Gears

[Morpheusgpr]

Would 4.30 gears be a good choice with NA as well as FI of either a SC or nitrous?

What would my rpms be at 80mph and what kind of gas mileage would I get with them?

What else would I need, just a new tune?

What gears are best for strength and noise etc. Should I do 3.73s or 4.10s or keep them stock instead?

 

[99SVTAddict]

Yes, with the right set of tires and the right suspension, 4.30's are great in either case.

I just had the 4.30's installed in my new solid axle....had 4.10's before with the IRS. 4.10's were fun, but I always though it needed more.

As for RPM...not sure, I have a Vipet T56 so mine would be different than yours. My 4.10's made no noise and neither do my 4.30's....although I was told that 4.30's are more prone to whine.

MPG...depends how you drive it. Mine was worse cause I was always on the gas You might want to consider an aluminum driveshaft. Or see if it vibrates with the stock one first....if it does then get the aluminum one. Finally, yes, you will need to adjust the speedo. That's it.

 

[DirtySanchez]

Yes, with the right set of tires and the right suspension, 4.30's are great in either case.

Damn! Beat me to it.

What would my rpms be at 80mph and what kind of gas mileage would I get with them?

Click here for an rpm comparison. Click here for a thread on gas mileage.

 

[99SVTAddict]

Sorry....your just too slow.

 

[DirtySanchez]

T56 + Pro Chamber = not fit

My T56 swap is almost done, but the new cross member sits further back than the old one, and my prochamber hits it. Does anyone here know which other offroad h-pipes do or don't fit with stock headers and cat back?

Edit: Oops, I meant to post this as a new thread and not a reply. I are smrt!

 

[Morpheusgpr]

With the 4.30s whats the top speed?

 

[Morpheusgpr]

Oh and anything I should do to beef it up any?

 

[DirtySanchez]

With the 4.30s whats the top speed?

I would guess around 160ish. You get a bit more top speed with a steeper rear because your 5th gear becomes useful. The theoretical maximum is 180 with 4.30's, but wind resistance will stop you before you reach it.

As for beefing up, you'll want a pinion nose brace. You might also want to consider upgrading to 03 halfshafts. If you're really serious about 1/4 mi times, you can improve traction and drop weight by swapping your IRS for a solid axle.

 

[mikewheels]

I had my '01 on a lift today doing full exhaust and was thinking 3.73s, now after reading this thread I guess not enough? And how much does the average shop get to do a irs gear swap? It looked like a big job compared to solid axle swaps.

 

[Morpheusgpr]

I was told around $450 to do 4.30s in mine.

What do we need to do about the speedo?

ehh 160 mph I guess thats fast enough...180 might even do.

 

[Morpheusgpr]

Oh so far plans are 150 wet shot to get me over 500 lbs of torque and well into 400hp once I get to my NA goal...so 4.30s will still be ok?

Nittos will be in order of course.

 

[Electricgreen99]

My car has the 4:30 gear, and imo if your just racing your car, it's the perfect choice, but on the other hand, if it's ur daily driven car, your making a big mistake, the speedo is off horribly, we're talking about 20mph, and the faster you go the more it's off.....I've had my speedo burried out, and the car was still pulling HARD. The gas mileage is terrible too. That's just my opinion, keep in mind, I hardly race so the 4:30 is way too low for me. If you race it quite often and still want it for your daily car, I'd say the 3:73 is ur best bet. Also, in between shifts, I can hear a big bump in the rear end.

 

[missouri_guy197]

My car has the 4:30 gear, and imo if your just racing your car, it's the perfect choice, but on the other hand, if it's ur daily driven car, your making a big mistake, the speedo is off horribly, we're talking about 20mph, and the faster you go the more it's off.....I've had my speedo burried out, and the car was still pulling HARD. The gas mileage is terrible too. That's just my opinion, keep in mind, I hardly race so the 4:30 is way too low for me. If you race it quite often and still want it for your daily car, I'd say the 3:73 is ur best bet. Also, in between shifts, I can hear a big bump in the rear end.

Get a speedcal and your speedo won't be off anymore...you are putting tons of unwanted miles on your car with the speedo/odometer off like that...

It's only $85 from brothers performance and it will save you some money when you go to sell your car later on...