ET Difference with 2.75 low gear - Page 2

ron mattson · 12-11-2010, 01:40 PM

I have tried both 2.75 and 2.91 first gears and the 2.91 makes the car a animal in 60
feet .03-.04 better in sixty ft but hurts et from 60 to 330 it seems like the motor gets
pulled down to much to recover efficiently. i think a higher torque lower rpm engine may
be better suited to this application.

junior barns · 12-11-2010, 02:26 PM

Quote:

Originally Posted by ron mattson

I have tried both 2.75 and 2.91 first gears and the 2.91 makes the car a animal in 60
feet .03-.04 better in sixty ft but hurts et from 60 to 330 it seems like the motor gets
pulled down to much to recover efficiently. i think a higher torque lower rpm engine may
be better suited to this application.

Which application?

ron mattson · 12-11-2010, 02:50 PM

I have tried it with both 1970 350/290 hp and 1972 350/278 with similar results in
both applications. im thinking if you could get the torque to a higher level between
the converter flash and 1-2 shift rpm it could work.

Tim Ellis · 12-12-2010, 01:24 AM

How about your reaction times, did they get quicker with the low gear set, seeings how you 60 footed better?

Jeff Lee · 12-12-2010, 02:08 AM

Quote:

Originally Posted by ron mattson

I have tried it with both 1970 350/290 hp and 1972 350/278 with similar results in
both applications. im thinking if you could get the torque to a higher level between
the converter flash and 1-2 shift rpm it could work.

Just think what you could do with a data recorder and a timed ignition retard...

Glenn1066 · 12-12-2010, 07:46 PM

I have a 65 chevelle 283/230 SS/MA @3390 lbs, changed from 208 glide to light weight 2.75 Turbo, found nothing, changed converters 600 higher, stall still nothing.

Glenn

J Kuchel · 12-13-2010, 01:50 AM

Do you think I would show a gain with a low compression big block Chevy? It is a foot brake car. It's weighs 3300# and has a 2.48 gear in it now. Just looking to better my 60' and 1/8th mile time.

ron mattson · 12-13-2010, 03:05 PM

Tim the reaction did get a little quicker as the car really wanted to wheelstand pulling the
wheels up out of the beams not rolling out. Jeff your on to something..Shhhhh...
J Kuchel- the deeper first will definatly help in 60ft, in the 1/8 im not sure most likely
would but a deeper rear gear will help all that if your only going 1/8 mile

bottombulb · 12-13-2010, 03:47 PM

Quote:

Originally Posted by Tim Ellis

How about your reaction times, did they get quicker with the low gear set, seeings how you 60 footed better?

About .015 difference in reaction time.

Tim Ellis · 12-13-2010, 08:06 PM

Thanx for the response guys

12-11-2010, 01:40 PM	#11
ron mattson Member Join Date: Nov 2005 Location: cloquet mn Posts: 466 Likes: 17 Liked 67 Times in 30 Posts	Re: ET Difference with 2.75 low gear I have tried both 2.75 and 2.91 first gears and the 2.91 makes the car a animal in 60 feet .03-.04 better in sixty ft but hurts et from 60 to 330 it seems like the motor gets pulled down to much to recover efficiently. i think a higher torque lower rpm engine may be better suited to this application. __________________ Ron Mattson 5015 STK

12-11-2010, 02:50 PM	#13
ron mattson Member Join Date: Nov 2005 Location: cloquet mn Posts: 466 Likes: 17 Liked 67 Times in 30 Posts	Re: ET Difference with 2.75 low gear I have tried it with both 1970 350/290 hp and 1972 350/278 with similar results in both applications. im thinking if you could get the torque to a higher level between the converter flash and 1-2 shift rpm it could work. __________________ Ron Mattson 5015 STK

12-12-2010, 01:24 AM	#14
Tim Ellis Member Join Date: Dec 2004 Location: Beavercreek Or. Posts: 272 Likes: 31 Liked 7 Times in 6 Posts	Re: ET Difference with 2.75 low gear How about your reaction times, did they get quicker with the low gear set, seeings how you 60 footed better?

12-12-2010, 07:46 PM	#16
Glenn1066 Junior Member Join Date: Dec 2007 Posts: 69 Likes: 41 Liked 1 Time in 1 Post	Re: ET Difference with 2.75 low gear I have a 65 chevelle 283/230 SS/MA @3390 lbs, changed from 208 glide to light weight 2.75 Turbo, found nothing, changed converters 600 higher, stall still nothing. Glenn

12-13-2010, 01:50 AM	#17
J Kuchel Banned Join Date: Apr 2005 Location: Sterling,Illinois Posts: 111 Likes: 0 Liked 0 Times in 0 Posts	Re: ET Difference with 2.75 low gear Do you think I would show a gain with a low compression big block Chevy? It is a foot brake car. It's weighs 3300# and has a 2.48 gear in it now. Just looking to better my 60' and 1/8th mile time.

12-13-2010, 03:05 PM	#18
ron mattson Member Join Date: Nov 2005 Location: cloquet mn Posts: 466 Likes: 17 Liked 67 Times in 30 Posts	Re: ET Difference with 2.75 low gear Tim the reaction did get a little quicker as the car really wanted to wheelstand pulling the wheels up out of the beams not rolling out. Jeff your on to something..Shhhhh... J Kuchel- the deeper first will definatly help in 60ft, in the 1/8 im not sure most likely would but a deeper rear gear will help all that if your only going 1/8 mile __________________ Ron Mattson 5015 STK Last edited by ron mattson; 12-13-2010 at 03:11 PM. Reason: added info

12-13-2010, 08:06 PM	#20
Tim Ellis Member Join Date: Dec 2004 Location: Beavercreek Or. Posts: 272 Likes: 31 Liked 7 Times in 6 Posts	Re: ET Difference with 2.75 low gear Thanx for the response guys