Diff R180 4.6 required for 240z

[zedchris]

I am after a r180 4.6 for my track sprint zed. Running 4.875 at the moment, rev limiter in fifth is getting annoying. Call me on 0418715200 if you have one available

cheers

 

chris

[Scoota G]

Close, but no cigar!

 

http://www.viczcar.com/forum/index.php/topic,11461.0.html

[d3c0y]

how about a 4.4 R180 LSD out of a subi i will have one here in september?

[zedchris]

Thanks, i do have access to a 4.375  but am really after a 4.675. My 4.875 is limmo now so really just need the ratio.

Cheers

[d3c0y]

So how do you even use 1st and 2nd gear?

[Jk_zeder]

What track's do you run? I know with my 4.6 on Lakeside I'm still on limiter halfway down the pits with 17/40 tyres.

 

I'm considering grabbing a 4.3 for Lakeside and just keeping the 4.6 for MP.

[zedchris]

Mp , occasional street sprint, need to get gearing right for the new long mp track, hitting 7000 in top twice now. Only done lakeside once and was coming onto straight on limitter. Dont want to go to tall, at mp need all the acceration i can to keep up with all the other zeds! Ideally 4.6 and a better fifth gear ratio, but if i have to i will go 4.4. and yes 1st and second are usefull???

[260DET]

I'm not sure that I understand this popular low diff ratio thing and what advantages is has, given the time it takes to shift gears and other relevant factors. A 7000rpm engine should have at least a 3000rpm power spread, keeping in mind that it is not always practical to shift at the optimum rev point. I find that it's faster to shift as little as possible and to have a diff ratio which enables this without running out of revs at critical points. Of course if you have more power than most but with a narrow power band the situation may be different.

[d3c0y]

Yeah i agree Richard.

My point is that those gears must be realllyyyy short for you what speed are you doing top of second? I thought it was common to put taller first and second in even with a 4.11.

[bluerat]

It's all about torque multiplication fella's....

 

If you lived in Tassie Chris, I'd happly lend you mine to try.

[260DET]

More off topic But torque multiplication is done by the gearbox and the diff, there is no free torque gained by changing a diff ratio if the gearbox ratios can fill the gap. What a lower ratio diff does do of course is effectively bring the gearbox ratios closer together. Which may or may not be an advantage as previously mentioned.

[bluerat]

Okey Dokey Pal

 

[zedchris]

I might be wrong but after changing down tyre sizes, which equates to changing final drive ratios, so that i am using all the rev range in every gear i have just got my quickest time round  mp even after hitting rev limit in top twice per lap. Maybe i need to go to a 4.4 just to see the affect on my times?? I believe that if i only have basic engine, okay but nothing special in the power department compared to some cars out there, i need all the acceleration i can find. Keep the ideas coming, i'm always open to interesting discussion that might lead to quicker times.....By the way does anyone have a 4.6 diff??? And apart from nismo, 4.4 only comes in r200. I run r180 cos its lighter. cheers

[1600dave]

I thought quite a lot of the Subie STi R180's were 4.44 ?

[d3c0y]

Yeah i have subi 4.4s coming in my next container. You can even just swap out the ring and pinion into your diff if you want.

Are you currently running an LSD?

[peter mc]

in my silly opinion the 4.4 is the only way to go in a L28 race engine with 17 wheels and a good engine that will rpm to 8000 power from 4500 to 8000 and you have one fast car

if i was racing a L24 id have 4.6 4.8 and rpm the engine harder all the way to 9000 with a built engine

[dat2kman]

Wot he sed!

I still got a complete open r180 wid a 4.375, used, with halfshafts, in a housing, out of a 240Z circuit car, on 14" wheels, that would run at 8000 rpm

 

When these WERE available, they'd sell jst the CW&P at $1200

They were a "special order" for competition application.

 

Nowadays you just chuck in any old r200 out of a dr30, but, they do not come with full complement of LSD plates!!!

Be aware!

[Jk_zeder]

Front diff from a datsun 720 4x4 ute can carry the 4.6s - it's where mine came from.

[PZG302]

Front diff from a datsun 720 4x4 ute can carry the 4.6s - it's where mine came from.

 

that's ratio is for a petrol one, diesels ran the 4.875.

[zedchris]

Yes mine is plate style lsd. How much am i looking at for the subi 4.44 cw&p to fit my r180?? and how far away are they. I need one pref tomorrow but more realistically before november.

And on the nissan 720 diesel petrol ratios, it looks to me like it was a lucky dip, i have had 4.6s and 4.875s pulled from either with no apparent pattern...or maybe i was just unlucky. Shame i didnt keep one eh.

Twould be nice to build a new engine capable of higher rpm but mine only basic, need a money tree.

[HKSZ]

I've got a few 4.6s just not available till the end of the month

[zedchris]

What are you asking for a r180 4.6, and out of curiosity, where are they coming from.

cheers

[HKSZ]

Pm'd $200 to $400