TFI Conversion questions.....

[billyrb]

After reading many of the previous posts and readers websites (incl irbob's), I have a few questions: First, for an 85 GW with a 360, which parts & part numbers do I need? Will the part numbers from irbob's page match with my year/motor? Next, what are the advantages to adding an MSD box? Is the cost vs. benefit ratio worth the added cost? Third, I have read about people trying to bypass the resistor after making the conversion, and others talking about NOT bypassing the resistor....which is the preferred method? Fourth, does anyone have a clear, concise, step-by-step method for this conversion? Any help is greatly appreciated!

~ryan

[bchesley]

The parts on irbobs website is the list you need. I just bought them friday and all the numbers are still good. The aftermarket ignition boxes are going to give you multiple sparks per hit and not a hotter spark. The hotter spark is what we are after. Adding a box will make it burn more efficent but wont have that much more impact unless you have a really hot motor. The TFI upgrade is worth the money for sure. I will probably add an MSD box an even hotter coil when I add a intake and fourV carb. I left the resistor wire alone, and I got the results I was looking for. The steps are just like a normal tune up except you are going back with different parts. The hardest part was getting at the passenger side rear spark plug.

[irbob]

The part numbers will work but some have diffrent prefrences on manufacturer of those parts but the ones that I listed worked for me and many others so far. If you can change a spark plug you can do this upgrade. Just replace the old with the new. The cap on your OEM coil is replaced with the TFI plug so that may be a bit confusing but not bad. Hummmm I guess i need to add another section to my TFI page. I listed all that great information but didn't think about the install instructions. Let me know if this helps out any. Later, Bob.

[bentpushrod]

I just finished up my TFI. Went very smoothly. Like Bchesley mentioned the hardest part is the rear passenger side spark plug. But even that isn't bad. I found by crawling under the Jeep it was actually easy to get at.

I see no reason to buy a coil bracket, it's very easy and quick to modify the existing bracket to work. I did mine then went to irbob's site. His bracket is just like mine.

By the way irbob, very nice site. smile.gif

[irbob]

bentpushrod...thanks and good job on the TFI. Maybe we need to start a TFI club. <JOKE> :D

[FlakeyJake]

I have a question on the TFI upgrade. If the objective is to get the 'hottest' spark, then wouldn't it be better to use an even 'better' coil like the MSD Blaster which touts 45kV? I've seen mention that the TFI coil supplies 30kV and the stock is 20kV. If that's the point, then spend the extra $15 and get a blaster II coil.

Am I missing something?

[irbob]

I see your point about the better coil however you can always find something better no matter what it is. The idea behind this TFI upgrade is to be able to hit the salvage yard and pull all these parts for cheep. That's why I put pix on my site so you would be able to identify what's needed. I didn't know what a TFI coil, dist adaptor, or larger cap looked like so I ended up buying all new after my parts guy showed me what it all was and what vehicle it goes with.

For the cost this TFI upgrade is all most people will ever need to get a little boost of energy. For those that want to build a hopped up 400 hourse monster buy the best you can. This upgrade may not be for you.

[ElkHunter]

I went for the MSD Blaster coil and so far am happy.

I'm going for the MSD ignition box next, but not until after hunting season. Gotta keep the priorities straight, you know.

Anyway, with the hotter spark on the coil, should the spark plugs be set to a wider gap to take advantage of the hotter spark?

Anyone know?

ElkHunter

[Stauter]

Elk Hunter I went with the Blaster II coil also. I opened my gap up to .045 didn't seem to help. Decided to change to A/C Rapidfire plugs, these were a marked improvement over the autolites. I left them gapped at their preset .035. They are a little pricey at $3.99 but they sure made a difference in my idle and throttle response. I would recommend adding them to your TFI upgrade.
Craig
(we have been running them in my son's scout for a while now and am still impressed)

[irbob]

I would still gap those plugs at 40-45.

[Puslinch]

I had a MSD Blaster coil in the garage left over from another project. Instead of the TFI upgrade I swapped in the Blaster this made the biggest difference other than the EFI installation. I've been running for over a year with stock spark gap. No problems with the cap or rotor, I did upgrade the wires to 8.5.

[ElkHunter]

Thanks for the responses, guys.

I'll leave the plugs as they are. And at some point I'll upgrade the plugs and go to the MSD ignition control. I usually end up doing these things in stages. Easier on the budget and the marriage.

God bless all Americans today after yesterday's tragedy.

ElkHunter

[JeepFreak]

I guess I'm gonna be the exception to the rule here because I didn't notice hardly any difference when I did the upgrade. But I was chasing another problem as well though. The TFI coil cost me $25 brand new and the blaster coil was listed at $75. Well 50 dollars is alot of money to me so I just went with the TFI coil and it work's just fine. I went with all Orielly's parts and they crossed the part numbers listed on Irbob's site with no problems. Only thing I got different was Accel wires for the 460 instead of the Kit ones.

[Lindel]

I'll put my $.02 here. I've done the TFI mod, sort of. I upgraded the cap, rotor and wires, already had a Jacob's Ultra coil, being driven by 12v, not the 5 or 6v the stock coil is hit with, but didn't mess with the dist advance springs. I'm using the stock dist, driving the vacuum adv off of intake vacuum, not ported vacuum. I haven't tweaked the adv (yet), but will play with it soon. I run my plugs at about .40 with good results, they only show the usual normal wear as they age. BTW, I'm using the stock ignition box, since the Jacob's unit died after 4 years. So far, so good. I also avg 13.5 combined city/hwy mpg, with 3.54 gears, and 31" tires.