Dyno Differences Between 4.10, 3.73, and 3.27?

[BCE03]

Has anyone taken a completely stock 2V with stock 3.27 and dynoed it against another stock 2V with 3.73 or 4.10? I've heard you actually lose a few horsepower at the wheels when you switch from 3.27 to a lower ratio like 3.73 or 4.10.

My friend's '01 feels slower with his 4.10s than it did with the stock 3.27, so I can't really go by seat of the pants.

 

[goshia]

In theory 0 HP gain, but I'm testing away to get up to 10HP gain. It still is going to help with quicker times off the line.

 

[tomustang]

The number of teeth.

 

[Mike97gt]

Has anyone taken a completely stock 2V with stock 3.27 and dynoed it against another stock 2V with 3.73 or 4.10? I've heard you actually lose a few horsepower at the wheels when you switch from 3.27 to a lower ratio like 3.73 or 4.10.

My friend's '01 feels slower with his 4.10s than it did with the stock 3.27, so I can't really go by seat of the pants.

every car I ever drove with 4.10's or 3.73's feels faster than a 3.27 car with the same mods.

But yes with 4.10's your drivetrain will be slightly less efficent. but your car will run faster with traction, it's been proven by all the big names in modular racing.

 

[BCE03]

What about trap speeds? Are they giving up 1 or 2 MPH at the finish line for a slight gain in ET?

 

[hognutz]

there is "0" hp gain. any change on the dyno would just be mechanical advantage of one gear over another.

define feels slower. I mean you have to notice first gear is alot shorter. second should pull alot harder.

now I will addmit a gear change is not like adding 100hp but I don't know how you would not think the car is quicker. I mean I only have 3.73's and if I am not carful I am all over the rev limiter in first in a hurry. with 4.10's it is even quicker.

the whole theory behind a gear changer is to get the car in its powerband in all gears quicker. in the 1320 you want to be fairly close to redline in 1:1 gear. so you would gear your car according to trap speed basically.

the only way 4.10's would make your car physically slower is if you left a bunch of rubber at the starting line and your 60' was horrible. other than that it is going to be quicker bottom line.

 

[RoadconeTuning]

in theory tq should be slightly higher from gear reduction...

 

[jstreet0204]

in theory tq should be slightly higher from gear reduction...

Not in theory, torque IS higher with a gear reduction. That's what gears do. One thing to remember though, is that the torque you see on a dyno is calulated by measuring the torque measured at the wheels then deviding it by the final drive ratio.

 

[dustang50]

I don't need a dyno to tell me that 4.10s are the way to go. You'll agree when you get on the throttle...

 

[billfisher]

this isn't another "are 4.10's worth it" thread is it?

i know this isn't one of those. or i'm gonna have to kill someone.

 

[01Steeda]

Actually I think it may be a " do 4.10's effect dyno numbers thread" as in will my dyno read different with a change to 4.10's?

 

[BlackenedSVT]

this isn't another "are 4.10's worth it" thread is it?

i know this isn't one of those. or i'm gonna have to kill someone.

 

[turbomaxx]

So when I install my FRPP 3.73 will it be a noticable difference? I always thought it would but people are trying to tell me it won't make much difference. I don't see how it couldn't???

 

[NitroDuck]

So when I install my FRPP 3.73 will it be a noticable difference? I always thought it would but people are trying to tell me it won't make much difference. I don't see how it couldn't???

Unless you suffer from NBD (Numb Butt Disorder), you'll notice the difference.

 

[timeless2]

So when I install my FRPP 3.73 will it be a noticable difference? I always thought it would but people are trying to tell me it won't make much difference. I don't see how it couldn't???

You'll notice a difference. Whoever doesn't needs to turn in their keys.

 

[squeak93]

No power gains but I know going from 3.27's to 4.30's I almost chit myself the first time. Was a HUGE improvement..... First became non existent w/o tires but still fun. Always nice to pull a hill at 45 in 5th..

 

[bhuff30]

As others said, you will likely make LESS power on the dyno with higher gear ratios (3.73, 4.10, ect). There are 2 effects happening on the dyno.

The first, is that higher gear ratios absorb slightly more power. The teeth are angled slightly more to get the same contact patch on the gears and they just absorb a bit more power.

The other effect is the load on the engine. Higher gear ratios put slightly less load on the engine than lower gears. Similar effect to dynoing in 3rd instead of 4th.

 

[02nightmaregt]

So when I install my FRPP 3.73 will it be a noticable difference? I always thought it would but people are trying to tell me it won't make much difference. I don't see how it couldn't???

Slap them in the face I noticed a huge difference.
OP: I don't know what you mean by "slower?" but its definately NOT slower.

 

[turbomaxx]

Slap them in the face I noticed a huge difference.
OP: I don't know what you mean by "slower?" but its definately NOT slower.

Thank god! I was worried I was wasting money!

 

[02nightmaregt]

The HP won't change, but TQ will.