How does the LSD help in the snow? Or would that be for play purposes?

John

 

Okay, thanks for the math lesson

I have done this in a GS400, I had the TRD unit installed using my original stock gears. I have around 10K miles on it and have had no problems. The TRD unit didnt have any clutches in it at all unless I missed something, but I dont think so. I wasnt told of any special break in process but maybe you only have to do that with the Clutch type LSD's

As for snow, I dont know how much it would help or not, the biggest factor I would think would be the tires. If you had snow tires I could see where it would help some with traction to both tires.

 

Here's a good FAQ on clutch type LSD's.

http://www.club4ag.com/faq%20and%20t...ential_101.htm

And the How Stuff Works is on the simple side but good for an intro...

http://auto.howstuffworks.com/differential.htm

.

 

I agree Hameed. The tach on the GS is large enough to clearly see. When I got my 3.76,
I took a good look at it and at 80mph, the needle is spot on the 3000 mark - not above --- spot on.

 

Vette Boy, I also wanted to mention to you that you are blowing this issue out of proportion and are potentially robbing yourself of an awesome mod.

I am willing to bet that if you did a poll to find out if anyone regrets going to the Supra LSD with 3.76 gearing, nobody and I mean nobody will have any regrets about doing this mod.

Trust me, you will not look back and regret doing this mod at all. Bottom line, find a member close to you and go for a drive if that is possible. Better yet, if you are within 10 hours of D.C., come out to the big meet that is being planned right now in the NE forum. Lots of members including myself will be there and you are more than welcome to take my car out for spin to see if this is a real issue for you. I highly doubt it.

 

If you actully take the time to determine how much more gas you will pay for with the 3.76 gears vs. stock, the difference is minimal. For example, if you drive 20,000 miles a year your fuel cost is $1,767 (based on 21.5 MPG and $1.90 gal). Mileage with 3.76 gears drops about 1.5, so I expect I would get 20 MPG on average. The annual fuel cost would go up a whopping $133.00 or about 37 cents per day. Based on this, I think I will be getting this mod!

There is also the concern of higher engine RPM's on the highway. I never cruise above 80, so I think 3,000 RPM is reasonable. Certainly not too much to harm the fine lexus engineered powerplant! Your mileage may vary, but the cost of this mod in gas money is really not an argument for me.

 

ok, just a little correction, hameed meant to say at 80mph it's at 3k rpm

 

Thanks for clearing that up Rom!

 

All I can say is 3.76 = more fun, more fun = more gas and who ever does this mod is most likely willing to give up X gallons for X*2 more fun

 

This is how cars work. If you switch the final drive gear, the rpms go up across the board, it's not a constant 300rpm across the board. If you don't have a scan tool and are using an analog tach as you measuring instrument, then you can't really know what RPM you engine is running to the accuracy level you are claiming.

BTW, I've done this mod to two different car, both times when I measured the RPM difference with an OBDII scan tool, the "real world experience" matched the theory perfectly.

 

I appreciate your input, I've read your post here and I can tell you are really into the GS. I've modded two cars extensively, I know what I want. I like a nice quiet car, if I want to kick some butt, I'll haul out my 12 sec Vette with the sub 4.5 sec 0-60 time. For me, a 3.76 with a 0.7 overdrive and 25" diameter wheels is too much.

 

I've driven rear drive v-8s all my life. My last one was my first with LSD. The difference in the snow is huge. After my last car turned me on to how important LSD is for a rear wheel drive car, I swore I'd never own another cat without LSD. The GS has traction control, I thought it would be enough, after the last few snowstorms here I decided to install LSD in my GS.

 

There's another issue, It's very difficult to install the needle at the factory spot on. A slight angular error is common, +/-50rpm is very good. The only way to really know your RPM is to use an OBDII scan tool.

No matter what the actual RPM, I can promise you when you changed your gear from a 3.23 to a 3.76 your engine speed went up 16% for all gears (1-5) and engine speeds. If the engine speed didn't go up, you wouldn't like this mod so much.

 

i dont know Hameed sounds like he knows what he is talking about

any more info VB

like lets someone was going to supercharge
how bad would it be if i went with the supra rear as opposed to the other unit

 

Traction is a problem when supercharged with the stock gearing, thats why I chose not to go to taller 3.73 gears, I couldnt imagine how it would be.

also my tach does read different than my SAFC rpm readout.