When is a Race trans not a race trans....
#2588217
12/06/18 07:21 PM
12/06/18 07:21 PM
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Joined: Jan 2003
Posts: 3,943 Melbourne.....Oz-land
Moparmal
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OP
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Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
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Before I start, the subject question is rhetorical....but....
A few mths ago I got talked into buying a “Race” 727 with rmvb from a well known commercial trans company.
I wanted to go with CRT....but international shipping was just too much with our dollar so ended up going to a local retailer and buying a RMVB from CRT and billet servos from a seller on here.
Unfo my upgrade strategy didn’t go far enough....
A guy I know just had an issue with his “race’ trans, and on inspection, we found a lot of ‘heavy duty’ components simply weren’t included....which is kind of surprising as the company claims the trans is good for 800+ HP.
ANYHOW...my question is this.
If I change to a low band apply RMVB....how important is a bolt in sprag?
The motor will be making around 500hp at 3700lbs.
Last edited by Moparmal; 12/06/18 07:27 PM.
67 RO23 clone with 6.1 SRT Hemi and dual quads. Soon to have Drag Pak induction and Throttle body.
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Re: When is a Race trans not a race trans....
[Re: Moparmal]
#2588221
12/06/18 07:23 PM
12/06/18 07:23 PM
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Joined: Jun 2014
Posts: 5,183
Porter67
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Posts: 5,183
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Re: When is a Race trans not a race trans....
[Re: Moparmal]
#2588245
12/06/18 07:55 PM
12/06/18 07:55 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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A bolt in sprag is nothing more than a stock sparg.. they are used when a sprag has spun in the case and a stock one is put in.. A super sprag has many more rollers and is much less likely to blow.. you can pull the VB and use a stock one
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Re: When is a Race trans not a race trans....
[Re: Moparmal]
#2588263
12/06/18 08:32 PM
12/06/18 08:32 PM
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Joined: Jan 2003
Posts: 26,044 Rio Linda, CA
John_Kunkel
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Too Many Posts
Joined: Jan 2003
Posts: 26,044
Rio Linda, CA
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LBA takes a lot of load off the sprag but sprag failures have been known to happen even with Super Sprags and LBA. At you HP level it's less likely.
There is no universal agreement on what constitutes a "race trans", some of us believe that a lot of the "race" components are just glitter....nice if you want to spend the money but not needed at some power levels.
The INTERNET, the MISinformation superhighway
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Re: When is a Race trans not a race trans....
[Re: Moparmal]
#2588264
12/06/18 08:34 PM
12/06/18 08:34 PM
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Joined: Jul 2008
Posts: 30,547 Florida STAYcation
dOc !
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,547
Florida STAYcation
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I would invest in an alum or steel billet front drum
Last edited by Doc Fiberglass; 12/06/18 08:34 PM.
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Re: When is a Race trans not a race trans....
[Re: Moparmal]
#2588339
12/06/18 11:33 PM
12/06/18 11:33 PM
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Joined: Mar 2011
Posts: 3,114 Michigan
A727Tflite
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master
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Posts: 3,114
Michigan
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Before I start, the subject question is rhetorical....but....
A few mths ago I got talked into buying a “Race” 727 with rmvb from a well known commercial trans company.
I wanted to go with CRT....but international shipping was just too much with our dollar so ended up going to a local retailer and buying a RMVB from CRT and billet servos from a seller on here.
Unfo my upgrade strategy didn’t go far enough....
A guy I know just had an issue with his “race’ trans, and on inspection, we found a lot of ‘heavy duty’ components simply weren’t included....which is kind of surprising as the company claims the trans is good for 800+ HP.
ANYHOW...my question is this.
If I change to a low band apply RMVB....how important is a bolt in sprag.
The motor will be making around 500hp at 3700lbs.
A standard 727 properly assembled without any tricks, will easily handle your power and vehicle weight. The billet front clutch retainer will keep you from getting hurt and breaking the case if you have a driveline issue. Take a look at an old Direct Connection catalog which shows “race” transmissions available. These were new, production transmissions built at the transmission plant, using production parts. No bolt in ORC, billet drums, etc. The problem that I have seen repeatedly is the builders ability to know what is good and what is questionable when reclaiming some of the parts. Another reason why some builders insist on using new drums, planetaries, etc. If it fails they can blame the supplier of the part while taking the risk out of the equation. This same mentality is seen in some dealer repairs, Not criticising, just stating some findings and facts.
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Re: When is a Race trans not a race trans....
[Re: Moparmal]
#2588437
12/07/18 03:34 AM
12/07/18 03:34 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Posts: 52,972
Romeo MI
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I was gonna tell you if the RPM was low enough (below about 6300) you wouldnt have anything at all to worry about.. RPM is what causes drum failures.. IF the ORC fails that lets the drum to spin 2.2 times the engine rpm..drums have have been spun(used old drums)and they tend to fail at right about 13K rpm which is close to 6,000 rpm but giving a cushion.. I have been running a stock drum from day 1.. if you dont do stupid stuff you dont have a issue.. I've been turning my engines to about 8100 and some as high as 9600rpm(not often to 9600).. that was a test
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Re: When is a Race trans not a race trans....
[Re: Moparmal]
#2588453
12/07/18 06:35 AM
12/07/18 06:35 AM
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Joined: Mar 2009
Posts: 2,475 Sydney,Australia
tex013
top fuel
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top fuel
Joined: Mar 2009
Posts: 2,475
Sydney,Australia
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Mal, Sorry to see/ hear your results . Lets just say i heard once what TCI means but i have not used them so thats not for me to say . Here is a couple of my thoughts , as i am in Aus just like you . And i have built,worked in auto shops . I have a foot brake B&M . Cracked old case and no BB core . I ended up with a Griner RMVB . This trans ran 10.50s behind my 505 . It ran about 9 years with only regular servicing . Only broke 2 front flex bands , swapped to solid band solved that . No other issues. Still on my shelf for a spare . Current trans has a brake and has gone 10.20s off the brake @4000 trapping just over 7000 This has a billet drum and is set for racing , though i daily drive it . And yes i paid $ for it , similar to importing a CRT . Both trans have low band apply to help . Fred @ Protrans here in Sydney built it . I rang B&M when choosing theirs and they said 600hp is the round about limit as delivered . I guess its all a pick and a poke . Who will look after you ?
Tex
Last edited by tex013; 12/07/18 06:36 AM.
New best ET 10.259@129.65 . New best MPH 130.32 Finally fitted a solid cam, stepped it up a bit more 3690lbs through the mufflers New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive
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