What converter slippage do most try to achieve? How can you tell if you are driving through the converter??? PS. Is 15.5% to much?? Thanks in advance
Brian Mollison 2013 American Dragster 2020 Sumerduck Dragway VA Top ET Champion 2017 Sumerduck Top ET & SSS Track Champion 2017 MAC Top ET Track Champion 2009 Sumerduck Dragway Va Top ET & IHRA SSS Track Champion 2008 IHRA Division 1 Top ET Bracket Final Runner-up 2007 Colonial Beach Dragway Top ET Track Champion
March 08, 2022, 03:25 PM
329L
quote:
Originally posted by 00 DEAD ON: What converter slippage do most try to achieve? How can you tell if you are driving through the converter??? PS. Is 15.5% to much?? Thanks in advance
I went 4.47 @ 154 and the FTI 93B converter slipped 18%. That is with mt3195s (110.5) 4.11 gear and dextron vi trans fluid and 1900lbs. This is in the 1/8 mile.
Jeremiah Hall
March 08, 2022, 03:26 PM
1320racer
Not if it runs it’s quickest/fastest.
My stuff slips less than 10%.
March 08, 2022, 04:12 PM
markemark
Mine was 18.8% for 1/8 mile at the last race of 2021. The DA was below minus 700’. My car is geared 1/8 mile only.
I want to be on the ragged edge of driving through the converter and it slipping in the very best air that the car will run in. What happens by doing that is as the weather cools off, the engine makes more power, and the engine will drive through the converter, thus helping it be consistent versus getting faster. I want my RPM to drop between 500-800 on the fallback of the gear change
March 08, 2022, 04:25 PM
Goob
Spragless Coan built / FTI tuned 8" at 16%
"Despite the high cost of living, it remains popular." Dave Cook N375
March 08, 2022, 05:10 PM
Bucky
quote:
Originally posted by markemark: Mine was 18.8% for 1/8 mile at the last race of 2021. The DA was below minus 700’. My car is geared 1/8 mile only.
I want to be on the ragged edge of driving through the converter and it slipping in the very best air that the car will run in. What happens by doing that is as the weather cools off, the engine makes more power, and the engine will drive through the converter, thus helping it be consistent versus getting faster. I want my RPM to drop between 500-800 on the fallback of the gear change
My humble opinion is that while this may not always be the fastest setup.....it tends to be very predictable and consistent.
Foxtrot Juliet Bravo
March 08, 2022, 06:48 PM
WHOMPWHOMP
quote:
Originally posted by 1320racer: Not if it runs it’s quickest/fastest.
My stuff slips less than 10%.
Thru the 1/8th..l
March 09, 2022, 11:35 AM
FTI
There are a lot variables to play into answering if a slip percentage is "ok" or not. perfect world, car setup correctly I would mid single digits is target. BUT if you are strictly bracket racing, as others mentioned a looser(higher slip%) converter will be more forgiving and more more consistent at the cost of some ET & MPH. Gearing and track distance are also a commonly over looked variable when considering slip%. A car setup for 1/4 racing and only slipping 4-7% in the quarter, is very likely to see slip% numbers in the mid to high teens at the 1/8.
Some other common data points that can be used to determine converter performance are RPM fall-back @ gear-change & RPM flash @ launch & stall
-Dalton
FTI Performance Competition Converters and Racing Transmissions "Some call it cheating, we call it the competitive edge." www.FTIPerformance.com info@ftiperformance.com
March 09, 2022, 01:14 PM
Mike Rietow
23% in this video, 3500 lbs crossing 6600 rpm at 109 mph 3.89 gear 28" circumference tire.
Same TSI spragless converter slips 3.5%, 3200 lbs, 7400 rpm, 114.50 mph 1/8 mile 5.29 gear, 28" tire.
March 09, 2022, 01:33 PM
Mike Rietow
It's so smooth, you could win a Super Pro bracket race on a 8.5" wide tire on this car, dial'd 6.40.
March 09, 2022, 01:54 PM
TOP38
quote:
Originally posted by FTI: There are a lot variables to play into answering if a slip percentage is "ok" or not. perfect world, car setup correctly I would mid single digits is target. BUT if you are strictly bracket racing, as others mentioned a looser(higher slip%) converter will be more forgiving and more more consistent at the cost of some ET & MPH. Gearing and track distance are also a commonly over looked variable when considering slip%. A car setup for 1/4 racing and only slipping 4-7% in the quarter, is very likely to see slip% numbers in the mid to high teens at the 1/8.
Some other common data points that can be used to determine converter performance are RPM fall-back @ gear-change & RPM flash @ launch & stall
-Dalton
Agree but left out some items worth mentioning.
- % slip vs wheel speed - if more slip equals more wheel speed it's probably a good thing and usually means the converter put the motor in a happier power range - same slip with more wheel speed - better converter design hands down! - reducing top end slip does not mean more MPH, it can but not always and usually it doesn't unless the converter was out to lunch to start with - if you are comparing one car to another with regards to converter slippage, you have to ensure you are comparing apples to apples, if you assume they use the exact same motor and the cars weigh the same but one uses a 31" tall tire and the other a 33" tall tire they won't be equal. A converter is a load sensing device, add more load you get more slippage, take away load and you will drop slippage, more HP, lower gearing, more weight, more drag will all add load and therefore increase slippage
- lastly and the most important one is - The Cone Crusher has more slippage between his ears than any converter on the planet!
March 09, 2022, 01:57 PM
1320racer
March 09, 2022, 02:03 PM
Mike Rietow
That's wrong, more hp isn't more load.
Going up a hill is more load all things equal, as an example.
Going up a hill with more hp is less load all things equal, not more.
Common sense.
TOP 38 is clueless again.
March 09, 2022, 02:18 PM
"The Bender"
quote:
Originally posted by Mike Rietow: 23% in this video, 3500 lbs crossing 6600 rpm at 109 mph 3.89 gear 28" circumference tire.
