4T65E-HD Transmission Struggles

Was looking at Riv plans for 2016 and seems like I am stuck at the transmission.

Seems like without the GMR 1" trans chain, we are limited to 400WHP with 4t65hd

Looked into 4t80 swap but could only find dreww who attempted it on a Riv but was inconclusive.

I was considering turbo but if we are limited to 400WHP without the rare legendary GMR parts for the 4t65hd then I will have to accept that fate and plan around it.

Anyone else have any more ideas? TEP rates their best built trans with 7/8" chain and 2.93 gears to hold up 400whp.

Looks like we are limited by the transmission after all..

You're thinking into it wayyyyy too far, dude. The GXP/Monte Carlo V8 guys are building 600hp cars and are doing ok with the 4t65e. It isn't until they hit 800hp that the trans starts grenading.

Unless you're planning on making a full blown drag car, I wouldn't be concerned.

Abaddon wrote:

You're thinking into it wayyyyy too far, dude. The GXP/Monte Carlo V8 guys are building 600hp cars and are doing ok with the 4t65e. It isn't until they hit 800hp that the trans starts grenading.

Unless you're planning on making a full blown drag car, I wouldn't be concerned.

Is that right? I have never heard of a 4t65e pushing 600hp. I will have to check that out.

My research has lead me to believe the limitation of available parts for the 4t65hd is 400whp unless you have the 1"GMR chain.

I will investigate further....

TEP says..."The weak link in our HPS4 build is the 7/8" Single Chain set once you get into the mid 400s-whp range, so if you are fortunate enough to acquire a hard to find GM Racing 1" chain set you greatly increase the power handling of the transmission to well above and beyond 450whp. There are also stronger input shafts out there other than the typical 300M styles, again GM Racing parts. Unfortunately for the 4T65E enthusiasts GM Racing pulled the plug on these parts in late 2008 so they are getting very hard to find and very expensive in new or used condition."

One thing to keep in mind is the other end of the power transfer. Its one thing to say the 4t65 is good to 600HP on street tires, vs saying it is good to 600HP on drag radials. Being in the middle of the chain the transmission deals with much different torque forces with sticky tires. Also keep in mind transmission ratings are usually listed in TQ and not HP for that very reason. Similar is the concept that 600 turbo'ed HP has different effects on the transmission vs. 600 supercharged HP. The difference is all in the TQ and WHEN the TQ happens. So its not as simplistic as "this transmission needs X to handle X HP." or "This transmission can't do X HP."

I also forgot to add weight of car. Makes a huge difference in what a transmission can or can't do. Like how the fiero guys can get away with the getrag 282 against a supercharged 3800 when its only rated for something like 125 ft lbs of TQ.

got an email from the install manager at ZZP today saying they are working on a 1" transmission chain as a GMR replacement.. He said he does not have an ETA for it to be released but did confirm it's in the works...  

It's been known for ages the 4t65e is "made of wood". It can fail at stock HP/TQ levels, or it can take a bit in certain situations. Under big torque, the hard parts can break. For HP it's more about heat management. Keeping up with Dexron VI changes every 20k miles, and using a good trans cooler can keep up with higher HP - use a bigger cooler if needed. For the big torque, there are ways to get around it. Tuning shift points goes a long way, as well as how you modulate the throttle in driving. Doing burn-outs and hard launches at the track with drag radials puts extra stress on the trans, but you can run a 600 HP daily-driven car all year long if you apply the power from a roll, smoothly. A hard launch from time to time with big torque, you take a risk. If you want to do this on a regular basis, call up Triple Edge and problem solved.

AA wrote:

For HP it's more about heat management. Keeping up with Dexron VI changes every 20k miles, and using a good trans cooler can keep up with higher HP - use a bigger cooler if needed.

 

I am trying to launch from every stop with 600WHP. Without 1" GMR chain TEP reports they cannot build a 4T65 past a safe 4-450WHP transmission. TEP will not put anything but 2.93 gears in their MOST POWERFUL stage 4 build because of this weak link. This is the limitation of 4t65e-hd.
We have found the 2.93 ratio 7/8" single chain set (Factory ratio for most 3800 Supercharged and also LS4 V8 applications) proves to offer the best longevity and for this reason is the onlyratio we offer for this rebuild option.

ZZP notes on their stattama turbo kit page:
All kits over 14psi or 400WHP should have the 1" transmission chain


need GMR 1" chain + GMR 1,200 horsepower race input shaft. It's the only answer.

600WHP from a stop = tire smoke. You will not accelerate. Power is dynamic. Install an Aeroforce gauge and watch calculated HP while you drive. You'll be surprised at how often you can actually make use of 600 HP (hardly ever). Look at dyno graphs. Power at launch RPM is between 50-100 HP, depending on tires.

At the track with very wide drag radials you can use more of that power, and if that's your mission, maybe these shafts are a good idea, as insurance. I do know the 800 HP turbo GP used the stock diff, and nobody thought they could get away with it, considering how many street cars had them breaking. A big part is how you roll into the power, imo.

power is dynamic? o rly? I thought a 300 WHP car made 300 WHP from 0% throttle to 100% throttle

I didnt mean put 600whp on a launch. Come on..

I am sure that 800HP GP had GMR parts. This thread is not a help thread for answers. It's a support thread for all of us, those trying to make 400+WHP on a 3800, that are limited by the availability of these ultra rare parts. And to envy and plot against dudes like Cody who has acquired them..

Srry, misinterpreted "Struggles" and "Stuck" as seeking help. It read to me as if you were worried the bigger chain and shafts would be a requirement for a 600 WHP car. You need to pull the trans in order to swap these parts, so that's $1000 labor right there. Do you perform this upgrade as preventative maintenance? Or, do you see how the 4T65E-HD holds up and fit these stronger parts when they break? I would build power until something snaps, then drop the cash and perform the swap/rebuild.

AA wrote:

Do you perform this upgrade as preventative maintenance? Or, do you see how the 4T65E-HD holds up and fit these stronger parts when they break? I would build power until something snaps, then drop the cash and perform the swap/rebuild.

LOL thats the question.. Right now I am looking at TEP doing the build and install. Whether I drive the Riv there or tow it there... that's up in the air..

I have been doing all my track time in Milan Michigan lately and it would be a bitch to get stuck there late on a Wednesday night with a broken trans and have to get it towed home and then down to Indiana. May just get it built this spring so I dont have to worry about it.

It was acting funny at the end of last season so I'm not sure how much life it has left.  

Pull the trans yourself and ship it to TEP for rebuild? If you can afford the downtime. I bet they turn it around in a reasonable amount of time.

AA wrote:

Pull the trans yourself and ship it to TEP for rebuild? If you can afford the downtime. I bet they turn it around in a reasonable amount of time.

Downtime is fine. They are only 2 hours away from me. I would just take it and drop it off for a week or 2.