Top End Speed

[Mike827]

I was wondering how much top end speed will I lose if I install 4.10 gears???

[ImpalaSlayer]

over 9000!

[SC Cheesehead]

IIRC, the rpm difference between the stock 3:55's and the 4:10's is around 10%, so the overall impact of the gear swap on top speed is minimal.

How fast you planning to go? If you're going to exceed 115 mph with 4:10's on a regular basis, you'll want to replace your driveshaft with an MMX unit.

Also, keep in mind that the stock tune is speed governed for top end (around 120 mph or so?), so when you get the tune modified for the gear installation, have the governor disabled.

[musclemerc]

^^^^ What he said!

[Mike827]

I have already had my car dynoed and tuned...the governor was removed. how much is the mmx unit

[burt ragio]

With the gear change from 3:55 to 4:10s you will see a 500 rpm difference. As for gas milage I noticed no change. Unless you plan on running the salt flats I wouldn't be concerned. The gear change will enhances all around drivabilty.

[SC Cheesehead]

I have already had my car dynoed and tuned...the governor was removed. how much is the mmx unit

You've got two options: Used or new.

You can search auto salvage yards for the correct CVPI and pick up one of those. Details on what you'll want to look for are here:

http://www.mercurymarauder.net/forum...=matrix&page=3 (http://www.mercurymarauder.net/forum...=matrix&page=3)

Reinhart sells them, will set you back around $600
http://reinhartautomotive.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=12345&Category_Code=9

There are prolly other sources as well, but that's your ballpark price.

[rayjay]

When I did mine I was concerned at 1st about this too. However, I asked myself how often I make a real high speed run and the answer was install the 4.10s. You won't be sorry. :coolman: Well worth the loss in top end that you really rarely use.

[Vortech347]

Gear wise even with 4.30's you'll never rap out 4th. The cars don't have enough power without a blower.

[knine]

Plenty fast to collect as many tickets as you need. ;)

[FordNut]

With 4.10s it will still go over 145 mph. Fast enough.

[LANDY]

With 4.10s it will still go over 145 mph. Fast enough.
i thought we are not supposed to use 4th gear, to prevent the trans from gong bad.:help:

[Smokie]

I was wondering how much top end speed will I lose if I install 4.10 gears???

This LINK (http://www.race-cars.net/calculators/mph_calculator.html) will give you your answer. A lot of top end questions have been asked over the years, I hope you safely find what you are looking for.

[FordNut]

i thought we are not supposed to use 4th gear, to prevent the trans from gong bad.:help:

Who said anything about 4th gear. But driving in 4th won't hurt anything, it's stomping it and downshifting that kills the trans.

[LANDY]

Who said anything about 4th gear. But driving in 4th won't hurt anything, it's stomping it and downshifting that kills the trans.
i said 4th gear because im doing 129mph on 3rd at 6200 rpm with 4.10s.
i did 147mph with my older vehicle with 4.10s, never done it again.
i have been thinking about putting the 3.55 back on, to just use 3 gears.
not sure how it will affect the 1/4 mile.

[GAMike]

In my previous Marauder I was 140+ N/A in 3rd. The problem was the fuel pump could not keep up. All I know is that the needle was burried. The Banshee is much faster, and much quicker :-):burnout:

[LANDY]

In my previous Marauder I was 140+ N/A in 3rd. The problem was the fuel pump could not keep up. All I know is that the needle was burried. The Banshee is much faster, and much quicker :-):burnout:
stock gears?

[ctrlraven]

You won't ever reach the speed long enough to even worry about it.

My MM did 149 mph around 6300 rpms in 3rd on the dyno with 3.55 gears.

If your's is NA you'll need some space to get to 140 +.

[Vortech347]

Bonneville... Just wait.... I gota get our 01' Cobra in first this year (wife driving) and my car in the 150 club. Then MM is also taking a trip down the salt. I did the 130 club last year and it was awesome and CAKE in my fox.

I'm 99% sure I'll have no problem hitting the 130-140mph speed in the mile with the MM. The only thing that would hinder me is the traction out there.

[juno]

Just to clarify for the milionth time, 4.10's are 3 'steps' up from 3.55's rpm wise. Each stage of lower gears is about a 5% increase in rpm's and torque. (3.55-3.73-3.90-4.10).
So 4.10's are about a 15% increase in rpms. Stock tires and gears in 4th is about 2350 at 80. 4.10s would be about 2650 at 80. 150 would be about 4400/5100.
Don't forget to take any difference in rear tire size into account also.