Ok im tired of blowing tranny so im swaping in the 6 speed! I just got my car boost and the same week blowed the the 5 speed tranny. Ok I have the dek and at low boost 6psi I could beat a 13.5 car by about a car so im guessing if i got it to the track with the 5 speed I could run onsay 13.3-.13.4 just guessing. I beat him 5 times in a row once or twice when I got of the line real good by two cars in the 1/4. So im wondering if the 6 speed tranny wil shave any time of my E/T ? Just by having a better lsd and closer gears. I have a 7,000 or if chose to a 7,300 redline I would finish the race in the top of third before. Im not sure about the 6 speed as im working on it now.

 

im not sure if it will help. 1st gear is taller so you will get better traction, and 2nd-4th are shorter for better acceleration. but theres more driveline losses with the 6spd

 

why more drive train loss? im going with the lighted 6 speed flywheel. My stock 5peed flywheel is 18lb and im getting a 13 lb 6speed flywheel

 

extra rotating parts.

 

Ok I see....

 

6-speed = ~17%
5-speed = ~15%

 

Not with the 4.133 FD in the Spec-V tranny he is using. You have to consider the product of the FD and the individual gear ratios.


95turbo gxe, how do you expect people to give you accurate answers if you do not give them any background information? This is the second thread you have created today with this problem.

All 6-speed boxes are not the same.

 

The difference between the 2 isn't all that much. We're talking about 8-9 for a car that has 400 at the crank. I think personally the additional drivetrain los is more than acceptable for that 6th gear as well as the taller first and shorter mid gears. I have every intention of going to a 6 speed after i get the eu installed.

edit: He's using a spec-V tranny?

 

i think for a boosted max its a must, reliabilty reasons.

i dont see how a LSD will help with traction ,i dont see cars with them run faster!!??

also i would say a helical 6 speed over a open diff 5 speed will be more than a 4whp loss. years ago even before cattman thought of having quailfe make helicals for the 5 speed i called them and talked to someone there. now they wont advertise this but the guy told me (after i asked about extra drivtrain loss )that there was a drivtrain loss you could see on the dyno through the whole powerband . he said it takes torque away everywhere.

what iam getting at is if open diff NA maximas can run 1.7's 60's and the helical is known to take power away then its prob not the best for a NA setup.


the only reason ill ever go 6 speed (with no helical )is if my 5 speed busts like yours did . to bad our 5 speed cant handle power

 

There's been some talk about the drivetrain loss comparisons between the 5MT and 6MT lately so i decided to put some online calculators to good use. I used this formula to determine drive wheel torque in every gear taking into account tire diameter, gear ratios, final drives, and drivetrain loss percentages.

[Flywheel torque x Gear Ratio x F/D ratio / (Wheel radius in inches / 12)] x .85 (5MT) or .83 (6MT)

I assumed:

260 lb-ft flywheel torque
205/55/16 tire size
17% (17.5% for HLSD) drivetrain loss for the 6-speed (pretty close based on stock dyno's i've seen)
15% drivetrain loss for the 5-speed (ditto)
4.13 F/D of the A34 6MT
Open differential


The results were quite interesting. I will list the drive wheel torque numbers gear by gear for both transmissions...



6MT 5MT

1st- 2,716 lb-ft 2,685 lb-ft

2nd- 1,786 lb-ft 1,512 lb-ft

3rd- 1,280 lb-ft 1,040 lb-ft

4th- 914 lb-ft 780 lb-ft

5th- 698 lb-ft 650 lb-ft

6th- 543 lb-ft


Cliffs: Despite the higher drivetrain loss percentage the A34 6MT puts down more torque to the wheels in every gear due to higher torque multiplication.


Not sure what these numbers are worth, but there they are. I'll crunch the numbers out for the A33B 6-speed tomorrow. (if someone doesn't beat me to it)

Edit: This still doesn't take powerband and top speed in each gear into consideration so i don't how exactly they compare when it comes to average acceleration so take this with a grain of salt.

Edit part II: The top speed in 4th with an A34 6-speed is around 116 @ 6600 so i'm fairly confident that any 5-speed car that has to shift into 4th before the end of the 1/4 mile would benefit from the 6-speed's gearing.

 

anyone get around to doing the numbers for A33B 6spd?

 

A33B 6MT

1st- 2,508 lb-ft

2nd- 1,544 lb-ft

3rd- 1,107 lb-ft

4th- 844 lb-ft

5th- 645 lb-ft

6th- 502 lb-ft

 

so either 6spd would probly get you down the track faster, since 2nd, 3rd and 4th have higher torque multiplication and are closer ratio than the 5spd

 

However, the A33B comparison to the 5MT is so close, that it's probably negligible in gains. The only one that seems to really take off is the A34MT, and I'm going to guess that the reason the gearing has a higher torque rate at all is because the newer maximas weigh so much. But in either case the best swap would be the A34, but is that possible in the 4th gen?

 

it is possible, i believe 3 people have already done it. im wrapping mine up.

 

In all reality I don't think it does help with the 1/4 mile. In fact I remember a couple of years ago when people were able to buy the quaife LSD, there were a few people who installed the quaife and found that they could not get any better 60's with the LSD over the open differential. It was one reason why there wasn't a higher demand for them. The LSD really is only beneficial in auto-x or in bad weather, at least for our cars.

 

Well i don't think you'd go down the 1/4 mile ANY SLOWER than the A32 5-speed with an A33B 6-speed. Furthermore, no differential bearing or input shaft bearing issues like the 5-speed's have, you get a lazy 6th for highway mileage, and the 6-speed is stronger out of the box. The A34 6-speed is ideal sure, but either tranny is an improvement IMO.

 

Did you get your tranny from a junkyard in NY?

 

nope, arkansas

 

The transmissions are interchaneable. A33B's have been installed before but the A34 can be installed just as easily.