Can I get 20 more Horsepower?

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Nut124
Posts: 748
Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: Can I get 20 more Horsepower?

Postby Nut124 » Fri Apr 20, 2018 8:32 pm

Ward, the Guy Croft books were written quite a while ago. Good books, have them. HP ratings back then are not the same as today, IMHO. It seems to me today's 120HP is a good 10% stronger than 120HP of the 1980's.

0-60 times are very difficult to obtain w/o very expensive instrumentation. Any attempt to measure 0-60 using your spedometer and a stop watch is flaky at best. I have a GMeter that seems somewhat accurate. New ones may be better yet.

1/4mile times reflect HP pretty well IMHO and can be had at any local strip test-n-tune nights, at least where I'm at. The US V8 guys will look at you a bit, sometimes with genuine interest. And there are also many rice rocket young folks there, so you will be cool. At least here in MI.

Mine ran 16.1 - 16.2 1/4 miles at 85MPH ET years ago at a local track. A bad launch could easily make it a 17s run. However, if you read contemporary road test results, most Fiats ran 18-22s 1/4 miles at 65-70MPH. The Abarth Rallye 1800 was published at 17.1s or so and was supposed to have 128HP at the time. Figure that out.

In the time slip, you'll see that 1/8 mile ET was 10.3 at 68HPH. The speed is a last 60ft average. If you look at typical speed vs time curves, you could estimate 0-60 time maybe somewhere in the 8s range.

For comparison, based on publisehed data, an early Miata with an 1800 118HP FI engine ran mid to high 16s initially. It may have been a bit heavier than a Fiat. Later versions with 128HP ran low 16's. and then later yet with 158HP ran mid to high 15's per published data IIRC.

The only reason for considering the why wheel for my next build is that a steel wheel is safer than a cast one at 8000rpm, which is where I will be at 145HP with my next 1800, one day. It will do nothing for power.

Image

ward00
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Your car is a: 1975 Spider

Re: Can I get 20 more Horsepower?

Postby ward00 » Fri Apr 20, 2018 10:00 pm

If i could/can achieve your numbers i will be a happy camper. Will
need to optimize jetting and dyno first.
75 Spider
75 Sport Coupe restoration

MLACartwright
Posts: 1
Joined: Tue May 01, 2018 10:33 pm
Your car is a: 1973 Fiat Abarth 124 Rally

Re: Can I get 20 more Horsepower?

Postby MLACartwright » Wed May 02, 2018 6:33 pm

The 1978 Fiat spider was burdened with those massive ( and ugly) bumpers.
Removing those bumpers and related hardware altogether would be a great help in improving the mass : power ratio as well
as esthetic value.

Consequently one may need to install lowering springs. Perhaps a set of the Abarth Rally bumperettes to fill the gaps?

ward00
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Your car is a: 1975 Spider

Re: Can I get 20 more Horsepower?

Postby ward00 » Wed May 02, 2018 7:09 pm

Yes - the bumpers are removed on my car - bought it that way. I'm currently waiting on Chris Olbet in Santa Cruz to jet the car and perhaps change cam-timing (he has a long wait list). I suspect there are improvements to be made as my IDFs came with 28 chokes installed. Will post if Chirs is able to improve performance, which by the way I'm not complaining about. but I do want more HP.
75 Spider
75 Sport Coupe restoration

Nut124
Posts: 748
Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

Re: Can I get 20 more Horsepower?

Postby Nut124 » Wed May 02, 2018 10:10 pm

The 28 is the standard Weber choke for the 40IDF. Not sure what the original 40IDF application was but 28 chokes seems too small for what you are trying to do.

My 1800 now has 40's w 34 chokes and I'm going to 44's with at least 36 chokes. The Fiat Abarth Rallye had 48IDFs.

Do you have an O2 sensor/mixture readout? It is a great help when jetting. I installed one in mine and could not do without it.

ward00
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Your car is a: 1975 Spider

Re: Can I get 20 more Horsepower?

