I already put this in the stickied thread, but I thought I would open this up for debate here. I hope you all agree.

There are a couple things I would like developed.

One thing is a nice alternative to the GM Racing Torsen Differential. It's $1300 which is outrageous compared to other trans diffs. Despite the price it is the only diff on the 4T65e market that is worth owning since it is gear based and not clutch based like some of the other units available. Since I plan to daily drive my car I need a design similar to the GMR diff or else I can expect a bunch of metal in the trans pans from all the grinding.

Another thing Id like to see suspension wise is a legit set of Lower Control Arms. ZZPerformance made a tubular set but they aren't the quality I was looking for. The way they were designed was very poor, and unsafe. Its only a matter of time before they snap and end up flipping someones car and killing the driver.
A guy named Ron Vogel would modify the stock LCAs and weld new Moog parts into them. They were a legit upgrade to the stockers, however, he no longer makes them and doesn't share his secrets.

Finally, GM Racing needs to start making 1 inch chains for the 3.29 gear set again. They can't even be found used for anything less than $1000. The price needs to drop, its simply inflated due to it being discontinued. There are 7/8 and 15/16 chained gear sets, but they will stretch over time and break. The GM 1 inch chain never had a problem with stretching.

The trans is the weakest part in the W-Body platform. It has some nice hardened parts already designed for it, but an alternative, cheaper, torsen/quaife differential and a gear set chain that won't stretch is a must.

A nice set of LCAs would help our FWD platform stick better and launch quicker which ultimately reduces 1/8th and 1/4 times, especially the 1/8th which is growing in popularity.

Thanks,
Martin

 

Gear based LSD's are good for autocross, however they don't take shock loads very well (i.e. drag racing) for straight line improvement off the line, which I would suggest is what 99+% of people in an LS4 would use one for, a clutch based LSD would be the way to go. As far as the bigger chain, I have yet to hear of one of our 4T60E-HD's wrecking one, even with the torque advantage that it probably enjoys over your modified supercharged w-body. Perhaps your older tranny is not up to the task or you just have more wear and tear due to mileage.

Not familiar with your apparent beef with the lower control arms, but I figure GM has had a couple of decades to iron out any problems with the w-body's suspension under normal use. Again, the target audience on the LS4 cars was not for hard core racers, they are sporty front drivers and nobody is going to spend money to develop parts unless they think there is a market for them. Case in point are your LCA's. They would fit on essentially all w-body cars, a pretty big market right there, but the level of 'quality' you want is not there. It seems that to get what you are looking for might be better served by building your own one-off custom stuff. While it is a wonderful thing to dream of cheap, top of the line parts, the reality is that 'cheap' and 'top of the line' are mutually exclusive. No manufacturer is going to spend an extra $10 on a part unless they are POSITIVE they will make that extra unit cost up (and then some) on additional sales.

 

You make some good points. I also realized I didn't clarify a few things. The clutch-based are very good for the straight line, and a car that almost strictly sees track usage and not the streets. I can use the old Intense Racing Diffs as an example, which they no longer make. Dave (Trannyman), of Triple Edge Performance, can attest to this as well as he has plenty of Intensed broken trans lying around his shop from customer. The Intense diff just didn't last for street usage. Some guys I talked to said theirs didn't even last 10-15k miles. Basically, I want another option available for us guys that want a street worthy Torsen/Quaife diff. I'm not saying the GM Racing diff is bad at all. In fact the few I've talked to that own one say its like night and day and one of the best they've ever owned. I have no problem spending $1300 for the GMR diff, I just simply would like to see another option out there with a competitive price.

As for the gear set chains. I have no idea what its like in the newer trans. I will ask Dave about them for some more insight. I thought we bbasically had the same exact trans.

ZZP is on the right track with their LCAs, however its the way they were designed. They will work great now, but the point is they are unsafe. It likely won't happen right away, but it will happen eventually.

As for custom LCAs, I'm in the works to modify my spare stockers.

Thanks for the reply and constructive criticism.

 

I think a 15/16 chain should be fine. Your only talking about a small amount of extra metal with a 1 inch chain. I think the newer hard internal parts have help save chains. The newer parts flex less putting less stress on the chain helping to minimize streatch

 

I haven't had any problems with my 15/16th chain. The "only" 15/16th's chain I trust is Intense's other than that I would have gone with a 7/8th instead by ZZP or TEP.

-Mike

 

mgpeagle, did you notice any performance increase from the lower stall and better gears?

 

I noticed a BIG difference in acceleration with the higher stall and lower gearing. It is also great on the highway too. My milage hasn't suffered a ton either. I also did a ton of research on the stall speed of the stock t. conv. I have been told that it stalls between 2200 - 2700 by about 5 different vendors. The higher stall does create a lil' more heat but I cured that.

I have never been to the track but a buddy of mine that races the GTP's has driven the car and thinks it is capable of high 12's right now. He had a low 11's turboed Monte Carlo. Who knows though?

-Mike

 

In response to the topic of the thread, I would want headers, better lifters, and more cam choices. I actually like the LS4 cam.

-Mike

 

It isn't so much the size in this case as is the quality. Surprisingly the 7/8th chain made for the 4t65e's is stronger than the 15/16th.

GM Racing just happened to build an awesome gear set.

I hope you're right about the hardened parts. Hopefully the chains will hold up a little better.

 

how much did the stall and gears run you?

 

Dave, at TEP, now makes custom TQ's for your applications. I was going to build my 3800 with methanol injection, a GenV M90, xp cam, and a N2O shot. I talked to Dave about custom making me a 1500 stall, or lower. I believe stock stall is around 1750 on the Series II w-bodies.

 

The gears and chain ran me about 450.00 or so and the t. conve. ran me 400.00.

BTW-The stock stall for a 4T65E-HD in the V-6's are 1875 according to GM and Zoomer at ZZP. Hope this helps.

-Mike

 

No chance on that being right for the LS4. My stall will BRAKE stall at 2650, that means the real stall has to be around 2800 or better.

 

ya that seems really really low, was install hard or was it professionally installed

 

No, the LS4's do stall higher than the V-6's. Even Zoomer said the factory stall spec seemed low for the V-6's, but he said that's what GM "lists" it as. Our cars are about 200 - 300 higher than the V-6's. I was told it is somewhere between 2200 - 2700. This was one reason I went with a 2800 stall. I figured it was very close or slightly higher than stock. Plus, I put a T. Conv. in that weighs 6 lbs. less so the trans does spin quicker, and you can tell it does. I had a friend take the trans. out and had a local guy build it that builds all the GTP's around here. He has done a ton of them so I trusted him the most. My total cost was somewhere between 3000.00 - 3300.00 and that for all the parts and the labor.

-Mike

 

i can brake stall to 3000RPM

 

Ryan, from Sinister Drag Designs, was talking with me about doing a LS4 swap into my Series II. In the discussion he said the LS4 Stall was definitely generously higher than the 3800's.

 

Well, now we know another reason why these 4T65E-HD's in our LS4's run hotter than the trans. in the V-6's. I bet this is another reason a lot of us has had problems with them. I now have my trans. directly hooked up to a very large trans. cooler now. It helped a TON!!!

-Mike