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R&P opinions?

Posted: Sun Dec 27, 2015 2:00 pm
by ericteti
Hey guys,

I'm planning on having a shop take a look at my (incorrectly set up) 2-way LSD, and while they're there I figured I might as well replace my ring & pinion. I'm planning on picking a new one up from Weir. Which gear ratio do you feel would suit me best?

I'm planning on taking the car on the track and doing some auto-x, but I still want to be able to enjoy cruising around town and jumping on the highway to go to meets. I'm interested in 4.77 because people seem to love it, but will my highway experience/casual driving suffer immensely? Should I stick with the stock 4.3, or maybe just up it a bit to 4.5? What do you guys think?

Thanks so much!

Re: R&P opinions?

Posted: Sun Dec 27, 2015 3:53 pm
by Deuce Cam
- What engine/mods and hp/tq?
- Is the car a daily?
- How much would you be on the freeway, or above 55-60 mph?
- How important is high speed cruising to you?
- How loud is your car: exhaust, itbs, stripped interior, sound deadening, etc.?

These are the questions you have to ask yourself.

On a stock ae86 gts engine I've made the switch from oem/4.3 to 4.77. Gearing down really seemed to wake up the under-powered 4ag. OTOH, expect a 400-500 increase in rpm for any given mph switching to 4.77 - I'm pushing roughly 4200 rpm at 65 mph...

My car wasn't a daily when I made the switch (it is now...). I haven't taken the car to the track. I use to live in flat Phoenix, AZ with nothing but grid. Now I live in twisty mountain back road heaven near Greenville, SC (I'm not near a freeway an rarely even have a 55 mph limit). Right now I'm fairly happy with the 4.77's on the twisty/hilly back roads, but when I lived in PHX near the freeways I wasn't in love with the final drive.

I think 4.5 is a good compromise. 4.77 might be better for the track but it depends on the setup. If it's a daily car you may want to consider sticking with 4.3. I'll admit that it's not an easy choice.

Re: R&P opinions?

Posted: Mon Dec 28, 2015 2:35 am
by totta crolla
Another compromise might be to load the car up with low profile 13" wheel /tyres and use these at the track. Cruise around on normal profile 15's. Keep the 4.3 Final drive.

4.3 70mph 186 60 13 4100 rpm
4.3 70mph 195 60 15 3600 rpm
4.7 70mph 195 60 15 4100 rpm


Re: R&P opinions?

Posted: Mon Dec 28, 2015 4:01 pm
by ericteti
Deuce Cam,

Thanks for the reply!

I'm running a stock 16v and don't planning on doing much in the power department, and it's not my daily. I'm not on the freeway much, but I'd say 1 out of 3 times I drive it I'm on a 55mph road for about an hour. I don't ever care about driving the car above 75mph for the most part. I'm about to put in a Brave exhaust, which isn't obnoxious, but a bit louder than stock.

I think 4.77 would be awesome at times, but the freeway drives might make me go insane. 4.33 is only $318 from Weir, but they don't offer a 4.55. I'd have to do an OEM r&p, which would run me ~$650. I'm wondering if that's worth the cost.


I like that idea! That might be the way to go. Thank you!

Re: R&P opinions?

Posted: Tue Jan 26, 2016 9:52 am
by SgtRauksauff
I've got 4.778:1 with a Kaaz 2-way in my GT-S. Mostly used for Autox and HPDE/Lapping/Time Attack. I will also drive it sometimes just for fun, but not generally as a DD.

Running 195/60-14 Falken Azenis, I tend to be closer to 4500-5000rpm driving 75-80 on the interstate.
I have a set of something bigger, like 195/70-14, from a Camry, that I plan to run in the back to see if the highway-speed manners get a little better. The staggered-diameter tire sizes looks pretty nice as well; it really fills up the rear wheel wells (I'm running the celica-supra wheels.)

Using 255/40-13's at autocross, I am in the meat of the powerband in 2nd and 3rd gear for some courses, and the amount of acceleration you get from this is amazing.
using 225/50-14's at autocross, I'm sometimes in that zone between needing 3rd, or revving out 2nd longer than I should. but the mechanical grip is ridiculous.
I've not had the opportunity to try the 275-35-15's, but its diameter is around an inch taller than the 255's, but a little shorter than the 225's.

Knowing what I know now, after the experiences I've had.... I would still choose the 4.778:1 because the car is more fun with it, and I just really really enjoy being a contender for FTD at autocrosses with a 30-year-old, naturally aspirated 133.0whp, 2245lb, RWD car.

Were I to have another engine, say a BEAMS for instance, with ~200hp + on tap, I would probably change to a higher gear ratio, because I would not need the mechanical torque multiplication that the 4.778:1 gives the 4AGE. In turn, this would give me a better top end, so on road courses like BIR, I'd be able to match, if not beat, my 3-400whp AWD EVO/STi friends, because I'd still have the handling that out-corners them, but I'd also have a power-to-weight ratio that gets me the acceleration and top speed that they have. win-win!


Re: R&P opinions?

Posted: Tue Feb 16, 2016 3:21 pm
by ariel_86
Any updates?