2.73 rear gears?...

[GreekGod]

...my Crown Vic has so much bottom end torque, I'm thinking I should go to 2.73 rear axle ratio, to help "kill" bottom end torque. I'm planning on going to 31 spline axles and a Detroit Locker (with slicks for occasional test & tune drag racing). Might not make 3rd gear in the 1/4 mile! It would be cool to have a quick 60' time w/ a 2.79 rear gear.

What I'm wondering about is, have any members gone this route? I know 4.11's are preferred by many, and I will be installing them in my MM, but the CVPI is planned more for Bonneville or Maxton.

[ImpalaSlayer]

seems like a reallllly high gear@!

[a_d_a_m]

2.79?
Wasn't that a rear ratio from the '70s? Never heard of that being available for the newer cars.

Newer-model (98 and newer) civilian vics had 2.73's, I had those in my Marquis.

[Joe Walsh]

2.73s!!

Plug that into a gear selector calculator to see what kind of top end it would give your Marauder....:bows:

[Pops]

Dale is talking about Mad Max.:) 5.4 with a Whipple on it.:eek: Dale put up a picture to get the minds rolling!;)

[GreekGod]

My mistake, it is a 2.73, I will fix me 1st post. I think it is the lowest # Ford made for the 8.8".

[GreekGod]

http://www.mercurymarauder.net/forums/../gallery/data/3/MdMxRubr001.jpg MdMxBurnedRubber

[Pops]

Ok Dale now show one of the front of the car. That also helps explain a few things for the ones have not seen Mad Max!:bows: Mad Max has made a trip down the quarter that would give my carr a good run.:burnout:

[justbob]

I hate when that happens! Oh yeah, also when taking in for a warranty, it is a good idea to spend a few hours cleaning that off!

[4play]

whats that? did you run over a pile of cow poop?

[GreekGod]

I noticed many of the Drag Week cars had highway gears, and they still did wheelies. I have 3.55 gears currently.

My .030 over 5.4 Lightning with the Ford upgrade Whipple:

http://www.mercurymarauder.net/forums/../gallery/data/500/medium/MadMaxEngineLF.jpg (javascript:;)

[RF Overlord]

Fixed thread title...

[RoyLPita]

When did you fix the engine?

I would keep the stock gears and try for some very sticky tires.

[GreekGod]

When did you fix the engine?

I would keep the stock gears and try for some very sticky tires.

The engine still needs work. I am trying to do long and short term planning. If I borrow slicks from John Kuhn, I need 31 spline axles (first). If I get the axles & new DL diff., I think I should go with the 2.73 at the same time, too.

I only get ~7-10 mpg, so I don't think it matters what ratio I have, and It has so much bottom end torque, I fear even the slicks will lose grip with the 3.55's. I wish someone that tried the 2.73's with 500< RWHP would comment.

Either way, I suppose I will find the weak point in the driveline (getting it to hook with either gear).

[Joe Walsh]

The engine still needs work. I am trying to do long and short term planning. If I borrow slicks from John Kuhn, I need 31 spline axles (first). If I get the axles & new DL diff., I think I should go with the 2.73 at the same time, too.

I only get ~7-10 mpg, so I don't think it matters what ratio I have, and It has so much bottom end torque, I fear even the slicks will lose grip with the 3.55's. I wish someone that tried the 2.73's with 500< RWHP would comment.

Either way, I suppose I will find the weak point in the driveline (getting it to hook with either gear).

I know that Tom Doan is running a low (numerical) set of gears in his Eaton S/C Marauder.
IIRC Tom has a set of 3.27s in his 8.8".
'PM' Tom to see what he thinks of his gears.

[GreekGod]

Great suggestion, Mr Walsh!...I read some of his posts, and found this:

[I have the Eaton becuse it has more low end torque and my car is set up for it with the T/C and rear gear. Kenny Bell, Whipple, Maugenson are a options and I have allready done a Vortex hair drier with bigger numbers, how much rwhp/rwt do you want and at what rpm do you want it, they all go fast. My rwhp is 404 but rwt is 444 at real low rpm, I had Dennis tune it just for me to give me the grunt at 1000rpm, we did other pulls that had more at 6200rpm but I don't drive at 6200. The stock Eaton is good to 17psi with reliableity declineing after 16psi on a stock Cobra motor, I'm running 14.5psi. All the other blowers will beat the Eaton112 after 3600rpm but till then I'm making more torque and this is where I spend 99% of my time, I got so much grunt and gear that I'm driving around in 2nd. most of the time with "drive" being an overdrive to me. When Dennis had it on the dyno 5000rpm was way over 140mph in third gear. This car feels like a big block for smooth manners in daily driving. BUT you are making me want to do Shamu2 a real killer whale.]

Here is a link to the thread, which pretty much helps convince me I should go with the "extreme" type 2.73 gears!..>>>

http://www.mercurymarauder.net/forums/showthread.php?t=35717

<<<(His brother-in-law had an interesting explanation of why a car with a well matched torque curve, ie:"area under the curve" can perform so well)

[RoyLPita]

How about 3.08s?

[GreekGod]

How about 3.08s?

I should do the math for top speed and the Coefficient of Drag of our cars, with rpm under 6000 (need to know power required, and the "wall" for our chassis). In other words, how much power to go 160, 180, 200...and I wish I knew if the Marauder rear spoiler really works!

[babbage]

I should do the math for top speed and the Coefficient of Drag of our cars, with rpm under 6000 (need to know power required, and the "wall" for our chassis). In other words, how much power to go 160, 180, 200...and I wish I knew if the Marauder rear spoiler really works!


I had heard that 3.08 is a bad ratio for CV & MM cars. Even with a good drive-shaft the resonance was very bad.

I'd think that the 2.73 RAR would be good with a better than stock torque converter, you have an MMC driveshaft in it already? Did you purchase Mad Max from "Sal Manilla?"

Nice ride BTW!

[GreekGod]

I had heard that 3.08 is a bad ratio for CV & MM cars. Even with a good drive-shaft the resonance was very bad.

I'd think that the 2.73 RAR would be good with a better than stock torque converter, you have an MMC driveshaft in it already? Did you purchase Mad Max from "Sal Manilla?"

Nice ride BTW!

Yes, Salvatore Mennella built & tuned the car. I don't know what shaft is in it now, but I will be installing an aftermarket shaft. The lower the numerical RAR is, the lower DS speed is, and the safer it is to avoid a critical speed. That is why Ford sets lower rpm limits with PI's and 3.55's.

[RoyLPita]

According to Ford, The stock driveshaft for the CVPI for that year is an MMX.

What stall converter is in the vehicle?