7 " vs 8 " converter?

danny waters sr · 01-22-2010, 09:38 PM

First of all the car is a 66 chevy ll 4- door 283 220 hp stocker. With driver it weighs 3045. P/G with 202 low gear 28x 9 hoosier ,538 MOSER 12 bolt 4 wheel disc brakes . So far i have had my best 1/4 mile et of 12.25 @ 105.388 mph. 1.65.. 60 ft time ,4.90.. 330 ft ,7.69 1/8 mile @ 88.238 mph. This is with a 7 " converter leaving @ 4200 and shifting @ 6400. any rpm above that just don't pull. It will turn 7000 easy just no power. I had an 8 " in it and ran a 12.42 but could only leave @ 3000 and it was trying to creep then and 60 ft stayed the same as above. I guess what i am asking is would a looser 8 " be faster. It seems like the 7 " don't actually try to lock up til around the 60 ft mark. and is so sloppy loose that i am also having a hard time to find a spot on the tree. Any input would be appreciated. Thanks . If you don't want to say anything on here just pm me. I am happy for the progress i have made in 2 1/2 years as this car started out running 12.98 -13.00's.

Lapeeracing · 01-22-2010, 10:02 PM

I would think that the 8" converter w/45-5000 stall should help you. My experience with the 7" is that you need a LOT of rpm to make it work. Testing will be the final proof! Call Lenny @UCC-great to deal with and has worked with a lot of stockers.
good luck,Lyn

Adger Smith · 01-22-2010, 11:11 PM

It will run quicker with the correct 7" converter. You are just looking at the 8" Vs 7" size and not how the 2 converters are configured. You have no torque, you need the right converter to multiply what little you have. I have a known A-1 that might be close. You could test with it and then we would know where to go.

GTX JOHN · 01-22-2010, 11:49 PM

We run a 318/230 in N/SA. We started with a 8" that would stall about 3000. Every time we loosen the darn converter it would pick up both 60 Ft. and ET. We are on the fourth converter that goes easily to 3800 against the brake (No 2 step) and it show 4800 about 20 feet out. At 12.25 Et we only go about 102 MPH with a 1.56 .60 Ft. Bear in mind our car is 3520 LB. with a touquefite. We had no luck our selves with even a tight 7"..... was just terribly loose by 1000'. We were lucky we get a deal on converter adjustment! It is not unusual to cycle a half dozen converter changes to find out what any of our low horsepower combo's like.. Hope this helps!!! We shift around 6400 and go thru lights 6800. Just my opinion

Mark Yacavone · 01-23-2010, 12:13 AM

The 8" converters in Stockers, usually start out with a factory designed stator profile. Those designs most often multiply more torque due to their larger diameter, among other things .
The 7 inchers most always use a fabricated stator, which fulfills it's function to a certain extent but are usually used in a super high RPM range.
Given the lower torque curve, (dual plane manifold, small ports, valves ) of a 283 Stocker,
I would tend to favor the 8" style. That's not to say that 7 inchers haven't been used successfully in Stockers.
Sorry for not giving a definitive answer here, but I think it may depend on who you're working with.
I don't want to leave anyone else out but I think I would want to work with A-1 on a 7" in your application.

Adger Smith · 01-23-2010, 12:52 AM

Mark,
PM to you

01-22-2010, 09:38 PM	#1
danny waters sr VIP Member Join Date: Apr 2007 Location: lagrange,nc Posts: 2,224 Likes: 1 Liked 0 Times in 0 Posts	7 " vs 8 " converter? First of all the car is a 66 chevy ll 4- door 283 220 hp stocker. With driver it weighs 3045. P/G with 202 low gear 28x 9 hoosier ,538 MOSER 12 bolt 4 wheel disc brakes . So far i have had my best 1/4 mile et of 12.25 @ 105.388 mph. 1.65.. 60 ft time ,4.90.. 330 ft ,7.69 1/8 mile @ 88.238 mph. This is with a 7 " converter leaving @ 4200 and shifting @ 6400. any rpm above that just don't pull. It will turn 7000 easy just no power. I had an 8 " in it and ran a 12.42 but could only leave @ 3000 and it was trying to creep then and 60 ft stayed the same as above. I guess what i am asking is would a looser 8 " be faster. It seems like the 7 " don't actually try to lock up til around the 60 ft mark. and is so sloppy loose that i am also having a hard time to find a spot on the tree. Any input would be appreciated. Thanks . If you don't want to say anything on here just pm me. I am happy for the progress i have made in 2 1/2 years as this car started out running 12.98 -13.00's. __________________ Danny Waters, Sr / 73 Duster "340"

01-22-2010, 10:02 PM	#2
Lapeeracing Junior Member Join Date: Mar 2005 Location: Michigan Posts: 17 Likes: 0 Liked 0 Times in 0 Posts	Re: 7 " vs 8 " converter? I would think that the 8" converter w/45-5000 stall should help you. My experience with the 7" is that you need a LOT of rpm to make it work. Testing will be the final proof! Call Lenny @UCC-great to deal with and has worked with a lot of stockers. good luck,Lyn

01-22-2010, 11:11 PM	#3
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: 7 " vs 8 " converter? It will run quicker with the correct 7" converter. You are just looking at the 8" Vs 7" size and not how the 2 converters are configured. You have no torque, you need the right converter to multiply what little you have. I have a known A-1 that might be close. You could test with it and then we would know where to go. __________________ Adger Smith (Former SS)

01-22-2010, 11:49 PM	#4
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,733 Likes: 2,802 Liked 2,486 Times in 697 Posts	Re: 7 " vs 8 " converter? We run a 318/230 in N/SA. We started with a 8" that would stall about 3000. Every time we loosen the darn converter it would pick up both 60 Ft. and ET. We are on the fourth converter that goes easily to 3800 against the brake (No 2 step) and it show 4800 about 20 feet out. At 12.25 Et we only go about 102 MPH with a 1.56 .60 Ft. Bear in mind our car is 3520 LB. with a touquefite. We had no luck our selves with even a tight 7"..... was just terribly loose by 1000'. We were lucky we get a deal on converter adjustment! It is not unusual to cycle a half dozen converter changes to find out what any of our low horsepower combo's like.. Hope this helps!!! We shift around 6400 and go thru lights 6800. Just my opinion

01-23-2010, 12:13 AM	#5
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,817 Likes: 2,907 Liked 5,124 Times in 1,953 Posts	Re: 7 " vs 8 " converter? The 8" converters in Stockers, usually start out with a factory designed stator profile. Those designs most often multiply more torque due to their larger diameter, among other things . The 7 inchers most always use a fabricated stator, which fulfills it's function to a certain extent but are usually used in a super high RPM range. Given the lower torque curve, (dual plane manifold, small ports, valves ) of a 283 Stocker, I would tend to favor the 8" style. That's not to say that 7 inchers haven't been used successfully in Stockers. Sorry for not giving a definitive answer here, but I think it may depend on who you're working with. I don't want to leave anyone else out but I think I would want to work with A-1 on a 7" in your application. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

01-23-2010, 12:52 AM	#6
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: 7 " vs 8 " converter? Mark, PM to you __________________ Adger Smith (Former SS)