I obtained a powerpoint slide today from Aichikikai, the company that manufactured our six speed transmissions. I have been exchanging dialogue with someone in the North American office because I am in need of a taller 6th gear and this slide shows that one is available. I will keep you all posted on any updates and if I am able to get my hands on the parts I want.

 

do they make the 5 speed transmission as well? would 5 speeds be able to obtain a taller gear also?

 

Yes they make the 5spd trans in the 4th gen. The altima (older altima, which shares the same 5spd transmission) has a slightly taller 5th gear in it - .740 vs .790 which is really hardly any change at all.

 

man that would be nice for highway our 5spd 4th and 5th are like identical...the 5th is almost pointless.

 

Thanks for the info Matt. Now filing in the "reference" folder...

 

I also want to mention that the picture doesn't show all of the ratios available through Nissan.

 

subscribing...

 

Dear Mr. SR20DEN
I know that there is a 0.54 6th gear in the list.
However I believe that you could not obtain that gear set. Because Aichi Machine Industry does not produce and sell any kind of gear set for after market. And all products that Aichi Machine Industry produces are sold through the Nissan dealerships.
I regret that we will not be able to meet your requirement.

Best regards,
Guy at Aichikikai



DAVE B? Can you help here?

 

Nissan part numbers were kindly supplied by my contact at Aichikikai today. Now we wait and see how the overseas ordering goes.

 

Should drop the 80 mph cruising speed of around 2500 RPMs to roughly 2150. Worth it depending on the final pricing.

Makes you wonder why nissan went with .67 and .63 if .54 was available. They could have claimed better highway fuel economy for 5.5 and 6th gens.

 

The 3.812 and 0.630 do 60mph @ 1950 and my 4.133 does 60mph @ 2125. With the .54 that will drop to 1825 (4.133) or 1675 (3.812).

The 80mph specs are (24.8" tire dia.)

4.133
x .63 = 2825 rpm (what I am dealing with now)
x .54 = 2425 rpm (what I will be getting)
-----------

3.812 (oe gear in the '02-'03)
x .63 = 2600 rpm
x .54 = 2225 rpm (probably too tall for most of you)

 

Oh, and I have already requested data on the RS5F50A and the brand new RS6F94R (Versa and new Altima 6 speed). I will post them if he gives them to me. I wouldn't be suprised if they have taller gears for the 50A.

 

What size? 1" smaller dia. than stock?

 

245/45-17 halfway worn. Should be the same as the OE 225/50-17. I based the math on the exact gearing based on my dynojet mph data.

 

25.86" is OE (225/50). 25.68" = 245/45 - 17. Of course this is from the sidewall specs.

 

Yeah you're quoting unloaded brand new tires. When you load them your effective diameter is reduced. They're further reduced with tire wear. The 24.8 is the result of vehicle loaded and 70% worn Nitto 555s on a dynojet 248c. I have dynojet data with 1600mile OE blotenzas. I'll look it up and post that too if you want.

edit: I couldnt find my low mileage data but the medium mileage data on my 225/50-17s come up to the exact same 24.8.

(6550rpm at 120mph, 2002-06-20)

 

I had ~20% on my blowtenzas and saw 130.0 mph in 3rd @6400 RPM. That's from my dyno data.

I'm going to find my dyno with my new tires...



Upon further review of my dyno plots, looks like my stock blotenzas @ 20% remaining tread were actually 23.65"...

 

Work my numbers for a brand new set of 19" Toyo T1Rs. 245/35/19. I bet you I still won't be saving sheit for gas mileage even with the taller gear.

 

From the sidewall spec, you're actually smaller than stock by 0.1". You need a dyno run file to get the real #'s.

 

I bought and installed two of these in my tranny and doubled my gas mileage!!!!111one

 

Sorry everyone else. I tried.



Dear Mr. SR20DEN
You are welcome.
With regard to your more questions, I regret that I could not inform you. Because the F50A manual transmissions are applied for the Nissan vehicles in European market, I don't have any information on it. And I don't absolutely know the brand new Nissan RS6F94R. It is a wonder that you know the brand new Nissan RS6F94R.
Best regards,
Aichi Guy

 

Could you pass this along to blackbird. He likes manuals and Europe.

 

Using my dyno graphs with my 245-45-17 Nitto 555R DRs which were probably half worn at the time, I calculate 25.02" tire diameter from one run and 25.01 from the other for my tires.

edit: I should clarify, this is using a .954 4th gear and 3.823 FD as per the FSM.

 

Passing power in top gear....

 

The gear set has been ordered. It will probably take 4-8 weeks to get to me from Japan. So you all will have to wait till about February for me to give you the final report. :jeopardysong:

 

So instead of overnight parts from Japan, you are getting ground parts from Japan?

 

what gear set did you end up going with. Also did they ever say anything about the 5spd trannys?

 

0.54

Post #8


Post # 21

 

Ok i was reading as the .54 was a mistake that they did not acctually make that and you could not order that gear.

Also about the 5spd i dont what i was thinking with that i remembered reading it but thought they might have had the gears. Good luck with the new gears gives me something to look at once i swap the 3.5 and 6spd in.

 

He did explain in that particular email that he couldn't help me. But after I pressed him more on the issue he managed to supply me with the Nissan part numbers. But as far as I am concerned, I am NOT in the clear untill I have the correct parts in hand.

 

ahh well hopefully you will get the right parts. This would be a big thing if we could lower that last gear with the .54. Cant wait to see the results and goodluck with getting the right parts.

 

Found this info on this webpage - http://www.maxthrottle.com/viewtopic.php?p=589

Look at the final drive on the second transmission. Whoa...

could just be a typo though.

 

The gears arrived today. So far everything looks legit. The Input gear has 50 teeth and the main gear has 27 teeth so that does equal 0.54. By the end of the day I will have these test fitted on a gear-set I have laying around. And if/when it works out I am sure the Tibby owners will also want to know about this, as well as any other MFA60 equipped vehicles.

 

4.67 holy crap! And I thought the Spec V 4.42 was steep!

 

Sick!!


I though you'd given up on this...

 

It only took four months to get them.

 

Wow the mpg gains could be great

 

Somehow I managed 28mpg on a trip to Atlanta this weekend. VERY unusual. I normally get 23-24mpg on that trip. I don't think it was the new bumper cover/new paint, so maybe they changed the fuel blend at the gas pump. Very very odd.



Pics of said gears.


http://www.vq35de.com/Images/MFA60/0540/

For reference the input gear is on top of a CD.

 

Nice. My mpg has been **** since my heavy wheels and bbk.

I still need to find the right tranny for my 6speed swap.

 

This is great work. Way to go!!
Would you happen to have a side profile of the gear?