The project: Replace the ACC Boss Hog 2800-3200 converter with 6 seasons on it with a higher-stall, higher-quality Hughes GM40HD converter.




I had a new SFI flexplate, so that was going in while the tranny was out.




I heard a clink of something hitting the floor when I pulled the original 1966 396 flexplate off the crank. Can you guess what made the clink?




I feel much better with the new parts going in.




First T&T is next Saturday. Hope to get it back together this weekend to be ready assuming the weather cooperates next weekend. It'll be interesting seeing how much difference it makes.

 

hmmmm must be an adjustable flex plate with those slots in it lol. hopefully the new converter helps you out a little bit. any real reason for the switch besides just having some age on the converter?

 

I was getting inconsistencies, primarily in 60'. I'm hoping the Hughes will resolve that.

 

ahh. hopefully this takes care of it, hopefully i'll be seeing you this year at div V finals.

 

That would be cool. I missed it by one round in 2008 - held at the home track, no less. First time I wasn't qualified to go since 2002.

 

Because the SFI flexplates are date coded, I have to replace mine every 3 years. Just replaced the last one a few weeks ago. One broken tooth is enough to yank it out anyway but for some reason I also found a few loose mount bolts.

Red Loctite and torqued the bolts and I'm good for another 3 years.

Worst part is that the SFI shields are only good for 5 years. That means the flexplate needs be be replaced before the shields are due.

 

those are the smallest mounting tabs i've ever seen on a converter on that black one. I wouldn't feel safe running something with tabs slightly thicker than the hole drilled into them.

 

I actually bought the flexplate last year. Late in the 2007 season, I had a knocking noise after time trials. Pulling the tranny bellhousing cover revealed loose torque converter bolts - two were actually stripped. I did a pit repair on the bolts, but it wasn't completely quiet. That week I looked into it further and discovered the flexplate bolts were loose. I tightened them the best I could without removing the transmission, and kept running. I got the flexplate in the off-season, but never got it installed last year (a lot of travel for work). This year I decided I had to get it done one way or another, and had decided on the new TC while I was at it. Only one of the 6 flexplate bolts was really tight (all of the torque converter bolts were tight - I had replaced them with longer grade 8 bolts, put lock nuts on the other side, and used Loctite).

The ARP instructions said to use their moly thread lube on the threads and under the head, and torque to 62 ft-lbs; or 80 ft-lbs if using 30 wt oil. Stock torque is 65 ft-lbs. Since I had some of their thread lube, I just used it. Seemed to torque up very easily - almost like I didn't really have them tight, but they were.

Oh, I'm not required to have an SFI flexplate, but figured while I'm at it, I might as well get one.

 

They looked a little whimpy to me, too, but they're still fine. Estimated 500 RWHP w/100 shot moving 3900 lbs down the track, no problem.

I like the look of the Hughes ring mount much better.

 

Cranked it over this afternoon. Funny, it's a lot quieter cranking now. . .

Overfilled the tranny, so I need to drain some out before I take it off the stands. Hasn't move under its own power yet, but it's cold, windy, and has been snowing outside today - not sure I really want to take it out.

 

I have a hughes GM4o convereter myself, and have always had a converter slip issue, about 12 percent, let me know if you have the same problem or if it is just me.

 

I'm not sure I remember my trap RPM exactly (was below the shift RPM, that much I remember), and I'm not sure about tire growth. But, using TCI's slip calculator, looks like it was more like 15%.

I chose the HD version because it's supposed to have a little stouter sprag. We'll see how it does - I suspect it'll change things from "go" to "whoa".

 

By 15%, are you refering to your boss hog converter?

 

Correct.

 

I had a Hughes 3000 converter in my car for a while, I loved that thing!

 

15% is a little excessive, for that matter so is my 12%, it makes me wonder how much you have to spend for a good converter, I paid over 500 for mine, and I am not real pleased, and I do not want to fork over the money for a custom converter, so I guess it will just slip a little.

 

The Boss Hog was a big step up in performance from the Saturday Night Special I had before that, primarily because of the higher stall, I'm sure.

