Just wanted to let everyone in on a little testing I just completed.
I mixed my trans fluid 50/50 with tractor hyd fluid. I used 1/2 Castrol Type F and 1/2 fluid that meets John Deere J20C specs. I used O'Reilly Auto Parts "Premium Hyd Fluid" It meets that spec. The J20C is for their newest tractors and has additives that work well with clutches. The JD brand itself is HyGuard
I had heard of this tip from a couple of buddies of mine that run a ORSCA Limited Street car. 2000+hp, 3K lbs, true 10.5 tire, no wheelie bars, huge BBC + LOTS of nitrous. They tune how high they want the stall by the % of hyd fluid. The J20C is thicker than type F and will tighten a converter. richter69 (Jon) convinced me to try it.
My converter has been a bit loose by about 200-250 rpm. It's a 9" soft hit. Originally a BTE, but rebuilt last by PTC. Kenny at PTC said it's as tight as he can get it without either changing the soft hit CCX stator or getting really ineffcient. It was stalling 6200-6250 against the brake.
The hyd fluid tightened it up to about 6K. This past weekend it produced 60's that were in the range of my best on what was otherwise a really poor track surface. I was Silver Dollar Raceway In Ga for a 3 day NMRA event. It went 1.098-1.102 on most passes. Normally it takes nearly *perfect* conditions to run like this. Based on my log book it should have been going 1.117-1.125. Keep in mind this is a "soft hit" converter. I give up some on the line with it in order to hit it softer for a crappy track.
Overall the 60' was better and the 330' as well. I gained back what I had lost at the end of last season. Last year I exploded a trans planetary. I put in a 1.80 straight cut vs the old 1.76 helical cut. Stronger, but it takes more power to turn. I lost an average of .05. Got that back.
Not bad for $8 per gallon from O'Reilly's
BTW, had a blast at the NMRA race hanging out with QtrWarrior (Mike) and Stephen Jordan. All three of us were still in down to 12 cars when the rains came and we were done. Split the purse 12 ways.