If you go from a 2.76 gear in a a4 coupe to a 3.42 gear what it that equal to in horse power. A rough est. Here what I was debating. C.A.I, Hi flow cats, X pipe , cat back is what i know that I'm doing. Now money becomes a factor or I would just do every thing. With those mods would I benifit more from adding an Intake and headers or gears? I know I'm covering a lot a ground here any help would be great,or other combinations

 

Adding gears does not give you HP.

A CAI will give you about 5 -7 RWHP, a good set of headers and exhaust is good for 30RWHP.

Gears will improve you acceleration response.

 

If SOTP acceleration is what you are looking for, then go with gears and a higher stall torque converter. It will be quicker then a cold air intake and headers.


Clayton from Las Vegas

 

Roughly about 75 hp.
Gears and converter is the most bang for your buck period!

 

What is that estimate based on??!?!??!?!!!

Keith

 

You will lose hp with a gear upgrade. Not much, only about 5hp or so, due to higher drivetrain losses. Don't let that frighten you though, gears are the best, most usefull upgrade for autos with a 2.73 diff. If you just want fun, tire-ripping acceleration, gears are where it's at.
Higher number gears spin the tires slower, but increase torque at the wheel. So be prepared for traction issues. Just to summarize, gears make the car "feel" faster, but its not really that much faster, since the powerband has just been shifted. The high stall is the last piece of the puzzle. Adding a high stall TC, along with the gears should take ~.5sec off the 1/4. Very few mods could do this for the same amount.
The Vararam CAI intake (IMO) is the best and has shown the most gains. Most people only see 5-10hp on the dyno (if that), but most also concede the Vararam takes .4sec off the 1/4.
Headers increase power, along with a good tune. Very nice sound. Adding headers and a loud cat-back can be over-the-top loud.

So for everyday driving, I'd go with the Vararam/gears and TC first. You'll realize that more than anything. I'd do the cat-back just for sound.

Next up would be the headers. Do the x-pipe/cats same time as the headers since many are a matched set and you won't have any fitment issues down the line.

 

Most bang for the buck would be nitrous.........not a big fan of it myself, but you can't deny 150hp for ~500. Can't even buy a decent TC for less than 500.

Are you saying that gear and TC upgrades would be equivalent to the same car with 75hp more? I think that's pretty steep.

 

As far as I know gear mesh efficiency has nothing to do with ratio. Unless you change AGMA quality level or the types of bearings supporting the gears there will be no difference in power loss. You will simply increase torque at the rear wheels which translate to SOP feel.

 

You seem to be contradicting yourself. I disagree that gears don’t make the car much faster. 0.5 sec is significantly faster, especially if you’re the loosing car. I do agree that the Vararam is the best of the CAI on the market. At speed, you can feel the difference, as most users will attest to.


Thanks,

Clayton from Las Vegas

 

I agree 150hp for ~500.00 would be fantastic if it were truly the entire cost.
However I have not seen that in a very long time, if ever.
Just how much hp do you think it will take to make a 3200 lb car ~.5 sec quicker in a 1/4 mile?
Besides he asked for a rough est. so I gave him one, something no one else did.
JMHO

 

3.42 would be the equivelent of adding about 60hp to your car.

I think he is looking for a comparison, he knows that a gear does not logically add HP to a car.

 

Yea, that is what i was trying to ask. If I could get the same performance by adding 60 hp worth of bolt ons, as I would from changing to a 3.42 gears ,then i rather go that route and keep my fuel economy up. Plus I get to say I have a 400+ hp car.

 

Better yet, if you race and win, you can say “your car is stock and that something must be wrong with your car”


Clayton from Las Vegas

 

I just completed a 3.42 gear/3200 stall TC/Header install on my wife's 2.73 A4 and it is significantly faster. We just got past the TC break-in period last night. I did a few WOT runs on it and was impressed with the improvement in acceleration. It chirps the tires 1-2 now and definitely is much faster than before the swap. Here's a thread of my install.

http://forums.corvetteforum.com/show....php?t=1753571

Mods prior to this were Blackwing and TI exhaust.