Moparts

bracket car converters/trans parts- 10.0 area

Posted By: RustyM

bracket car converters/trans parts- 10.0 area - 02/05/18 05:08 PM

looking at/studying converters, converter technology for high 9 low 10 second cars in the 2800 - 3400 lbs car range.
Most ruNS down here are 1/8 mile.

Main questions:
1. Many in my area are very fond of the old Mopar Hemi J converter.
To my understanding this converter reworked/ re-stalled is still soft on 60 ft and simply cannot compare with the newer technology /engineering available today.
Please let me know if my research is faulty.

2. I've been looking at/talking to : FTI, Coan, PTC and working from engine dyno sheets, not a lot of difference in recommended stall speeds between them but rather converter construction .
Spragless conversation does come up.
What are the thoughts/ experiences here.

3. what are the best ways/means to improve over all efficiency of 727/converter ?

4. A@A recommends ultimate steel front/high clutch drum - some recommend aluminum- thoughts?
A@A recommends billet steel 4 pinion planetary - some down here say that isn't needed on 650 to 700 hp engines- thoughts.

I don't mind spending money wisely, don't like to waste money.

efficiency /consistency/reliability/safety are important .

j converter - while great in its day and good today, this just doesn't seem to be smart spending on a new build to me but, I'm open to my thinking being all wrong as well.

Thanks again for this site, you folks- your all amazing in taking the time and effort to help , i appreciate you.

Rusty
Posted By: fast68plymouth

Re: bracket car converters/trans parts- 10.0 area - 02/05/18 05:17 PM

I'd call Lenny at ultimate, give him the specs for the combo, and tell him you want fairly tight 9.5" unit that stalls around 4700 to go behind that TF headed 505.
Posted By: oldkimmer

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 02:29 AM

.........I agree that new technology is best..........I have ran a J converter for years on a car built to run 11.0s. 440 engine. best 60 foot 1.34-1.37.......kim......
Posted By: dartman366

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 02:54 AM

Originally Posted By fast68plymouth
I'd call Lenny at ultimate, give him the specs for the combo, and tell him you want fairly tight 9.5" unit that stalls around 4700 to go behind that TF headed 505.
iagreeI E-mail Lenny my info and he called me the next day and we discussed what I wanted and needed, bought his 8" 5200 stall unit for my 512/727 build needless to say,I am happy as a pig in poop, go with the steel high gear drum, the planetary, I went with the 5 pinion from CRT just to be safe, It may be overkill but I am famous for being that way. up
Posted By: Dan Brewer

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 02:58 AM

I had run J conv for years in a mid 11's heavy B body. Last summer I switched to Trans specialties spragless at the same stall speed. Car picked up .10 in 60' and .25 at 660'
Posted By: CMcAllister

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 04:11 AM

As per Coan - "A spragless converter will never be faster than one with a sprag, but that doesn’t mean a sprag is always the best choice. Often times a car with a high horsepower-to-weight ratio can run both converters and see negligible difference in performance. For this reason spragless converters are often favored due to superb consistency and durability."

I don't disagree with this. If I were doing a Stock-Super Stock car, it would have a sprag. Bracket or throttle stop class, spragless.

Stall speed around 1200 less than max RPM. Stall speed is one part of the equation. 2 converters, same WOT stall but with different internal set ups can work completely differently.

727 efficiency? Lightweight parts and roller bearings. The best units today are the Pro Trans trans built for Hemi Super Stock racing. 7k+ new, but they are around used. Maintenance would be more of an issue on one of these. Any of the Mopar trans guys can help, but expect to pay a premium to gain a few tenths.
Posted By: skrews

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 08:33 AM

ATI or Ultimate would be my first choices.
Posted By: shorthorse

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 05:11 PM

For item #4 -
http://www.hotrod.com/articles/15-tips-improve-727-torqueflite-trans/
"On the left is A&A’s Ultimate Steel Drum. Unlike the cast-iron stock unit with its deformable stamped metal retainer ring (right), the Ultimate Drum (PN 22555BSWR) is machined from a chunk of 4140 steel billet and has been spin tested to 32,000 rpm. The stock drum explodes above 12,840 rpm. Why is this important? If the over running clutch/sprag fails (see above), this front drum is instantly accelerated to twice the speed of the crankshaft. So if the tachometer reads 6,000 rpm when the stock sprag fails, the spinning drum accelerates to 12,000 rpm, the edge of disintegration."

