Fitting a Nine-Inch
#1
Posted 30 September 2008 - 09:16 PM
After some info on issues you have had/seen/heard of when fitting a nine-inch, even if not to a Torana. Things to get right, and what happens when you don't!!
Or what to use to get something right.
Things like:
Control Arm mounting location
Pinion Angle
Pinion's hit floors
Adapting stock brakes
Adapting aftermarket brakes
Wheel PCD's
Tailshaft and exhaust clearance
Housing straightness
Widths
Available axles
Wheel bearings
All responses appreciated.
It will definitely be a big help to everyone in the future.
Grant..
#2
Posted 01 October 2008 - 12:56 PM
#3
Posted 01 October 2008 - 03:14 PM
#4 _waz355_
Posted 01 October 2008 - 03:31 PM
This is the 3rd nine inch conversion I have done the other 2 were on a HG and a HK. I have always had a play down the strip with my cars and pinion angle is something I always adjust. All the conversions I have had did not have the correct pinion angle to get the traction required to get off the mark. So adjustable top arms are great for that, which is what I have always run.
Obviously exhaust clearance is a problem with 9 inch's in torana's mine goes under the diff as I would imagine everyones would??? This is a real hassle with putting the car on a 2 post hoist as the suspension hangs on the exhaust system.
I had a set of billet axles made with the diff housing the whole lot cost me $1500 without the centre for those wondering about cost. If you want I can give you his details - in Brisbane.
I run the standard rear drum brakes, but will go to bigger brakes later. The axles I had made have both the torana and the HQ stud pattern you just have to move the wheel studs to change stud pattern so changing to HQ brake is not a big deal.
I know adapting the standard sway bar can be an issue sometimes, but mine just fits.
Haven't had too many other problems will keep you posted on my current one anyway.
Edited by waz355, 01 October 2008 - 03:33 PM.
#5 _lx-304_
Posted 01 October 2008 - 07:14 PM
dave
#6 _Bomber Watson_
Posted 01 October 2008 - 07:38 PM
Be carefull how much narrower than standard you go if your fitting the disks, i had to get custom smaller springs made up and cant fit hand brake cables.....
Cheers.
#7 _kolman_
Posted 09 October 2008 - 12:46 PM
Control Arm mounting location
who ever you get to do the conversion should get this right or there will be problems
Pinion Angle
not an issue, i guess this would be set by the above
Adapting aftermarket brakes
If fitting commodore disk brakes a bit of modification is required but nothing to difficult for the average home mechanic. From memory you need to swap brakes from left to right side to avoide the shocks. if preferred you can modify the backing plates with a bit of cutting, bending redrilling to suit. If you want a handbrake you will need to swap the left and right handbrake mechanisims over so they are activated by a cable pulling the lever. I found that I was unable to get the cable and lever 100% perpendicular so not as effective as it could be but it still works.
Wheel PCD's
Depends what you want, you can use the ford axles you might get with a 9" but then you will need ford rims. Some rims have multi stud patterns (ford 5x4.5 / chev 4x4.75 ) such as convo pros so this can work if you have chev pattern front and ford pattern rear. Get holden axles resplined / modifyed so you have holden PCD. Get billet axles made to suit diff with what ever PCD you want.
Tailshaft and exhaust clearance
Should not have an issue with the tail shaft, I run a 3" shaft with no clearance issues. Exhaust is an issue with no easy solution, there is not to many installations that I have seen that have been done the same. You can go over but there is not much room with a 9" and you are limited to what size exhaust you can use. I run a 3" system to the mufflers, then have a flange so I have a couple of options.(1) I can run 2 1/4" inch over the diff which is good for the street but is quite restrictive and you can notice the power loss. (2) bolt on 3" tail pipes that go under the diff which causes ground clearance problems and is a pain when jacking up cause exhaust his diff. (3) chuck on some dumpers, not police friendly
If you want to attemp the conversion yourself you will obviously need to know a bit more. The best thing to do is work out want you want and how much its gonna cost. Also triple check any measurments cause if you get it wrong it will end up costing double.
rough estimate of what i paid.
complete 9inch minus centre to suit torana with HQ axles and drum brakes. $700
Sold axles and brakes for $200
Shorten the housing couple of inches and determine axle measurments. $500
Billet axles. $500
commodore brakes second hand complete. $70
New rotors. $110
Hand brake cable modified. $200 I think??
