Good to hear! One thing also that is cool about all of this is that you will notice how say 5th-6th gears for instance "wake up" haha!

 

lol yup I felt it a bit but no highway driving yet. BTW how can I get better traction in first. Lsd is coming in the future.

 

I can only guess yes on your response taking off from a stop. You are getting 15% more torque to the ground, so whatever throttle reponse you were giving before will in essence be multiplied.

You say you are new to manual so this won't matter to you but if you are a heel/toe downshifter you may be surprised the first few times you do it. Re-learning comes within a day or so. Not a huge learning curve.

Also, it sounds like you have come accross a rare find these days. Not many people can say they live near a "speed shop" and a fair/competent one at that. Hope it's all good from here.

I wouldn't waste any money until you get the LSD UNLESS you are planning any upgrades in the tire/wheel, etc. area anyway. I did gears AND LSD at the same time and the first thing I noticed is that I was sure glad I did the LSD because otherwise I would be spinning one tire all of the time. I could tell how much increase in acelleration I had and figured it was enough to break the tires loose with an open diff.

It's too bad you maybe couldn't afford to do it at the same time because you will be paying $200+ twice to do the labor for removing the rear and now you will have to be stuck with no car while they do it or pay twice to put your old rear back in until the LSD is ready. You are going to have to come up with an efficient plan someday to add LSD but you'll get it. Congrats on the gears! Have fun...

 

Yep. It still pulls hard if you are already going 80. BUT you really start to hit some high rpm already at 130. And I think you would redline a few mph before the 155 govenor(?) Small price to pay for the improved driving response. Hopefully I'll never have to outrun someone to save my life

 

Yea didn't want to spend an extra $1000 for lsd now because I have to pay for school. Yea for me especially with an hr first gear is pointless even from a 20 roll. Yea I would probably do it on the weekend or so. Just adding lsd should take more than a day. lol yea there's tons of shops like that in the Fl area. Thanks, definitely enjoying it.

 

Hey guys, sorry for a kinda noobish question, but I looked through this thread, as well as a google searching the heck out of this but I could not find a definitive answer.

Anyways, I'm trying to find out what the RPM for a 2004 6spd car should be with a stock rear end at 60mph.

Im asking because i was not the first owner of my current vehicle and it was modded somewhat from the previous owner…

The mods list I know the car has are as follows;

Greddy CAI
Hotchkiss Swaybars and springs
Test Pipe
Aeromotive FPR and Fuel Rails
Unorthodox Pulleys

Mystery tune, and possibly gears?

Now a buddy of mine swears, the car has some sort of tune in it, from when it used to be turbocharged. I want to agree with him, and it seems pretty logical. I know it used to be turbocharged because the exhaust manifold is welded and i found the Harness and other miscellaneous stuff like vacuum lines act…I bought the car at an auction…It had 245 and 285 19s on when i bought it, which I sold for something else…

My issue is this, I average about 15-16 MPG in the city and about 24-25 on the highway, so part of me wants to think it has gears in it too…In my personal experience, the car doesn't seem fast at all to me, but he once again swears its WAY faster than a stock one(apparently he built quite a few of them at Central Florida Turbo years ago)…

I didn't really believe him, until just recently i finally raced a few guys on the highway…a 370 and a 335i, both of which i pulled pretty convincingly, multiply times…of course I had no camera in the car to back it up, but you'll just have to take my word for it…I don't race the car too often, but I used to drag race quite a bit year ago, and to me, i think i could probably squeak out a low 13 in the car…When i first got it I went to the track with a buddy in a bolt on GT that was running consistent 12.7-8s, well on our way home we lined up and he pulled me on the highway from 60-140 by about a 2 to 3 cars…

Anyhow TLR sorry, whats speed should i be looking for at 60mpg in 6th?

 

Stock 3.5 ratio should be around 2250 rpm, 4.08 would be about 2500 rpm @ 60.

 

thanks bro!

