As far as driveshaft concerns? That is 600 torque on the driveshaft whether with a auto tranny or a dumped clutch manual.

I am not talking about propeller shaft (tranny to diff) I am talking about the driveshafts from diff to spindle. Those are the ones you will see go first. FWD cars can break theirs at around 400-500 ft lbs of torque. But ours are longer and transmit torque better. No one knows our limits yet, but I know the V6 altimas have bigger driveshafts than the 2.5 altimas do because of that concern. So assuming Nissan decided they needed a thicker driveshaft to get the car thru a normal lifetime without breaking (150k or so miles), you can deduce that the driveshaft is good for at least some more than that when they designed it.

Neons driveshafts go at around 300 lb ft of torque (worst case), drag cars typically have solid axles which hold up better under high torque apps.

As long as your wheels are slipping though, your driveshafts are seeing nowhere near the peak torque.

Better Life thru Chemistry
Black on Black 03.5 Sedan 6MT - Custom Catback, Custom Intake Tube, HyperGround Kit

 

Hey Guys

I have decided to come down to L.A. for the weekend to attend the Stillen day. So anyone that wants to see/ride in/drive my car in SoCal to see the mods (especially this last one) is welcome to do that at Stillen day. According to the posts in West forum about the stillen day, a lot of you guys that I know from socal are gonna be there. Hope too see everyone there.

So who is coming?

Gurgen



<P ID="edit"><FONT class="small"><EM>Edited by gurgenpb on 11/14/03 12:53 PM.</EM></FONT></P>

 

I'll be there. I can't wait to check out your ride. Hopefully my Crawford comes in today so I can have it on before Saturday. Looks like you're the one with the most and best mods on the Sedan around here.

 

Hey guys

AN IMPORTANT UPDATE

I started noticing some pinging in the 6000+rpm range. Will be seeing todashi (the TechnoSquares wizard extraordinaire) on Monday morning. More details coming soon. The A/F is now at approximately 13.1 (was 12.5). Will be checking the A/F with Todashi's machine in my pre-cat location on the cat tubes.

More soming soon...

Gurgen

 

G35Lakers.... did we meet there? I don't recall your ...

Bruce (BKChang). nice ride man!!!! I decied to get rims too, but will most likely stay with 17" for performance reasons....

Grugen

 

Also, did some more runs.... Will be doing some more G-tech runs to straighten out the situation and will report back.

Gurgen

 

<blockquote><font class="small">In reply to:</font><hr>

So, the 6mt is faster than a stock 5AT when it dumps the clutch: 220lbs/ft vs. 176 lbs/ft. This is kind of apples and oranges though... The 6MT has the advantage by being able to do high rev launches.
But if you compare the same stock 6MT vs a tuned T/C 5AT (something that's not possible with MT's), there is just no contest: 220lbs/ft vs. 451-492lbs/ft !!!.

<hr></blockquote>

I can not help but to TOTALLY disagree with your understanding of how a torque converter works, and the "torque multiplier" you discuss. The only way that an engine can deliver more torque to the drivetrain than its dyno'd torque figure, is due to the surge of power that is available when the engine is moving at a faster speed than the transmission, and that difference is suddenly equalized. As soon as the tires lite up, which should be AT launch, the entire drivetrain should be equalized, with minimal slippage (except from the tires). Using your logic, "the "torque multiplier" would be infinitely higher in a MT car than an AT car....up to the point where a clutch can no longer handle the power and starts to slip.

While I would not for a minute dispute that your modded torque converter has made a huge improvement to your launch, it will not deliver any more torque to your rear wheels than a MT would, in fact it's probably still less.

The reason that most serious drag cars run automatics has little if anything to do with our cars. The predictable slippage allowed by a torque converter helps to manage the excessive power of a dedicated drag car and allow that power to be laid down progressively. While this can be done by feathering a clutch in an MT car, it's simply not as repeatable. With import drag cars, the high-power-handling automatics that exist for American muscle cars aren't as readily available, so most (perhaps excluding the 1,000hp types) use MT's. I would think that for a car like ours, a MT would make for a faster drag strip time, even compared with a modded automatic. If one were bracket racing, it might be different.


04 G35s 6MT BS Aero Kit/Nav/Prem
Warning: Objects in Mirror Are Losing!

 

And I in turn PARTLY disagree with your assessment.

I never sai that the torque is there throughout the acceleration run. The multiplication factor quickly goes down to 1:1, actually about 75 feet after launch. So the tq numbers cited are for launch only, thats why I kept saying AT LAUNCH! AT LAUNCH! (when quoting those numbers)!!!! In fact, the AT DOES AND ALWAYS WILL HAVE MORE TQ AT LAUNCH THEN THE MT witht eh right T/C.

