Getrag 282 insights
Moderators: The Dark Side of Will, Series8217
- Shaun41178(2)
- Posts: 8415
- Joined: Fri Nov 19, 2004 7:12 pm
- Location: Ben Phelps is an alleged scammer
Re: Getrag 282 insights
So what you are saying Steven is that you end up with a huge rpm drop between 1-2 or 2-3 pending on ratios chosen. It seems you don't mind the 1-2 drop with the 2.05 2nd as its better when going to 3rd vs the 2.19 2nd
- Series8217
- 1988 Fiero Track Car
- Posts: 5984
- Joined: Thu Jun 02, 2005 9:47 pm
- Location: Los Angeles, CA
Re: Getrag 282 insights
Correct.Shaun41178(2) wrote:So what you are saying Steven is that you end up with a huge rpm drop between 1-2 or 2-3 pending on ratios chosen. It seems you don't mind the 1-2 drop with the 2.05 2nd as its better when going to 3rd vs the 2.19 2nd
-
- Peer Mediator
- Posts: 15624
- Joined: Wed Nov 24, 2004 11:13 pm
- Location: In the darkness, where fear and knowing are one
- Contact:
Re: Getrag 282 insights
All 282's have a 1.38 third.Shaun41178(2) wrote:So what you are saying Steven is that you end up with a huge rpm drop between 1-2 or 2-3 pending on ratios chosen. It seems you don't mind the 1-2 drop with the 2.05 2nd as its better when going to 3rd vs the 2.19 2nd
With 3.50/2.05 you get:
1-2 shift drops 41.4% RPM (RPM after shift is 58.6% of shift RPM)
2-3 shift drops 32.7% RPM (67.3%)
With 3.50/2.19:
1-2 shift drops 37.4% RPM (62.6%)
2-3 shift drops 37% RPM (63.0%)
With the 3.50/2.05, 1-2 is wide and 2-3 is somewhat narrower
With the 3.50/2.19, 1-2 is narrower and 2-3 is wider, such that both shifts have about the same RPM drop. This works really well for the Northstar's torque curve. YMMV.
- Shaun41178(2)
- Posts: 8415
- Joined: Fri Nov 19, 2004 7:12 pm
- Location: Ben Phelps is an alleged scammer
Re: Getrag 282 insights
I guess pending on what motor you have, its power curve, and your design purpose of the car, will determine which gear setup would be best. I am not a fan of the stock fiero 1-2. Maybe I would like the more even 1-2 2-3 drop more. on paper it seems like it would be better. So if the fiero is 32.7% and the Quad 4ish is 37%,that is about a 300 rpm difference with shiftpoint of 6k rpm.The Dark Side of Will wrote: All 282's have a 1.38 third.
With 3.50/2.05 you get:
1-2 shift drops 41.4% RPM (RPM after shift is 58.6% of shift RPM)
2-3 shift drops 32.7% RPM (67.3%)
With 3.50/2.19:
1-2 shift drops 37.4% RPM (62.6%)
2-3 shift drops 37% RPM (63.0%)
With the 3.50/2.05, 1-2 is wide and 2-3 is somewhat narrower
With the 3.50/2.19, 1-2 is narrower and 2-3 is wider, such that both shifts have about the same RPM drop. This works really well for the Northstar's torque curve. YMMV.
-
- Peer Mediator
- Posts: 15624
- Joined: Wed Nov 24, 2004 11:13 pm
- Location: In the darkness, where fear and knowing are one
- Contact:
Re: Getrag 282 insights
Shifting 2-3 at 6k RPM gives:
2.05: 4039 RPM
2.19: 3780 RPM
At 7k RPM:
2.05: 4712 RPM
2.19: 4411 RPM
The big difference is max speed in gear. With 2.19 and 3.61 I need 7,000 RPM to clear 60 in 2nd.
2.05: 4039 RPM
2.19: 3780 RPM
At 7k RPM:
2.05: 4712 RPM
2.19: 4411 RPM
The big difference is max speed in gear. With 2.19 and 3.61 I need 7,000 RPM to clear 60 in 2nd.
-
- Posts: 423
- Joined: Sun Mar 11, 2007 11:26 pm
Re: Getrag 282 insights
https://docs.google.com/spreadsheet/ccc ... sp=sharing
I made this spreadsheet a while ago to look at torque curves through gears and help visualize ratios.
I made this spreadsheet a while ago to look at torque curves through gears and help visualize ratios.
car.