mcarther101

iTrader: (8)

I know there's a similar thread already, but this is geared towards the 4.36FD gear ratio, and Quaif SMG gearing for fun. So now that 4.36 FD is an option... let's discuss:

http://www.f-body.org/gears/

Tallest/Longest to Shortest gears:
3.53FD
3.9FD
4.08FD
4.36FD

Speed @ RPM
RPM----1st----2nd----3rd----4th----5th----6th
8000----47----77----110----141----179----226
8000----43----70----100----128----162----204
8000----41----67----95-----122----155----195
8000----38----62----89-----114----145----183

7500----44----72----103----132----168----212
7500----40----65----94-----120----152----192
7500----38----63----90-----114----145----183
7500----36----59----84-----107----136----171

7000----41----67----97----123----157----197
7000----37----61----87----112----142----179
7000----36----58----84----107----136----171
7000----33----55----78----100----127----160

6600----39----64----91----116----148----186
6600----35----58----82----105----134----169
6600----34----55----79----101----128----161
6600----32----52----74-----94-----120----151

If your rev limit is between 7500RPM and 8000RPM on a non-HR, I presume the engine is built, the oil system is upgraded, and can handle the abuse. Now a bit of bench racing math:

3.53 = baseline torque of 100%
3.9 = 110.48% increase in torque VS 3.53 gear
4.08 = 115.58% increase in torque VS 3.53 gear
4.36 = 123.51% increase in torque VS 3.53 gear

Since torque is a factor in calculating horsepower, and assuming a baseline 300whp on a built NA motor:

3.53 = 300 baseline
3.9 = 331.44
4.08 = 346.74
4.36 = 370.53

Yes, I know gears don't "increase engine horsepower," but this would basically be the equivalent of 331/346/370whp on 3.53 gears in terms of real world acceleration from the increased torque multiplier. I know I'm not factoring in shifting, or where the power band is, but that all changes on overall engine design anyhow.

Of real interest, is the 4.36 FD gear on a RPM limit of 7500 to 8000 RPM.

Now people may argue, 1st and 2nd gear will be useless, but that argument is invalid, because that's just a matter of traction (LSD/tire size/tire compound). Somehow there are turbo cars making 400, 500, 1000whp, and they manage to put the power down in 1st and 2nd gear... doing 10 second or less passes still with good 60' times.

Now imagine someone put the 4.36FD gears on a fully built NA race car.

Calculations based off 275/35/19 tire w/ OEM 6-speed gearbox
1st------2nd--------3rd-------4th------5th--------6th
3.794----2.324----1.624----1.271----1.000----.794

Now... let's get crazy, and imagine Quaife 6 Speed HD Sequential Transmission 350Z combined with that setup. Compared to the OEM 6-speed you'd have better traction/longer gears in 1st, 2nd, and 3rd, with 4th being about the same, but 5th and 6th getting a boost in top end torque output to fight against that high speed drag.

Quaife 6 Speed HD Sequential Transmission gear ratios:
1st-------2nd-------3rd-------4th-------5th-------6th
2.769----2.057----1.579----1.260----1.104----1.000
________________________________________________

3.53FD + 6spd OEM gearbox torque multiplier & top speed:
1st-------2nd-------3rd-------4th-------5th-------6th
13.39----8.20------5.73------4.48------3.53-----2.80
47--------77--------110-------141-------179------226 MPH @ 8000RPM

4.36FD + 6 OEM gearbox torque multiplier & top speed:
1st-------2nd-------3rd-------4th-------5th-------6th
16.54----10.13----7.08------5.54------4.36-----3.46
38--------62--------89--------114-------145------183 MPH @ 8000RPM

4.36FD + Quaif torque multiplier & top speed:
1st-------2nd-------3rd-------4th-------5th-------6th
12.07----8.96------6.88------5.49-----4.81------4.36
52--------71--------92---------115-----131--------145 MPH @ 8000RPM

Thoughts? Anyone else out there considered the 4.36FD at one point?

Edit:

I graphed MPH vs gearing, it looks like 4.36FD is not at all useful beyond 60mph, I now advise against this mod because science/math.

cashmoney03

I put 4.08s in my 37s coupe 6spd and felt that it would have benefited more from 4.36s. But with the z weighing significantly less, I wonder if they wouldn't be slightly overkill. But as the old saying goes, overkill is underrated and with that being said, I'm seriously considering them in my Z.

mcarther101

iTrader: (8)

I'm a bit conflicted on these 4.36 FD now, not sure if they're worth it after graphing them vs speed.

3hree5ive0ero

iTrader: (95)

Interesting. I didn't realize there was a 4.36. What is that from and who sells it? Didn't know Quaife had SMG either.

tommy smith

I can't read all that ^^^^
If it's not an HR & is an N/A engine then it will cost you so much money to make that engine spin/make h.p at 7,500 to 8,000 rpm and hold together that you'll be able to buy 3 LS G.M. engines for that money.

If you have an HR engine with cams & ported polished heads that can make H.P to 7,800 + or - rpm & using 28"-30" rear tires then those gears should work fine. I can't think & won't much more about this post/subject.

The_Assassin

I would love 4.36 FD. Right now I have 4.08 FD in my hr and its amazing. Z1 motorsports sells them for $648. Anyone install them yet?

http://www.z1motorsports.com/350_g35...oducts_id=4523

DarkZ03

iTrader: (11)

I have a DE, but I really think that unless you have a reason to rev past 7500, there is no point to get anything more aggressive than the 4.08 especially with aftermarket gear ratios.
In Grand Turismo 6 I use OS Giken gear ratios and 3.9 FD, I like the way it drives and it tops out at about 180 mph at 8000 rpm. It's a game but it is as close to real life as its gooing to get without spending the $$$.

nachospizza

iTrader: (1)

If I didn't rebuild my DE engine with just bolts on? What's the benefit of installtion the 4.83? My shop told me I start rolling faster but will not pickup as fast as the OEM final drive when going higher speed? I see someone selling a used one in a really good deal. Should I get it or should I just stick with my OEM?

The_Assassin

come on guys we need more opinions on this.

DarkZ03

iTrader: (11)

Good luck, the few brave enough to go the expensive and less rewarding route never spend money on the transmission (which is a shame considering that gearing is everything to a NA car) if you go on youtube there is a video of a guy driving a early model 350Z at a local track to me, he has a OS Giken clutch, gear set and 4.08 final and his car sounds pretty cool.
I was not able to find any info on the vehicle however, I've gone through most of the FD thread and the general consensus is 4.08 on a HR and 3.9 on a DE if you street drive your car, if it is a track car then go crazy and run what you think is better for the tracks you go to. If I stay NA (not sure if I want to) I will try to go for a OS Giken gear set and 3.9 FD

0jiggy0

iTrader: (13)

What vehicle did the 4.36 come from?