(updated FIXED)11.3 et @ 114.9 is my mph low?
10-24-2012, 02:42 PM
#23
At what rpm does your trans shift?
I will calculate, estimate.
1st, 6300
2nd, 6300
Now current mph at shift.
28" tire; 1st-42mph 2nd-79mph 3rd- 114.9mph@5650rpm
26" tire; 1st-39mph 2nd-73mph 3dr- 115mph@6100rpm
Notice that you are reving the motor to achieve the same and loosing in the bottom and midrange.
Does your car weight transfer?
I will calculate, estimate.
1st, 6300
2nd, 6300
Now current mph at shift.
28" tire; 1st-42mph 2nd-79mph 3rd- 114.9mph@5650rpm
26" tire; 1st-39mph 2nd-73mph 3dr- 115mph@6100rpm
Notice that you are reving the motor to achieve the same and loosing in the bottom and midrange.
Does your car weight transfer?
10-24-2012, 03:17 PM
#25
I really don't know where exactly my trans shifts, but if you look at my dyno (follow the link in an above post) I would assume 6600-6750 area.
I'm not sure I understand why you are saying too much rpm. My peak hp is at 6500 and falls slowly afterward
I'm not sure I understand why you are saying too much rpm. My peak hp is at 6500 and falls slowly afterward
10-24-2012, 04:27 PM
#28
I think either the trans is slipping or it short shifted being in OD instead of D. If your car is shifting between 6500-6700 next time out and the mph isnt higher i would look into the trans. A guy i know had a t/a making 430whp and on the same gear and tire and similar stall with a 1.41 60ft he ran 10.8@122, with 1.5 60ft's he would still run low 11's@119-121. I know dyno's can vary and all but for an fbody running low 11's it should be trapping at least 117+
10-24-2012, 05:17 PM
#30
What is happening to the torque in the upper rpm range?
Look at your dyno sheet.
200rpm from where you are now, would put you somewhere from 117 to 119 mph
Get your hands on some 27" tires.
28" tire; 1st-42mph 2nd-79mph 3rd- 114.9mph@5650rpm
27" tire; 1st-40mph 2nd-76mph 3rd- 118mph@6000rpm
Look at your dyno sheet.
200rpm from where you are now, would put you somewhere from 117 to 119 mph
Get your hands on some 27" tires.
28" tire; 1st-42mph 2nd-79mph 3rd- 114.9mph@5650rpm
27" tire; 1st-40mph 2nd-76mph 3rd- 118mph@6000rpm
11-02-2012, 03:07 PM
#31
obviously in attempt to not over-complicate things in this discussion i left out a ton of other variables including my stall, shift extensions, and some way more complicated stuff.
looking at my dyno and all of my gearing and crunching numbers it appears as if (on paper) that my shift rpm ideal range is going to end up higher than my rev limiter.
looking at my dyno and all of my gearing and crunching numbers it appears as if (on paper) that my shift rpm ideal range is going to end up higher than my rev limiter.
11-02-2012, 03:37 PM
#32
you are def missing about 5mph
my car consistantly did
1.60
7.2@94
11.42@120
MPH is the same, ET is basically the same (with same 60' time)
BTW I still have a LS1 intake so it MPH's like ****, I should be 124 or so
My guess is your trans is slipping in high which is most likely, the mph clocks were off, or you lifted early
my car consistantly did
1.60
7.2@94
11.42@120
MPH is the same, ET is basically the same (with same 60' time)
BTW I still have a LS1 intake so it MPH's like ****, I should be 124 or so
My guess is your trans is slipping in high which is most likely, the mph clocks were off, or you lifted early
Last edited by Grr; 11-02-2012 at 03:42 PM.
11-02-2012, 04:03 PM
#33
Hey brr, thanks for sharing your timeslip, it helps alot comparing the two. Our cars would have been right next to each other the whole way down the track
Do you have a Dyno graph that you can share as well?
By the looks of your build in your sig and your mph, i would have guessed you would have had a bit faster et. slap a good intake in there!!!!!!!
Do you have a Dyno graph that you can share as well?
By the looks of your build in your sig and your mph, i would have guessed you would have had a bit faster et. slap a good intake in there!!!!!!!
11-03-2012, 12:40 PM
#37
You should be thinking about it the other way! You are running good ET's for your current mph.
That converter is loose enough that you will see the gains in the short track but possible leave a little mph off the top due to it being less efficient. Unless you are locking it. Your 60' tells me the verter is doing its job. For the mph you are running, a 1.49 60' is pretty good and the reason your ET is as good as it is with you given mph.
This is a perfect example of why a dyno is a tuning tool, not a "how fast it should run" predictor.
That converter is loose enough that you will see the gains in the short track but possible leave a little mph off the top due to it being less efficient. Unless you are locking it. Your 60' tells me the verter is doing its job. For the mph you are running, a 1.49 60' is pretty good and the reason your ET is as good as it is with you given mph.
This is a perfect example of why a dyno is a tuning tool, not a "how fast it should run" predictor.
11-07-2012, 12:05 AM
#38
Lil ss, im thrilled with these times believe me, but even so wouldn't you still agree that something is outta line as far as my mph? Has anyone seen some rear gearing changes cause a +-5 mph scenario. If the rear gearing changes don't usually affect mph too much, then I'll have to datalog and record transmission slip data
But I did just pick up a 9" with 4.57 gears. So tempted to try these out and probably give my rev limiter a test
But I did just pick up a 9" with 4.57 gears. So tempted to try these out and probably give my rev limiter a test
11-07-2012, 06:08 AM
#39
What converter? You say 4k stall it gets out ok , but we were doin that 60ft with 70less whp at same weight.. I'm gonna say your converter is inefficient upstairs, before I condemn the tranny.. You monitor tranny temps?
Last edited by IllusionalTA; 11-07-2012 at 06:15 AM.