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aym23q

Viscous vs Helical diffs for street/drag

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I know but already got the r33 diff dude.

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I wouldn't bother working it out, just get a mate to drive along the road in front of you at agreed speeds and tweak it til the speedo is reading right.

 

You can wire it in anywhere pre speedo really, where ever is easiest to get to that allows you to reach the thing to make adjustments

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fair enough ill use my GPS and try to match it to that on say 60kmh and it should remain accurate for any speed

 

Just gotta find what wire on the cluster rear is the speed signal.

 

Thanks alot :)

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Just an updateJust an update on this

 

Fitted the diff and yes the car revs out heaps quicker now..

 

Funny thing is, because im running 19inch wheels my speedo was off, now with the 4.11:1 diff ratio my speedo seems to have corrected itself.

 

Does that make sense? i would of thought because the gears are still heaps shorter now that the speedo would still be off? sounds conflicting

 

Any thoughts?

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I would think win, no f**king about with speedo.

 

One balances out the other, maybe the speedo was low to begin with?

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well with standard rims the speedo was accurate, with 19s it was average 10kmh too slow, now with shorter final drive it's back to being accurate. Weird...

According to my calculations the overall ratios of the gears are indeed shorter (ie 110kmh at 3100rpm in 6th as opposed to ~2700 with standard diff)

so technically the speedo should still be off????

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What did you end up doing?

 

Did you swap the diffs? or just the gears?

 

I'm thinking of using R33 4.11 gears and putting them in an S15 diff so helical center.....

Thought I read somewhere that the R200 centers and crown/pinion are interchangeable but cant find it again now

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im quite interested in all this too

plan to rebuld my box and along with that the diff too

atm i have a 1.5 LSD or some sort [bought car with it, so dont know ratios]

but with the 4.1, it should have extra bite

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I swapped the whole diff. Got my helical up for sale. All R200 centres are interchangable. But pinions can differ. 4.1 ratio keeps the revs up and the engine on the boil. Redline comes real quick, you change gears and tge revs dint drop down below 5500 or so. Change gears again for what feels like a couple of seconds, before you know it your reaching 180kmh and looking for 6th lol

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Yep my power keeps climbing and my max power is in that range. My dyno sheet shows max power and the power curve is almost flat between 5500rpm and redline. My peak torque is at 5500 rpm it's perfect lol

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that is pretty insane

since im throwing everything into my build,

i might have to investigate this further

i dont want to lose the 1.5 though dry.gif

its real good for keepin both wheels spining at the same rate

appart from the clunk clunk clunk as you do slow turns on throttle

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Just keep the centre but change the ratio!

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It's pretty tight on the street I can't notice much difference

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How hard is it to change diff centers out? i have a nismo 2way to put in a r200 diff...

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Thought i'd bump this up with my situation...I currently have standard manual s14a diff gear,which are 3.692 or there abouts.Looking for something in the range of 4.11's or so.Now for people that have been there and done that,What is easiest/best:

 

A) go for a skyline r33 4.11 diff,and change skyline 5 bolt setup to standard s14 6 bolt half shafts into that diff and put it all together.

B ) Find a JDM s14 4.08 diff (close enough ratio) and put that in and save myself the headache of changing around half shafts etc.(what are these worth??) Have seen them around for $300+ mark,reasonable price?

C) Find some 4.11 gears and bolt them on my current centre.

D) Start from scratch,Get myself a Helical s15 diff centre,some 4.11 gears,bolt it all in my current diff housing and dont worry about shimming.

 

Please note,my car has no ABS.So does this mean if i buy an ABS equiped diff,i can just leave the sensor disconnected? And also note that i will be shimming the Viscous diff centres whichever one i use.Few options here and have been juggling between them and not sure on costs all round.

 

P.S- new to nissans...and shit ADM ratios.Car is for street,not drift.Thanks in advance

 

EDIT* can get, r33 gtst 4.11 non abs diff for $240,which seems like a good option

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Abs diff housing is longer so you would use the Abs tailshaft to compensate . If you pull the centre out you have to have the lash adjusted. This costs money unless you have experience doing it. Your best bet. Would be to buy a non Abs 4.1 complete in housing or you will require a tailshaft swap don't forget to match up your halfshafts too. I run a 4.4 diff with a nismo gtr centre + drive shafts and it works like a charm just took a mass of f**king around with crowns housings and pinions to make it all work

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