4.27 Gears???
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Driver
Joined: Feb 2007
Posts: 181
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From: TX
4.27 Gears???
So I want to get my car faster off the line and I got 20x10 and 8.5 all picked out... So I found the whole pumpkin off a automatic SC300(4.27) and I was trying to figure out if its a direct swap into my 01 GS430... Any info will help...
Lexus Champion
Joined: Feb 2002
Posts: 4,466
Likes: 13
From: Cali
The biggest bummer will be the open diff with that short final drive.'
Great for "peg leg" burnouts, though!
I have a 5-speed Supra Turbo diff on the way (LSD). I thought these
were closer to the stock 3.26, but apparently they are 4.08
Great for "peg leg" burnouts, though!
I have a 5-speed Supra Turbo diff on the way (LSD). I thought these
were closer to the stock 3.26, but apparently they are 4.08
Even a 3.92 should work well enough for the GS400. 4.27 is way too high.
At 80mph, the engine will be revving at the following speed:
3.26 Ratio: 2600 RPM
3.76 Ratio: 3000 RPM
3.92 Ratio: 3100 RPM
4.08 Ratio: 3300 RPM
4.27 Ratio: 3400 RPM
Compare the OEM gearing to the 4.27. Huge difference. The guys with the 3.76 gearing are already reporting a ~2-3mpg drop over the OEM gearing. Imagine another 2-3mpg drop with the 4.27. So whatever you're at right now, expect a 4-6mpg drop if you cruise on the highway a lot.
As stated above, I wouldn't go that high without LSD anyways. If you have too much power while turning, that open differential will be no good.
At 80mph, the engine will be revving at the following speed:
3.26 Ratio: 2600 RPM
3.76 Ratio: 3000 RPM
3.92 Ratio: 3100 RPM
4.08 Ratio: 3300 RPM
4.27 Ratio: 3400 RPM
Compare the OEM gearing to the 4.27. Huge difference. The guys with the 3.76 gearing are already reporting a ~2-3mpg drop over the OEM gearing. Imagine another 2-3mpg drop with the 4.27. So whatever you're at right now, expect a 4-6mpg drop if you cruise on the highway a lot.
As stated above, I wouldn't go that high without LSD anyways. If you have too much power while turning, that open differential will be no good.
I have the 3.92 and it's great for quicker acceleration. The 4.27 are a direct bolt on just as the 3.92's are. The only thing with the 3.92's is that your top end will be limited to 125/130 mph.
love the 4.27 gears. I have another SC300 diff on the way and also a Supra TT LSD.....cant wait to have this combo back on and yes the 4.27 pumpkin is a direct bolt on.
GSteg is correct in the RPM level is 3400 at 80mph with 4.27 gears. https://www.clublexus.com/forums/sho...ratio+research
GSteg is correct in the RPM level is 3400 at 80mph with 4.27 gears. https://www.clublexus.com/forums/sho...ratio+research
Last edited by slowdiver; Jan 2, 2008 at 02:57 PM.
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