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build borg warner or go 9inch

Started by RB-30-ET · 20 Oct 2016 · 18 replies

Preserved from CalaisTurbo. Original authors and dates are shown; archived members are not current Holdcom accounts. View original archive ↗

RB-30-ETArchived member
Just wanting peoples opinions on diff options for VL turbo. Car is manual, setup awaiting tune targeting 450-500rwhp on E85. Am I better building the borg warner, full spool 31 splines and TA cover or have a 9 inch built for commodore. Car is used for street duties, but also interested in seeing what it can do at the track once its complete. Once ive run it a couple times, it will probably never see the race track again.
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tzatzikiArchived member
U can do ur job with a built borgwarner diff.. But 9 inch diff is alot stronger, for higher hp apllications
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RB-30-ETArchived member
what times are VL's doing with a built borg warner, any reliability issues.
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RB-GEMArchived member
Gears will be your only weak point once you build the Borg Warner as you can only use the factory stuff . I bought all the best gear for my diff , still cost me close to 3 grand
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deenoArchived member
Hey mate have you thought of going a trutrac with 31 spline axles can handle a lot of power and easier on the street than a spool? Sent from my HTC_PN071 using Calais Turbo mobile app
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GouldyArchived member
Just put a 9" inch in and be done theres **** all weight difference ive got 500rwkw behind mine 3.7 gears trutrac 31 spline mark williams axles doesnt miss a beat
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RB-30-ETArchived member
Quote: Originally Posted by RB-GEM [View Post] Gears will be your only weak point once you build the Borg Warner as you can only use the factory stuff . I bought all the best gear for my diff , still cost me close to 3 grand I have found new gears on ebay for sale spicer brand, would these be any stronger in the borg warner than the factory stuff? ---------- Post added 22-10-16 at 21:41 ---------- Quote: Originally Posted by deeno [View Post] Hey mate have you thought of going a trutrac with 31 spline axles can handle a lot of power and easier on the street than a spool? Sent from my HTC_PN071 using Calais Turbo mobile app how much power would the truetrack and 31 splines handle? ---------- Post added 22-10-16 at 21:43 ---------- Quote: Originally Posted by Gouldy [View Post] Just put a 9" inch in and be done theres **** all weight difference ive got 500rwkw behind mine 3.7 gears trutrac 31 spline mark williams axles doesnt miss a beat I am seriously thinking about the 9 inch but it is more expensive on a limited budget. If I'm not going to need it, the money can be spent elsewhere to bring the car up to spec.
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vltnitronArchived member
I had a borgy with 31 mosers and full spool. run 9.0 with approx 600kw with no issues. The t/a rear hat helps them a lot for support. Also the falcon gears from eb on xr6 are the strongest. 3/4" tooth they come in 3:45 and 3:7. best to buy a new set tho esp with a manual Any questions on this give graham a call at boss diffs Adelaide.
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RB-30-ETArchived member
Thanks mate, good to hear first hand experience with the Borg Warner and huge power. Ive decided to stick with the Borg warner. I just ordered the Harrop 31 spline truetrac, and trying to work out which gears to purchase in the 3.73 ratio. Looking at buying new spicer M75 or M78 both 3.7/3.73 ratio. The diff shop told me the VL borg warner need the M75, the M78 although similar would not fit or may need machining. Does this sound correct? M75 http://www.ebay.com.au/itm/M75-NEW-H...EAAOSw-jhUBwDd (http://www.ebay.com.au/itm/M75-NEW-Holden-Ford-Nissan-GENUINE-OEM-3-73-3-7-Diff-Gears-Borg-Warner-Gearset-/201310461680?hash=item2edf09def0:g:J7EAAOSw-jhUBwDd) m78 http://www.ebay.com.au/itm/M78-NEW-H...EAAOSw-jhUBwDd (http://www.ebay.com.au/itm/M78-NEW-Holden-Ford-Nissan-GENUINE-OEM-3-7-Diff-Gears-Borg-Warner-Dana-Gearset-/191999996027?hash=item2cb417707b:g:J7EAAOSw-jhUBwDd) Also.. where is the best place to buy axles and a TA cover. looking for a good deal on some Moser or similar 31 spline. cheers Quote: Originally Posted by vltnitron [View Post] I had a borgy with 31 mosers and full spool. run 9.0 with approx 600kw with no issues. The t/a rear hat helps them a lot for support. Also the falcon gears from eb on xr6 are the strongest. 3/4" tooth they come in 3:45 and 3:7. best to buy a new set tho esp with a manual Any questions on this give graham a call at boss diffs Adelaide.
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RB-GEMArchived member
