Just got back from the track and i was a little dissapointed . I only knocked 2 1.7? 60ft and around 10 1.8? 60ft. And to make thing even worse the tires are done after 2 track visit a total of maybe 30 passes . My best pass of the night was my second pass at 6pm 11.751 @117.58 and 10 11.8? slips. The DA was +66 . I was hopeing to hook up better when the temps went down but it only got worse. I think i should be happy because i still went .03 faster . I mean it could have been worse if i lost an axle. So the BFG's 315/35R17 old tread design were worsed than the 295/35R18 new tread design. So whats next, I need tires. What do you guy think Mickey ET Streets or ET Street Radials or the M&H ? I also need to figure if i want to be in 4th at 5500rpm or try to get it to stay in 3rd with a taller tires.
Nice times there. The tire issue. Seems the ET DR's work very well, but are shorter. You may et a little better, but the MPH will drop. ET's win races. I had the 295 BFG's, but was shifting into 4th about 150' out. 1st pass on the 305/45-18's and I shifted into 4th right at the finish line at 122.003. That was a mild cam only with a 100 shot. Your still NA so this probably won't help. You would probably trap over 120 NA with the tires I'm using.
I gotta get back on the drawing board and figue this on out. I don't know too much about gears and gear ratio but what do you guys think N/A, finish in 3rd at 6500 of 4th at 5500
Great times man. I agree with Hal. I too, had the BFG 295's. Blah. 4th gear 100 - 130 feet out. Now using the Nitto 555r's. Great DR's.
I wonder whats the highest rpm you can take it to in 3rd before it hit limp mode 6850 or 6900? Has anyone stretched it this high in 3rd?
Even the Predator has a maximum RPM before it will shift anyway. I don't recall the actual number. With stock-sized rear tires, I trapped at 123.05 without shifting into 4th. I'm going with the shorter tires and shifting into 4th 300 feet before the end. That's what PPP did/does on his record 60' times/record 1/4 mile times.
OK then. With my mild tune and extended shift points I didn't really get close enough to to 3 - 4 shift. DA was around 2800 when I trapped 120.886. If I had got going earlier, and got some of the 500 DA air, I probably would have set a new MPH record, and knocked down a few more 10ths on my ET. I should have driven hard thru the traps to see what I shifted at 6600. Didn't even think about it
OK then. With my mild tune and extended shift points I didn't really get close enough to to 3 - 4 shift. DA was around 2800 when I trapped 120.886. If I had got going earlier, and got some of the 500 DA air, I probably would have set a new MPH record, and knocked down a few more 10ths on my ET. I should have driven hard thru the traps to see what I shifted at 6600. Didn't even think about it
Hal, what tune do you have? Custom B&G? I think the Predator raised shift points are shift - 6400 and rev limiter 6500. I seem to remember that the shift point is where the shift is initiated and the motor will rev 50 to 70 rpm over that before the trans drops into the next gear? I think it was Redfoxx? that did a valve reving it at 6700 or just over?
Hal - whatever the standard raised shift points in the Predator are, I think I would have shifted in the 124-125 mph range. My thinking is since I'm already at 123 anyway, may as well get that shift out of the way and enjoy the 10% better gear ratio from the shorter tires. It's all theory for me though - won't run on the short tires for another 4 weeks probably. Still cold here.
They don't have huge spreadsheets for figuring all that out on paper? You know how long it takes to shift and where you are on the power curve at the top and bottom of each gear and what speed you're going at those points and how much distance you've covered getting there. I'd think you could get a rough estimate of the crossover points for particular tire sizes. Unless you're in a gray area between sizes you should have a good chance of picking the best size before you go to the track right?
It all depends on what brand of muffler bearings you're using, and whether your Kuhneutson Valvle is operating in it's ideal range. Depending on whether you hooked your flux capacitor in series or in parellel, it can easily vary th discombobulation effect by an easy 50 ft.
