Hyundai Genesis Forum banner
1 - 20 of 29 Posts

·
Premium Member
Joined
·
10,780 Posts
Discussion Starter · #1 ·
Once again, McFly came through with some great info regarding gearing, Thanks bro...

Note: this applies to NA V6 guys mostly, but a good read for I4 turbo guys also. (NA=Naturally Asperated, no forced induction, no boost, no turbo/supercharger). Cliff Notes is provided at the end for those not interested in all the details

I've been studying the gearing on our car, and how effective it is for acceleration. I've come to the conclusion that the gearing will be too long, and we would find up to a 15% increase in acceleration with a basic mod that will cost us around $600.

Here's the information that I've come to a conclusion with. First of all, there have been several dyno graphs showing that the rev limit can be changed to about 7500RPM's. It's not known 100% how exactly. Some say it's done by simply turning off Traction/Stability control (ESC), and some have guessed it may be a reflash (like myself originally). Next, after doing some calculations I found that 2nd gear will top out at about 70mph, and 4th will top out at about 130mph. Ideally, a car that tops out it's 2nd gear at 60mph, and it's 4th gear at the speed it goes through the 1/4mile (I'm predicting a 106mph with ESC off STOCK, and up to 112 with the best NA build), this would make for a faster car. This is why cars are tested to 60mph and the 1/4mile, because it's a good indication of it's acceleration/power delivery ability. You might say that you don't care what it does in those measurements... it matters not if you care about those measurments, but it does make your car accelerate faster had you improved your car in those measurements. Well, who really cares, on to the data...

So, how do you make your car top out the gears in the proper speeds? And which is better to focus on? Can we get both done at the same time? The answer is a simple change the final drive... AND, lucky for us, and what Hyundai gave us, one final drive change will optimize both of those numbers.

So, wait 15% improvement in acceleration, and only one change, what is this?

It's the gear in the rear end between the axles that tranfers the power from the drive shaft coming from the motor. Have you ever heard of muscle car guys talk about rear end gears? That's what this is.

Here's my data, and it's improvement:

GenCoupe (shifting at 6700)
1st - 37.5mph
2nd - 62.5mph
3rd - 89mph
4th - 117mph
5th - 144.5mph
6th - 182mph

GenCoupe (shifting at 7400)
1st - 41.5mph
2nd - 69mph
3rd - 98.5mph
4th - 129.5mph (this is ridiculously long for 1/4mile)
5th - 160mph
6th - 201mph

with a 4.1 final drive and 7400 shift (what I believe would be optimal for 0-60, and 1/4mile):
1st - 36mph
2nd - 60mph
3rd - 85mph
4th - 112mph (should blow through the 1/4mile by 106mph without any other mod)
5th - 138mph
6th - 174mph

As a comparison, lets look at a 350Z/370Z:
Here's the 370Z ratio's, and Final Drive:
1st = 3.794
2nd = 2.324
3rd = 1.624
4th = 1.271
5th = 1.000
6th = 0.794,
FD = 3.692 (350Z had a 3.538)

And, here's the GenCoupes ratios, and Final Drive (you're going to think I retyped this, but I didnt'):
1st = 3.848 (different, but not far off, less than 1mph different)
2nd = 2.317 (same thing as above, practically)
3rd = 1.623 (same thing as above, practically)
4th = 1.233 (same thing as above, slightly diff)
5th = 1.000 (exactly as above)
6th = .794 (exactly as above)
and here's the kicker... drum roll please...
FD=3.538 (exact again!)

Yes, the same exact ratios as the 350Z, in every gear and final drive (with a final drive change on the 370Z).

I also found out that it's a popular mod for the 350Z's to get a 4.08 final drive:
Few questions about an upgrade (4.08:1) - Nissan 350Z Motoring Forums

**** 4.083 Gears/Final Drive Installed**** - MY350Z.COM Forums

I predicted that a 4.1 would be best, and there it is. We have the exact gear ratios, and final drive, and we need the same ratio final drive they go to.

Now, I'm wondering if I can purchase a 4.08 final drive for a 350Z and fit it into our Genesis Coupe. Probably not, but it's possible, quite possible.

Note: I also checked tire sizes, and they are also the same height (wider on the sport package 370Z, but exact otherwise), providing the same ratio.

