tightest converter???
I only use YANK for a number of reasons and the biggest is the customer service and the higher accuracy of getting exactly what you order. There are so many more variables than just the max stall speed and the str when you really get serious about squeezing every 1/10 of et and mph out of your car. The biggest reason to use only YANK or Precision is noted below.
FWIW - Back in 99 when I originally bought my Z new, and before I got together with Dave Inall from Incon systems to develope the TWIN TURBO system prototype work on my car I had tested/ran a number of different converters from Yank. 4 different converters as the car went from bone stock to a 4 mod screamer. With only an air lid/ exhaust cutout/3.73 gear & converter anf factory weight 1 - 13.0 w/ a 3000 stall, 2 - w/a 3500 stall 12.7
3 - 4000 stall 12.5 and 4 w/a tp4400 12.3 @ 110. Then back to a 3000 with the TWIN TURBO(Back in 2000) Then I bought a complete TH400 conversion w/ Yank 8" 5000 stall converter in 2000. I removed the TWIN TURBO KIT and ran 11.9 @ 111.5 and every converter was perfect. I sold the car after that and now have it back with a century 4l60e w/ a pt4400, again perfect and I have a Gear Star level IV built 4L80E sitting in the garage with a yank 3600 which Im sure will also be perfect. Many guys make claims based on a single purchase and that is there right but I've owned 6 different YANK converters and all were perfect. So perfect, that Mike, the owner of YANK, and I have become close friends only because of his companies products...
FACT:
Stall Torque Ratios: Only two companies in the performance converter business have the capabilities and resources to test the actual stall torque ratios and efficiencies of the converters they produce. Yank and Precision Industries. All the other companies are making false claims based on untested combinations. Don't be fooled. Yank has all of their converters tested for actual efficiency and stall torque ratio by using General Motors' $1 million dollar transmission dyno.
Any claims I mentioned above can be verified on LSI.COM ARCHIVES
My old screen name there was FAST ORANGE
Good luck on your decision.
Jason
FWIW - Back in 99 when I originally bought my Z new, and before I got together with Dave Inall from Incon systems to develope the TWIN TURBO system prototype work on my car I had tested/ran a number of different converters from Yank. 4 different converters as the car went from bone stock to a 4 mod screamer. With only an air lid/ exhaust cutout/3.73 gear & converter anf factory weight 1 - 13.0 w/ a 3000 stall, 2 - w/a 3500 stall 12.7
3 - 4000 stall 12.5 and 4 w/a tp4400 12.3 @ 110. Then back to a 3000 with the TWIN TURBO(Back in 2000) Then I bought a complete TH400 conversion w/ Yank 8" 5000 stall converter in 2000. I removed the TWIN TURBO KIT and ran 11.9 @ 111.5 and every converter was perfect. I sold the car after that and now have it back with a century 4l60e w/ a pt4400, again perfect and I have a Gear Star level IV built 4L80E sitting in the garage with a yank 3600 which Im sure will also be perfect. Many guys make claims based on a single purchase and that is there right but I've owned 6 different YANK converters and all were perfect. So perfect, that Mike, the owner of YANK, and I have become close friends only because of his companies products...
FACT:
Stall Torque Ratios: Only two companies in the performance converter business have the capabilities and resources to test the actual stall torque ratios and efficiencies of the converters they produce. Yank and Precision Industries. All the other companies are making false claims based on untested combinations. Don't be fooled. Yank has all of their converters tested for actual efficiency and stall torque ratio by using General Motors' $1 million dollar transmission dyno.
Any claims I mentioned above can be verified on LSI.COM ARCHIVES
My old screen name there was FAST ORANGE
Good luck on your decision.
Jason
On the yank vs vig battle, I think most every one that has had them both chooses yank. Heres why I do.
I went from vig 3800 to yank SS4000. The vig was much, much looser. They both cut close 60's but I'm spinning with the yank so there is better 60's in it. The ET vig 12.2 - yank 11.9, the mph vig 109 - yank 114, thats .3 et improvement and 5mph improvement
Those are some serious gains if you ask me. It was hotter and more humid the day I got the new times with the yank. The only other change in my set-up was 3.23s to 3.73s and I'm sure thats why I couldn't hook as well but they sure can't take credit for that good of gains. I'm sure they did help with the looseness of the converter though. Overall, I was very dissapointed with the vig and love my yank.
I went from vig 3800 to yank SS4000. The vig was much, much looser. They both cut close 60's but I'm spinning with the yank so there is better 60's in it. The ET vig 12.2 - yank 11.9, the mph vig 109 - yank 114, thats .3 et improvement and 5mph improvement
Those are some serious gains if you ask me. It was hotter and more humid the day I got the new times with the yank. The only other change in my set-up was 3.23s to 3.73s and I'm sure thats why I couldn't hook as well but they sure can't take credit for that good of gains. I'm sure they did help with the looseness of the converter though. Overall, I was very dissapointed with the vig and love my yank. 
