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3.31 gears vs. 3.73 gears for road course

I have seen some talk on S197 forum talking about how the 3.31 is better than the 3.73. I haven't had any issues with my 3.73 gears and I was wondering, for those of you who do road courses, what do you think about the 3.73 vs 3.31? Would you change to the 3.31? I think if you do AutoX 3.31 gears would work great.
 
You could also consider the 3.55 gears. The 3.73 gears work fine for me and the MT82 gear ratios work well with the Boss powerband. Do you have your rev limiter set at the stock 7,000 on your 5.0?
 
Wouldn't it depend on how each particular course is set up? Some courses are tight and slow, when others might be straighter and faster. On certain courses you might shift from first (to launch) to second and only use second thereafter. Other courses you might use first, then shift to second, then to third and back to second... I guess, the answer is: It depends....
 
NFSBOSS said:
Do you have your rev limiter set at the stock 7,000 on your 5.0?

Yes, just stock. Most of the tracks I drive I am in 3rd and 4th gear, and 5th in the longer straights. I haven't felt like there wasn't enough gear as the fastest I have gone is 120mph. I will be doing TWS twice this year and I can see the straight there is were I might run out and have to use 6th gear. Other than that I haven't found it to be a problem and I found it strange others have so I thought I would ask here where ever one has the 3.73 gears.
 

ArizonaBOSS

Because racecar.
Moderator
8,552
2,392
Arizona, USA
I know the Vorshlag guys love the 3.31; but they do a lot of auto-x as well.

I really like the 3.73, but I have a 7800 RPM limiter. Typically shift at 7000 unless the overrun is needed, though.

Bigger tracks like TWS as you mentioned you might hit over 150; you can also increase your rear tire diameter if you're worried about running out of revs.
 
ArizonaBOSS said:
I know the Vorshlag guys love the 3.31; but they do a lot of auto-x as well.

I really like the 3.73, but I have a 7800 RPM limiter. Typically shift at 7000 unless the overrun is needed, though.

Bigger tracks like TWS as you mentioned you might hit over 150; you can also increase your rear tire diameter if you're worried about running out of revs.

You brought up a good point with the tire and wheel size. I forgot about that. That would make sense when you start looking at slicks to run on a 18" wheel.
 
ArizonaBOSS said:
I know the Vorshlag guys love the 3.31; but they do a lot of auto-x as well.

I really like the 3.73, but I have a 7800 RPM limiter. Typically shift at 7000 unless the overrun is needed, though.

Bigger tracks like TWS as you mentioned you might hit over 150; you can also increase your rear tire diameter if you're worried about running out of revs.

Yes, we (Vorshlag) originally got the 3.31 because of autocross combined with a shorter than stock tire.

Now when we go to TWS we see 165 with the 3.31 and not much additional power.
 
1,281
3
Tulsa, OK
Good info that you guys have hit 165. I know my car with 3.73s and stock tires could not hit that speed in 5th. I have since raised my rev limiter but I'm also on shorter tires. I'm thinking I could see maybe 150-155. I guess we'll see.
 
roadhouse said:
Good info that you guys have hit 165. I know my car with 3.73s and stock tires could not hit that speed in 5th. I have since raised my rev limiter but I'm also on shorter tires. I'm thinking I could see maybe 150-155. I guess we'll see.

We don't often use overdrive on the track. Overdrive gears tend to be weak compared to the lower and direct drive gears. I would hesitate to use and overdrive gear under power on the track and usually just use it to cruise once I've hit the target speed. That's not to say Terry has never used OD, but I recommend against it.
 
roadhouse said:
Good info that you guys have hit 165. I know my car with 3.73s and stock tires could not hit that speed in 5th. I have since raised my rev limiter but I'm also on shorter tires. I'm thinking I could see maybe 150-155. I guess we'll see.

What did you change your rev limiter to? And did you upgrade the valve springs?
 
1,281
3
Tulsa, OK
Budget Boss said:
What did you change your rev limiter to? And did you upgrade the valve springs?

I added a boss intake manifold and tune by AED. They set the limiter at 8k (Yikes!) but I don't take it that high. Normally only 7500 or so. No valve spring upgrade.
 
roadhouse said:
I added a boss intake manifold and tune by AED. They set the limiter at 8k (Yikes!) but I don't take it that high. Normally only 7500 or so. No valve spring upgrade.

Well I can't wait to see ya at TWS. I liked to see you on the track and how your car does. I am thinking of going in the same direction as your set up.

Edit: did you have to get a different TB for the Boss intake?
 
1,281
3
Tulsa, OK
Budget Boss said:
Well I can't wait to see ya at TWS. I liked to see you on the track and how your car does. I am thinking of going in the same direction as your set up.

Edit: did you have to get a different TB for the Boss intake?

Can't wait to get down there either! We'll have to compare car setups and how they handle TWS.

No, you can use the stock TB with either the stock intake or aftermarket. I'm using a C&L intake with no issues.
 
roadhouse said:
Good info that you guys have hit 165. I know my car with 3.73s and stock tires could not hit that speed in 5th. I have since raised my rev limiter but I'm also on shorter tires. I'm thinking I could see maybe 150-155. I guess we'll see.

Are you driving TWS counterclockwise or clockwise? I've only been there once and we went counterclockwise. You probably will not see 150 going that direction. Also, the 3.73's were not very good there since there were so many short straights that you would hit the rev limiter a few seconds before you would hit the brakes. It just wasn't worth shifting. I think 3.55's would be perfect for that track (counterclockwise). JMHO
 
I was think about this again. The reason is I just drove the car back home from the dealer after they replace the front passenger side control arm. Any way 1st gear on my car is useless and I have to start out in 2nd gear. I might get the 3.31 gears and give them a shot. If I don't like them I can always put the 3.73s back in.
 

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