GEARED TOO LOW

The forum for all of your technical questions on your classic FIAT autos
cstorry
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Re: GEARED TOO LOW

Post by cstorry » Mon Apr 05, 1999 10:02 am

From: Chuck Storry
Email: storry@sympatico.ca
Subject: Re: GEARED TOO LOW
Date: 923331748
Poster: cstorry
In-Response-To: 14808
--
I second that. I would like to get highway crusiing rpm's down to
2500 or so. It seems like the power is there but I haven't done
the math.

Chuck


Keith Cox wrote:
: Hello, I am just throwing another of my questions into the air
: about the Spider. I am planing on rebuilding and making some
: modifications to my car. Has anyone been sucessful in changing
: the gearing in the Spider? Mabey a different differential? Also
: if that is possible, how do you change the spedo? I have alway
: wondered why it was geared so low, and fifth is not realy an
: overdrive, as its only 300 rpm difference.
: Regards,
: Keith
1983 Pininfarina Azzura
gemery
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Re: Geared for performance

Post by gemery » Mon Apr 05, 1999 10:09 am

From: George Emery
Email: gemery@aol.com
Subject: Re: Geared for performance
Date: 923332152
Poster: gemery
In-Response-To: 14808
--
Keith Cox wrote:
: I have alway wondered why it was geared so low, and fifth is
: not realy an overdrive, as its only 300 rpm difference.

If you want more rpm drop for fifth gear, you'll need to change
just that gear (or fourth + differential). I don't know what's
available. Changing the differential won't help you unless you
want to change the ratio for all gears. And you can temporarily
try a differential change by using taller tires.

Remember, you have a sports car, not an econobox! Sports cars
should have tight gear ratios for performance at high speeds,
allowing you to stay in the powerband.

George Emery
gemery@aol.com
http://members.aol.com/gemery
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vandor
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Re: GEARED TOO LOW

Post by vandor » Mon Apr 05, 1999 10:15 am

From: Csaba Vandor
Email: vandor@ionet.net
Subject: Re: GEARED TOO LOW
Date: 923332530
Poster: vandor
In-Response-To: 14810
--
For those who wish to change their gearing, the following gear
ratios were available on the Spider:

4.1:1 '68-70 1438
4.3:1 '71-78 1600, 1800
3.9:1 '79-85 2000
3.58:1 '79-85 auto tranny 2000

So if one has a Spider 2000, they can switch to an axle from an
auto tranny 2000 for higher (numerically lower) gearing, and
lower rpm on the highway.
Of course torque to at the rear wheel will also be less by the
same proportion.
______________________________________________
Csaba Vandor
Mechanical Power Technology graduate
Seeking employment!
Volvo enthusiast and Fiat fanatic
'84 Volvo 245Ti '70 124 Spider
Csaba
Parts: http://www.autoricambi.us
Cars: http://italiancarclub.com/csaba/Fiat.html
'71 124 Spider, much modified
'72 124 Coupe, new project, ex-Pete, ex-Eli, ex-Jack car (all Mira members)
'73 124 Wagon, no floors
cstorry
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Re: Right On George!!!!!!

Post by cstorry » Mon Apr 05, 1999 11:43 am

From: Chuck Storry
Email: storry@sympatico.ca
Subject: Re: Right On George!!!!!!
Date: 923337801
Poster: cstorry
In-Response-To: 14820
--
Well the 45 minute commute (yes I'm piling on the miles but it's
my car and that 45 minutes is much more fun in the spider) gets
pretty noisey when cruising at 4500 the whole way. Its actually
quieter with the top down (or seems so). My only complaint is
noise not performance (and I don't want to give up lower gear
performance).

BTW I hope to make it for FFO'99 and that looks like a 16+ hour
drive so comfort level is important.

Chuck

Jack Ivemeyer wrote:
: George Emery wrote:
: : : Remember, you have a sports car, not an econobox! Sports
: cars
: : should have tight gear ratios for performance at high speeds,
: : allowing you to stay in the powerband.
: -------------------------------------------------
: I'll never understand the reasoning of taking a car that lives
: in the upper RPM range say 4000 to 4500 and then gear it to
lope
: along at 2500 RPM...Hell man,this is one area that Fiat
excelled
: in, gearing the car to match the motor...but if you must gear
up
: you can try to find a auto differential 3.58:1, I believe.
: BTW I assume you have a 124/2000 series...as i don't think you
: mentioned what make,model and year.124/2000 series used a
number
: of differential gear ratios i.e.
: >4.10:1
: >4.30:1
: >3.90:1
: >3.58:1
:
: Jack Ivemeyer Grover Beach,California
: '72 124 coupe, 2 litre U.S.A.
: '89 Mercury Sable (Susan's ride)
: Web Page: http://expage.com/page/grayxx
:
:
1983 Pininfarina Azzura
davemeredith
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Re: Geared for performance

Post by davemeredith » Mon Apr 05, 1999 2:03 pm

From: Dave Meredith
Email: DMeredith@kineticsnoise.com
Subject: Re: Geared for performance
Date: 923346231
Poster: DaveMeredith
In-Response-To: 14829
--
Keith Cox wrote:
........ So in conclusion the suggestion of the automatic
: differential is a good idea.


This is exactly the conclusion that I reached myself about 2
years ago upon discovering the rear pinion gear in my Spider had
only 8 1/2 teeth left, in lieu of the 10 teeth that it should
have had.

Swapped the 5 speed ring and pinion (10 teeth pinion, 39 teeth
ring gear) for a set from an automatic (12 teeth pinion, 43
teeth ring). Result is a slightly slower acceleration, but with
more relaxed 5th gear cruising --- A trade off which, for me, is
just fine.

Dave Meredith / Ohio
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vandor
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Re: Right On George!!!!!!

Post by vandor » Mon Apr 05, 1999 2:44 pm

From: Csaba Vandor
Email: vandor@ionet.net
Subject: Re: Right On George!!!!!!
Date: 923348650
Poster: vandor
In-Response-To: 14826
--
Chuck Storry wrote:
: My only complaint is
: noise not performance (and I don't want to give up lower gear
: performance).

Is it engine noise, wind noise or exhaust noise?
With the top up I get all 3. I noticed that playnig with how far
shut the windwings are can make a difference in wind noise.
Pinins don't have windwings, though...
I am planning on adding a second muffler for reduced exhaust
noise, and adding insulation on the inside of the firewall,
tranny tunnel and floorboards to less engine noise. But I think
the Spider is just a noisy car compared to modern alternatives.
______________________________________________
Csaba Vandor
Mechanical Power Technology graduate
Seeking employment!
Volvo enthusiast and Fiat fanatic
'84 Volvo 245Ti '70 124 Spider
Csaba
Parts: http://www.autoricambi.us
Cars: http://italiancarclub.com/csaba/Fiat.html
'71 124 Spider, much modified
'72 124 Coupe, new project, ex-Pete, ex-Eli, ex-Jack car (all Mira members)
'73 124 Wagon, no floors
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