As mentioned earlier, we switched my Spicer for an Allison 647, upgraded the C60 injectors to N65, and added Jake brakes. We took a little trip over the FofJ weekend. It was only about 100 miles round trip but involve descending and climbing a grade that was at least 8% in 100 degree temperature. I am still happy with how this is working out. I really do think that the 2-stage Jake is great. For much of the descent, I could just leave it in low and coast down the hill between 40 and 50 mph. Putting the Jake in high would start slowing the bus down and require a little throttle to keep at that speed. Formerly, I would go down this hill in 2nd at about 30 mph to avoid braking.
The bus was able to keep an even speed on I-10 in spite of minor inclines. The C60's would often require me to downshift. I always felt I was spending to much time out of 4th. Now it is much more acceptable.
The bus is still no mountain goat. A 6v92 would have done wonders for climbing, but this is what it is. I always take a running start to attack the Yucca Grade and that was no different this time. However, what was different was that formerly I would always have to get down into 1st to crest the hill. I was now able to do it in 2nd at around 1600 rpm. The real good news is that the temp gauge stayed pegged at about 190 for the climb. It used to hit 200. The difference there could be that air leaks around the radiator were sealed, we used some condensor cleaner on the radiators since last summer, and the rear mud flap has been removed. This is important since we mounted the transmission coolers in front of the radiators and there was a theoretic possibility that this would reduce cooling. Also there was a question about whether the N65 injectors would be producing more heat. Where it makes sense that both of these things effects cooling, our small improvements were more than enough to compensate. I think that once I remount the mud flap behind the rear wheels, I should be pretty safe.
Sorry to bother anyone with this stuff, but I thought that it might be useful information for anyone considering similar changes.
Glad it worked out for you. I still drive my ole 7 by the temp gauge and have made improvments but still am not satisfied. Just something on my check list. Part of owning a bus!!
Awesome, no bother to us, always enjoy hearing how things work out or a follow-up on a problem or fix,
even if your just gloating or bragging :D
Scott,
Do you have a skirt running across the bus just behind the rear wheels. I have been told that it is one of the best, cheap cooling enhancements available. Skirts across that back by the bumper are a no no though.
I have a pair of flaps behind the wheels but not across the entire bus. I might try that.
Scott,
Apparently, by having the flap go completely across the bottom of the bus, you create a strong negative pressure behind it. This reduces the back pressure the fans have to deal with and allows more air to be pulled through the radiators. Voila-- a free cooling increase. I'm sure that you have made sure that no air gets around the radiators. Also HD has an aerosol can of condensor cleaner for around $7. Getting the radiator fins cleaned can only help if it has not been done in a while.
Scott, we call this a poor mans wind tunnel but if use a piece of yarn on each side of the bus drive it and watch the yarn if you really want a flap it will tell you what the best spot is take the guess work out of it
good luck