Five Oh Brian

Happy to give first hand insights. I've always been happy with bigger stall converters in my automatic cars, but this one was the first I've done in a Mustang (my first five Mustangs were all manual transmissions).

70MACH1OWNER

Well I stopped by to see my local mechanic about a price to swap out the converter. He accually put the task in the computer just like the Ford dealer and gets hours for the job. He quoted it at an 8 hrs job X $60/hr. Which included a fluid change and filter change. So basically $500 bucks plus fluid and new filter. Not as good a deal as Brian got but I am happy with his quote. So looks like as soon as I get $1K saved up I am going to do the TC. And going back and reading the amount of improvment that Fuddle racing claims of .6-.7 tenths on a stock car and up to 1 sec on modified cars this really is a pretty cheap mod for that amount of improvement. Very big bang for the buck. Only other mod than will give that much improvement for 1K is nitrous I think.

Five Oh Brian

$500 to install is fair. I made a killer deal with our transmission guy. Ford's flat rate is over 7 hours, but he agreed to charge for just 4 hours, which is about what it ended up taking. He's one of the best transmission guys in the business and has been doing them for a few decades.

All the stall converter companies have big claims for ET improvements. My GT improved "just" .25 seconds in the 1/4 mile, but I did not do ANY tuning to take full advantage of the stall converter. I fully plan to have this addressed during my upcoming dyno tune.

70MACH1OWNER

I am curious as what they can do to the tune that will help. I will surely ask Brent about an updated tune when I can pull the triggers on this mod. What can they adjust? I already have a pretty radical auto trans tune from Brent. My tune at present won't let 1st or 2nd gear shift until I hit 3000 rpm in each gear. And my OD won't kick in until 55 mph and will drop back into 4th on the decel at 50. Keeps the car on it's toes all the time. And all of Ford's torque managment is turned off. It really is already pretty aggressive. What else can they do?

Five Oh Brian

Scott, my understanding is that you can tune a few more items in the trans. Line pressure can be bumped up to firm up shifts (and increase trans life by reducing heat in the process). A good aftermarket stall converter has a much bigger clutch (my Fuddle converter has twice the surface area vs stock and they claim it can hold the lock up at WOT), so you can tune in a much earlier lock-up for 4th and 5th gears. With 4.10 gears, I finish the 1/4 mile in 4th gear, so locking up the converter in 4th gear would really help my trap speeds and that final push at the tall end of the track. I've heard some say that you can tune to lock up the converter in all gears, but I thought this could only be done in 4th and 5th. If you can do it in the lower gears, then tuning those to lock up at a specific rpm (i.e. 5,000+ or so) may net some additional acceleration. You already have the Ford torque management turned off, so I'm not sure what else can be done. On a side note, Toyota Prius owners should have the torque management turned off in their cars for some fun. I'm told that without it, the electric motor (peak torque at 0 rpm's!) would fry the tires. With proper traction, a Prius could likely hang with our cars in the 1/8 mile. Crazy stuff! Torque management keeps the Prius from unleashing all that low speed torque. Not as crucial in our dinosaur-sippin' cars, but still good to address. I haven't had the torque mgmt turned off in my tune yet, so I still have some improvements left on the table (hence the moderate .25 second improvement I've seen with my stall converter).

Sounds like with the tune you already have, you'll see a better improvement than I've seen at this point. 1/2 second in the 1/4 mile is very reasonable to expect. I'm planning on a dyno tune later this month and will have my trans & converter factored in for better gains. Coupled with the supercharger, I'm hoping for 12.30's or better in the 1/4 mile (sure would be a bonus if an 11.99 or better came along).

$1,000 for a 1/2 second improvement in the 1/4 mile is quite the bang-for-the-buck. Every GT automatic owner should be considering a high speed stall converter.

70MACH1OWNER

I called to Brenspeed today and talked to Dave about my present auto trans tune from them and what they might change when I put in the TC. Basically he said they will change thing I want but suggested I just use my present tune first to see how I like it. That is probably the smartest thing to do starting off.

