(No0b hat on)

Does the G's drivetrain not have a torque converter?

Reason I ask is because I have not seen a single aftermarket high-stall tc for our cars available anywhere.

What is the factory stall RPM anyway?



- For those who don't know the benefits - you can spend about $1500-$2000 for a tc and gears (installed) and your car will likely be quicker in the 1/4 mile than those who spend more on the same model car for bolt-on stuff. Really, I saw it quite a bit on Vettes. It really ticks off the guys who spend $2k on CAI, headers (installed), and get spanked by a car with a stock engine.

 

Yes your car has a torque converter if it's an automatic.

 

all automatics have a torque conveter it's a must. Without it the enigne would stall. The TC allows slippage when the car is in gear and stopped. Manuals have a clutch so the TC is not necessary.

 

because there isn't that high a demand for it in these cars.

I can't imagine a large quantity of people wanting a similar setpu on a g35 as to what I had on my mustang - 4.10s (wish I had 4.56s ), 2800pi stallion tq converter and a transgo shiftkit fully drilled out (hardest setting)

 

Don't bother unless your're going FI or getting a built motor IMO.

 

Yes, there are torque converters available for these cars. There are a few 350Z and G35 owners with aftermarket TCs. Check my350z.com for more information. If I remember correctly, the stock stall on the 5AT is around 2600-2700rpms which is pretty dang high for an OEM TC. The aftermarket TCs kick up the stall to around 3200rpm or so. Unfortunately, it seems like none of the owners that have aftermarket TCs actually race the cars so we have no idea how benefical the TCs are.

There are downsides to higher stall TCs though. They generate more heat and make the car less responsive around town. Also, I know that one G35 owner was experimenting with various stall rpms and if the stall gets too high, it starts messing with the driveability and sensors. I can't remember what rpm stall caused the issues though.

As for gears, the 5AT is already optimally geared. Changing to a 3.5 or 3.9 gear would force unnecessary shifts into 4th and make you cross the finish at a less than ideal rpm. These cars aren't like the 4ATs used in the F-Body and Vette. The stock gear ratios of the G's 5AT are far more aggressive plus the TC has a much higher stall. My 94 Z28 auto had a 1,700rpm stall hence the reason why F-Bodies and Vettes take so well to 2,800rpm aftermarket stalls. Comparing 3.73s in an F-Body 4AT to the OEM 3.3 gear in the G35 5AT is apples to oranges.

 

Plenty of shops do VQ torque converters. SGP, performance motorsports, Level10, protorque, edge. Google the tranny number for additional vendors. RE5R05A.

Here's the G tranny info if you haven't seen it.

 

I thought it felt rather high. I had a Yank Stealth 2600 in my 450lb/ft Vette and it wasn't as snappy from a stop as the G is. Now I see why most folks who do occassional drag strip racing don't want a higher stall converter - the stock G TC is already as high as many aftermarket TCs. Anything above 3k on most cars is not going to be pleasant to drive around town, unless you like a little bit of whiplash everytime you touch the gas.

It also explains why our gas mileage sucks ***. I'm not complaining though, that's two less parts that I need to buy (TC and gears).

I'll tell you what though, for a general purpose daily driver/performance car, I don't think there is a better geared tranny than the 700R4/4L60E (the Vette one, not the one in the Camaro/Thunderchicken). Relatively short 1st gear for quick lauches, OD to keep RPMs low, shifts into OD at WOT - what more could you ask for?


Torque Converters - the real reason why they invented transmission coolers. j/k

Seriously though, I don't know how reliable these trannies are, but I've seen plenty of weekend drapstrip guys with high(er) stall converters (2800-3200) on their DDs and not have any heat-related problems as long as they had a tranny cooler. Without one, you may as well put your order in to Art Carr now because by the time he actually has one ready for you , your tranny will be nothing more than a core.

 

I respectively disagree Have you heard about GMs new 6 speed auto being used in the Vette, some Caddy's, and their light trucks? Wow! The 6AT C6 is quicker than the 6MT C6. The 4L60E Vette's and F-Bodies were already nearly as quick as their 6MT counterparts, but now the 6AT has filled that gearing void these cars had between 1st and 3rd. The 4L60E in my 94 Z28 was extremely responsive to throttle inputs and I wish my G's 5AT was the same way. But overall, the 5AT in the G/Z is pretty dang good and the gearing/TC is dang near perfect. If the car had an additional 30wtq off idle, would be perfect.

 

So how do you read the lockup data on this chart? My 03.5 5at sedan used to get decent gas mileage (for a G) but lately that has dropped significantly. I'm not sure the torque converter is locking up properly. How can you tell?

 

Lock up occurs after the specified speed in 4th and 5th gear (above about 30 mph) when the throttle is at less than 1/8 position.

The other factor to consider is torque multiplication (TM). Our TCs have a TM of 2.0 (pretty good). Nevertheless, after market TCs can up that to 2.2-2.3. In addition they can apparently reduce "clearances" to reduce drivetrain loss and make the TC more efficient.

SGP and Edge racing are the two that I have heard about.

Also keep in mind that most people go for new TC with a LOWER stall speed after they have gone FI so that they can get better traction and better launches. I was advised to go for a 2.2/2.3 TM upgraded TC with a 2200-2400 rpm stall speed for a twin turbo. Better launches and better mpg...

 

Sounds like Andre from Edge.