1 quick general question.

[phoenix99]

What is the best gear ratio to use in a '99 3.8 firebird for quick quarter mile times?

[Devilboy28]

4.56 :D

[phoenix99]

If I want to use the car for going to work school etc would the 4.56 be OK? I see you have 3.73...are these better for street use?

[96_V6_Fbody]

4:56 is really low especially if you plan to do any highway driving. That will kill your gas mileage.

[John D.]

Most people like the 3.42's. They are a good middle point between acceleration and cruising. Some like 3.73's, they will get you out of the hole quicker but your engine will rev higher while cruising.

Either one will require a PCM flash.

[phoenix99]

this might sound stupid, but I'm a beginer: what is a PCM flash?

[Fabian3679]

Do you have to get a PCM flash if you drive a M5?

[zlexiss]

Eh, I'd hate to shift that much for just a quarter mile..

<blockquote>quote:</font><hr>Originally posted by Devilboy28:
4.56 :D <hr></blockquote>

[SixBanger]

4.56??!! thats crazy for the type of driving you will be doing. I will go with 3.42, but no more then 3.73.

[Red V6 Raider]

<blockquote>quote:</font><hr>Originally posted by phoenix99:
this might sound stupid, but I'm a beginer: what is a PCM flash?<hr></blockquote>

PCM Flash is just reprogramming your computer for your new gears so speedometer and shift points won't be off.

Fabian3679, for manuals, you can get it flashed but just for the speedometer to be correct. But you could get a HPP3 to fix the problem.

[Devilboy28]

4.56 was a joke guys. I would like to ride in a 4.56 geared F-body though. 3.73s are as low as I would go for street use. I still have PLENTY of top end, and great acceleration. Gas mileage is still good also.

[phoenix99]

thank you to all you guys that posted replies! I just got on this website a few days agao and have gotten a wealth of information. Now being so armed I feel I'm ready to start doing some really good mods on my car. I'll keep everyone posted: thank's again!

[Riles]

I just thought I'd chime in with 3.73's or 4.10's.

I installed my 3.73's beccause I was afraid of 4.10's, but it turns out that I was just being an idiot. My mileage went up (I gained 3 mpg on the highway) with the gear swap, and its plenty quick. I only wish I got 4.10's.

Also, instead of getting a PCM flash, or an HPP3, you can buy a recalibrating device for $90-$120 that will correct your speedo for you. Its the ceapest and simplest way I know of.

But you are thinking right- gear swap=fun.

[BATMAN]

i have 3.42s Ive heard opions on both 3.42 and 4.10s it really depends what your looking for. I think the 4.10s are going to give you more torque and less HP. Pretty much from what i've read here the 3.42 is the best of both worlds. its right there between 3.08 and 4.10.