Gears of Choice!!!

Which Gears do you have???? Prefer? Why???

  • Total voters
    45
96_Lincoln_LSC said:
OK looking at your pic, How many RPM's do you get with a run of 100 or 110MPH?
Is the top end going to be really that bad? I cruise to work on the PA turnpike @ 80-85MPH and I was taking not that I was sitting around 2700 I have the LSC and Run 3:27's going to the 4:10's which I am pretty sure I'm gonna do, what RPM can I look for running the same speed. Lets just say on a clear road I've cruised @ 100-110MPH.. Am I going to be close to the threshold for the car with the 6K redline?

Thanks

PS.. Geno, do you know a reputible person to install the gears as I have never built my own rear... Approximate cost involved to have the rear assembled..?
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If you have stock diameter tires then you will be at 4040RPM @ 110 MPH with 4.10 gears.
 
Ok maybe I'm nuts but that seems quite high for highway driving.

I remember switching my Ford Focus from the 3.82 final drive ratio to 4.06 and I absolutely HATED the car after that. I couldn't get rid of it fast enough. I was at like 3500rpms or some ridiculous number at 80mph. So is that basically what happens when you up your gears that much?

I don't care about the mileage aspect, but engine wise wouldn't driving for prolonged times at a higher rpm like that more damaging or demanding on an engine resulting in quicker wear on the whole drivetrain?

Another thing I've been curious of is why I don't see aluminum flywheels for our cars. I don't exactly understand auto transmissions. Do they have a flywheel like a manual? I know it's a dumb question but I do not understand even remotely how an auto transmission works. Wouldn't lightening the drivetrain components like the flywheel and driveshaft be safer and better for our land yachts? My Mustang really changed from a roll with a aluminum flywheel.

Man I need to find someone local that has 4.10's or 3.73's. I'm curious how it really is in person.
 
ONEBADMK8 said:
Man you Gen 2 Guys run HOT!!!! I thought it was 2650. Ill put my new tach module in and see, my tachs been broke for 4 years now.
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Not really. I think they are dummy guages. They go up to there and never moves up or down until you let the car sit for hours.

My 94 will actually move like the temp is fluctuating, in town / highway / stop and go, etc... Gen 2's dont do that.

Pic is with 4.10's in OD.
 
LaserSVT said:
Rich88LSC: In third gear with the stock tires and 4.10s the car would only go 125mph at 6500 RPM.
In 4th you could do 150 @ 5500 RPM.
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Good catch. My mistake

LaserSVT said:
I am going with 3.73 because I would rather be at 2500RPM @ 75 MPH then 2750RPM with the 4.10s
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I am not going to argue but i really just don't understand the logic. We are talking 250rpm at 75mph.

ripped camel said:
Ok maybe I'm nuts but that seems quite high for highway driving.

I remember switching my Ford Focus from the 3.82 final drive ratio to 4.06 and I absolutely HATED the car after that. I couldn't get rid of it fast enough. I was at like 3500rpms or some ridiculous number at 80mph. So is that basically what happens when you up your gears that much?
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Again I don't get the logic. That is less then a 10% difference. If you were turning 3500rpm at 85 with 4.06s then you would still be turning almost 3300rpm with 3.82s.

ripped camel said:
I don't care about the mileage aspect, but engine wise wouldn't driving for prolonged times at a higher rpm like that more damaging or demanding on an engine resulting in quicker wear on the whole drivetrain?
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Technically yes but the old adage that most wear occurs during startup and while outside normal operating temp is true. Cruising a few hundred rpm higher is not going to do much even in the long term.


ripped camel said:
Another thing I've been curious of is why I don't see aluminum flywheels for our cars. I don't exactly understand auto transmissions. Do they have a flywheel like a manual? I know it's a dumb question but I do not understand even remotely how an auto transmission works. Wouldn't lightening the drivetrain components like the flywheel and driveshaft be safer and better for our land yachts? My Mustang really changed from a roll with a aluminum flywheel.
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Auto equiped cars have a flexplate. They are usually thinner and lighter then a flywheel as it only provides a connection from the crank to the TC.
 
ripped camel said:
I don't care about the mileage aspect, but engine wise wouldn't driving for prolonged times at a higher rpm like that more damaging or demanding on an engine resulting in quicker wear on the whole drivetrain?

