What is Your Favorite Gearing for Your Street Car and R&P - 4.12, 4.37. 3.88???

[rick m]

I'd be curious what everyone has found to be their optimum gearing for their street car...as well as for the motor size and weight of their car. It would be interesting to hear all the various combinations based on motor, use of car, etc.

I have always favored the 3.88 for my street cars due to the strength. I tend to like longer 1st and 2nd gears and a closer third and fourth. With a big motor I have never had any issues pulling taller gears.  What is your gear stack and ring and pinion of choice for your application?

Rick Mortensen

[modnrod]

All highway work at 110-115kph, in a mild '73 Squareback 1641.......
        4.125........3.78/2.06/1.34/0.89. Tyres were 205/65R15 rear.

Around town and terrorizing V8s with a few drag DYO events, '63 Bug beater and a Superstocker 1641........
         4.375.......3.78/2.06/1,41/1.00. Tyres were 185/60R14 rear.

Do everything daily driver, drive across Australia, drive through traffic, drive the V8s nuts, tow a 500kg trailer, sleep overnight at the drags (dragbike), the usual! All done in a '68 Squareback with a 1762cc stroker (Holden 161 pistons and rods, gives 3.38"/85.8mm bore and 3"/76.2mm stroke), W110, 1.25 rockers, sidedraught Dell 40 DHLA, nice 35/32 heads........
         4.375........3.78/2.06/1.26/0.82. Tyres were 185/75R14 rear.
Bloody nice little Squareback that one, 12km/L on the highway, just sneaked into the 14s on radials, quiet and comfy.

My little "73 Superbug is going to be the same as the do-everything Squareback. I'm thinking either 3.875 with 1.35/0.93 3rd/4th, or 4.375 with 1.26/0.82 3rd/4th. I rarely go over 100kph on the highway nowadays, but will still go to the city occasionally and scare the V8s at the track, can't help myself! I'm probably going to run a little 83mm bore/76mm stroke mild torquer motor.  What do you think Rick?

[pupjoint]

i personally prefer 4.125

[Fastbrit]

You can't talk about 'optimum gearing' unless you know the points at which the engine produces max torque and bhp, which will vary from engine to engine.

[rick m]

Ah....so true.  Must guys are not that deep into it.  Since my motor makes all it's torque from 2000 to 5200rpms and I primarily use it as a cruiser, I geared it for that use.  I would venture to say most vw enthusiasts have not even changed the gearing in their boxes...unless they have some type of specific use for it that the gearing would help accomplish.  Just provoking some discussion. 

I spent Saturday helping a friend check out a hurt 1915 with an ENGLE 100 cam that was placed in a 71 bay window with a stock pict 34 carb on it, stock dog house cooler and who knows how it was built.   If that was not enough to work it to death...he told me the owner had taken out the lower R&P and installed a taller one in it so it would do better on the highway.  Guess what happened to the motor? Tall gears, a motor that would not breath for the C.I. displacement and a 3000lb + vehicle...

Like your point...everything matters when you start building a purpose built car.

RM

[Bruce]

I have always favored the 3.88 for my street cars due to the strength.

Were you having trouble breaking other R&Ps?

If using a stock 3.78 1st gear, my preference is to use a 4.12 with it.  It makes starting from a standstill on a hill easier than the 3.88.  If you were worried about the strength, get an "O" type 4.12 from a Thing gearbox.  According to Eric at ERCO, it is "almost" as strong as a 3.88.
My current gears:
4.12 R&P
3.78
2.25
1.48
1.13
.82
I have found the 1.13 to be too low for climbing long steep mountain grades.  Next time the gearbox is apart, a 1.04 is going in.

[Zach Gomulka]

My current gears:
4.12 R&P
3.78
2.25
1.48
1.13
.82
I have found the 1.13 to be too low for climbing long steep mountain grades.  Next time the gearbox is apart, a 1.04 is going in.

That's exactly how I would build a 5 speed (with the 1.04). I'd love to drive your car someday.

[Bruce]

My current gears:
4.12 R&P
3.78
2.25
1.48
1.13
.82
I have found the 1.13 to be too low for climbing long steep mountain grades.  Next time the gearbox is apart, a 1.04 is going in.

That's exactly how I would build a 5 speed (with the 1.04). I'd love to drive your car someday.

OK, I'll bring my car to you next week. 
When/where are the Phoenix cruise nights?

[Zach Gomulka]

My current gears:
4.12 R&P
3.78
2.25
1.48
1.13
.82
I have found the 1.13 to be too low for climbing long steep mountain grades.  Next time the gearbox is apart, a 1.04 is going in.

