FieroAddiction

I'm looking for some input on a torque converter for the LS4/4T65E. I know there are some out there (Intense, ZZP) for the 3800 cars, but I don't know how the advertised stall speeds for the 3800 will compare when used with an LS4 with more power. So far it has a GMPP LS hot cam, 8000 RPM race lifters, heads shaved for 10.6:1 CR, LS2 intake, injectors and throttle body. I have no idea how much power it's going to make, but it will be considerably higher than a stock 3800SC and can certainly benefit from a better converter. I'm considering sending the stock LS4 converter to get it worked over. Has anyone else changed their converter yet? Suggestions?

Jon

Count of Monte Carlo

Well our converter stalls at 3500 or so anyway so its pretty good already in that respect...

Nacho SS

iTrader: (4)

What would you like to change about it?

FieroAddiction

I've never driven a car with an LS4, I'm swapping one into a Fiero. I've read that the factory stall is around 2800? How are you getting 3500?

Having never driven the stock setup, I can't say exactly what I want to change about it. It should be tight and drive like a stock one while cruising until you stand on it, then it should flash to a stall speed that is optimal for the mods that have been done to the engine. I also want to switch to the smaller/lighter 245mm converter.

Jon

06WHITEMCSS

Ive only got bout 1800 outa my monte ss. Whats every-one else got?, before the wheels spin?

Count of Monte Carlo

Honsetly I keep forgetting its either 3000 or 3500..Eitherway I'm shocked, but that wouls also explain the looseness in the driveline. Brake torque and you'll see where it stalls at.

GXPJAY

I wish I would have changed the Converter when I rebuilt the tranny, the stock converter is very "loose" you really have to get on the gas to get the car to move from a stop, pain in the ***. We had discussions about this before, something to do with STR, I dunno, lol

I wouldn't use it, big difference compared to getting in a car with a proper converter.

Mgpeagle

iTrader: (6)

ZZP converters are supposed to be the best but only come in a 245mm. We have a 258mm converter. You can buy a L36 (Non-Supercharged, V-6) flexplate to fit the new converter. Numerous people have went this route with the supercharged V-6 L67 GTP engines. The GTP's also have a 258mm converter. Hope this helps. P.S. - Our converters stall at about 2750 or so according to the local trans. guy that rebuilds tons of 4T65E-HD trans for the racers around here.

-Mike

Count of Monte Carlo

A 3800 flex plate is is not an even balance, only ment for that engine. It would not be a good idea to to use that at all.

Mgpeagle

iTrader: (6)

I hate to be the bearer of bad news but our LS4's already use the same 258mm flexplate the GTP's use. You can always drill your old flexplate to mount the new converter.

-Mike

Count of Monte Carlo

Last time I checked this wasnt on the back of the LS4
http://www.zzperformance.com/products_img/330_1.jpg

http://www.gmtuners.com/Customer/LS4...flexplate1.jpg

38 is externally balanced.

scarlett

I have raised inbetween 3000-3300 rpm not good to always do though man does my tranny get hot after runs like that.

Mgpeagle

iTrader: (6)

Ok, if the LS4 doesn't have a flexplate then how do we mount the Torque Converter? I'd love to know.... If the 2nd pic you posted is an LS4 that looks like a flexplate to me.... You can also drill the one on the car to fit the 245mm TC. A 245mm TC is 5 to 7 lbs less rotating mass than a 258mm TC. I really don't care what people do... I know what is going in my car...

-Mike

Mgpeagle

iTrader: (6)

I suggest anyone that wants a factual response then contact the Trannyman95 on Grandprixforums.net. He is the one that actually owns Triple Edge Performance. www.tripleedgeperformance.com

He told me that our cars DO have a flexplate since he rebuilds the 4T65E-HD all the time in the GXP's.

-Mike

Count of Monte Carlo

That is not what I said. The LS4 is internally balanced and runs with a symetrical flex plate. The 38 is externally balanced and runs with an asymetrical flex plate. If you use any 3.8, 3800 1-3 flex plate on the LS4 you are going to vibrate the engine towards failure. And vice versa. BTW I'm an Automotive Engineer, transmissions is something that I know pretty well. If your heart is set on using that flex plate you will need to balance it out. And considering how much material that would have to be removed it would not be advisible since it will not be as strong as it was designed to be.

Mgpeagle

iTrader: (6)

Well Count, that was a good explanation. I think GM screwed us with the way they gave us a V-6 trans. in a V-8. They should re-call every LS4 for trans. problems. Mine is being traded in after Christmas for a SRT-8 Charger instead. I am getting tired with all the problems on these cars. BTW - Sorry if I was a douche...

-Mike

Count of Monte Carlo

Yeah well people do have days of density. Lord knows I have them way too often. One other thing, the you could weld up material but that would be just as hokey. LS4 a fine engine doesnt need all that oddness to make it work. One other thing, the converter we have ain't so bad if you use it to your advantage. Let the converter do all the work for you, with the big engine we have the car will get to speed alot quicker than you think. Its matter of making fine adjustments with the fuel pedal. A great example is pullingon the Interstae and having the tach at 3500 in 2nd gear with like 40% throttle and just letting the converter bring you up to speed. Also when its all said and done and you drop the hammer, that converter is the best. Some LS1 F body guys wold love to have a converter that stalls like ours does. As well these cars are very deceiving on how fast they get to speed.

The transmission really is not a weak point. It is the day that is was made by a particiular technician that is the weak point and always has been for the most part. The rendition of this transmission is the best there is and I know of no FWD gear box short of the 4T80E that can take this power. And honestly the things that have been done to this gearbox just may as well supercede the 4T80E. I have yet to find a company calibrate a gear box that was so smooth yet so quick with the shifts with power still going through during a shift. Yeah I've had my share of problems, by now I hope that they are all ironed out now at 27K. the car stops steers and drives. I'm in it for the long haul.

Mgpeagle

iTrader: (6)

The functionality of this trans. is great. I have 157k on my 97 GTP's trans. with no problems. It actually shifts better than the GXP's does. The thing that bugs me is the GXP's is starting to slip and shudder and the tach bounces when I am cruising on the highway. I NEVER beat on this car either. I am just frustrated and want out of this car now. I can't wait to get the SRT-8....

-Mike

Count of Monte Carlo

Well I can's say for sure as to what the shuddering is but I know GM has this Torque Converter lock up strategy that stays partially locked in order to dampen vibrations which honestly I'm neither hear nor there with. With that, the loose converter and smooth shifting make the gear box seem loose when in fact it isn't. I really had to learn how to drive this car differently than I drive other cars. Furthermore I never been in a GXP so I dont know what the shift strategy is like on that car, I know the Monte's is very smooth at times I don't even feel them. When I get on it its a pleasent firm. Hopefully your ride won't give you anymore issues...Are you tuned at all?

neilownz

Just a poor exhaust design. If the crossover wasnt as close to the trans it wouldnt overheat the fluid and burn up under load.