How many mph would it take off from your top speed, if you have a 5at and you get the 3.9 Final Drive?? And also if i get everything preassembled, would they include a LSD in it? Because i dont have a lsd.

 

Nevermind, i kno the answer to whether the lsd would be included or not, however i just need a couple of questions answered before i can go about this. Thanks in advance.

1. How much mph is taken off of the Topspeed, if im a 5at and i switch to the 3.9 final drive??

2. I was wondering what do they mean by core exchange, they want my old pumpkin back?? If so, does it matter that i dont have a lsd, would they still take it?? Cause i dont have one. LoL.

3.If i was to get a preassembled unit w/ LSD, do i need to do anything else to make it work since i didn't have a lsd before?? or i just have to pay for the simple installation of the housing and im all set?

4. Is it mandatory to do a ECU reflash for the 3.9 final drive to work?? Or i can do without it??

5.My last question is: Is the OS Giken lsd better than the nismo lsd??

I apologize if any of these questions are stupid.

 

I've asked some of the same and have been following ISM's post on thsi subject, so allow me to pass along some of that in return.

1. Not certain, but it looks to be about a 10-15MPH reduction.

2. Yes, core exchance means they want your OEM one back. And with an auto, you're in the same boat as ISM. The swap is for a 6MT pumpkin, so you'd have to buy one of those in order to have a 6MT core to exchange. You can avoid the core exchange by paying $1700, but a 6MT pumpkin can be found for cheaper.

3. See #2 above and #4 below.

4. Nothing else is really needed if you get the pre-assembled pumpkin. No ECU reflash, etc... ...but you will lose your cruise-contol with the swap. ECU sees the difference in speed vs. pre-programmed RPM parameters and thinks there's a problem so turns itself off.

5. The NISMO and the OS Giken LSD are both going to be too hardcore for a daily driven car on the streets. Good for the track only. And it's my understanding that the OS Giken is even morehardcore than the NISMO in this regard.

 

Hey thnx alot for the answers!! Wow i never knew the nismo lsd was that hardcore, i saw a couple of ppl in this forum that has one. I wonder how they did it. By the way what would be the cheapest way to get a 6mt pumpkin besides goin to a junkyard??

 

Would getting a Nismo or OS Giken lsd actually have a negative effect on my everyday driving though? Because its only $170 dollars more, kinda hard to pass up. =P

 

And I think that's where the mistake might often be. It's not much more... ... . I've heard that they are pretty loud during operation, and I'd assume that their operation is more pronounced... ...like an on/off switch.

 

Pretty much on target there, GT. The car will chatter and screech as you drive normally - in parking lots, etc. It really is much more sensitive and positive in what it does. the Nismo and Giken units are designed specifically for track use.

Also, GT - all good answers to the other questions...

 

ISM- someone had asked about using the LSD in their 2005 auto sedan, and you had mentioned that the answer was a few posts up- I didn't completely understand that answer.

I also have the 2005 auto sedan w/ LSD- can you confirm that the 3.9 gears can swap right in and work with the stock LSD? Is there any other mod that is suggested to go along with the gear change, or should it be a reliable straightforward mod?

Thanks a ton for all of the info you have provided.

 

2. Yes, core exchance means they want your OEM one back. And with an auto, you're in the same boat as ISM. The swap is for a 6MT pumpkin, so you'd have to buy one of those in order to have a 6MT core to exchange. You can avoid the core exchange by paying $1700, but a 6MT pumpkin can be found for cheaper.

3. See #2 above and #4 below.

4. Nothing else is really needed if you get the pre-assembled pumpkin. No ECU reflash, etc... ...but you will lose your cruise-contol with the swap. ECU sees the difference in speed vs. pre-programmed RPM parameters and thinks there's a problem so turns itself off.

So being an AT, and the core exchange being for an MT, you'll need to double your effort by buying that 6MT pumpkin for the core exchange on top of what the normal cost of the swap is.

 

Why the need to "exchange"? Why can't you just go buy what you need and be done with it?

 

Thread revival.

I have an '03.5 5AT and just want to add VLSD. I'm tired of smoking the right rear tire and having the VDC com on.

I do NOT want to change the gearing ratio.

Can I just get the pumpkin from a 5AT 350Z and do a bolt in swap? Fron reading this thread, it appears that they have the same great ratios. I should be able to retain the cruise control as well, right?

 

Does anyone know if I can just swap a pumpkin with a 5AT Z to get VLSD?

 

I believe you can - you should contact BJ over at 350EVO to be sure though.

 

As for the cruise control. When I did a gear swap on a toyota tundra I got a speedo corrector which basically watched the waveform from the output shaft on the transmission and corrected by the appropriate percent so the ECU saw the correct output shaft speed relative to the ABS sensor speed, and also corrected the speedometer error caused by the gear change. I wonder if something like this would work in this case as well?

 

Nope...

The Speedo works off the rear wheel sensors - so it is not even an issue when the gears are changed.

The Cruise gets info from I think 4 places - possibly more - there's some info on one of the threads - may have been here actually.