Well the "Intense Racing 3rd Gen. LSD" finally gave the ghost on the Monte. I guess it's the ol' You get what you pay for thing. It was about $500 it gave me about 20 hard launches on the 1/4 and then I put it through hell at last years Super Chevy's "Autocross". Guess I got my moneys worth according to the mechanic. Least I did not lose the race built tranny, that would have really sucked.
So now we are in the process of acquiring either a GM performance Limited Slip for the 4T65E or the Quaife Limited Slip Differential made across the water in England. Either of these are some what spendy over $1600 for the Quaife with shipping or the GM at about $1900 with shipping. Posted a link below for the Quaife unit to give you an idea as to the internal differences these "Gear" driven units and the discontinued "Intense" clutch type units. Apparently this is the last time I will need to replace this LSD at these "Geared" units are strong and can take over 500 WHP all day.


http://www.sparktecmotorsports.com/qdf18b-1.html

Anyone have any experiences with these units "Good or Bad"? I'm in a crunch trying to get ready for the April 2011 Super Chevy event in Las Vegas.
Will keep you all posted as to how things progress......................

 

Well we ended up getting the GM Performance parts Limited Slip Differential for the 4T65E-HD. The Quaife LSD is unavailable according to Crowder a U.S. based authorized Quaife retail sales company, unless there was an order for 30 of these. Dont know that something like that would happen anytime soon, so we found the GM one from an east coast supplier. Will be here the end of next week. Will get a few pictures of it to post. Should be quite the unit, all Billet components. Also will get pictures of the failed unit and what went wrong, might be cool to see what actually failed with the Intense Racing component.

Should be a nice addition to the car and really help on aggressive cornering pulls. Just really stabbing the throttle about 3/4 way through the turn and both tires pulling hard. My launches on the 1/4 track can be really aggressive now instead of mid-range 3100 rpm boosted launches. If the F-body brakes can hold back the power, will try to launch about 3600 RPM's. I can see another set of tires in my near future............Drive it like you stole it.......

 

wish i knew squat about motors

 

I hate to say it, but for the drag strip- it has been pretty well shown that stock diff can launch just as hard as LSD's:

3800Pro.com Forum

From what I've seen, how hard these cars are launching seems to depend more on suspension setup (obviously the full tube chassis front end cars are at the top of the list), slick size/type, and overall vehicle weight than on what type of diff they run.

 

Yes I can see by the stats the stock Diff's can launch just as hard as the LSD, and my Intense gen III did very good. But they WILL FAIL at some point as mine did. I was happy with it's performance, but want the peace of mind offered by the gear driven LSD's that I will have a longer lived build. Dont want to have to baby the launches as the clutch driven ones age and then finally fail risking a potential transmission loss. We all know nothing is forever not even the Billet geared LSD's but hopefully it will not fail after 20 launches. I'm sure Cook's Diff. was either changed out often as he owned Intense and could afford to or it did fail. I bought the Motor from Bob Cook's 9 second Grand Prix for my Monte and it was supposed to only have a dozen passes on it. Ended up rebuilding the whole thing as all the bearings were spun on it and other issues.Then it blew up and had to build my original OEM block, which is what is in my Monte now. So if that happened to that motor with a dozen passes think how much stress the Tranny went through and I bet the diff. was crap by then.

 

I'll be honest, I've never heard of any major issue with stock HD diff's failing other than from operator error, even in the high power setups. I know a handful of pretty high power turbo 3800's that run stock HD diffs (although I know at least one of those has the diff squirter like ZZP was doing on their transmissions), and all of them have far more problems breaking other trans hard parts than the diff's.

It always seems like the hard parts that fail seem to be the input/output shafts or the drive chain (with an occasional CV in there)- and it seems like the highest power cars with full built transmissions mostly have problems with the chain unless they have the 1" GMR chain.

The only real incidents I've heard of people destroying stock diff's (especially the HD ones) are doing excessively long burnouts where one wheel speed was drastically different than the other.

IMO, there were 3 main problems with those Intense diffs- 1 being that they were clutch type LSD's. Obviously any clutch will wear as it ages- so you're adding an extra maintenance item that the stock diff didn't have (plus having to change the fluid/filter more frequently due to the extra particles being released); 2- that the Intense LSD's were never known to be a particularly well made unit (I remember seeing all the pics back in the day of transmissions filled with metallic dust after the LSD failing). I'm sure the massive negative feedback on the various forums didn't help with sales. 3- they didn't have a proven advantage with lower 60' times in drag race situations, the ZZP cars always managed to pull similar or better 60' times on a stock open diff, without having to worry about wear. This would definitely be different if more people auto crossed their cars, but being a heavy FWD car, most find it too hard to be competitive in that realm, and hence not many do it.


Regardless, if you're going to put an upgraded diff in for the autoX and stuff, I think the GMR unit is definitely the way to go. One word of caution- I could've swore I remember hearing something about one of the big GP trans guys having to do some kind of mod to them before he was selling them to customers. I don't remember what he was changing, or his name on clubgp, I just remember he died a few years back.

 

Hello again, I don't know all I need to about these things, thats why I had someone else build the motor and tranny. Spoke with them this morning and he agrees with you in general as I read him your statements. He said your right the open differentials are very strong and it's like you said, other parts tend to break first. We do have the upgraded GM chain etc. a totally built tranny, bet I have almost $5000 in the tranny itself. Matt said my challenge is and thats why we are using the LSD is "Traction" hooking up. He said what we dont know about the cars you describe is how they have the front suspension setup to keep equal pressure to each tire, how wide the tires are they are using and if they are slicks or not and other issues. I mentioned I respected your opinion as your not coming across like a smart *** type but as a constructive critic. He said if we can learn how your all setting up your cars and if my car was a drag car only that the open diff would be the better choice as they are strong and the cost for them is low. His shop buys parts from ZZP and he knows them fairly good. He is currently building an 07 Monte SS a member of this site has at his shop. All aluminum Dart block, war hawk heads, Jaradine Headers,Wilwood brakes etc. making about 800 whp so far in the first dyno phase. However since I Autocross it, street race it and then take it to the track, the LSD is a good all around solution.So thanks for clueing me in on the things I dont know about as thats why we come here to MCF, to glean knowledge from others. Appreciate your help.....

 

Not much to add, other then I went with a Torsen LSD and am pretty happy with it so far.

Joe

 

Any additional info on this yet?

 

i know i have on my rebuild trans when i took it in to get it fixed at the dealer they sent my trans to a trans shop to do it. all they did was just change out the single chane to the thicker dual one. with updated parts for it for some reason called for the police 4t65e internals for the police impallas. i am not complaning i do agre with bumpin with what he said on the differentials also the internals. the one thing i do have to ask is are you going to use it more on the street as a dd or a dd and strip? that you dont want to have some thing misshap down the road?