4.10 Performance at Various Speeds

[Ross]

OK, I have decided that I need a 4.10 rear end. Like we all know, all the mods in the world won't make this two ton beast hot off the line without the 4.10. I've read a lot of posts about this, and I know that the accelleration from a dead stop should improve drastically with the 4.10 and a chip programmed for the new gear. What about accelleration at other speeds? If I'm going 30, or 50, or 70, either in or out of OD, how will the 4.10 change my performance when I hit the gas? Or will it only make a noticeable difference from a dead stop, and not matter that much once I'm out of first gear? As always, Thanks. Ross

[darebren]

I find I can still pass anybody with ease. The 4.10 probably hurts a little, but since all cars slow down anyway as I approach from the rear (thinking I'm the fuz), I glide by with ease. The few times I've nailed it on entrance ramps, it's downshifted, RPM's up in the high range, and neck snap freeway entrace is initiated.

[CRUZTAKER]

I can't be sure yet, as my chip is not back from re-programming....but as it is now, I noticed a WOT at say 70 mph or so isn't as effective. This could be very well lack of programming, so take my advice with a grain of salt.


Ross: I love the sig. under your name....Houston, R.O.T.

That's great :lol:

[MN6]

I actually like the way the car accelerates with the 4:10's from both a Stop and on the road. Now keep in mind that I have other mods and my TC is locked at 1500 rpm's. The Locked TC has really made the most difference in driveability. The 4:10's round out the car and make it feel smaller and lighter than it is. My 2 cents.

[drkknight196]

I'm running the 4.30 gears and can say unequivocably my rate of acceleration is by far better across the spectrum. Most noticeable 0 - 70 (leaves about 12" of rubber on road between 1st and 2nd gear when WOT in "D"!), but trust me, from 70 to at least 130 mph it's pulling hard!!

[CRUZTAKER]

My chip cometh home!!!!!

Now I'll know the rest of the story.

[merc]

Originally posted by drkknight196
I'm running the 4.30 gears and can say unequivocably my rate of acceleration is by far better across the spectrum. Most noticeable 0 - 70 (leaves about 12" of rubber on road between 1st and 2nd gear when WOT in "D"!), but trust me, from 70 to at least 130 mph it's pulling hard!!

I wonder what's the differance between 4:10 and 4:30. I can leave rubber in 1 and 2 gear and almost snap off your neck.

:banana2:

[Reaper948]

I don't know guys.......I really like going from 70-100.......4.10 right for me?

definitely not sure.......wouldnt that hinder quarter-mile then?

[schuvwj]

Originally posted by drkknight196
I'm running the 4.30 gears and can say unequivocably my rate of acceleration is by far better across the spectrum. Most noticeable 0 - 70 (leaves about 12" of rubber on road between 1st and 2nd gear when WOT in "D"!), but trust me, from 70 to at least 130 mph it's pulling hard!!

drkknight196 now that you had the 4:30 gears for a while do you still recommend them?

I would really like to by some 4:30's but I still have drivability concerns. Can you cruse at 70-75 mph and what would be your RPM?

Thanks for your help!

[ghost]

The acceleration advantage of gears falls off after 60 m.p.h. or so.

It will improve your quarter-mile ET, however.

Eric

[Marauderman]

My .02 cents worth----how to you spell R-O-C-K-E-T.....I'm happy----eager to Feel TAF's under's though.......

[duhtroll]

And once again my pendulum swings back.

I'll probably go back and forth at least three more times on this. BUT (and please forgive the rehashing of this yet AGAIN)

I was CERTAIN I wanted the 4.10s when I did mods (waiting until 36000 which should be next year as much as I drive). I wanted to be sure that I was faster than all Pontiacs (new GTO notwithstanding) and those Mustang GTs. For the few times I was cruising University Ave (rare) I wanted to be able to show those dang kids (no offense to our younger MM enthusiasts here, of course :) ) who the boss really is around here. :)

HOWEVER . . .

Now I am thinking just chip, plugs, stat since 95% of my driving is hwy. If better passing acceleration, perhaps better MPG, and quieter hwy driving due to lower rpms is a result of keeping the stock gears -- to say nothing for being sure there will be no problems with them since I will not be changing them -- I am now leaning towards not doing the gears.

I need some help. This can be done via PM since I know there are some who are already tired of this discussion. But --

Can someone estimate how much one can expect to gain on the 1/4 mile ET from the 4.10s? We have already been thru MPG and I would sacrifice .2 MPG or so for them, but really want to know if the time shaving is worth it for someone who is not going to race much, but rather wants a badass highway machine that can occasionally spank them dang kids (again no offense).

Thanks again for any help offered. PM replies please to spare the board if ya like. :)

-A

[ductman]

Do the gears, the car is very drivable on the highway and if you are really worried about 1-2 MPG you should have bought a YUGO.:burnout:

[kj31067]

apparently i m missing three years worth of thread material

[duhtroll]

Uh, I've had 4.10s for years now.

And the drop was more like 4 MPG, so it was more significant in my case than in others.

So as you can see my concerns were well-founded, and this is a really, really old thread. :rolleyes:


Do the gears, the car is very drivable on the highway and if you are really worried about 1-2 MPG you should have bought a YUGO.:burnout:

[Breadfan]

The real point is for a good scientific comparison of the following items:

Rear gear ratio

Transmission gear ratios (all of them)

Power curve (by RPM)

Then you'll see how each rear gear will react throughout the acceleration range. It's entirely possible due to transmission gearing that a certain gear will perform better than others in one gear, but maybe a bit worse in another.