370Z ratios taken from
http://www.nissannews.com/assets/att...ecs_Final2.pdf


So, where do we get our 4.1 final drive, you ask? I don't know yet, but the I4 turbo Gen Coupe has a 3.9 Final Drive. That right there will be very close, here look at what a 3.9 Final Drive will do:

with a 3.9 final drive and 7400 shift:
1st - 38mph
2nd - 62.5mph
3rd - 89mph
4th - 117.5mph (should blow through the 1/4mile by 106mph)
5th - 145mph
6th - 182.5mph


CLIFF NOTES:
Get yourself a 3.9 or 4.1 Final Drive Gear for a 10-15% gain in acceleration for about $600Installed. The 3.9 comes from the I4 turbo, while the 4.1 is ideal, but not yet known where to be sourced from.

STOCK 3.538 Gear-- ESC OFF 3.538
6700 RPM SHift -------- 7400 RPM Shift

First ---37.5mph-------First ---41.5mph
Second --62.5mph-------Second ----69mph
Third -----89mph-------Third ---98.5mph
Forth ----117mph-------Forth --129.5mph
Fith ---144.5mph-------Fith -----160mph
Sixth ----182mph-------Sixth ----201mph

ESC ON 3.9 Gear -- ESC OFF 3.9 Gear
6700 RPM Shift --------- 7400 RPM Shift

First ------34mph-------First ----38mph
Second ---56.5mph-------Second--62.5mph
Third ------81mph-------Third-----89mph
Forth----106.5mph-------Forth--117.5mph
Fith-------131mph-------Fith-----145mph
Sixth------165mph-------Sixth--182.5mph


ESC ON 4.1 Gear-- ESC OFF 4.1 Gear
6700 RPM Shift ----------- 7400 RPM Shift

First ----32.5mph--------First ---36mph
Second -----54mph--------Second---60mph
Third ------77mph--------Third ---85mph
Forth -----101mph--------Forth---112mph
Fith ------125mph--------Fith----138mph
Sixth -----157mph--------Sixth---174mph


ESC ON
6700 RPM Shift

3.538 STOCK Gear ----------- 3.9 Gear ------------- 4.1 Gear ---

First ---37.5mph--------First -----34mph--------First ---32.5mph
Second --62.5mph--------Second --56.5mph--------Second ----54mph
Third -----89mph--------Third -----81mph--------Third -----77mph
Forth ----117mph--------Forth --106.5mph--------Forth ----101mph
Fifth --144.5mph--------Fifth ----131mph--------Fifth ----125mph
Sixth ----182mph--------Sixth ----165mph--------Sixth ----157mph

ESC OFF
7400 RPM Shift

3.538 STOCK Gear ----------- 3.9 Gear ------------- 4.1 Gear ---

First ---41.5mph--------First -----38mph--------First -----36mph
Second ----69mph--------Second --62.5mph--------Second ----60mph
Third ---98.5mph--------Third -----89mph--------Third -----85mph
Forth --129.5mph--------Forth --117.5mph--------Forth ----112mph
Fifth ----160mph--------Fifth ----145mph--------Fifth ----138mph
Sixth ----201mph--------Sixth --182.5mph--------Sixth ----174mph


PS. If you don't believe any of this, why don't you read the 27 pages of excitement over doing this over at the 350Z forums:



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3
 

·
Premium Member
Joined
·
2,997 Posts
Tufast this is good general info on gear changes. A couple of comments I will make:

1) What is good for one car does not mean it is good for another. You can't compare them directly like Mcfly is doing with the Z cars.
2) For every action there is an equal and opposite reaction. These types of gear changes have effects on drivability, fuel economy and performance (good or bad).
3) $600? Where does he get this figure from? Even if you could get some gears to do your swap, who's going to put it in for you? Most people don't have the tools to do such swaps and you will pay at least 200-400 bucks in labor (unless you have a friend who knows how to do it). You will be better off doing the Intake/Exhaust stuff first.
4) 6700 RPM to 7400RPM? Sounds easy right? Just flash it right? When the tools become available to do such a mod you will probably look at paying anywhere from 500-1500 for the flashing tools.

Now don't get me wrong, a gear ratio change can be beneficial in CERTAIN circumstances, but it's not the first mod I would do and I probably wouldn't even consider it unless that's all I did was race the 1/4 all the time and revved to 60mph in 2nd gear all the time (you wont be getting great MPG doing that). As this will be my DD it's overkill IMO.... You could essentially achieve a similar thing by changing your tire size. Get some taller diameter slicks for the drags and be done with it.

Now something I would rather see is the development of a LSD for the guys who are getting non-Track buyers. To me that would be a much more useful mod that a gear change. Just my opinion though.



Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
 

·
Premium Member
Joined
·
2,997 Posts

·
Registered
Joined
·
115 Posts
great info, glad i have my sights set on the 2.0t... otherwise, definately something to look into even with the few draw backs sabba listed, 4.1 is very common swap for draggers and off roaders with the more powerful rigs, and up to 5.8 for 4cyl toyotas, suzukis and such, i knew a guy whos samauri topped out at just 68mph! one thing sabba missed, speedometer might need to be recalibrated.
 

·
Premium Member
Joined
·
2,997 Posts
great info, glad i have my sights set on the 2.0t... otherwise, definately something to look into even with the few draw backs sabba listed, 4.1 is very common swap for draggers and off roaders with the more powerful rigs, and up to 5.8 for 4cyl toyotas, suzukis and such, i knew a guy whos samauri topped out at just 68mph! one thing sabba missed, speedometer might need to be recalibrated.
yeah with tire diameter changes you will mess up speedo calibration.. but right now the ring/pinion swap is not viable even though it may aid or benefit some driving styles.

It's good discussion though, usually something like this comes up for every car.



Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
 

·
Premium Member
Joined
·
10,780 Posts
Discussion Starter · #6 · (Edited)
Well, once you defeat the traction control & raise the rev limiter, you allow yourself a higher top speed. With the gears changing out at higher rpms, you will find that you are not getting the most out of your torque curve in each gear. At this point, it will be more proficient to lower the gearing slightly in order to get all the power you can before the torque drops back off. There will be a slight drop in fuel economy, but that's a given.

My Mspt 540i has lower gearing in the rear end from the factory compared to the regular 540i & as a result allows me to run 0-60mph in 5.7 secs instead of 6.1 of a non-M 540i. That's a considerable difference. Now, I'll admit that I pay for that higher revving in each gear with fuel, but for me it's worth it being I am a enthusiast. If someone's terribly worried about fuel consumption, they should not do this mod. But, for that matter, they should probably not do any mods regarding performance, since most will cause you to consume more fuel.

I'm not saying this mod will work for sure or that you can just swap out the carrier from the 2.0t w/that of the 3.8L, although it seems logical that this will work. I'm just saying that it's something to contemplate. As for price, that $600 would cover parts & labor in McFlys estimate. Of course that is not the dealer doing the work at that price, but a Indy shop. And that's only swapping necessary gears, not the entire carrier assy.



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3
 

·
Premium Member
Joined
·
2,511 Posts
My thoughts are for the manual tranny there may be some merit. For the ZF tranny it will get the engine and transmission all confused with the RPM differences. If the tranny and engine need to be revved matched with the ZF and then the RPM's are changed up I think the computer may get confused. I may be thinking about this wrong.
 

·
Premium Member
Joined
·
2,997 Posts

·
Registered
Joined
·
139 Posts
figures.they get ya one way or another. i will continue to look thru thr parts catalog to see what can be purchased separate. so far you can get the track sway bars and bushings, LSD rear end as a whole purchase 2800$. and some other misc. things. i will continue to update as i find.....
 

·
Premium Member
Joined
·
2,997 Posts

·
Premium Member
Joined
·
2,997 Posts

·
Registered
Joined
·
139 Posts
here is some stuff
548302m000 links front trk pkg
548143m000 brackets front trk pkg
548133k000 bushings front trk pkg
548102m250 sway bar front trk pkg
5300025500 LSD DIFF
these are part# for 2.0T platform not 3.8L
these may need moved to another section.
 

·
Premium Member
Joined
·
2,997 Posts

·
Premium Member
Joined
·
10,780 Posts
Discussion Starter · #18 ·
i checked the hyundai parts catalog to see if we can get internal parts for the rear end and you cant. its sold as a unit and its 2800$ for the LSD unit.
ouch, not changing that..

My thoughts are for the manual tranny there may be some merit. For the ZF tranny it will get the engine and transmission all confused with the RPM differences. If the tranny and engine need to be revved matched with the ZF and then the RPM's are changed up I think the computer may get confused. I may be thinking about this wrong.
+1...on confusing the computer possibly...

That itself justifies the cost of the Track package then!!!!!!!!! Basically get HID and Brembos for FREE!!!!!!!!!
+1........

OG, thanks for the info, it's appreciated..
+1....thanks a bunch..



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3
 

·
Registered
Joined
·
155 Posts
so im kinda confused mainly because im half asleep after eating some hawiian bbq that stuff me something good lol!

but is this saying that the v6 has the 4th gear that ends at 12xmph

or that the 2.0T is the one with the 12xmph 4th gear? im confused?
 
1 - 20 of 29 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top