Gurgen

 

There is a multiplication until the turbine speed equalizes:

http://www.tciauto.com/tech_info/tor..._explained.htm

http://www.converter.com/torqueratio.htm

An auto with high stall and approximately equal hp will always beat a MT over the first 75 to 100 ft because of this torque multiplication. And just for the record, the quickest NHRA Super Stock car 1/4 mile records are still held by Hemis with AT! Go for it Gurgen, now you just need a 3.91 gear set or a set of 235-40 tires! Whoo hoo.

<P ID="edit"><FONT class="small"><EM>Edited by jcv on 11/17/03 07:31 PM.</EM></FONT></P>

 

jcv

Thanks

Just got the 235/50 tires (same diamter). Kumho Ecsta KH11 (very highly rated on TireRack). Cheap too ($100 per pop).

Gurgen

 

OK guys, I see your point. But in reality, the difference AT and MT just isn't there for our cars. We don't have 1,000hp hemis, that can easily overpower their car's drag slicks. We don't have race motors that come on their cams at 5,000 -7,000 RPM, and need more slippage than a clutch can provide without cooking.

Your "all things being equal, an AT car will produce better 75-100' times" statement assumes that one can only launch a MT car by dumping the clutch at 4500 rpm. This dump-the-clutch technique might be the right way to launch an AWD car, but not a car like ours. With practice, you can launch a G from about 3500 RPM, with just a very slight amount of tire slippage, and the car will not bog at all. This is done with a slight slipping of the clutch. It is EXACTLY the same effect as the torque multiplier effect in an AT. The one difference, is that one is a viscous slippage effect, and the MT uses a friction effect.

And tell me how you plan to overcome the MT's closer spaced gear ratios? Even with a higher rear axle ratio (is that even available???) the transmission ratios are much wider in the AT (as compared to gears 1-5 in the MT). And if you change the rear ratio, don't you screw up your launch you are now happy with? Even if you can launch faster, won't a MT (G!) car with equal HP drive around you in the 1/4 because of better gear ratios? As far as I know, I don't think you can pick your own automatic tranny gear ratios for our car.

And jcv, if you think Super Stock Hemis have any relevance to our cars, think again. You want relevance, look at the lower classes of import drags. Almost all cars run MT's.



04 G35s 6MT BS Aero Kit/Nav/Prem
Warning: Objects in Mirror Are Losing!

 

racerx you evidently didn't read the article or are not familiar with high stall converters and how they work. You don't need a Hemi to utilize them. In fact, they are very, very effective with small displacment engines to get more torque to the ground, this is where they really shine.In effect this is somewhat like your slipping clutch but torque multiplication is in fact not the same thing- it actually is torque maultiplication.

Gear ratios can be an issue but none of us are using 5 or 6 gears in a 1/4 mile run that I know of with the stock gear set. The high stall converter, in effect, is another ratio, a very low 1st gear.

Most small imports aren't using AT with high stall converters simply because most small imports have sh$tty AT ,so the choice is made. With a good trans, a very small displacment engine can launch like a beast with a high stall converter. Combined with rear end gears and you've got a winner in the drags.Wait and see what happens when the high powered drag imports really get going.

Gurgen, too bad you already got the 235-50's instead of 235-40 or 45. This would have been a cheap ratio up grade and just right with your converter.

By the way, many, many moons ago I used to own one of those Hemi's with the high stall converter (3200 rpm), manual shift Torqueflite and 4.13 gears. Left lots of 4MT in the dust.And then there was the little 350 Dodge Dart with the same setup......

 

Hey, saw your ride at STillen day, but got there around 11:30. Couldn't tell who you were w/ all those people around. BTW, just got the Crawford put in. Can't wait for the exhaust, then Techno ECU upgrade. Heck, I work 5 minutes away from them anyways.

 

jcv...

I know i know.... Just wanted to stay with the factory specs.... Stupid... Should have gotten 45's... Damn it!!!! Perfect reasoning on the T/C stuff...

Racex...

<blockquote><font class="small">In reply to:</font><hr>

It is EXACTLY the same effect as the torque multiplier effect in an AT. The one difference, is that one is a viscous slippage effect, and the MT uses a friction effect.

<hr></blockquote>

This could not be farther from the truth. You do not get torque multiplication with the 6MT's. You get the higher torque being made at 3500 rpm (4500 was just an example.. I was talking about tq generated, not the best launch techniques - the numbers between these two rpms are similar), but you do not have the torque of the engine multiplied to another value.... (x1.6 in our stock T/Cs, x2.2 in tuned T/Cs). Of course you can;t modulate clutch with the AT's and you od get closer gear ratios asn more of them.... But then again, like jcv said.... You don't always use all of them, but i do recognize their advantage....


Gurgen

 

For those who don't believe a modern torque converter multiplies torque off the line, please explain the purpose of the small vaned rotating assembly in the center of this picture.
Hint - it's not furnace brazed (bronze color).


141059-ER - Street Edge Converter.jpg