Differential differences

[Fd_daderp]

Hi everyone, just wondering if there was a major difference in differentials with the non-turbo mkiii and turbo mkiii..

Thanks in advance!

 

[GrimJack]

Well... it depends. NA cars came with a different ratio, and *might* have the LSD, depending on what options were purchased with the car.

 

[Fd_daderp]

Oooh ok kool


Thanks

 

[Backlash2032]

Sport package N/A (TEMS, along with some other things) 4.30 LSD
Regular N/A 4.30 open
pre 89 turbo was a 3.91 LSD
post 89 turbo was 3.73 LSD

If you are going to put this on an N/A i would go with the pre 89 turbo differential. Drops rpm at highway speed to around 2500. Much better than the 3 grand im running with the 4.30..

 

[Fd_daderp]

Yea I have a pre 89 turbo and a 91 n/a but it's the one with the sport package (tems, sunroof.....)

So I was wondering which one would hold up better

 

[hvyman]

They all hold up fine. Did you have headlight squirters on the n/a?

3.91 in the pre and 4.30 in the post.

 

[Fd_daderp]

Lol I wouldn't kno, I got the 91 na shell without headlight units

 

[GrimJack]

The headlight squirters are in the bumper, not the headlights.

 

[Fd_daderp]

Ohhh no it's not in the bumper, but the bumper looks like it's aftermarket... Not the same material as the rest of the shell

 

[86_sports_1jz]

if your gonna stick with stock twins i would use the 4.30 but if your gonna go single i would use the 3.91... i have the 4.30 with a single and the gears seem real short, i have a 3.9 rear end i'm gonna swap with it.

 

[steveyblack]

if your gonna stick with stock twins i would use the 4.30 but if your gonna go single i would use the 3.91... i have the 4.30 with a single and the gears seem real short, i have a 3.9 rear end i'm gonna swap with it.

I need to say with the twins and 4.30 rear it makes for a fun car. But i do wish I had more gearing. 1-2 feel like they are just getting into boost before you need to shift. I want to try out the 3.91 though, let me know how it is.

 

[Scott 88-1JZ]

I swapped my 1j into an 89 shell with the 3.9 gears. It used to be in an NA sport package with the 4.3 LSD. I personally preferred the 4.3 for the acceleration and around town driving. The 3.9 just feel slow. But in the end I am putting on a gt35r so I figure when I up the boost it will feel right again. I am gonna save the 4.3 from the now parts car in case I want to go back.

 

[Fd_daderp]

Thanks guys for the very helpful info!!!!

 

[GrimJack]

I really wish I could find something lower than 373 for the rear end... as soon as the power starts to climb, the lower gears become completely useless, even with spectacularly good tires.

 

[RazoE]

Sport package N/A (TEMS, along with some other things) 4.30 LSD
Regular N/A 4.30 open
pre 89 turbo was a 3.91 LSD
post 89 turbo was 3.73 LSD

If you are going to put this on an N/A i would go with the pre 89 turbo differential. Drops rpm at highway speed to around 2500. Much better than the 3 grand im running with the 4.30..

LSD was a stand-alone option on NA 89+ cars, so you don't necessarily have to have the sport package to have an LSD..

but for USDM sake (as 1G cars and TTRs have different differentials):

ALL NA's are 4.30, all sport packages are LSD, all non-sport package 86.5 - 88's are open, 89+'s depend on whether or not the original owner opted for an LSD
ALL 87/88 Turbos have 3.91 LSDs
ALL 89+ Turbos have 3.73 LSDs

all are swappable, and all can pretty much hold the same ammount of power..

 

[Backlash2032]

Personally I would go with the 3.91.

I HATE my 4.30s. I cannot stand highway driving at 3k rpm. No drone but it bugs me having my motor revving that high.

Around town its even annoying. everytime you get going you almost always get to 4th, and most of the time 5th too. Too much shifting, i feel like im driving a grain truck..

 

[spencyg]

LSD was a stand-alone option on NA 89+ cars, so you don't necessarily have to have the sport package to have an LSD..

My 87 N/A has the 4.30 LSD option...right in the VIN and everything.

So I think its safe to say the LSD was optional in all years of the N/A. It would be specified right in the VIN...

SG in NE.

 

[RazoE]

The VIN wouldn't indicate it has an LSD, only the door tag..

sure it's not a sport package? LSD, headlight washers and TEMS, but I do know ABS was optional (my 86.5 sport package doesn't have it)...

 

[spencyg]

You might be right. I think it was the tag on the firewall that indicated the differential, engine code, trans code, etc. The special code for the 4.30LSD was there too

No Tems or Headlight washers on my car, but it did have the leather interior (at least...what was left of a leather interior)

 

[Flateric]

I really wish I could find something lower than 373 for the rear end... as soon as the power starts to climb, the lower gears become completely useless, even with spectacularly good tires.

I could agree more, you have no idea how many times I have said this exact same thing. 1st is gone quicker than possible to shift out of almost.

Jeff Lange told me once that all MKIII's sold in Canada came with LSD's NA or turbo.

I am running 3.73's BTW. Big single.