ballon78

just did a 454 to 502 swap and have TB V ignition with knock sensor. My rev limiter is too low at 4700-4800 so i want to change it. Can i just unplug the TB V ignition module and plug in the TB IV one? Will the TB IV work with the knock sensor or do i disable that too by unpluging it too?

What is the best Ignition module for my New gen 6 502 415hp carb holley 800, EMI headers with long tubes? IN a heavy baja outlaw24.

Dont want to go MSD, want to keep the super reliable TB ignition!

thanks

1BIGJIM

iTrader: (1)

Some else might speak up but isn't a TB V controlled by the ECM and knock sensor. TB IV does not have an ECM.

ballon78

Mine doesnot have a ecm just a Ignition module and the a knock module on top...let me see if i can get a pic..I know that some do have an ECM but i think only on TB V that ate v6 4.3. Mine was a 454 carb 330

ballon78

THis what I have....very simular to the TB IV...no ecm..

CHECK OUT PAGE 16, AND THEN THE WIRING CHART.
http://www.boatfix.com/merc/Servmanl/16/16B4R2.PDF

Griff

You could just get a TB IV module and the plug in harness that goes with it. It will not have any rev limiter. That or get a TB V module from a different, higher reving engine. PM rsteiny, he may have a V off his. You could probably also have the rev limiter raised in your module, but not sure about that.

ballon78

Griff, did u see what the module that i have looks like? It sort of looks like a TB IV module but its a TB V. its nothing like the HP500 or bulldog 500 TB V module, those look more like an ECM and have two conections on them. I know my module that i have isn't progrmable, the color on the wiring schematic are the same except for the wire that goes to the knock sensor. i just dont want to get into switching my entire harness over, cuz i just got done, extending some things and retapping and wire looming the whole thing before i droped my new motor in last weekend.

Do you think mt stock 502 mag shold rev more than 4700? i think thats where my rev limiter is set at but dont know.

502ss

iTrader: (3)

All the info you need can be found at the link below assuming you are talking a 502HO (450HP)

Max RPM = 5500

Max HP is made at about 5200

http://www.gmperformanceparts.com/En...8778&engCat=bb

Griff

Yes, I saw the pic. Yours is on page 4B-14 right??? Your module is the same as what was used on TB V carbed 500hp's. Yours is just mounted on the distributor and the 500HP ones were not.
http://www.mercruiserparts.com/Show_...RU+0L001772%29

ballon78

Ya thats mine, I think i figuared out what to do, i just need to get a 454 Mag module from a thunderbolt V!!! Dont know whay i didnt think of that way back......I however gooled the part number and cant find one unless i buy new and they are 400 plus dollors. Someone i'm hoping has one. I think the mag has the rev limiter at 5250.

806745A01 MODULE-Ignition Control old number 806745T5 (454 MAGNUM)

Griff

454mag will have a 5150 rev limit and the 500HP will have a 5350rpms limit. Either will work fine.