ET Difference with 2.75 low gear

Ron Middleton · 12-09-2010, 06:16 PM

My current '80 Camaro stocker has TH350 with stock low gear and I have a TH350 with 2.75 low gear. 350/190/287 combination in J/SA at 3760 lbs. What could I expect in 60 ft. and ET's with this change?
Anybody out there test the difference on first gear change only? Thanks in advance for help.

gsa612 · 12-09-2010, 07:07 PM

I went from the stock 2.52 low to the 2.75 on my low comp. bb stocker, gained .04 on the 60' about the same in the 1/4.also lost 200 rpm flash on the converter with the low gear. Your car has a sm. blk. and is 130 lbs. heavier so you might gain a bit more. gsa612

GTX JOHN · 12-09-2010, 07:25 PM

Our gutless small blocks pick up .05 to .07 with straight cut 2.75 in 60 over stock 2.45. The heavy 318 cars towards the high side and 340/360 toward the lower side. For our mopars about a $1,500. part.

Tom Turner · 12-09-2010, 09:53 PM

I got a solid tenth in my 305/q-jet Camaro and .08 in the injected car (90 350 TPI) but (as GSA612 said), the converter becomes an issue. I wish I had the Racepak in the Camaros (too cheap) cuz I think we left a lot on the table back when we were running those cars and I could be more informative. When we put the Racepak in the 96 Corvette, I learned more in 1/2 of 1 season than I thought I knew in all the years before. TT

Tom Meyer · 12-10-2010, 09:42 AM

I have yet to change to a three speed from a glide in my 283 ss car just how much et change could one gain from that change? Also with todays AHFS I not sure now I want to spend the cash just to get HP on my combo. Thanks Tom

Jeff Goss · 12-10-2010, 10:41 PM

Quote:

Originally Posted by Tom Meyer

I have yet to change to a three speed from a glide in my 283 ss car just how much et change could one gain from that change? Also with todays AHFS I not sure now I want to spend the cash just to get HP on my combo. Thanks Tom

Great question! I would like to know this also. I am no threat to bomb the index, but might like to get my big ol' Wagon moving a little quicker.

Tim Ellis · 12-11-2010, 01:06 AM

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

gmonde · 12-11-2010, 10:31 AM

i went from a turbo 400 2:48 first gear to a 904 2:74 and the 60' picked .010 consistantly ,i was hoping to get more out of the 60' the car weighs in heavy ,but you have to be on top of the 1-2 shift it come's up quick ,, i have a 2:45 for the 904 that i might try to see if it changes much gmonde

George Mirza · 12-11-2010, 11:12 AM

Ron,
From what I've seen is the car will pick up in 60' but it may struggle after the 2-3 shift. Overall it should pick you up some.

Garret,
Did you pick up .100 or just .010 with the gear change? How much did you see overall going to the 904?

George

gmonde · 12-11-2010, 11:56 AM

george :just .010 not anything big but its consistant,,over all the the trans swap was a huge gain a solid 2 tenth gain and 2 mph, the trans is trans i put together with a few aluminun pieces ,,also it was 45 pounds lighter than the th400 gmonde

12-09-2010, 06:16 PM	#1
Ron Middleton Member Join Date: Jan 1970 Location: Jackson, Ms. Posts: 350 Likes: 183 Liked 12 Times in 4 Posts	ET Difference with 2.75 low gear My current '80 Camaro stocker has TH350 with stock low gear and I have a TH350 with 2.75 low gear. 350/190/287 combination in J/SA at 3760 lbs. What could I expect in 60 ft. and ET's with this change? Anybody out there test the difference on first gear change only? Thanks in advance for help. __________________ #4892 J/SA. We are what we repeatedly do. Excellence then, is not an act, but a habit.” - Aristotle

12-09-2010, 07:07 PM	#2
gsa612 Senior Member Join Date: Jan 2008 Location: 100th Meridian Posts: 569 Likes: 116 Liked 280 Times in 139 Posts	Re: ET Difference with 2.75 low gear I went from the stock 2.52 low to the 2.75 on my low comp. bb stocker, gained .04 on the 60' about the same in the 1/4.also lost 200 rpm flash on the converter with the low gear. Your car has a sm. blk. and is 130 lbs. heavier so you might gain a bit more. gsa612

12-09-2010, 07:25 PM	#3
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,733 Likes: 2,799 Liked 2,483 Times in 697 Posts	Re: ET Difference with 2.75 low gear Our gutless small blocks pick up .05 to .07 with straight cut 2.75 in 60 over stock 2.45. The heavy 318 cars towards the high side and 340/360 toward the lower side. For our mopars about a $1,500. part.

12-09-2010, 09:53 PM	#4
Tom Turner Member Join Date: Jan 2005 Location: Lake Tapps, Washington Posts: 137 Likes: 0 Liked 0 Times in 0 Posts	Re: ET Difference with 2.75 low gear I got a solid tenth in my 305/q-jet Camaro and .08 in the injected car (90 350 TPI) but (as GSA612 said), the converter becomes an issue. I wish I had the Racepak in the Camaros (too cheap) cuz I think we left a lot on the table back when we were running those cars and I could be more informative. When we put the Racepak in the 96 Corvette, I learned more in 1/2 of 1 season than I thought I knew in all the years before. TT

12-10-2010, 09:42 AM	#5
Tom Meyer Senior Member Join Date: Aug 2003 Location: Pierce NE Posts: 936 Likes: 78 Liked 354 Times in 120 Posts	Re: ET Difference with 2.75 low gear I have yet to change to a three speed from a glide in my 283 ss car just how much et change could one gain from that change? Also with todays AHFS I not sure now I want to spend the cash just to get HP on my combo. Thanks Tom __________________ Tom Meyer 5240 SS Stock ???

12-11-2010, 01:06 AM	#7
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?

12-11-2010, 10:31 AM	#8
gmonde Senior Member Join Date: Nov 2007 Posts: 615 Likes: 56 Liked 165 Times in 59 Posts	Re: ET Difference with 2.75 low gear i went from a turbo 400 2:48 first gear to a 904 2:74 and the 60' picked .010 consistantly ,i was hoping to get more out of the 60' the car weighs in heavy ,but you have to be on top of the 1-2 shift it come's up quick ,, i have a 2:45 for the 904 that i might try to see if it changes much gmonde

12-11-2010, 11:12 AM	#9
George Mirza Senior Member Join Date: Jan 2002 Location: North Attleborough Ma. Posts: 522 Likes: 0 Liked 0 Times in 0 Posts	Re: ET Difference with 2.75 low gear Ron, From what I've seen is the car will pick up in 60' but it may struggle after the 2-3 shift. Overall it should pick you up some. Garret, Did you pick up .100 or just .010 with the gear change? How much did you see overall going to the 904? George

12-11-2010, 11:56 AM	#10
gmonde Senior Member Join Date: Nov 2007 Posts: 615 Likes: 56 Liked 165 Times in 59 Posts	Re: ET Difference with 2.75 low gear george :just .010 not anything big but its consistant,,over all the the trans swap was a huge gain a solid 2 tenth gain and 2 mph, the trans is trans i put together with a few aluminun pieces ,,also it was 45 pounds lighter than the th400 gmonde