Anyone have any experience with a B&M governor recalibration kit # 20248? I have one, and am looking to use its parts, or a combination of it and my TH400 parts. I would like to get 5800, or there abouts shifts. I want to keep it under 6000 rpm. Any hints, or starting points on springs and weights? Should I use the stock springs, and start messing with their weights? Should I discard my stock stuff, and use their weights and springs? Any suggestions on where to start, with colored springs and weights? I am not ready to do this yet, but am previewing the parts kit and instructions. Thanks for any insight. Regards, John.:TU:
Here is the instructions sheet, with the spring and weight choices. I hope this helps. Regards, John.
John, No shortcuts here, sorry. You have to do the trial and error method. Best advice I can give you is to change one thing at a time. Get a clean container to drain the pint or so of fluid you will lose every time you pull the governor. Try one lighter weight and everything stock. don't change the springs at all until you get in the ballpark with the shift points. then one spring at a time. It takes some time, but the testing is fun. The weights get you in the ballpark and the springs fine tune the difference between the 1-2 shift and the 2-3 shift. Check the 1-2 full throttle shift. Then take it out on the highway and floor it at 50 MPH, and watch where it shifts at from 2-3. You can minimize your fluid loss by jacking the back of the car up. Good luck.
I know lightening the weights will raise the shift points, but it won't raise both the 1-2 and 2-3 shifts by the same amount. The other variable which affects the shift speeds is the springs. To really tailor both shifts you will need to change the spring force as well as the mass of the weights. Sorry I am not much more help, but I have only done this twice and each tranny was different. Last one I did was two light weights and the yellow and I think orange for 5500, but I wouldn't slap that in there. You need to know where you are and then just make one change at a time. http://www.dragracingonline.com/technical/vi_9-bm-1.html Clyde
Thanks Larry. Thanks Clyde, nice link, very informative article. I had only one real question about it. It said to repeat the process on the second set of inner and outer weights. Are those weights going to have different numberd weights in them? My B&M kit only has one set of numbered weights. In other words, they all have different looks and numbers, up to 6. The lower #'rd ones are blocky and get pointier. But then as the numbers get higher, they go blocky and get pointier again, up to #6. Does this make sense to you? Regards, John.
John, you are looking at this from the point that a certain recipe will produce the same shift points in every car. Probably not, is what I would say. The best course of action is to get another governor. Then get a baseline with what you have in the car now. Change to your spare governor and get another baseline with that governor. Then change one inner weight and test to see what affect it has. Lighter smaller weights will raise the shift points. Keep going lighter until you get close to what you want. Then change one spring at a time. Typically you will get close to the RPM you want for the 1-2 and the 2-3 will be lower than what you want. A spring change will get the 2-3 higher while changing the 1-2 slightly. Again 1 thing at a time or you will make yourself crazy. If you mess up, you can always reinstall the original governor.
Larry is right, sometimes there is no rhyme or reason to these. The specific valve body calibration has an affect on it too. A Corvette valve body will shift different than a pickup truck VB and the governors will cause differences. I have never used the B&M or other recalibration kits. I always just mod a stock governor. I have an online aritcle on it here: http://www.nastyz28.com/forum/showthread.php?t=62163&highlight=governor
I will check out your link, but my question, is: From my understanding, there are two seperate inner and outer weight combos, on the governor. Do I only work on the one set, and leave the other alone? Do I need to change both of the inner and outer weight combos? If so, do I need another kit, or will the left over pieces be able to do the job? Do you understand my confusion? I understand that I will have to play around with it, but do I have to play with both sets of inner and outer weights? Or is there only one set of weights? From the pictures, it looks like two, 180* apart from each other.ou: Sorry I am so thick. Thank you so much to all that have tried to help, I do appreciate it. Regards, John.:TU:
Thank you for the link. It helps a lot. It looks as though I will need to play with both weights, to get what I want. I will go as high as I can, in the first weight set, to the #6 pointed weight, and if I need more, go to one of the lower numbers on the other weight set. Right? Or should I try to stay with more even inner weight numbers in both sides? In other words, use a #6 in the first set, and a #3 in the second. Or, use a #5 in the first, and a #4 in the second. There may not be a right or wrong answer, I am thinking. Am I picking this concept up? Thanks for the interest in my car! Regards, John.
one pair of weights and springs, so 2 of each total. I think the inner weight youre thinking of is more of a mounting pad for the weight/spring assembly to the governor. I was thinking about one of these kits (will probably do it), but also was going to get an adjustable vacuum modulator, what will the vacuum modulator effect? thanks
Steven, From what I understand, the modulator, will only affect the part throttle shifts, and only by a few 100 rpm, it will do nothing for w.o.t. shifts. Don't waste your time, if you are happy with the light throttle running of your car. Regards, John.
John, You need not be concerned with the outer weights. That is not what is in the kit. Only the inner weights are changed. One at a time. look at your present governor. Remove one inner weight, and compare it to the ones in the kit. Select a smaller one to increase the shift points. Remember, one at a time. Then test and evaluate (the fun part). Get some small needle nose pliers. The weight axles have small e clips. Once you set the governor up with these, weight changes are a snap. Opening the governor cover is the hard part. Try to save the fluid and not get burned. All the weights in the kit are INNER WEIGHTS.
I tweaked mine a little bit last week and managed to get my 1-2 low speed shifts to occur about 3-4 MPH later by drilling holes into the outer weights. This had absolutely no effect whatsoever on the full throttle shifts. With my inner weights ground as shown, my full throttle 1-2 shifts happen at around 5,300. 2-3 is a little bit lower, maybe 5,100 but I don't care about that.......I'm usually at least a few car lengths ahead of the other guy by the time the 2-3 shift happens anyway. :laugh: Just to give you an idea of the effect of weight on these secondary weights, you don't have to make huge changes to alter your shift points once you are in the ballpark. I was able to jump from 5,000 to 5,300 just by trying the springs you see in the photo. I got them from an extra stock governor I had laying around, and they are about 1/8" shorter than my stock springs were. And they feel to have the same amount of tension. Most of the improvement I got was from grinding so much off the weights. (my stock full throttle shift point was about 4,500 RPM) For some reason, when I changed out my 1-2 accumulator spring it affected my full throttle shift points a little bit, that's why I had to tweak things a little bit. I suggest that if you plan on installing a shift kit, do that before taking the time to set the governor. ou:
There are two inner weights, one on each axle of the governor, the 6 weights you show are pairs. #1 and #4 are the same, etc. You don't have to match the pairs, so you can use a #1 and a #4 together, or a #1 and a #5 together. I would start out with matched pairs though...
So if one didn't like his 2-3 shift (too early) but the 1-2 shift is about right, the springs should be changed to lighter ones to bring the 2-3 shift up a bit? In other threads, I've stated that this is my concern too, and have purchased the B&M recal kit but haven't had time to do any tuning.
