Taller gears for forced induction

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01-19-2006, 01:54 AM

#11

StickShifty

5th Gear Member

Join Date: May 2005

Location: New Jersey

Posts: 4,536

RE: Taller gears for forced induction

Quote:

ORIGINAL: JD1969

Quote:

ORIGINAL: StickShiftyGT

its pretty much because you will be more able to spin the tires with the gears.

This is a myth and is misinformation that I see on here all the time. If your spinning you need to get your suspension dialed in and run the proper tire. To answer the question; it has more to do with forced induction having a lot of torque and being able to turn that high easier. There are still lots and lots of people who run 4.10 and lower geras in a turbo/blower/n2o car, they just have specific performance goals in mind and a combination that calls for that gear in particular.

i was talking about a stock setup, you kinda read into it alittle.

a car with 430s, a blower pushing 25 psi, the right setup and a driver who knows what hes doing can get that car to hook like Velcro. and run a amazing 60' time.

01-19-2006, 02:20 AM

#12

Fallstar01

4th Gear Member

Join Date: Aug 2004

Location: Philadelphia, PA

Posts: 1,654

RE: Taller gears for forced induction

Quote:

ORIGINAL: StickShiftyGT

its pretty much because you will be more able to spin the tires with the gears.

uhh, not quite.

It's because you'll run into overdrive before the end of a quarter mile (or shift an extra time in the 1/8th...)
Shifting costs you time whether you're in an automatic or a manual so keeping it to a minimum, while making sure that you're not getting stuck below your powerband after a shift, is vital to performance.
With a manual, you want to be able to finish a quarter mile right at the end of 4th (or third with an auto) without ever having to shift into 5th. Larger tires will give you a little breathing room if you're close but they won't make up for an extremely short final drive gear.

Many unboosted guys finish the 1/4 in the high 90s, low 100s... many boosted guys finish at 110s, 120s, and beyond.

If you have traction issues with the proper gearing, that's really up to you to control the throttle or get better tires.

01-19-2006, 03:25 AM

#13

Dark_Horse

3rd Gear Member

Join Date: Oct 2005

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Posts: 850

RE: Taller gears for forced induction

i think that on a turbo car should have taller gears because it is under boost longer and the load will help the turbo spool faster

01-19-2006, 09:28 AM

#14

nanaki

Retired MF Moderator

Join Date: Aug 2004

Posts: 14,891

RE: Taller gears for forced induction

Quote:

ORIGINAL: Dark_Horse

i think that on a turbo car should have taller gears because it is under boost longer and the load will help the turbo spool faster

the same logic should be used for a centrifugal supercharger too

everybody assumes that ALL superchargers have power right off the line.

01-19-2006, 03:34 PM

#15

Birdieman4

5th Gear Member

Join Date: Oct 2003

Location:

Posts: 3,020

RE: Taller gears for forced induction

Quote:

Turbochargers, on the other hand, are exhaust driven, and come up to speed very quickly (almost instantly if properly sized), and will reach the same 8 lb. peak boost level as low as 2,500 rpm. The result is much more horsepower and torque being produced earlier at lower rpm levels with a turbocharger vs a centrifugal or roots supercharger.

thats from turbochargedpower.com
still don't see why you would need diffrent gears

Not necessarily. As a matter of fact, a positive displacement blower, on sheer principal of being belt driven vs exhaust driven, will bring on torque and hp faster than a turbo set up. As a matter of fact, it's not even debatable. turboshargedpower.com needs to stop confusing people, trying to sell turbos.
Fallstar touched on this above, but you really have two separate sets to consider in a boosted car. Street and track. For the track, as long as you can hook up, 4.10's could help maximize your performance. But, on the street, what's the point of having a fast car if it spins all the time. The whole point of doing short gears is to pick up a slight amount of acceleration. How can you pick up any acceleration if you're spinning? If you aren't at the track racing, I see essentially ZERO logic to doing 4.10 gears in a boosted stang.