I got Altra9 4140 Chrome Moly Axles in mine . Had Mosers in mine when i picked it up from the reputable diff shop . Bloke had mushroomed the hub smashing the wheel studs in couldn't get my brakes on . Pulled the axles out and they looked like they were cut down in a drop saw and chamfered with an angle grinder . Sent them back and got a refund for them the next day and ordered the A9 axles . I've got an original TA diff cover also that an ex mate ordered for me from the States . Only issue i had was the TA cover would sit on the Panhard rod whenever i jacked the car up . I've since had a custom panhard rod made to clear it now that I've mini tubbed the car
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joe185iArchived member
M75 is correct for VL. Everyone seems to call the Commodore diffs M78s, but they have 7.5 inch crown wheels (not 7.8 inch like the later Falcons for example). I know that the VK 1/2 to VS / VT1 Commodore and R31 Skyline gearsets are all interchangeable. I've got 450rwhp and I'm running custom billet 28 splines, TorqueLock Truetrac and Dana 3.89's in a manual, no dramas. The truetrac is great and I run et streets all the time, it's going fine.
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RB-30-ETArchived member
Hi mate, thanks for the tip on the moser axles, that's rubbish. I will look into the Altra9, what did they set you back? I ended up ordering the TA cover, is it possible to space the panhard to miss the cover, I have a whiteline adjustable in there. Quote: Originally Posted by RB-GEM [View Post] I got Altra9 4140 Chrome Moly Axles in mine . Had Mosers in mine when i picked it up from the reputable diff shop . Bloke had mushroomed the hub smashing the wheel studs in couldn't get my brakes on . Pulled the axles out and they looked like they were cut down in a drop saw and chamfered with an angle grinder . Sent them back and got a refund for them the next day and ordered the A9 axles . I've got an original TA diff cover also that an ex mate ordered for me from the States . Only issue i had was the TA cover would sit on the Panhard rod whenever i jacked the car up . I've since had a custom panhard rod made to clear it now that I've mini tubbed the car
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SteveArchived member
Where did you order the TA cover through? I'd like to get one soon...
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joe185iArchived member
They're on ebay
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RB-30-ETArchived member
Quote: Originally Posted by Steve [View Post] Where did you order the TA cover through? I'd like to get one soon... I ordered from diff technics in Sydney, call Dora wonderful to deal with and shipped same day. ---------- Post added 02-11-16 at 13:33 ---------- Quote: Originally Posted by joe185i [View Post] M75 is correct for VL. Everyone seems to call the Commodore diffs M78s, but they have 7.5 inch crown wheels (not 7.8 inch like the later Falcons for example). I know that the VK 1/2 to VS / VT1 Commodore and R31 Skyline gearsets are all interchangeable. I've got 450rwhp and I'm running custom billet 28 splines, TorqueLock Truetrac and Dana 3.89's in a manual, no dramas. The truetrac is great and I run et streets all the time, it's going fine. Thanks mate.. this was quite confusing as all my research including this site says the VL diff is M78. In fact it is a M75 that accepts a M78 carrier. For those looking to change gears in their VL, you need to order M75 or 0575 gear sets for this diff. how did you find the 3.89 with the manual, I am leaning towards the 3.73 ratio. Does anyone know any competent diff mechanics in Wollongong region. I know of Driveline gears, are there any others out there to consider.
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vltnitronArchived member
Boss Diffs told me he machines it so he must be fitting the m78 gears. Said something about 1/4" thicker gear. Stronger etc etc. I never had gear set problems after that. I did run a manual for a while which I did crack a stock set of gears. Ohh and if you are planning to race it might pay to have 1/2" falcon wheel studs put in as I bent both sides on mine at the track. Manuals kill everything
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RB-GEMArchived member
Quote: Originally Posted by RB-30-ET [View Post] Hi mate, thanks for the tip on the moser axles, that's rubbish. I will look into the Altra9, what did they set you back? I ended up ordering the TA cover, is it possible to space the panhard to miss the cover, I have a whiteline adjustable in there. They were $1000 with screw in studs instead of press in . I've seen people get that side machined down to clear but i wouldn't want to take any strength out of the cover
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joe185iArchived member
Yep I had M78 fitted into the carrier and my diff guy said he grinded the pinion down. No biggy really it's just something extra to do. 3.89's I'm running now backed with a T56 so it drives quite different. For an MX7 or Rb25 manual I'd go 3.7's for sure. I had 4.11's and they were fun but a real pig to drive stop start
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Jet R31Archived member
Even if you machine the ta cover..its still hits the pahnard rod. And if you run a jacked up style 28x9 car..or stock rear spring drag car ..i guarantee that the rod will hit your diff every time you launch making the suspension do weird **** There would be a few cars going around with that happening...lol cheers darren
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