which is quicker 4.11/4.44?

[sicksubie]

I really don't know trannies that well. From those SVX'ers that have done conversions I want to hear the good the bad and the ugly. Also which is better 4.11 or 4.44? I will hopefully be doing a lot of work over christmas break on my SVX. A tranny swap is one of the things that I was planning on doing

[SVXRide]

Everything else being equal, the 4:44 will accelerate faster - which should result in a faster 1/4 mile time (guess we'll see this weekend - right Tom/Chike?).
-Bill

[Chiketkd]

Originally posted by sicksubie
I really don't know trannies that well. From those SVX'ers that have done conversions I want to hear the good the bad and the ugly. Also which is better 4.11 or 4.44? I will hopefully be doing a lot of work over christmas break on my SVX. A tranny swap is one of the things that I was planning on doing

Which is better? That really depends on what you want.

Driving like a raped ape on the highway (90-110mph), Svxfiles gets about 19.5mpg in his 4.44 geared SVX. During similar driving when I was coming back from Richmond behind AmazonParrot, I got 23.5mpg in my 4.11 geared SVX (in regular 75-80mph highway cruising I get 25mpg, around town 21-22mpg).

4.44s are the best gears to get if your want to race your SVX heavily. However, I feel 4.11s offer the perfect trade-off between increased performance and everyday liveability. Just think on a stock car with 4.11 gears, I went 15.3 in the 1/4 mile. Road & Track got a 15.2 for a 4spd auto WRX wagon - which is not bad company to be in...

Originally posted by SVXRide
Everything else being equal, the 4:44 will accelerate faster - which should result in a faster 1/4 mile time (guess we'll see this weekend - right Tom/Chike?).
-Bill

We shall definitely see. Based on his g-tech testing, Tom should win by a lot, but I'll make sure my car gives a good show out there... Either way, by the end of the day, I can almost guarantee that the first 14sec SVX pass in an awd model w/ a 4EAT will happen!

-Chike

[svxfiles]

Driving like a raped ape on the highway (90-110mph), Svxfiles gets about 19.5mpg in his 4.44 geared SVX.

Sir, I most heartily dissagree. It was 85-105, and we actually got 21.9 mpg.

Closed course, professional driver, do not try this at home boys and girls.

[Chiketkd]

Originally posted by svxfiles
Sir, I most heartily dissagree. It was 85-105, and we actually got 21.9 mpg.

Closed course, professional driver, do not try this at home boys and girls.

My bad. Do you get 19.5 mpg around town then?

Ahem - definitely on a closed course with a professional driver!

-Chike

[svxfiles]

Normal driving, short eight mile commutes, with a four mile highway run, with a 4.44 gearset, 3000 rpm gives a true 75 mph. On normal city driving, it shifts out of first too fast, just like it did with the 3.545s.
With a 4.11, all of the ratios are 16% off the stock transmission, 16% more rpm, and torque in every gear.
With a 4.44, its 36% more in first, 31% more in second, and 25% more in third and fourth.
Evan before I swaped to an (Legacy) Outback transmission, my gas milage was five mpg less than Green_Eyed_Lady, same gas, both 92 SVX LS-Ls, similar commutes, different driving styles.
If things go well Saturday, we will all learn something.

I was very recently suprised that my two inch shorter tires (205/40/16s) gave a slightly slower speed in my G-tech 1/4 mile runs, compared to my 225/45/17s. The only explanation that I can figure is that the 17s weighed 3.5 lbs per wheel LESS than the stoch 20 lb wheels. The tires weighed the same. Tom

[svxfiles]

Usually 18 mpg around town, it was 16.6 mpg when I had the tps adjusted to .56 volts. Now, after testing .5 volts seems to work best.

[Chiketkd]

Tom,

after you adjusted my tps last Saturday, I checked my fuel economy on the rive back home. I got 25.21 mpg driving between 75-80mph on the interstate.

-Chike

[Myxalplyx]

Originally posted by svxfiles
I was very recently suprised that my two inch shorter tires (205/40/16s) gave a slightly slower speed in my G-tech 1/4 mile runs, compared to my 225/45/17s. The only explanation that I can figure is that the 17s weighed 3.5 lbs per wheel. Tom

Hi Tom,

I just wanted to be clear on a couple of things. When putting up your tire sizes on the miata tire calculator site (http://www.miata.net/garage/tirecalc.html), the 17s had 808.0 revs per mile while the 16's had 898.0 revs per mile. That's a huge difference. Are you sure the weather temperature and everything was pretty much the same?

Also, the 17s weighed 3.5lbs per wheel? Do you mean the 17's weighed 3.5lbs per wheel lighter than the 16s or just that the 17s weighed only 3.5lbs each? If you are saying they weigh only 3.5lbs a piece, that's .....that's......well...I'm speechless. I'm sure I'm reading into it wrong though.

[Chiketkd]

Originally posted by Myxalplyx
Also, the 17s weighed 3.5lbs per wheel? Do you mean the 17's weighed 3.5lbs per wheel lighter than the 16s or just that the 17s weighed only 3.5lbs each? If you are saying they weigh only 3.5lbs a piece, that's .....that's......well...I'm speechless. I'm sure I'm reading into it wrong though.

Kevin,

Tom used the stock SVX wheels when he ran the 205/40/16 tires. The 17" Locos he bought from Dayle weigh ~17lbs each.

-Chike

[Chiketkd]

To answer the main question posed by this thread - after doing the g-tech test-n-tune this past weekend - 4.11/4.44 gears are about even.

Here's why.

The modified 4.44 gears in the Legacy Outback have shorter 1st and 2nd gears - 3.027 and 1.619 respectively. This causes a car with these gears to get through the first two gears extremely quickly and shift into third gear (1.000) at around 67mph @ 6500rpms. Third gear is good to over 105mph, so basically a 4.44 geared SVX runs the 1/4 mile in third gear for a significant portion of the 1/4 mile run.

4.11 gears use the same gearing as the factory 3.55 gears, and the shift to third occurs at 76mph @ 6500rpms. The 4.11 geared SVX therefore stays in the 'shorter' first two gears for longer than the 4.44 geared SVX, and shifts into third at a higher speed.

By the finish line, I'm sure both cars would be pretty even.

-Chike

[svxfiles]

Myxalplyx
Thank you for catching my mistake, I fixed my post. The temp was colder on the night that I ran the 16s. Here are my notes;

G-tech
G-Tech Testing 92 SVX awd LS-L
All w/224 lb driver, all w/ gas below empty all w/225/45/17s
Now switching to 205/40/16s on stock 20lb wheels

Ran two back to back ¼ mile runs on a very flat strait almost deserted two lane blacktop, with the only worries, deer and police.
West 14.78, 97.3 mph 32f
East 14.72, 96.2 mph 32f
Switched back to the 225/45/17s and came back two days later, 8:15 pm.
East 14.43. 99.1 mph 39f. The 0-60 was 5.85.
West 14.54, 98.7 mph 39f. The 0-60 was 5.98.
East 14.75, 97.1 mph 40f. Did not see 0-60 time

[thundering02]

G-tech just put me at 15.37 @ 95 just the other night with the stock (slightly slipping) 4eat
Aproxx 40 deg. gas tank empty and 150 pound driver. no mods to the car.

[SVXRide]

Originally posted by thundering02
G-tech just put me at 15.37 @ 95 just the other night with the stock (slightly slipping) 4eat
Aproxx 40 deg. gas tank empty and 150 pound driver. no mods to the car.

Jeez, I can hardly remember when I only weighed 150!
-Bill (always looking for that extra 100# = .1 sec)

[sicksubie]

What is tps?