does anyone else think the Z's gearing isn't really ideal for FI levels of power?

1st gear is obnoxiously short - even with the 3.36 final drive.

It seems to me the ideal gearing would be to make
1st gear a lot taller
2nd gear a little taller
3rd gear roughly the same as stock
4th gear slightly shorter
5th gear shorter
6th gear a lot shorter

This would enable the car to hook much easier and even out the time spent in each gear at WOT to be roughly the same where as it is right now the lower gears are really fast and you spend a lot more time in the higher gears.

It seems like obviously the lower gears need to be taller and the higher gears need to be shorter for the best accelleration - this wouldn't be ideal for great gas mileage cruising down the highway though



I've attached a picture of the gear ratios I've plugged in. The gear ratios I've come to while still using the stock 3.538 final drive are:

2.97
2.09
1.65
1.32
1.1
.935

for reference, stock gearing is:

3.794
2.324
1.642
1.271
1.00
.794

you'll notice that as you shift at redline, the starting rpms in the next gear get progressively higher and higher which I think is exactly what you want when you're racing


I know it's possible to change gear ratios in the transmission, but probably isn't going to be cheap. 350EVO said they could do such a job if someone wanted to try it. I'm just thinking this seems like a better choice than something like a boost controller that limits the amount of boost in each successive gear


anyway, guys with turbos have gone to the 3.36 FD and that seems to make 1-3rd gears slightly easier to use, but at the expense of 4-6th being so much taller than before that you're losing a lot of accelleration in the higher gears - seems like a trade off rather than a 100% improvement


you'll notice in F1 racing that they spend roughly 2 seconds in each gear for the most part. Not, 4, 2, 2.5, 4, 6, 14 sec etc

 

It would be nice if a vendor could do a core program for 6MT tranny upgrades with something similar to what you've proposed.

 

something to note is that purpose built cars like the noble M400 have gearing similar to this.

Cars like the Z06 have tall 5th and 6th gears to reach the 198mph bragging rights top speed and get better gas mileage

but if you want to go fast and don't mind the slightly worse gas mileage I think this is the sorta thing people should be looking into as long as you're not wanting to go above 155 mph

I don't know if 350EVO would still do this sorta thing or not, but about a year ago I PMed BJ and he said that they could do such a thing

 

we need 7 gears in our next gen z.

 

I going to have to say ditto.

-Acree

 

we are in the final stages of our gear set production ,it should be released in the end of June latest end of July .we have been working on this project for the last year ,we are going to be offering two solution for the 350z gear box .

1- complete dog gear set (race /track use)

2-ratio change over gear set for street use

the ratio for the street are as follow

1ST 3.2
2ND 2.15
3RD 1.5
4TH 1.2
5TH 1
6th 0.79

sam

GT motorsports

 

how much are they going to cost?

 

$4k+ is my guess.

 

you can buy a completely brand new transmission for like $1400

I sure as hell wouldn't pay anything close to $4000 for a transmission that'll wear out over time unless you were maaaybe getting exact custom gear ratios to your spec

maybe someone needs to come up with a conversion kit to mount other transmissions to the Z

 

the price of the syncro gear set part # GTM-2006-s is $ 3927.00 ,we also will be offering gear box exchange program for the syncro set for $ 4581.72 .this will a ready to go gear box for installation .
as far or as the dog gear set the price will be $ 6360.95 for gears only and $ 7010.95 for an exchange gear box .
coupler other pointer ,we can custom make any gear ratio desire .also the street gear set will be offered in three different option

option 1 all gears are straight cut 1 thru six
option 2 all gear can be helical 1 -6
option 3 1-4 straight cut and 4&5 helical

as for the horse power capacity ,we are very convertible to say that the street gear set is capable of 900 hp + ,we will be install the gear set in our test vehicle 350z in the next 2 weeks ,our goal is to test the limit of of our gear box , and try to break it .
if we brake it ,we will be back to the drawing board ,if successful the gear set will be available for sale in the end of July

Sam

GT MOTORSPORTS

 

what would be the pros and cons for the racing dog gear transmission? Would it work fine on the street or does it need a higher load on it than it'd see on the street in day to day traffic?

 

Think LOUD.

 

what sorta loud are we talking about?

what sound is loud? gear whine?

I like a lot of the race car misc sounds. Didn't buy a luxury car

 

I do not think 350evo would be into this kind of R&D again, unless you could say you have 50 people cash in hand ready to do this and then from those 50 people you split the R&D cost! Especally since they have since sold their track Zs! But IF there is enough interest I will bring it up next time I talk to him!

 

Anyway you can make the trans sequential shift?

 

Straight Cut Gear set
Straight cut gear sets are relatively noisy in operation and have an inherent whine to them. This is due to the meshing of the teeth when the gears are rotating.
The meshing of straight cut teeth gives total contact along the tooth at all times which gives the straight cut tooth its added strength over the helically cut tooth .

Helically Cut Gear set.
Mainly used to transmit extreme power to the road in highly modified street cars. They are usually purchased by those wanting less gear noise than a Straight Cut gear set. Our Helical sets do produce slightly more gear noise than a standard factory gear set as a result of a purely motor sport based gear design which makes necessary compromises in regards to gear noise, to achieve uncompromised strength

Synchromesh Engagement (Synchro box)
GTM Synchromesh Gear sets enable factory style gear selection to be incorporated into your Helical or Straight Cut Gearbox. The Synchro’ Box is mainly used for street applications.we make the Synchromesh rings and hubs considerably stronger than factory components and incorporate our high quality materials and heat treating processes into the finished product ensuring durability you can rely upon for years to come.


Dog Engagement (Dog box)
Essentially a “race only” style of gear engagement, this has become more and more popular for highly modified street cars. Dog Engagement gear selection is available on either Helical or Straight cut Providing fast, positive gear selection, with or without the use of clutch. The GTM Dog Engagement gear sets are undoubtedly the strongest and most “user friendly” on the market. However it should be pointed out that Dog Engagement Gear sets require fast, firm gear selection and are quite noisy on each gear change

i hope this will help

sam

Gt motorsports

 

I hope someone makes a video and gives a brief review of them when they're available

 

i will be posting some pics ,you 'll like what are going to see

sam

Gt motorsports

 

Wow-I want the dog gearset but damn thats expensive...not having to use the clutch would make things that much better(dragging). I like the idea of this post though.

 

another thing is everyone seems so sure the 2007 or 2008 Z is going to have 7 gears and a stronger engine - wonder if that tranny (if true) will bolt right up to the 350