 

http://www.conceptzperformance.com/C...698.207.17.225

Has anyone tried the 4.36 FD?

 

I really wouldn't want that in my HR. The 4.08 gears are not what you want if you do a lot of highway driving (3.5k+ at 80mph), luckily my daily commute is on 8 miles with 4 being 80 mphish.

 

True... I just keep thinking about how much the 4.36FD would make 3rd and 4th gears feel even over the 4.08. Wouldn't the 4.36 put you at around 3k at 70mph on the hr's?.... I'm going to try to use one of the ratio calculators to figure this out.

 

As far as I can tell 6th gear ratio is 0.794 for all 6 speed 350z. That would mean a DE guy really wouldn't want those gears due to lower rev range. 4.36 gears would put you at 3250 rpm @ 70mph and 3700rpm @ 80 mph.

Believe me with 4.08 gears I never have to downshift on the highway to overtake bc I'm cruising at almost the plateau of the torque curve .

 

Your right.....4.36 would be a little over the top for anything daily....and I wouldn't want to over gear it.

 

I just wonder exactly why they are offering the 4.36 fd gears; must be a specific purpose because it would not be good for cruising at all (even the link to czp mentions that). Maybe they give some mechanical advantage in the 1/4, etc. It would be interesting to know more about the reasons for them in a Z.

 

I was wondering the same thing earlier. Possibly for autocross... but I'm sure traction at such slow speeds with 4.36 is an issue even with a good lsd.

 

I doubt that super short gears would be a positive in auto-x, when your total run is only about 60 seconds adding in 2-4 extra gear shifts will only hurt you. With my 4.08s I definitely feel more challenged to keep the rear tires from spinning versus my Z friends @ auto-X.

I'm not a drift fan but maybe it would be a good application (drifting) for someone that doesn't want to pour a bunch of $ into horsepower mods.

The gears are likely out of some other Nissan vehicle that has yet to be identified (i.e. 4.08s from a 4 cyl., manual Frontier, 4 door 2WD). Simply offering them surely someone will see a use for them.

I love my 4.08 final drive, along with the quaife diff, and setting it all up my self I can say is the most satisfying modifications I've done to my car. Gearing the car for so short of gears is not for the faint of heart (restless leg syndrome people will not have a problem), but if your not a highway commuter and gas mileage is at the bottom of your concerns you can't go wrong.

The 3.9 gear are a better solution for the DE guys that don't want to raise rev limits, tuning, engine safety concerns. HRs simply have that much more rev range and power up top the shorter gears aren't a huge deal (I personally hated the 3.5 stock ratio, shifting 1-2 at 40+ mph).

 

I bounced around this mod for awhile...it does help. I however kinda scared of the stories of shops messing up the build on them.

Currently tryna talk down a 3.7 complete pumpkin...this is after buying a 3.7fd for peanuts

fail

 

My guess would be guys with aggressive top-end cams and 9k rpms.

 

I thought you were heading to FL? I can do all the setup on gears myself (machined a good amount of custom press pieces) if you get down here.

 

Answered my own question... these 4.36FD would put down 23.23% more torque and horsepower respectively than 3.5FD. Also about 6% more than 4.08 gears; so the difference between 3.9 and 4.08 gears (~4%) is less than the difference between 4.08 and 4.36 gears.

I graphed what this might look like on my last dyno to get a sense of difference in real world application:


(Red stars simulate torque, blue stars simulate horsepower, green stars I just plotted on my actual torque to help me analyze the graph... ignore blue line-was a tuned 370z's dyno)

Here's some excel math:


I'm just imagining a built motor w/ cams, ITBs, full exhaust, and 4.36 FD running around the track on R comps. I bet it would kill some FI setups around the track running 3.5 gears, or if they ran 3.3 gears it would work against them that much more. Obviously there would be more shifting though, in which case I'd love to see someone with LOTS of money throw a SMG gearbox in to complete the build.

I really think that in these lower power (300-450whp) levels, gearing comes into play just as much as engine power output.