Hey guys, just converted my EL Fairmont Ghia to a T5 from an XH, except the gearing seems a little too long, and I'm only turning over 2000 RPM in 5th. I figure I should be doing about 2500 RPM @ 100 and probably 2700 at 110? The car still feels sluggish bit still much better than when it was auto, best mod I've done yet.

Its only got 3.45s in the rear, I'm looking at going to 4.10, the speedo will be out, is this something we can fix with the J3 or do I just buy one of those speedo corrector modules?

Will these gears fit? Are these the right ones for my diff? Just got standard EL Fairmont Ghia LSD 3.45 rear end.

http://www.ebay.com.au/itm/BORG-WARNER- ... 2a3e89dcbc

Hopefully this wakes her up a bit.

Thanks much guys.

If your aim is to pushing towards those rpms down the highway you'll be able to see the fuel needle moving... 4.10 or 4.11's as is more common are a a*** you'd run for just around town driving or track use...

Remember the auto with the 3.08 run like 1700 odd rpm at 100km/hr and both my bf turbo and ED run about 2k at 100 and 2200 at 110...

Sounds like the right gears... Remember there is a fair bit of work to installing them including replacing the collapsible pinion washer and resetting it's shims and preload... Then guessing the carrier shims and checking for it's preload and mesh pattern otherwise you'll have noisy gears in no time... If you're not into doing it yourself it wouldn't hurt to contact a transmission joint and get a quote to change over the gears...

Cheers,
Tim

Thanks Tim, the car feels pretty sluggish in 5th at 100, you have to drop down to 4th if you want to maintain any sort of speed going up a hill and if you want to overtake I go back to 3rd to get it moving quickly. I'm not sure if its because my car has headwork done and a cam but it seems like there is a lack of low down torque.

Or would I be better off with 3.9? The thing I'm worried about is it won't feel like much of an improvement from 3.45 to 3.9 to justify the cost?

I won't be doing this sort of stuff myself, local diesel mechanic is spot on with all this kinda stuff, I'll most likely be talking to him to see if he is capable of doing it, he rebuilt a mates gearbox so I'm assuming this would be up his alley too.

The car isn't my daily, just a project car too so it only gets the odd weekend here and there down the freeway @100/110 and up to a mates place who lives on dirt roads. Its all mostly highway but the car doesn't get driven too much really.

I have a factory AU VCT motor in my ED and rarely do I ever need to downchange to 4th for a hill... Even some of the steepest hills it'll only drop 5km/hr with the cruise set on the way up... Maybe the cam you've picked works too high and you've sacrificed all the torque the motor had... If that's the case then yeah this would help and if isn't a daily then the extra fuel usage may not hurt so much... Just seems backwards to make it work higher in the rpm range and then make it rev higher all the time to get the power back?

I noticed zip going from factory 3.27 (behind the gli manual) to a 3.45 xr lsd... tacho showed a difference... No wow factor but... Can't speak for the jump from 3.45 to 4.11's but... Someone else will no doubt read this and comment... 67RCE seems to be the expert in the field of diffs and ratios, if he doesn't see this I'd PM him for his opinion...

Worst part of doing the install is you need all the shims... If you don't work for a transmission place then you wont have the shims on hand to set it up... Keeping in mind they come in increments of like 1 or 2 thou... So the array of shims is rather large... The work isn't hard from what I can understand, it's the know how, shim availability and time are the costing factors...

Cheers,
Tim

By the sounds of it you want 3.89's mate. My AU (that currently inhabits the front lawn) has t5 and 3.89's. It did roughly those rpms in those speeds that you have mentioned. Awesome in gear tractability, 5th just pulls at highway speed.

One downside is 1st gear is b**ch short. Good for balls out launch though if you are that way inclined, just not perfect for ripping burnouts. Wheel speeds aren't high enough. You find you are using 2nd gear to take off under normal driving conditions. 2-3-5 around town.

You can get 3.89:1 gears from automatic R31 skylines. Manual R31's got the 4.11's. After driving a t5 with 3.89's, I would say I would not go anything higher.

CMS Stage 3 head with 2a cam, pacie 4499s, high flow 200 cell cat and full 2.5" mandrel bent exhaust, with a tune. Would porting move my torque higher up because the head has bigger exhaust valves and porting?

Point taken on the shims, might have to check out a trans place close to my region.



The same seller also lists 3.91 gears, I'm assuming these would be pretty close revs wise to 3.89, I heard a rumour floating around here that the Skyline/Pintara gears cause loud diff whine?

If first gets me to 20km/h by 3000 RPM I'm happy, I'm not the kind of person to go ripping burnouts or drag racing but I like my cars to have some balls which this thing feels like it lacks, theres nothing like the feeling of haullin' a** merging onto the freeway or overtaking someone with ease.

http://www.ebay.com.au/itm/BORG-WARNER- ... 2a3e89dba4

I'm also just running standard 15" wheels, 205/65R15, it used to have 17" 235/40s or something on it, when I changed them to factory wheels when I bought the car the revs picked up to 2000 RPM.

They shouldn't cause any whine if they are installed by a professional. The most likely reason they have that stigma attached is they are usually a home job done on the cheap without the necessary shimming and pre-load etc adjustments made.

Buying second hand diff gears is always risky with respect to diff whine. Unless the gears are inspected by someone who knows the craft, it's easy to buy clapped out diff gears from Ebay and then go scratching the noggin trying to figure out the whine.