2017 diff swap

[Tcoat]

Originally Posted by nikitopo

You shouldn't say this. FRS Justin is a very knowledgeable member.

THIS ^


Now if it was one of the incarnations of Ubersuber...

[FRS Justin]

Originally Posted by mrg666

So, I should believe "you" instead of a car magazine (not one btw)? You are so funny.

you can believe who or whatever you want, but your stance on gearing is wrong and that's a fact. I have the fastest N/A FA20 in the US and probably the fastest F/I FA20 in the US and I didn't make that happen by reading car and driver.
EDIT
You want facts here you go, My N/A car 13.74 @ 101mph 4:10 gears 13.47 @ 104 mph with 4:56 gears in the quarter,

[venturaII]

drops mic

[ermax]

Magazines are notorious for bad info. I’m in the IT business and remember when I was younger reading computer mags and thinking, WTH is this guy talking about. I remember reading the bios of the editors and some only had 4 years in the industry. Seriously, you want me to take advice from someone with only 4 years in the industry. The same goes for most mags. Someone already pointed out a discrepancy in their specs for the 2016 car. Also, I have never heard someone “speculate” that a car that has a drag limited top speed in top gear would be even slower with a higher final drive. This is car 101 kind of stuff.

[FRS Justin]

nailed it

[churchx]

But is top speed of our cars really drag limited? IIRC it was speed limited by ecu (don't remember though, if by wheels speed sensor or by specific rpms at 6th gear).

[Teseo]

Every time i see "top speed" and shit i say to my self: who the fuck drive up 100mph on daily basis.

[mrg666]

Originally Posted by FRS Justin

you can believe who or whatever you want, but your stance on gearing is wrong and that's a fact. I have the fastest N/A FA20 in the US and probably the fastest F/I FA20 in the US and I didn't make that happen by reading car and driver.
EDIT
You want facts here you go, My N/A car 13.74 @ 101mph 4:10 gears 13.47 @ 104 mph with 4:56 gears in the quarter,

The magazine data I quoted is about "the effect of final gear on top speed of stock car". And the discussion was about that. You are giving acceleration data of your car with most probably modified engine. Everybody, including me, already agrees that acceleration will be better with higher final drive. Congratulations on your fast cars though. So you might be right because of that whatever your point would be.

[nextcar]

Originally Posted by FRS Justin

Best bang for the buck period. I have used several different ratios in my FRS from 4.10 to 5.71. Buy a complete diff on ebay sometimes you can find them for 600 bucks. You wont be able to have it done cheaper than 600 bucks unless you do the install then its still close to 600. If you don't like it switch back to your factory and sell the 4.3. I suggest 4.56 tho it gives you great performance with the least amount of loss what I would call the best of both worlds
Good luck

In the spirit of more factual info vs hearsay... I was able to get a FRS complete differential with 4.10 gears/TSD and less than 20,000 miles wear for $250 form a Los Angeles wrecking yard... I was able to order my Toyota 4.56 gears from Japan for just under $400 including shipping. I still have days where I think about 4.88, but I have never driven them. The Toyota 4.56 gears are helical cut and exhibit no noise. I love the gears, but it is a bit on the expensive side. At $500 total it would be a no brainer, but all in I was closer to $1000. Of course I could offset that by selling my original differential with the stock 4.10s....

[FRS Justin]

Originally Posted by mrg666

The magazine data I quoted is about "the effect of final gear on top speed of stock car". And the discussion was about that. You are giving acceleration data of your car with most probably modified engine. Everybody, including me, already agrees that acceleration will be better with higher final drive. Congratulations on your fast cars though. So you might be right because of that whatever your point would be.

Hold on bro you cant have it both ways. The new model with 4.3 gears has a different FA20 configuration and hp rating. The big red intake is just one change. So how are you going to compare stock 13 and stock 17 when the 17 is a modded 13 design. That would be a apples to oranges comparison True comparison my N/A car dropped 3/10ths and picked up 3 mph with just the gear swap no tuning no changes to anything but the gearing yes it had a exhaust and tune but that was the same on both runs. you have to look at gearing like a cam swap. Sure you could put a big fat cam in a motor but it will run like crap with out supporting mods. Here is the biggest tech tip I can give you, DONT listen or believe any racing advice that comes from a guy wearing skinny jeans and drinking a latte while trying to look smart writing for a magazine.

[FRS Justin]

Originally Posted by nextcar

In the spirit of more factual info vs hearsay... I was able to get a FRS complete differential with 4.10 gears/TSD and less than 20,000 miles wear for $250 form a Los Angeles wrecking yard... I was able to order my Toyota 4.56 gears from Japan for just under $400 including shipping. I still have days where I think about 4.88, but I have never driven them. The Toyota 4.56 gears are helical cut and exhibit no noise. I love the gears, but it is a bit on the expensive side. At $500 total it would be a no brainer, but all in I was closer to $1000. Of course I could offset that by selling my original differential with the stock 4.10s....

weir performance in American canyon cali sells anything you need for gearing and does installs, Ive used them and never been disappointed. Mark Spencer in NH also does gear setups if on the east coast and he's awesome too.

[ermax]

Magazine editors are writers first. Car guys second. Mechanics.. not at all. Engineers... not at all. They have liberal arts degrees, not engineering degrees.

The only mag worth reading is Grassroots Motorsports.

[gtengr]

The magazine data is garbage, and really misses the point. The simple fact is a BRZ will pull 6th gear to its top speed, which could be 135 or 145 depending on who you ask and what day they did it, but that's irrelevant. What matters for the top speed discussion is that 6th gear redlines at ~165mph with 4.30 gears, and current top speed is absolutely lower than that. So, higher numerical rear gear = more horsepower to the tire at drag limiting conditions because of new higher rpm = more top speed (until the gearing puts you past the horsepower peak or hits redline).

[mrg666]

Originally Posted by FRS Justin

Hold on bro you cant have it both ways. The new model with 4.3 gears has a different FA20 configuration and hp rating. The big red intake is just one change. So how are you going to compare stock 13 and stock 17 when the 17 is a modded 13 design. That would be a apples to oranges comparison True comparison my N/A car dropped 3/10ths and picked up 3 mph with just the gear swap no tuning no changes to anything but the gearing yes it had a exhaust and tune but that was the same on both runs. you have to look at gearing like a cam swap. Sure you could put a big fat cam in a motor but it will run like crap with out supporting mods. Here is the biggest tech tip I can give you, DONT listen or believe any racing advice that comes from a guy wearing skinny jeans and drinking a latte while trying to look smart writing for a magazine.

Let me ask this way. Suppose you are not drag racing but you will try to brake a speed record for your car and you have access to a very long straight track. The length of the track is not going to limit your end speed. What final drive gear would you choose for your 700+ hp car? I would choose the smallest final drive I can, i.e. less than 4.1. Am I wrong?