Centre $1000
Just under 3K all up.
Hope this helps.
cheers,
#8 _moot_
Posted 09 October 2008 - 01:21 PM
brakes: i used vn discs on mine and i have moved the lower control arm mounts in 15mm. i had to mount the caliper on the top (in the 12 o'clock position) of the brake disc,where the factory spring used to be.i have 10mm between the lower control arm and the disc with no backing plate.and therefore no internal drum for a hand brake.
i have nissan pintara rear calipers and brackets,it bolts straight on and the calipers have a mechanical handbrake built into them that are attached via torana hand brake cables.as pintaras an commodores use borg waner diffs some brake bits interchange
bottom bit in bold text worked out really well.
also vn and hq stud patterns are very close,by the time i drilled the vn discs to suit 1/2" wheel studs they'll fit nicely on hq pattern axles
Edited by moot, 09 October 2008 - 01:28 PM.
#9 _ass308_
Posted 09 October 2008 - 01:42 PM
acording to my nine inch builder,the best way to get your nine inch shortened is to give the builder your car, nine inch ,and wheels.he puts wheels under guards where u want em and makes it suit.
in sydney if u want to run a nine inch with ten inch rims see http://www.consulmotive.com.au/ before u do anything
Edited by ass308, 09 October 2008 - 01:44 PM.
#10 _moot_
Posted 09 October 2008 - 01:44 PM
#11 _cruiza_
Posted 12 April 2009 - 08:21 AM
So yes it can be done but it was expensive
#12 _bathurst-racer_
Posted 12 April 2009 - 09:01 AM
We found that most cars are much better off using the Borg Warner LSD as found in later XE/XF Falcons and Fairlanes. Its a smaller diff, much lighter with many ratios available and able to cope with the torque of most cars running down the strip. I know the 9" is very popular and almost everyone will jump up and down at my suggestion but I hope to learn something by asking the question.
Edited by bathurst-racer, 12 April 2009 - 09:03 AM.
#13
Posted 12 April 2009 - 09:21 AM
I'm curious as to why you would run a 9" in a road going Torana. As it has been mentioned there are clearance problems and great expense involved in this conversion. Surely the weight issue and drain on horsepower would concern anyone who covers a big mileage due to increased fuel consumption and ill effects on handling.
We found that most cars are much better off using the Borg Warner LSD as found in later XE/XF Falcons and Fairlanes. Its a smaller diff, much lighter with many ratios available and able to cope with the torque of most cars running down the strip. I know the 9" is very popular and almost everyone will jump up and down at my suggestion but I hope to learn something by asking the question.
Excellent point.
To my mind,if the conversion is done for strength,it is a pointless excercise using resplined axles.Many other lighter conversions will do the same job if you are using resplines.
If the conversion is done for ease of ratio change,then I guess thats fair enough.But how often do you swap centres?
If aftermarket axles centres and/or brakes are to be used,(Mark Williams,Strange etc) why not stick a Chev 10 or 12 bolt in it?All the aftermarket stuff is strong as,and at least it will all still be GM.
Im not saying 9inches are crap,but they are far from bulletproof.If you are doing a conversion,keep the faith,keep it GM.
#14
Posted 12 April 2009 - 09:36 AM
I have noticed when fitting the 9" into LH/X, that the top p/s control arm may need a small amount of metal ground off to allow the control arm to pivot.
This has been the case with both my diffs.
#15
Posted 12 April 2009 - 12:15 PM
The LSD is the weakest point in a BW M78. If you have 300 HP+ then the BW LSD will not last long, you would have to look at replacing it with either a KAAZ, Lokka or spool.