And I ran a tune of Doug's for about 6 months that locked the converter in every gear if you were at least 50% throttle. I liked it but it kind of felt a little jerky because first the car shifted gears and than you felt a little bump when the converter locked. I asked Dave if the tune I am now running locked in every gear like that. He said "no'. Just 4th and 5th. He claims they have experimented with it but have not seen any benefit on the track so far.
And what is the stall speed of the stock converter again? I have seen numbers from 1600 rpm to 2500 rpm. But when I power brake mine it seems that the 1600-1800 rpm is more correct.

zipperhead

I have been reading this thread with interest. Only reason I have not upgraded my convertor is I believe I will just burn the tires off. I have tractions issues now. Maybe after I get my traction issue resolved I will reconsider this upgrade.

Just my two cents

Mikes_BLK_GT

Headers first then this but now this has become a definite upgrade for me.

70MACH1OWNER

Well I guess so with the KB 2.6 huffer and 3:73's. My little N/A car can smoke'm have way thru 3rd gear. Can't imagine what another 150 HP would be like.

zipperhead

I doubt I even making 150Hp at 2200rpms which is my launch rpm. At 6600rpms , well thats another story

Mikes_BLK_GT

Ive heard precision industries has a good converter for our cars that is multidisc. Any thoughts on them? I'm looking at deciding between PI and Fuddle I think.

70mach1owner this is a little off topic and I'll probably get slammed for this question but what has the cams done to your gas milage so far?

70MACH1OWNER

PM sent

Five Oh Brian

The stall speed is the rpm that the engine flashes to when you nail the throttle. It will be higher than the rpm's you get when you power brake (as the tires start to spin not letting you get to the actual flash speed).

That said, my stock converter (pre-supercharger) would power brake to about 1800 rpm's, but flash to about 2200 to 2300 rpm's, roughly. Take your car out on the road and move the shift lever to 3rd to lock it in gear, then mash the pedal you'll see what rpm you're flashing to.

Five Oh Brian

If your KB makes excellent low rpm torque, then you do not need an aftermarket stall converter. If the factory TC flashes to 2200 rpm's and your KB blower is making killer torque at 2200 rpm's, you wouldn't want to flash past that point.

However, if you're running a combination that is light on torque down low, but builds power as the revs rise, then you want a stall converter that flashes to the rpm's where you make peak torque. It's all about matching components to maximize performance in a desired rpm range.

Five Oh Brian

Kinda what I thought. You want the converter loose in the lower gears to keep your engine in the powerband. By the time your deep into the final gear (4th in my case) you want it locked to drive mph up to charge hard through the traps at a higher MPH. Also, at the higher speeds of 4th and 5th gears, aerodynamics really conspire against you and locking up the converter at higher speeds also nets you better fuel economy and lower heat.

Five Oh Brian

A quick look at your dyno graph to see where your peak torque is made will determine what stall speed you should consider buying. If your KB gets to peak torque by 3000 rpm's, for example, then plateaus after that with a flat torque curve (as I believe a KB likely does), then that's all the stall speed you want. Doesn't matter where peak hp occurs, you really want to focus on where the peak torque begins.

My centrifugal blower (much like a turbo) doesn't really start making serious power until much higher rpm's (not dyno'd yet, but probably 5000 rpm's or higher), so I definitely make good use out of a high stall speed (currently about 4,700 rpm's, or so). The 4.10 gear sure help get me out of the basement (rpm-wise) and into the thick of the powerband. Again, matching components for an intended powerband is key.

zipperhead

Looked at my graph and my torque goes straight up at around 1500rpm's so looks like the stock convertor is a good match. Good information on this thread.. thanks.. Now I can spend the $1K saved for the convertor on a traction components.

Five Oh Brian

Gotta love the instant torque of a roots or twin screw blower! No waiting for revs, just grunt & torque immediately!