3.266 diff crown and pinion - fit ISF diff or not?
11-02-14, 04:31 AM
#16
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I think you have to bear in mind that the IS350 diff represents about a 40% change in ratio from stock, so its probably not surprising that such a big change had some adverse effects.
Whereas the 3.266 is about an 11% change, and the 3.133 is about 7%. I dont think there will be any adverse effects from these changes or at least if there are they will be a lot less noticeable, but until someone tries it we wont ever know....
Whereas the 3.266 is about an 11% change, and the 3.133 is about 7%. I dont think there will be any adverse effects from these changes or at least if there are they will be a lot less noticeable, but until someone tries it we wont ever know....
Last edited by Sci; 11-02-14 at 04:37 AM.
11-02-14, 08:58 AM
#17
I think you have to bear in mind that the IS350 diff represents about a 40% change in ratio from stock, so its probably not surprising that such a big change had some adverse effects.
Whereas the 3.266 is about an 11% change, and the 3.133 is about 7%. I dont think there will be any adverse effects from these changes or at least if there are they will be a lot less noticeable, but until someone tries it we wont ever know....
Whereas the 3.266 is about an 11% change, and the 3.133 is about 7%. I dont think there will be any adverse effects from these changes or at least if there are they will be a lot less noticeable, but until someone tries it we wont ever know....
11-02-14, 12:45 PM
#18
This maybe something not measured in percentage terms but rather like a light switch that's either on or off. Either you have the correct ratio or you don't. But as you said, we won't know until someone tries it. I for one regardless of the outcome will be keeping the stock ratio.
11-02-14, 08:52 PM
#20
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To the guys willing to try, go for it. Just be aware Toyota does a lot of unusual stuff in their ECM. If you read about the details of the IS-F Bob Norwood built with turbo charging, one of the most difficult issues he faced was a table limiting acceptable engine acceleration. More than likely Compthis ran into a mismatch between expected parameters and measured parameters. With as big a change as the 350 gears are, it's not surprising. With smaller changes, it might be OK. Then again, it might be all pissed off too.
There are any number of rear end gearsets which might work fine in the F. I went through the part number exercise a couple of years ago too, there's a thread with the info in it somewhere here. Seriously, if it works, it could be the ticket to get the car into the 11's.
This thread - https://www.clublexus.com/forums/is-...s350-diff.html
At the end, Crazymikie was going to put in the 3.266, but he never posted if it worked or not.
There are any number of rear end gearsets which might work fine in the F. I went through the part number exercise a couple of years ago too, there's a thread with the info in it somewhere here. Seriously, if it works, it could be the ticket to get the car into the 11's.
This thread - https://www.clublexus.com/forums/is-...s350-diff.html
At the end, Crazymikie was going to put in the 3.266, but he never posted if it worked or not.
Last edited by lobuxracer; 11-02-14 at 09:16 PM.
11-08-14, 09:26 AM
#24
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Not exactly. It will help most at low speed. As driveshaft speed increases the difference will get smaller and smaller - same as a light flywheel. It is most noticeable in low gears, and less impactful as load increases. The gearset will remain an improvement to acceleration regardless of speed in a way mass reduction (while good) can't match.
11-27-14, 04:37 AM
#26
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Excellent. Have you considered finding out if one of the speedometer correction units will work with the car? Changing the ratio to 3.26 gears effectively is like installing a tire roughly 23" in OD. Stock is in the 26" range, I believe.
11-27-14, 05:31 AM
#27
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Ive deliberately not looked into the issue of speedo correction because there seems to be some thought here that at least one speed measurement comes off the hub sensor(s) of the wheel(s) and thus is unaffected by the diff ratio.
Whether that is correct or not i dont know but certainly all the Toyota/Lexus ive known about have had speed sensors on the transmission.
I think i'll get the diff done and make sure im happy with the change, then worry about other things later
Whether that is correct or not i dont know but certainly all the Toyota/Lexus ive known about have had speed sensors on the transmission.
I think i'll get the diff done and make sure im happy with the change, then worry about other things later
11-29-14, 09:17 PM
#29
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No they are not. Put your car on four jackstands and spin the back wheels. The speedo works just fine like this. AMHIK. Gear ratio won't impact speed indication, but it is not because the front wheels are measuring speed.