Postby ward00 » Wed May 02, 2018 10:35 pm

I think the person I bought the car from wanted more low end torque - hence the 28 chokes. I'm pretty sure the original IDFs for Spiders came with 32s. We'll see what Chris Olbet determines is best. If 32s are the choice, then obviously all my other jets need to be changed. For my setup, it might require 34 chokes (as per Guy Croft). I could do endless experimentation with the jets and a fuel ratio sensor myself, but I think paying someone else will be more efficient, and quicker.
75 Spider
75 Sport Coupe restoration

narfire
Posts: 3959
Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: Can I get 20 more Horsepower?

Postby narfire » Fri May 04, 2018 4:05 pm

I put after market cams in my 2L. Ran a bit better but after having them degree'd in properly it was like a different engine. Pulls very well after about 3000 rpm regardless of what gear I'm in.
Sooo if you can source someone that can do that, it is worth every penny spent.
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
2018 F350 crew long box

BEEK
Posts: 1830
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: Can I get 20 more Horsepower?

Postby BEEK » Sat May 05, 2018 8:01 pm

My current build for my spider 1800, 1975. I would post pictures if i could to that directly, I do not use a photo hosting service.

84.4mm bore 9.8-1 pistons, slightly decked block
2.0 lancia efi head ported and polished, port roofs raised considerably
port matched waffle manifold with 40 idf, 34mm chokes
plex 201 ignition driving a msd 6
42/82 cams degreed in to 108 lobe centers
header

this will be running in a week or 2, i have just ordered jets as my original setup in the factory idf's was way off according to gcre.
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider

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joelittel
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Your car is a: 1980 Spider 2000 FI
Location: Evanston, IL

Re: Can I get 20 more Horsepower?

Postby joelittel » Mon May 07, 2018 9:52 am

I’m hoping we can all make an effort to get our cars on a dyno and post the charts. I know it’s expensive, but it’s incredibly valuable to know the modifications as well as hp at the rear wheels after said mods. This type of information will only help the community in the long run.

MIGHTY 8
Posts: 302
Joined: Sat Mar 04, 2006 9:55 pm
Your car is a: 1980 Spider
Location: North Chatham NY

Re: Can I get 20 more Horsepower?

Postby MIGHTY 8 » Thu May 10, 2018 3:13 pm

Great reading here!

Couldn’t help but add a question....

How does one go about researching a dyno/ tune shop?

Any recommendations would be very helpful. I have an 80 Spider with dual 44’s and extensive mods. Running great right now, but just looking for some final tweaks after re-installing engine.

Located now in NYC.

thanks all.

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joelittel
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Your car is a: 1980 Spider 2000 FI
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Re: Can I get 20 more Horsepower?

Postby joelittel » Thu May 10, 2018 6:36 pm

Make sure it’s a steady state dyno, otherwise it’s a waste of time

MIGHTY 8
Posts: 302
Joined: Sat Mar 04, 2006 9:55 pm
Your car is a: 1980 Spider
Location: North Chatham NY

Re: Can I get 20 more Horsepower?

Postby MIGHTY 8 » Fri May 11, 2018 10:35 am

Got it...thanks. Was hoping for recommendations in the area. I’ve looked up on google, but thought I’d ask here as well...

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joelittel
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Your car is a: 1980 Spider 2000 FI
Location: Evanston, IL

Re: Can I get 20 more Horsepower?

Postby joelittel » Fri May 11, 2018 8:01 pm

Dyno shops are surprisingly hard to find.

Mustang Dynos are even harder.

What about going to a local Cars and Coffee event and asking the hot rod crowd who they use?

mrgizmo04
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Joined: Thu May 03, 2018 5:33 pm
Your car is a: 2005 M3 with Fiats in family

Re: Can I get 20 more Horsepower?

Postby mrgizmo04 » Sat May 12, 2018 12:50 pm


fiatfactory
Posts: 506
Joined: Sun Jun 13, 2010 11:22 pm
Your car is a: 1970 128

Re: Can I get 20 more Horsepower?

Postby fiatfactory » Sun May 13, 2018 7:36 am

.
nothing to see here... move along.


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