Bracket Talk
Rear gear suggestion

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/3577072496

September 13, 2020, 12:56 PM
inferno camaro
Rear gear suggestion
I put a 4.86 in it and it runs the same et/mph/60 as it did with the 4.56. I did take slip at the strip down from 15% to 10%. Car doesn't feel or act any different.
September 13, 2020, 01:44 PM
markemark
quote:
Originally posted by inferno camaro:
I put a 4.86 in it and it runs the same et/mph/60 as it did with the 4.56. I did take slip at the strip down from 15% to 10%. Car doesn't feel or act any different.


Mike Rietow quote “I'd do a 5.13 or a 5.00 with a 1.64 low. Just doing a 4.86 won't move your program forward. Do a 1.64 low w/ 5.00 or 5.13 , you'll be shifting lower rpm just to get in high gear sooner. Cross 7400 rpm wfo, or less ripping it.”
September 13, 2020, 03:43 PM
Mike Rietow
quote:
Originally posted by inferno camaro:
I put a 4.86 in it and it runs the same et/mph/60 as it did with the 4.56. I did take slip at the strip down from 15% to 10%. Car doesn't feel or act any different.


If it reached the shift rpm sooner on the new 4.86 graph, in comparison to the 4.56 graph, it would be quicker et.

Relatively speaking you want the converter loose early and efficient late.

Post the two graphs over layed DS and engine rpm, or text it my way, I'll post it for ya.

Changing the gear, essentially you put a more efficient converter. Not tighter stall, but more efficient.
September 13, 2020, 06:15 PM
inferno camaro
Was not an option to finish off the year. Thought it would show me more what it likes or doesn't and actually tells me nothing.

quote:
Originally posted by markemark:
quote:
Originally posted by inferno camaro:
I put a 4.86 in it and it runs the same et/mph/60 as it did with the 4.56. I did take slip at the strip down from 15% to 10%. Car doesn't feel or act any different.


Mike Rietow quote “I'd do a 5.13 or a 5.00 with a 1.64 low. Just doing a 4.86 won't move your program forward. Do a 1.64 low w/ 5.00 or 5.13 , you'll be shifting lower rpm just to get in high gear sooner. Cross 7400 rpm wfo, or less ripping it.”

September 13, 2020, 06:26 PM
inferno camaro
I'll have to down load them tomorrow after I unload the car. Don't have your number to text it to you.

quote:
Originally posted by Mike Rietow:
quote:
Originally posted by inferno camaro:
I put a 4.86 in it and it runs the same et/mph/60 as it did with the 4.56. I did take slip at the strip down from 15% to 10%. Car doesn't feel or act any different.


If it reached the shift rpm sooner on the new 4.86 graph, in comparison to the 4.56 graph, it would be quicker et.

Relatively speaking you want the converter loose early and efficient late.

Post the two graphs over layed DS and engine rpm, or text it my way, I'll post it for ya.

Changing the gear, essentially you put a more efficient converter. Not tighter stall, but more efficient.

September 14, 2020, 07:05 AM
Rick!
Is the changed low gear and rear gear gonna take care of this stuff?
1. The Semi-dead hook at launch,
2. The camelback shift RPM (I've never seen that before),
3. The RPM drop after the shift is complete?

Below is a capture of your vid of the 4.56 rear gear and I've attached data from a 2100lb dragster with less 100hp than your hot rod. Dead hooked Hoosiers, 4 magnet driveshaft sensor and hi resolution on the RPM data, 19% slip at 660ft.




Here's what the suggested gearing could do in virtual land: (yes, qj's 60ft rpm is off but the incremental is pretty close) Knowing your 330ft would help dial in the simulation a bit better.

September 14, 2020, 11:33 AM
inferno camaro
From this weekend with 4.86

1.099 60
3.259 330
5.046 660
137.84 660 mph

If someone could give me an email or number I can send data logs for you to upload here.

This message has been edited. Last edited by: inferno camaro,
September 14, 2020, 11:37 AM
Mike Rietow
It also tells me if you shift it 7100, 7200, 7300 rpm, instead of 7400, 7500 as usual (4.56), with the 4.86 gear shifting lower, it'll go quicker.

If I'm right, keep going down 50 to 100 rpm at a time in shift rpm, until it doesn't pick up et.
September 14, 2020, 11:44 AM
inferno camaro
The range the weather conditions were that day.

Barometer was 29
temp from 76-84
water grains 110-128
da was 3000-3500
head wind 7-9 mph
September 14, 2020, 11:50 AM
inferno camaro
It was shifting to high @ 1.84 seconds with the 4.86 and 1.96 with the 4.56
September 14, 2020, 04:17 PM
Mike Rietow
It looks like it grabbed the tire and pulled the engine rpm down (arrow) before flash stall.

You need to work getting the driveshaft looking something like i've drawn on the graph. Ya really some shocks on this with more clicks of adjustment, so you can fine tune the wheelspeed.

Do you moniter converter pressure Inferno?

The car isn't bad, I looked at the slips, straighten out the driveshaft a little, it'll be a mean machine.


September 14, 2020, 04:35 PM
inferno camaro
No I don't monitor pressure. The converter never done that before.
September 14, 2020, 04:42 PM
Mike Rietow
quote:
Originally posted by inferno camaro:
No I don't monitor pressure. The converter never done that before.


It just grabbed the tire, look at the driveshaft starting at the arrow.

The car is a lot better than these graphs indicate, I looked at the slips. Ya get the driveshaft smoothed out a little and this thing will turn on a lot of win lights. Shocks with 4 clicks of adjustment on rebound and compression and 4, 4.5" travel total, gonna be hard to do I'd imagine. It works pretty good now but if you straighten the driveshaft out you'll know before you get in if it's gonna run a 4 or 5. Instead of flipping a coin on a 4 or 5.
September 14, 2020, 05:32 PM
inferno camaro
Shocks are on the list for winter but limited on what will fit. From the rearend hitting the tin work to driveshaft hitting a cross bar on the frame is a total of 6" of travel.
September 14, 2020, 06:08 PM
Mike Rietow
quote:
Originally posted by inferno camaro:
Shocks are on the list for winter but limited on what will fit. From the rearend hitting the tin work to driveshaft hitting a cross bar on the frame is a total of 6" of travel.


That'll work good. Keep me posted.


September 14, 2020, 07:20 PM
inferno camaro
Doesn't the 330 seem off compared to the 60 and 660 mph?
September 15, 2020, 08:08 AM
Mike Rietow
quote:
Originally posted by inferno camaro:
Doesn't the 330 seem off compared to the 60 and 660 mph?


That's a good problem to have, it tells you it's not a power issue.