Guys with 4.10s...

[Jay 02 TA ws6]

How many of you guys daily drive your cars? Do you do much freeway travel? How is the cruising ability effected -- including engine noise and fuel economy by going to the 4.10s? Just trying to get some ideas for the future, and I am trying to decide if 4.10s might be too aggressive for me... I already run LT headers with no cats, so engine noise is already pretty significant at 1800 RPMs... and I do lots of freeway travel so fuel economy is important too.

So it's between 3.73s and 4.10s

Thanks.

[N20LT4Bird]

4:10's naturally aspirated with a 6 speed.......or.........
3:73's with an automatic or with a power adder

Usually this is the general consensus for this question.

[TimeLord]

I have the 4.11s and at cruising speed[60-70 mph] it is about 2100-2300 RPM with the T56.

6th really pulls though.

[wolfdogs]

overall average..i get better mileage with 4:10's than i did with 3:42's. i can put it in 6th at 60mph...fith at 45.......

granted..it run the lt4 hot cam and some other stuff..but i get 26 to 28 open road....... thats not too bad, now is it?

[Jay 02 TA ws6]

Originally posted by N20LT4Bird
4:10's naturally aspirated with a 6 speed.......or.........
3:73's with an automatic or with a power adder

Usually this is the general consensus for this question.

So since the plan is to eventually go with a supercharger, and a cam with a much higher redline, but stay with the 6-speed... you'd say go with 3.73s... ?

Ken -- you still get 26 to 28 mpg highway? Wow...

[N20LT4Bird]

When I run N/A, I have some RPM left over when I am running through the traps. When I hit the nitrous, I am running through the traps @ around 6500 RPM in 4th gear. I am running a 3:73; any steeper and I would have to shift again before I finished the 1/4.

I dont really understand why this is (maybe someone can chime in), but if your running a power adder, you might want the 3:73's. But, then again, if you go to a blower, you may need a 12 bolt out back (like I do).

[Jay 02 TA ws6]

Originally posted by N20LT4Bird
...any steeper and I would have to shift again before I finished the 1/4...

Or go with a cam that allows for higher revs, right? This is what I am debating between... no matter which ratio I go with... I will be sure to go with a cam that won't force me to shift into 5th gear.

[N20LT4Bird]

Yea, but you can only get so many RPM's out of a small block and still have the lower end grunt for the street.

[wolfdogs]

most of the fast folks i know running boost or Nstuff get 3:73's with a six speed. the 4:10's are just too squirley.....

[wolfdogs]

Originally posted by Jay 02 TA ws6
So since the plan is to eventually go with a supercharger, and a cam with a much higher redline, but stay with the 6-speed... you'd say go with 3.73s... ?

Ken -- you still get 26 to 28 mpg highway? Wow...

yup..if i keep a feather foot...and cruise at about 72-75 mph..i get unreal mileage.....in 6th of course......

ive actually used 6th at 55mph on flat roads....

[M3EATER - GG '00 WS6 T/A]

Originally posted by N20LT4Bird
I dont really understand why this is (maybe someone can chime in), but if your running a power adder, you might want the 3:73's. But, then again, if you go to a blower, you may need a 12 bolt out back (like I do).

The Power adder ...

Oh .. sorry... Hi guys....!

Anyway, the power adder increases the torque so you don't need the extra torque multiplication from lower gears. In fact, with the power adder it's better to NOT have all that gear multiplication so the engine torque doesn't so easily overcome the traction available at the tires.

The extra torque from the power adder will allow the taller gear to then pull at a better RPM through the traps too.

Umm... I think ....

Gordon
PPC
www.provenperformanceconcepts.com