuff inside and out, and if he can't give you the answers he can send you to the right direction.
Click to expand...

Ken is the MAN at Novak. His LJ sure runs good with the 5.3 in it. When I was with him he lifted the drivers front tire off the ground like a TJ running a shortarm kit. His long armed LJ would be a street racer if it had an automatic in it.
 
Tacoma

Tacoma

Et incurventur ante non
Location
far enough away
If it was me, I'd run an aftermarket tach on the column or something, and forget about converting it.


EDIT: is there some reason you need to run the stock tach? Some ECM issue??? If not, DITCH IT. Tach's are cheap at any parts store. Or you can buy mine for like $20 hahah
 
eatrocks

eatrocks

Registered User
The Dakota interface for the tach is 80.00 plus shipping and easy to set up. The install that redline does to install the VDO tach in the stock cluster is about 200 to 300 if you can get them to do it. I am always looking for a better way. The YJ tach will work with the Dakota unit, its part number SGI-8 Novak has them in stock (I’m looking at them and one is in my hand as I type this) CJ YJ MJ and XJ are easy lets not talk about the 05 or 06 TJ/LJ or my current reson for loss of sleep the JK.

I like my 6 speed! The NSG370 is nice and holding up well. No auto for me thanks. The picking up the left front tire, during that test ride with rholbrook and his son, is the only time I have gotten the LJ to do that in 100k miles  This weekend should mark 10k miles since installing the 5.3 the 1st week of January. All is well save that snack the aluminum eating rock in Moab had and the fix to that was a car oil pan.
 
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UNSTUCK

UNSTUCK

But stuck more often.
gravesdiggerxj said:
Josh (who I'm paying to do the motor swap) from the Rad Jeeper...


#3. Not that I mind (because I like this stuff)... but why the heck am I doing all the leg work if I'm paying someone to do this swap for me???... lol :confused: :D[/B]
Click to expand...

Let me just clarify a few things here.

Yes, I am being paid for this job. Yes I do some contract work for the Rad Jeeper now and then. No, I am not an employee of the Rad Jeeper ( I was a full time employee for a coulple of years. That ended over a year ago).

You do the leg work because you asked to do this kind of stuff during the project in order to keep your cost down. Remember? ;)
 
Grim

Grim

Well-Known Member
Location
Roy, UT
eatrocks said:
T

I like my 6 speed! The NSG370 is nice and holding up well. No auto for me thanks. The picking up the left front tire, during that test ride with rholbrook and his son, is the only time I have gotten the LJ to do that in 100k miles  This weekend should mark 10k miles since installing the 5.3 the 1st week of January. All is well save that snack the aluminum eating rock in Moab had and the fix to that was a car oil pan.
Click to expand...

looking forward to seeing your jeep on the 22nd
 
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
Oh ya I forgot to update this. I ordered the Dakota Digital conversion box from Novak. Just waiting for it to show up. Anyways I'll have a full update once I get it installed.
http://www.dakotadigital.com/index....tegory_id=287/home_id=59/mode=prod/prd127.htm

prd_zm_127.jpg


hope this helps others in the future
 
O

oldschoolyj

Registered User
Location
Bluffdale
I used the gauge pods from Quadratec, part # 12500.222 and 12500.220, and then I used autometer gauges. Fits very tight and has a factory clean look to it. I am running the 5.3 and I turned the Autometer tech to read for a 4 popper and it works great.
 
eatrocks

eatrocks

Registered User
I have found that sometimes the tach output on the GEN3 is too weak. To bring it up stronger put a 680 ohm resister across the tach output and 12 volts switched with the ignition. this is acalled a pullup and increases the spike.
 
Gravy

Gravy

Ant Anstead of Dirtbikes
Supporting Member
Location
The Land Northward (Bountiful), Utah
Grim said:
keep us posted on the swap , i think this is my next big project
Click to expand...

Josh installed the tach conversion and it worked for about 1 day. He had shorted two wires together incorrectly.

I'm still trying to find time to sort it out. Kind of annoying to have no tach but in an auto it's not like you NEED it to drive. I just am trying to figure out if my idle is high and what rpm's it turns on the freeway to maximize my gas mileage.

eatrocks: I'll have to give you a call and see if you can help me get it to work. I can bypass the module and get a tach signal... it's just way off.
 
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