It doesn't take horsepower for a drum to fail, it takes RPM's. If you've ever seen the results of a drum explosion or if you like your feet, get a billet drum. I have a steel one but I can not speak to the pro's or con's of steel vs aluminum. I'm sure someone here will know.
Posted By: moparx

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 05:22 PM

not being a transmission expert [but building several over the years], i "thought" a steel [band] lined aluminum drum was the best of both worlds ? aluminum drum for light weight, and a steel [outer] liner for wear resistance. any truth to that ?
beer
Posted By: jwb123

Re: bracket car converters/trans parts- 10.0 area - 02/06/18 06:47 PM

I ran a J converter for years, 3200 lb car low 10's, I don't think you could have a much better converter with that combo. low 1.30 60 feet and very consistent. BUT when I got the car to go into the 9's I started having trouble with slippage on the big end, sometimes my shift light never went off the entire pass. I struggled with a couple converter manufacturers, most hit the tires too hard at the starting line. My ET was actually better, but the 60 feet dropped off and I could not cut consistent lights. I have a 4-link and about wore out the bolts trying different combinations. PTC converters set me one up and it works good. 60 foots came back and my light really improved.
http://www.ptcrace.com/ I have a lot of fellow racers I know go through several converters before finding one that works like they want. I don't think it's really a manufacture issue on quality, just finding the right setup is hit and miss, more an educated guess than a science, I provided dyno sheets and all the info they requested, and 4 companies gave me four different converter combinations, if it were a science, I would think the calculated combinations would have been much closer to the same. But they went from 8, 9 10 inch and sprag, spragless, etc. A 8 inch was what I ended up with.
Posted By: MoparBilly

Re: bracket car converters/trans parts- 10.0 area - 02/10/18 06:11 PM

looking at/studying converters, converter technology for high 9 low 10 second cars in the 2800 - 3400 lbs car range.

Main questions:
1. Many in my area are very fond of the old Mopar Hemi J converter.
To my understanding this converter reworked/ re-stalled is still soft on 60 ft and simply cannot compare with the newer technology /engineering available today.
Please let me know if my research is faulty.

The "J" Converter was designed as a soft hit converter, used as a band-aid because engine torque was ahead of tire technology. Really has no place in modern bracket racing, unless running in a small tire, stock suspension type deal.

2. I've been looking at/talking to : FTI, Coan, PTC and working from engine dyno sheets, not a lot of difference in recommended stall speeds between them but rather converter construction .
Spragless conversation does come up.
What are the thoughts/ experiences here.

Loved the spragless in my glide, but wasn't concerned with best 60 foot, only interested in consistency and not breaking it when running the occasional N20 pass.

3. what are the best ways/means to improve over all efficiency of 727/converter ?

Smallest converter with the lowest stall speed that works with your combo. Example: An 8 inch 4800 stall will always be more efficient than a 9 1/2 inch 5500 stall. Depending on your combo however, it may not be faster! The typical 10.0 car is right on the edge of needing a 9 inch over the 8, based on torque output. My 3000lb Valiant street car has an 8 inch JW Performance converter that stalls around 4900 behind my stroker small block that puts out 550 ft lbs of torque. It's great on the street, just a tad tight on engine, but I cover that up with a low gear set. It runs 10.39-128. When I toss 150hp N20 hit on that, it runs 9.43-139 and the stall jumps to about 5600! I'd like to up the N20 hit to 200-225, but my previous experiences have shown me that the converter couldn't handle it, the stall would likely go to 6000, and I'd build a ton more heat in the transmission, and not go any faster. So, I can choose to be happy where it is, or order a 9-9 1/2 that can handle the increased torque load.

4. A@A recommends ultimate steel front/high clutch drum - some recommend aluminum- thoughts?
A@A recommends billet steel 4 pinion planetary - some down here say that isn't needed on 650 to 700 hp engines- thoughts.

I've recently purchased a Steel drum for both my 904 and 727 from TCS Products (A MOPARTS Sponsor) and am thrilled with the quality, but my brother has built 727s for years that handle the rigors of mid ten to high 9 second racing with little more than good clutches, and band, with a quality RMVB or brake with added line pressure, and of course, the Coan 16 roller Super Sprag (not to be confused with a "bolt in" 12 roller stock sprag).
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Posted By: Iowan

Re: bracket car converters/trans parts- 10.0 area - 02/10/18 06:45 PM

Call John Lane at ATI, 410 298 4343.
Posted By: RustyM

Re: bracket car converters/trans parts- 10.0 area - 02/10/18 11:34 PM

thanks guys- the general consensus from all I spoke with, sent dyno results / car set up, estimated weight/tire etc was- 4800 / diode/billet/ anti ballooning /furnace brazed etc, etc.
In other words- a good/modern 4800 stall converter.
will re- stall if need be after testing the car.

car is back from frae shop- glad I took it.
Looked/measured good here but- frame machine /operator found her twisted a little across the front which explained door gaps being slightly off side to side.
All squared/plumbed up in all planes and so- on with the build breathing easy.

One again- My thanks to all.
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