The next weak point is where the axle tubes are plug welded into the cast iron centre. If you have 500 HP+ and run slicks on the weekend then this may be an issue.
#16 _cruiza_
Posted 12 April 2009 - 03:23 PM
I'm curious as to why you would run a 9" in a road going Torana. As it has been mentioned there are clearance problems and great expense involved in this conversion. Surely the weight issue and drain on horsepower would concern anyone who covers a big mileage due to increased fuel consumption and ill effects on handling.
We found that most cars are much better off using the Borg Warner LSD as found in later XE/XF Falcons and Fairlanes. Its a smaller diff, much lighter with many ratios available and able to cope with the torque of most cars running down the strip. I know the 9" is very popular and almost everyone will jump up and down at my suggestion but I hope to learn something by asking the question.
I can not really answer that question for everyone, obviously, but in my case I had the option of Borg warner or 9 inch both were disc braked and out of Falcon coupes, knowing the 9 in had the ratio i wanted and was Limited slip and lets face going 9 inch is not normally going to be a mistake. It never gave me any trouble the limited slip was perfect for the car once setup correctly and the brake balance was spot on too. Also at the time it gave me the option of later on going to a big horse power motor although in the end I found nearly 400hp to be enough for general street duties, AS for fuel economy I used to get better then 20MPG, which was way better then any of my mates could do with standard Banjo diffs and less power. Mind you they did not spend the money I did on reseach and building the thing.
I think though if the cost of converting a 9inch or any other diff are simalar then most would opt for the 9 inch
#17 _bathurst-racer_
Posted 13 April 2009 - 10:30 AM
You're right in pointing out that the BW diff isn't for everyone. I only wonder why people would run one in a Torana size road car which may see some strip action. A well built BW can handle up to 300hp on street tyres and most of us fit into that category. With 500 hp and slicks, particuarly in a heavy car then the next 9" problem arises, that of the pinion winding up on the crownwheel and pushing the bolts out of the housing where the front pinion bearing carrier mounts up.
Then its time for a Dana.
What actually made me curious about all of this was a LJ, stove hot six, Aussie 4 speed and 9". The rear end groaned everytime we had it on the hoist. If that car had a decent V8 and a proper rear suspension set up fair enough but as a street car and potentially a 14 sec time card to its credit the 9" was a very poor choice of components.
#18 _studricho_
Posted 28 April 2009 - 08:35 AM
Over kill? Yes, but I was sick of changing diffs. Also they add up after a while too.
Extra weight? Yes, I noticed that the car behaved different with the extra weight, but no more blow diffs.
The guy that did my conversion was rough. It was about 14 years ago, but I have had all the faults fixed and it's working well for me with the RB25DET power plant. It also gives me piece of mind that it won't break as I squeeze more power in the future.
Having said that. If I had my time again i won't go 9" again. Many people are using different diffs that are strong enough to handle the power like said before.
I'm running a 3" exhaust over the diff. It's tight, but works okay. I have no issues with tail shaft or pinion hitting.
I guess that's due to the different floor plan in the UC.
#19
Posted 28 April 2009 - 06:01 PM
#20
Posted 01 March 2010 - 04:33 PM
#21 _brendan_h_
Posted 02 March 2010 - 08:31 PM
as for exhast is there any legal issues with going under the diff?
what about dumping it before the diff? i have herd its exhasut must finish some many MM after the last opening window
this is for NSW
Edited by brendan_h, 02 March 2010 - 08:31 PM.
#22
Posted 02 March 2010 - 09:25 PM
i have herd its exhasut must finish some many MM after the last opening window
I can't wait for the english translation! LOL
#23 _brendan_h_
Posted 03 March 2010 - 02:03 PM
i have herd its exhasut must finish some many MM after the last opening window
I can't wait for the english translation! LOL
i realy need to re read what i write.
i have herd the exhaust must finish so many MM after the last opening window
#24 _mello92_
Posted 03 March 2010 - 02:06 PM
#25 _brendan_h_
Posted 03 March 2010 - 05:45 PM
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users