Hello people of Nico, I am the new guy.

[LS6HLS30]

Howdy. Signed up to the forums to do some research and maybe gain some more technical knowledge. I have a 72 240z with an LS6 and TH400, and I am trying to figure out if anyone makes (OEM or Aftermarket) a R&P gear set below 3.54 for the Q45 LSD R200 diff. With the TH400, stock Q45 diff gear set and a 24inch tall tire I am in the low 3000rpms while at 65mph. That needs to change, for the sake of my wallet and my hearing. I can get a bigger tire under the car but it wouldnt be enough to get me into the rpm range Id like to see. I am trying to crunch some numbers and figure out if a new transmission/drive line or R&P gear set would be more cost effective. Any suggestions?

[alphapig]

My only suggestion is to post pictures of said LS swapped Z

Also, make a post in the classic Z forum

[MinisterofDOOM]

Welcome!

http://www.grimmjeeper.com/gears.html

Great calculator for trans/diff/tire ratios. Since it's meant for 4x4s you'll need to plug 1:1 in for the transfer case and then you'll be set. It'll give you vehicle speed in a given gear with your selected rear end ratio so it should help figure out what to shoot for. Even accounts for tire size.

[LS6HLS30]

Holy sweet baby Jesus, that site does all the math for me.

[addicted4life]

Welcome!

[jdansmith]

Welcome aboard!

[windbooster]

hello, nico and new friends.

[float_6969]

Welcome to NICO!

Although I have to laugh at your complaining about 3K @ 65mph, LOL. I WISH I could get my motor that low, but the little 1.8L turbo in my S14 becomes a useless hunk of metal below 3K, LOL. Good luck with the R&P set. Nissan used A LOT of different gear sets in stock cars and most of the time what you want can be found from another vehicle.

[M35-Brad]

LS6 in a 240z...holy smokes. That thing has to scary fast! Working on a S30 280z as a side project...always loved those cars.

[PapaSmurf2k3]

Welcome to NICO!
I thought the 300zx TT got a low gear set, although I can't remember what the ratio was.
Edit, google is showing 3.692. Nevermind

[float_6969]

I think he's gonna have to find something out of a truck or a pathfinders.

[AZhitman]

Welcome aboard!

Float, I think he means "low" as in numerically. I vaguely remember a 3.35:1 ratio diff in one of the R200 cars, but I could be wrong.

Aha, found it: the-ultimate-final-drive-gear-ratio-thread-t228683.html

Combining the 3.35 ratio with a slightly taller tire should get you substantially closer to your goal.

[nissangirl74]

Welcome to NICO! Pics of the Z?

[float_6969]

Welcome aboard!

Float, I think he means "low" as in numerically. I vaguely remember a 3.35:1 ratio diff in one of the R200 cars, but I could be wrong.

Aha, found it: the-ultimate-final-drive-gear-ratio-thread-t228683.html

Combining the 3.35 ratio with a slightly taller tire should get you substantially closer to your goal.

Bah, I always get that backwards.

[hannibal]

The Z32TT is an R230 diff.

And I woulda lost this bet. I thought the Q's 3.54 was the lowest diff gear...

[LS6HLS30]

Welcome to NICO!

Although I have to laugh at your complaining about 3K @ 65mph, LOL. I WISH I could get my motor that low, but the little 1.8L turbo in my S14 becomes a useless hunk of metal below 3K, LOL. Good luck with the R&P set. Nissan used A LOT of different gear sets in stock cars and most of the time what you want can be found from another vehicle.

I bet your 1.8l gets outstanding MPG next to my 5.7l

Welcome aboard!

Float, I think he means "low" as in numerically. I vaguely remember a 3.35:1 ratio diff in one of the R200 cars, but I could be wrong.

Aha, found it: the-ultimate-final-drive-gear-ratio-thread-t228683.html

Combining the 3.35 ratio with a slightly taller tire should get you substantially closer to your goal.

Looks like the 350z that had an AT came with a 3.35, but the diff is labeled as a R200V (Along with the Q45 diff)? People over at the Hybridz forum seem to label the Q45 diff as R230. Are the two differentials the same?

[AZhitman]

The early (90-96) Q had the R200V. They're probably referring (R230) to the later Q diff, which you don't want anyway.

I'd check part numbers and dimensions for the R&P for a slushbox Z33 and compare them with what you currently have. I'm pretty certain they'll play nice together.

Alternatively, snag a Z33 diff from a junkyard (they're plentiful) and crack it open!

[LS6HLS30]

Might have to come to these AZ junkyards where Z33's grow on trees

Ill go harass the local Nissan Dealership's parts counter guy and see what I come up with.

[float_6969]

I bet your 1.8l gets outstanding MPG next to my 5.7l

I doubt it. I'm on E85 and my mileage is in the upper teens. I'm HOPING that some creative tuning will let me break into the low 20's. But when it was still on pump gas, I did get 35mph out of it if I kept my foot out of the loud pedal, LOL.

[LS6HLS30]

13-15mpg if i keep my foot out of it. :/

[nissangirl74]

13-15mpg if i keep my foot out of it. :/

My Frontier only gets 2 mpg better than that, if I keep my foot out of it.

[PapaSmurf2k3]

I get about 26-27 in the Miata when I completely beat the s*** out of it... although I do have a decent "cruise" tune. But yeah, when accelerating, hold on. 1.8 liters baby! I've gotten 36 during low speed (55 mph) cruising.
LS6HLS30- how well does your car hook? Can you make good use of your power? I'd love to see a video.
What are your air/fuel ratios?

[AZhitman]

Might have to come to these AZ junkyards where Z33's grow on trees

www.car-part.com - Give that a whirl, brotha!

[LS6HLS30]

I get about 26-27 in the Miata when I completely beat the s*** out of it... although I do have a decent "cruise" tune. But yeah, when accelerating, hold on. 1.8 liters baby! I've gotten 36 during low speed (55 mph) cruising.
LS6HLS30- how well does your car hook? Can you make good use of your power? I'd love to see a video.
What are your air/fuel ratios?

The car hooks very well. I have hardly any wheel spin, I run ET Streets and I like them more than my M/T slicks. My A/F cruising is in the 14s and 15s, WOT is in the 11's.

[frapjap]

I get about 26-27 in the Miata when I completely beat the s*** out of it... although I do have a decent "cruise" tune. But yeah, when accelerating, hold on. 1.8 liters baby! I've gotten 36 during low speed (55 mph) cruising.
LS6HLS30- how well does your car hook? Can you make good use of your power? I'd love to see a video.
What are your air/fuel ratios?

The car hooks very well. I have hardly any wheel spin, I run ET Streets and I like them more than my M/T slicks. My A/F cruising is in the 14s and 15s, WOT is in the 11's.

You need more gears
Any reason you didn't go with a T56?

[hannibal]

The Q's R200 diff is often mislabeled as an R230. But it does in fact use a 200mm ring. IMO the source of confusion stems from the Q using bigger axles like the Z32TT so people assumed the diff was larger.