I'm more interested in consistency than getting every nth of ET or MPH. Hopefully that will be the result.

Last night I started it up again (after getting the fluid level down where it should be), dropped it down from the stands, warmed it up a bit and made sure it went forward and backward. I tried a couple of stalls (not the smartest thing in the garage, but hey, it's my house and my car), it seemed to pull through the brakes at a lower RPM than the Boss Hog did. I don't have a playback tach, but I'll see in a week or so how it does at the track. Of course, rarely is a change made independently - I'm also trying a different carb tune for the E85, so the next shot at the track won't be just a converter comparison.

 

I think anything with more than 10% is too much. My TCS 6000 stall converter gives me less than 5% slip.

 

I missed T&T last weekend because my mom passed away last week. They ran Saturday, but weather canceled Sunday. Still haven't pulled it out of the garage. This weekend the forecast is horrible through Saturday (already raining today, supposed to snow tonight and through Saturday), but Sunday looks better. I might get out there in the afternoon. The first race of the season is next Friday, so if I don't get out there this weekend, I'll have to try a Wednesday night T&T - usually a big crowd, a lot of street tire FWD in the groove, not the best for obtaining data.

I'm making 3 changes at the same time - converter, carb mods, and electric water pump. So, which is doing what will be hard to determine.

The way things typically go for my "upgrades", it'll run exactly the same as it did last Fall . . .

(Make that 4 changes - also have taken 30 pounds out of the driver's seat.)

 

sorry to hear about your mom, but congrats on taking that 30 pounds out of the driver's seat! looking forward to hear your results

 

I wish you and your family the best sorry to here about your mother.

 

First T&T this evening, only 3 passes, and I only remembered to look at the tach when crossing the finish line once, and I'm not completely sure I read it correctly. But, looks like about 9-10% slip.

The other end looked pretty good, though. 60' went from 1.87 or worse last year (never better than 1.85 that I recall) to 1.783, 1.804 (pushed in the beams that run, had set the rev limiter 100 RPMs higher), and 1.795 (humidity was rising by then). Along with the electric water pump, ran 13.02 (goofed up the 1-2 shift), 13.00 (ran out of fuel about 1200') and 12.98 (finally a good pass), compared to 13.2's to 13.4's last year (13.4's in April, 13.2's in October). RT's were .040, .038, and .027 - not too bad for shaking off a full winter's worth of rust, new configuration, and limited test opportunities. MPH went from 99-101 last year to 103 tonight.

We'll see how it goes Friday night for the first points race.

 

Couldn't get a green light in the two allotted time trials Friday evening. A -0.003 leaving at 3100 RPMs, and -0.002 leaving at 3000 RPMs. For first round, I set it back to 2900, it sputtered when I let go of the brake (not sure exactly what happened there), poor light, slow run, lost.

Saturday was rained out.

Today was a "special" race, jackpot races and "king street". Had a nasty head wind (20 MPH+) most of the day. The jackpot was standard box/no-box & trophy, the king street has a 12.75 or better requirement, which requires power adder for me. I tried a 50 shot, and that produced mid-12.3's, so I stayed with that. Lights were green again (not sure what's up with that). I was running NA in the no-box class. A bit of a challenge remembering what configuration you're running, getting the right dial-in, etc. In the 3rd round of no-box I had a .011 RT and got treed for a .0014 MOV loss. Kept going rounds in king street until I got to the semi-finals (5th round), and went brain-dead for my worst RT of the day (which was still better than what my previous 4 opponents in that class had).

Best NA 60' of the day was a 1.75, worst 1.77. I think I can live with that. With the 50 shot, 1.66 to 1.68. A little more variation than you might want to see, but I was dealing with other things as well (such as an alternator field wire that pulled out of the terminal, which dropped my battery down before I could fix it, and made having the same temp when staging each time difficult). Certainly better than the Boss Hog had been.

 

Video of a NA run.

http://videos.streetfire.net/video/4...49015.htm?ref=

Remember, 5800' elevation, 3830 lb car, and there was a 20 MPH head wind that day.