Limited-Slip Differential

[davida1_hiwaay_net]

What can you wise gentlemen tell me about finding a limited slip diff for a 440T4 transaxle? I'm gathering parts for my next tranny upgrade. In addition to a less destructible torque converter, and some line-pressure boosting items, I want to go limited-slip.
Did GM ever use this? Is aftermarket the only option? Does it aggravate torque-steer problems?

[sharkey]

engeneered performance is the only company that makes a limiter slip for your application. many people swear by their products. i have not used oner personaly, but id sure like to get one in my car.

http://www.engineered.net/eplsd.htm

and gm never used an lsd in their fwd cars (except for about 7 w41 quad 4 race cars). however, it is in my opinion that gm was on lsd when designing their fwd automatics.

[davida1_hiwaay_net]

That's exactly what I need! Will have to wait until weekdays to call and ask about price and availability.
Have you this unit in your Cavalier?
David

[sharkey]

no i dont, id love to have one though. a friend of mine has one in his getrag 282 and loves it.

[davida1_hiwaay_net]

I've had good luck with GM's FWD trannys. My mom's 1989 LeSabre ran 340,000 miles (yes, miles not KM) before the 440T4 tranny needed to be rebuild due to a failed radial-roller thrust bearing.

[davida1_hiwaay_net]

Hey I looked at your homepage. Neat engine swap! My engine came from a sadly deceased 1985 Z24. With the turbo, it is quite stout. Has yours got the metered-air fuel system or speed-density?
Someone who has never dome an engine swap doesn't really know just how involved it is to make it work, and have everything (all accessories) still operational. How long did it take you to get everything together?

[sharkey]

i used to have an 86 z24 that came factory with the ironhead v6. sadly, i got hit by a drunk driver in june and the car was written off. i found this car for $400 with no rust, but it was an rs 2.0l auto. i had bought back and stripped my old car of everything, so it all just bolted in. in a week and a half i stripped the engine bay, swapped the dash, mounted pedals, rebuilt the 5 speed, swapped all the suspention and brakes front and rear, installed the motor, tranny and ecm and had it all running and driving. when you have everything from another car, an engine swap doesnt take that long.

my car did have a mass air flow setup. gm didnt start with speed dencity till 1988 or 89, and at that point they retrofitted speed dencity back to 87, as it only required a different chip. my car is now running on a megasquirt 2ecu, running fuel and ignition. my stock ecm used a rom instead of an eprom, so without serious computer modding, i want able to burn chips.

[davida1_hiwaay_net]

Awe, that is terrible about the drunk driver!! Since you didn't mention being hurt I will say it is good you weren't seriously hurt!
I jumped in headfirst with the chip-tuning. I like the well-proven GM hardware int he ECM's. Since I travel alot in my project cars, I wanted to be able to get replacement parts on the road if it came to that.
Plus I have 3 engines with C3 ECM's and 1 with a P4; and the same tuning hardware can be used to edit all them. At first the learning curve was steep, but now I am glad I went this route.
I can honestly say to people that yes, this car does still have a factory-type ECM and injectors.
I did swap it's original metered-air ECM for a speed-density ECM which was pin-compatible (almost) with the original. I figured this would be the easiest way to adjust the fuel to the turbo engine.
How much time and effort did the MS2 ECM take to get constructed, installed and tuned for your engine? How many parameters does it have? Is it fully mapped or does it use mathematics to curve the ignition timing?
Lots of questions but I am still learning myself!

[sharkey]

it took me about 16 hours to build the stim, relay board and megasquirt, and took me a day and a half to install. as for tuning, im still working on that. it took me a couple days to get it to run and drive nicley, and im just working on the fine tuning now, aswell as playing around with different settings.

it is fully mapped, 12x12 tables. there is a lot to tune. the best thing to do is downlaod megatune and set it up with code 2.6 (you need to download that code parameter, they changed it from what comes with megatune) and have a look through it. there are some realy nice fetures that make it easy to tune with. if you have a wide band o2 (i highly recomend it) you can set up a target air/fuel table and use auto tune and it will tweak your fuel table. you can also set up ego correction so that instead of tuning to 14.7:1 it will tune to your air/fuel target table. there is also megalog viewer, a program for viewing your data logs. its very handy for finding holes in your tables, and it has the handy feture of correcting your ve table based on your data logs (only with wideband o2).

if you have more questions on it, hit me up on msn, its in my profile

[gpse3400]

You can also try www.PhantomGrip.com. Ran that in my car till I crashed it. Can be had via ebay, or jegs.

Transmissions in E,C,H cars off the assembly line seems to last a whole lot longer for whatever reason...

[sharkey]

i have installed several of those inserts and im not impressed with them. basicly all they do is put pressure on the side gears to press them against the carrier. this pressure will make it harder for the gear to spin in the carrier. the problem with this is that it causes exessive wear on the carrier. the side gears also dont get the oil between them and the carrier needed for proper lubrication, and if you get a one tire fire, you could wipe the carrier out in no time.

a true limiter slip diff works in the same fashion, but you have clutches between the sidegear and carrier. this allows for a much better bite for better holding power. also, if it happens to wear out, you can order another set of clutches and your good to go.

i dunno, $349 for the phantom grip insert, or around $500 for a brand new full limited slip. i know what id go for

[geoffinbc]

The EP diffs are NOT brand new. They are just modified cores. I have installed one is a Z24. The components they used were good. However whoever took the bearings off nicked the journals and used a torch to remove them. Bad work practices. EP should have rejected that core as far as I am concerned. But so far it has held up fine.

[sharkey]

quite often to get the bearings off you need to heat up the race or even cut them off with a cutoff disk. i had to cut mine off when i built my trans in summer. i did nick the journal, however it wont affect it in any way, unless the cut is deep.

even if they arent brand new carriers, i would rather have a well designed clutch style limited slip rather than a couple chunks of aluminum and some springs that will just wear the carrier out anyways.

[gpse3400]

Honestly... I was tired of wiping out the spider pin. The side gears can take the extra loading. It has nice wide surface, and the wear that I saw was negligable. I'll wipe out 5 set of spiders and pins before I ever kill the side gears and the carrier. I got my set new off of ebay for $200. Worked well at the track. The website price is suggested.

[Superdave]

The EP diffs are NOT brand new. They are just modified cores. I have installed one is a Z24. The components they used were good. However whoever took the bearings off nicked the journals and used a torch to remove them. Bad work practices. EP should have rejected that core as far as I am concerned. But so far it has held up fine.

So, how hard is it to install one?

I'll be splitting my case to swap the bellhousing over to a GTZ trans in a few weeks and i've been considering a LSD for a while now.