this weekend, went from a Yank ST3500 to a Vigilante 4800 and the 60's got a lot better. I also went to a traction bar setup. Traction Bar Actually made my own. This elminated the rear sway bar and rear air bag.

With the new traction bar setup the best 60' I could do was 1.55-1.57 now I'm cutting 1.50-1.52. The traction bar setup let's me run a higher PSI in the slicks, I'm currently running between 16-17psi in them. The track this weekend was cold, track temp was 50 degrees, and this was done at night. Can't wait and see what it would do a day run, hopefully she will be dropping in the 1.4's

 

nice runs Ken, what were your actual times? 4800, do you know the STR and shift extensions with the new stall?

 

Nice times man! I just installed a 3000 stall in my car, I can't even imagine what a 4800 would be like

 

11.40's on this converter, I think it was 11.41@117, humidty was very high that night. DA was good but the power was just not there.

Shifting about 6950 and it's dropping down to about 5500-5600.
STR not to sure what's the rating on this one, I'm borrowing this one to see if I like it or not.

It hits as hard as my 3500 did if not just a tad harder.
I will know more this coming weekend if I like it or not. I thought the ET would be more than that compared to my 3500. Need another weekend of testing to see if I like it or not.

 

Whats your take on the new converter....????

 

Still not decided with it, the only bad part is that it builds heat up in the tranny quicker than the Yank. We might come down on the stall speed to a 4000-4200. We also made a change to the camshaft. We went ahead and advance the cam 4 degrees. I will find out more this coming Friday night if the 4 degrees helped out or not. I was expecting the car to be running in the low 11.0-11.2 close to 120mph range. We will soon find out.

 

I am glad you saw an improvement, but I am not sure the times you report as being "a lot" better. But if you are happy, great!

Rich

 

Rich, The only thing that were better was the 60' ETs this should have netted a better 1/4 ET but it did not. This tells me that the converter is not right for the combination thats I'm using. Hopefully advancing the cam might make it better, really won't know until this Friday. The cam is a custom grind cam on a 108LSA and has a very large lift for a hyrdaulic 620+. I'm running quicker than I was last year almost 3-4 tenths quicker on virtually the same motor combination, just the cam change and bumping the compression up a little 12.5 to 1.

We are never happy with any setup that we come up with. Seems like its more a delayed response than anything else. My goal is to get the car in the 10.90's with the 355 than we will get the 383 going and bust some 10.20's-30's with that combination. We have a good combination for a 383 (proven) just not a good combination for the 355 yet.

 

A lot of times the rpm drop at WOT can give you a close estimate of the stall speed. Even if gearing drags the rpm below the stall speed, the converter should flash to the stall speed until the rest of the car catches up. It's very hard to see when driving since it's so fast. I watch mine after a run on a playback tack running at 1/3 speed. With everything slowed down, you can see so much more happening.

My converter stalls at 5700 on the transbrake. I shift at 7000 and the rpms don't drop below 5700.

Stall speed rating of a converter is only a guideline. The same converter behind different engines will stall at different speeds. Stall speed is determined by the amount of torque put into it. What works well in one car may not work very well in another. Even racing at different altitude tracks will change the stall speed since less HP and torque are produced at higher altitudes. Going to race at a high altitude track might mean changing to a higher stall converter to bring the engine's rpms back into it's prefered operating range.

 

Thanks Stephen, that's all I need is another variable thrown in the pot. I have logged the run and it drops down to about 5500-5550 between shifts and shifting at about 7K (6950 to be exact). Hopefully advancing the cam will get me what I need and if not...The biggest item in bracket racing is making things consistant, right now the stall is generating to much heat between rounds. Going to try to get my tranny temps to be the same between rounds.

Got the cam advanced and fired her up tonight, neighbors just love me.

 

In general you do not want the rpms to drop below the stall speed of the conveter at the shifts.

Rich

 

Ken what did your 3500 drop down too?????

 

The 3500 dropped down to about 5200 between shifts.

 

My car uses a rad from a turbo Firefly (alcohol engines run very cold). Right beside it is a tranny cooler almost the same size as the rad. It keeps my tranny oil temp down below any dangerous temperatures. I run a temp gauge in the engine and tranny oil pans. I don't have a fan on the tranny cooler yet but it may be an option in the future to help bring the oil temp down when coming back up the return road. I really see the temperature climb when I'm on the transbrake. Unlike the electric water pump and fan for the engine, the tranny oil doesn't circulate through the cooler when the engine is shut off so you need to get the temp down before you shut it off.

I've seen guys use leaf blowers aimed at the torque converter when in the pits. That's where most of the heat is retained.