That's exactly how I would build a 5 speed (with the 1.04). I'd love to drive your car someday.

OK, I'll bring my car to you next week. 
When/where are the Phoenix cruise nights?

Wow, good answer! I'd say the best one going on is at the Scottsdale Pavillions, every Saturday night.

PM me!

[Jason Foster]

VW people rule

[Bruce]

OK, I'll bring my car to you next week. 
When/where are the Phoenix cruise nights?

Wow, good answer! I'd say the best one going on is at the Scottsdale Pavillions, every Saturday night.

PM me!

OK, I have the location sussed.  What time do cars start to arrive?

[Zach Gomulka]

The old guys get there pretty early, around 3-4. It goes until the people leave, I'd say it's strongest between 5-8.

[javabug]

Zach, the catch is you have to drive Bruce's car all the way back to Canada.

[Zach Gomulka]

Zach, the catch is you have to drive Bruce's car all the way back to Canada.

Deal!

[Frenchy Dehoux]

     I must be a real old guy than. The Friday of Barrett Jackson I arrived at the Pavillion at 10:00 PM and stayed until Saturday 10:30 PM I was there for 24 hours and 30 minutes I'll take that back I must be Car Crazy. I had the 32 Hot Rod. Hopefully some day I can have the NSU there.

Frenchy

[Bruce]

Zach, the catch is you have to drive Bruce's car all the way back to Canada.

No Mike, my car is going the other way!

Frenchy, will you be there this Sat?

[Torben Alstrup]

Ah....so true.  Must guys are not that deep into it.  Since my motor makes all it's torque from 2000 to 5200rpms and I primarily use it as a cruiser, I geared it for that use.  I would venture to say most vw enthusiasts have not even changed the gearing in their boxes...unless they have some type of specific use for it that the gearing would help accomplish.  Just provoking some discussion. 

I spent Saturday helping a friend check out a hurt 1915 with an ENGLE 100 cam that was placed in a 71 bay window with a stock pict 34 carb on it, stock dog house cooler and who knows how it was built.   If that was not enough to work it to death...he told me the owner had taken out the lower R&P and installed a taller one in it so it would do better on the highway.  Guess what happened to the motor? Tall gears, a motor that would not breath for the C.I. displacement and a 3000lb + vehicle...

Like your point...everything matters when you start building a purpose built car.

RM

For your car and a 4 speed trans, I would have chosen a 3,88 w. 0,89 4rth, here. But, knowing the climate where you live, I´m not so sure. There I would most likely stay with the 0,93 4rth to make the engine/fan rev slightly faster. OR adjust the fan speed with one of those new smaller alternator pulleys or simply liberate  a 912 engine for one.

T

[Frenchy Dehoux]

Zach, the catch is you have to drive Bruce's car all the way back to Canada.

No Mike, my car is going the other way!

Frenchy, will you be there this Sat?

Bruce

I will be at the Scottsdale Pavillion if you do not mind looking at a Hot Rod with a funny motor etc ...

Frenchy

[TexasTom]

I run the following:

3.88 r&p, 4.11 1st, 2.47 2nd, 1.65 3rd, 1.21 4th, .93 5th

tires: 185sr15, 215/60s or 215/65s

TxT

[Udo]

3.44 R&P and you can use the original 1.2. gears :-)

Udo

[TexasTom]

Actually thinking of going that way, Udo!
Already have the r&p from Berg ...

[rick m]

Torben....wow...you have some great intuition. I have a 3.88 with an .89 4th.  It works great. motor is turning 3400rpms at 70 mph. It likes it right in that range when on the road. I use a 912 pulley on my motor with a BERG large pulley on the crank.

RM

[Torben Alstrup]

Hehe. OK I hit the nail on the head then. Good to hear that it works, and to find out that my assumption was good.

T

[rick m]

Drove it to a cruise night this evening.  Fifty mile round trip....Still runs incredibly strong...loves a load on it and pulls hard. Have fun surprising a lot of unsuspecting V8 guys.  :-)

Rick M

[Frenchy Dehoux]

    Rick

  Which cruise night did you go to. I was at the Pavillion in Scottsdale with Bruce hoping to see you and Zach so that we could of gotten together talking with Bruce on his way down to Mexico and Guatemala. We had a great time until midnight. Most of you guys would of been in bed not this young guy LOL!!!!!!!!!!!

Frenchy

[Zach Gomulka]

If Rick went to the Pavilion's it would have been a 100 mile round trip

I wanted to go but the missus had better plans for me