Another thing I've been curious of is why I don't see aluminum flywheels for our cars. I don't exactly understand auto transmissions. Do they have a flywheel like a manual? I know it's a dumb question but I do not understand even remotely how an auto transmission works. Wouldn't lightening the drivetrain components like the flywheel and driveshaft be safer and better for our land yachts? My Mustang really changed from a roll with a aluminum flywheel.

Man I need to find someone local that has 4.10's or 3.73's. I'm curious how it really is in person.
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If your talking phyisically, yes it will cause quicker wear on the internals. If your talking REALISTICLY, Your never gonna notice it. If anything the higher gears are eaiser on the engine because your using less power to move it off the line.


http://auto.howstuffworks.com/automatic-transmission.htm

The link takes you to a site that does a VERY good job explaining the workings of an auto trans.



Not too many people deal with this situation in a MarkVIII, but I have found that a heavier flywheel helps get my barge off the line a bit quicker than an aluminium unit. (more stored inertia ready to be transfered to the wheels.) Out on the highway, Yes, a lighter wheel will help. It's all about where you use the car.
 
Had 3:73s in my old MN12 Thunderbird, enjoyed some improved 1/4 mile times after the gear change. All depends on what you're going to run them for.
 
ONEBADMK8 said:
Thats another reason people cannot comprehend my average at 19.3, its all because you use less pedal to get moving.
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I get that. It takes less engine effort to get you out of the hole so the steeper the gear 3.73 to 4.10 to 4.30 etc, the better the city gas mileage. However highway gas mileage would go down at the same time that city goes up.
 
Some people mistakenly think 2750 to 3000 rpms cruising is too high.

These engines redline at 6000 and many people spin them to 7000 rpms. This isn't the old pushrod technology where redline was significantly less.

Usually the most efficient rpm determined by Brake Specific Fuel Consumption for a typical gas engine is around 58-63% of maximum rpms which puts it well above 3000 rpms for a 4.6L DOHC. BSFC is typically highest at peak torque but is dependent upon load. BSFC typically falls faster at higher rpms above peak torque and falls much slower at rpms below peak torque resulting in a maximum mean BSFC several hundred rpms below peak torque. So while the peak torque may be at 75% maximum rpms, the best BSFC is likely at 60% maximum rpms.

Technically, you're 'lugging' the engine in OD at most legal highway speed limits for the sake of a couple miles per gallon. You notice this most when cruising at highway speeds and you need to accelerate. Once you properly address possible NVH issues in the drivetrain at higher rpms, I think the Mark VIII is much happier with higher gears. ;)
 
for the little mod the car got might as well go with 4.10 and some jiuce.....how does your car stay that cool........its like you just started the car up


ONEBADMK8 said:
Dude had them 12 years will never look back. No top end Froggy? LMAO Come take a ride son.:D Dont know when and where you "Lose" top end with 4.10's. Ill take it to the grave with me 4.10's all the way baby!

I do 75 mph at approx 2650 and get 27.2 mpg. Also why on Earth would gears make you "rip your trans" out more frequently? LOL?

Your more then welcome to come by for a "test drive" so I can show you what your MISSING anytime just give me a heads up.

Even at 150 I get 24.5! LOL!
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flyin.jpg
 
That really didn't make a big a difference as the tstat did. The Griffin was maybe 5% cooler if that.
 
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94m5 said:
The 03' Cobra Radiator works very well. I have one in the 94'.
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Good to know! I dont have any temp problems now but when my rad does fail then I will do a 03/04 Cobra and a 160 T-stat.
So I guess in theroy since the car will run 20-30* cooler you could add another couple degrees of timing?
 
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