Works real well expecillay if your over all wheel and tire dia is more then stock.
It will be a lot less harsh on your trans.
A high stall converter would work very nice with it.
I thought that the autos were speed limited due to heat, so I would guess nothing. It's a 15% drop, so it would just get there quicker! It would help our 5th gear for sure; if you're into driving fast.
It's limited by absolute transmission output shaft RPM, so taking the simple ratio between 3.23 and 3.73 into account, I estimate it would knock off almost 25 MPH from the top end. Not that 150 MPH is, um, slow...
This might not be the best solution for 1/4 mile drag racing. By my calculations (inputing in a calculator), the 3.73 gearing is going to cause a 4-5 shift at around 115mph. That is in contrast to the 3.23 allowing you to go through the traps in 4th gear provided you trap under 130mph.
If I plug in a 6,600 RPM redline, I come up with the same figures. I assumed a 6,200 RPM redline as my auto shifts at around 6,200 RPM. So you would have to raise the TCM's shift point and possibly raise the engine's rev limiter to get to 6,600 RPM.
Although, I think the 4 to 5 shift even at 122mph is less than ideal for the modded cars trapping in the 122-124 range. The 1/4 mile trap speed is really a mathematical average of the time to cover the last 66' of the 1/4 mile run. So if a car is shifting right before the final trap lights, it is going to hurt both the trap speed and the ET because of the late shift.
The calculation table also indicates 2200 rpm at a cruising speed of 75 mph with 3.73s, which is not too bad at all... as opposed to 1900 rpm @ 75 mph with the 3.23s http://www.f-body.org/gears/
My question was aimed at seeing if the center section was a bolt-in replacement. Obviously it is a lot of labor to dismantle everything and pull the axles so the center section can be removed. But if then all we have to do is swap the center sections and re-assemble, it is a whole lot easier than having to change out the entire rear end assembly. And the cost for major parts would only be the center section. This is the lowest cost change you could ever make to get lower ET's.
I am upgrading 2011 v-coupe.....cam, heads, headers, upper/lower pulley, plugs....the whole 9 yards. Auto with 323 rearend....Does anyone think a 373 rear would give me more torque feeling without compromising engine life and highway driving? The car has overdrive. Any ideas if torque converter would be helpful? thanks for the help.
If my memory serves correct, most who put 3.73s in their A4 LS1/LT1 Camaros and Firebirds weren't all that happy with their decision based on excess noise at cruising speeds and reduced gas mileage. Most of those A4s came with 3.23s (although some had 2.73s) and although 4th was an overdrive (0.70:1), most A4 people were happy going from 3.23s to the 3.42s, which was the stock gearing in the M6 (which had a more extreme 6th gear overdrive ratio of 0.50:1). Even with 4.10s, the manual cars would still cruise at 70 mph at around 2200 rpm and deliver around 27 mpg!
My gut feeling about installing 3.73s in your modified V is that it is too much gear and would present a real problem getting traction and putting the torque to the ground - especially with that numerically high 1st gear!
Pick a Part in Cleveland has complete rear end assemblies (brakes and all) in both ratios for around $1800. I think they're having a Christmas sale as well.
I realize this is an old post but was wondering if this would be an easy swap for my 03 cts? Is there any reason this would cause me issues of any kind and is it as easy as topping my diff and replacing it with this 373?
----------
meant to say "...DROPPING my diff and replacing..."
I realize this is an old post but was wondering if this would be an easy swap for my 03 cts? Is there any reason this would cause me issues of any kind and is it as easy as topping my diff and replacing it with this 373?
So click the "Edit Post" button and fix it rather than "Reply".
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Cadillac Owners Forum
4.8M posts
369.7K members
Since 2002
Cadillac Forums is the perfect place to go to talk about your favorite Caddys including the ATS, CTS, SRX, Escalade, LYRIQ, Vistiq, concept and future Cadillac models.