Right? Or am I totally missing the point?

At anyrate, one thing I wish we could do was design our own tranmission gearsets based on what you want...want drag racing you select certain gears based on your power curve, want road racing, get a different setup that keeps you in the rev's.

I just think that sure we can change our rear ends, but we lose flexibility in having 4 more gears ahead of that which we cannot change, so keep that in mind when choosing a rear end ratio.

[Rider90]

When I switched from OEM 3.55s to 4.10s my car performed better from a stop, and better from third gear at 70 MPH. No doubt in my mind about that. Performance was better all around.

[Vortech347]

3.73's here. People say "no difference" BS! Cruising at 80mphish has the tach at 2500. 4.10's would have it at what 2800? Top speed and top end charge will absolutly be stronger with 4.10s at any mph. You're keeping the car in its powerband more effectively. Thats why TQ converter swaps on these cars are such a great improvment!!! 1-2mpg? Since my 3.73 swap and DR tune if i granny a tank I get 270ish before the light comes on. Before stock with 3.55's I'd get 295-300

[Rider90]

What is an mpg?

[JACook]

What is an mpg? Apparently some model of Yugo... :D

[ductman]

3.73's here. People say "no difference" BS! Cruising at 80mphish has the tach at 2500. 4.10's would have it at what 2800? Top speed and top end charge will absolutly be stronger with 4.10s at any mph. You're keeping the car in its powerband more effectively. Thats why TQ converter swaps on these cars are such a great improvment!!! 1-2mpg? Since my 3.73 swap and DR tune if i granny a tank I get 270ish before the light comes on. Before stock with 3.55's I'd get 295-300

MPG=miles per gallon... 270 miles from 19 gallons(tank size) is 14.21 MPG with gears and 300 miles from 19 gives you 15.79 stock. That is a 1.58 MPG difference for 3.73s...for 4.10s maybe say double it so we'll call it a 3 MPG difference. Yes it is an old thread, but it is still very relevant for anyone that is thinking of gears, the search engine does not discriminate. ...I hear they are having a sale on Yugos:pimp:

[duhtroll]

Yeah, I'm apparently really worried about it. :rolleyes:

There's a difference between having accurate data and changing your mind as a result of the data. If you had done any more reading of old threads, you'd know that most who had done the gear swap were claiming no mileage loss, or much less than in actuality. My point is that numbers don't lie. You trade speed for efficiency.

Also, in the three years since this thread had been active my needs/wants for the car changed, which is why you shouldn't really be commenting on things over 3 years ago as being current thought, 'cause they aren't.

You're correct on one point -- the search engine doesn't discriminate. That's why people are supposed to be able to read.


MPG=miles per gallon... 270 miles from 19 gallons(tank size) is 14.21 MPG with gears and 300 miles from 19 gives you 15.79 stock. That is a 1.58 MPG difference for 3.73s...for 4.10s maybe say double it so we'll call it a 3 MPG difference. Yes it is an old thread, but it is still very relevant for anyone that is thinking of gears, the search engine does not discriminate. ...I hear they are having a sale on Yugos:pimp:

[StevenJ]

If you're only getting 270 per tank, even with 4.10s you must be driving way too hard or nothing but stop and go! Sometimes I get that low but if you ease up on the gas, you can pull 300+ per tank.

[Pat]

What about accelleration at other speeds? If I'm going 30, or 50, or 70, either in or out of OD, how will the 4.10 change my performance when I hit the gas? Or will it only make a noticeable difference from a dead stop, and not matter that much once I'm out of first gear? As always, Thanks. Ross

Ross, I do a few trips a year from 200 to 600 miles (one way) and I've experienced improved acceleration at the speeds stated in your post.

I have more confidence in passing cars using shorter distantances than with the stock 3:55 gearing. When I elect to pass and hit the pedal I'm at 90 MPH before I know it and let off the gas and coast around the traffic.

The improved performance is very noticeable, to me, at highway speeds, the RPM is at 2500 @ 70 MPH and my economy is about 22.4 w/AC on in hot weather.

I'm very pleased since going to 4:10's.

Pat

[BigCars4Ever]

I had an 03 with 3.55's and averaged 22mpg with about a 50/50 mix highway/city. That same commute with my 04 and 4.10's and I average 19.5mpg. If I keep my foot out of it and cruise most of the tank with hwy I can hit just under 21mpg but never better. The 03 hit a max of 25mpg under the same conditions with the 3.55's

[Vortech347]

When my light comes on I usually fill 15.5-16ish in fuel. NOT 19. If the Merc got that kinda mpg it would be gone. I literally saved around a hundred bux a month going to the merc from my exploder 5.0 that did 12-14mpg.

[Donny Carlson]

June 9, 2003!!

http://mysite.verizon.net/resog5vy/sitebuildercontent/sitebuilderpictures/shermanpeabody.jpg

"Yes, Sherman. If this thread were a dog turd, it would have turned into white dust by now."

[O's Fan Rich]

I likes my 4:10's.
I likes my Trilogy.
I gets 16-17mpg around here with frequent playtime. I likes that.
I gets 22.8 mpg on the highway ( after Lidio dyno tuned it). I likes that, too.
This thread reinforces my belief in a resurrection. That's a good thing.