Waffle Manifold

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BluePaulie
Posts: 9
Joined: Fri Aug 03, 2012 3:35 pm
Your car is a: 1978 spider 1800

Waffle Manifold

Post by BluePaulie »

Hi There - I've had the Fiat for a couple months now and I laugh every time I drive it!

Question - Is the waffle manifold a good thing to own? My 1800 has a pair of 40 idf's (I think - all butterflies open at the same time and they both have a tube that comes out of the carb and opens above the throats) mounted to one and I was wondering if this thing was a single or dual plane manifold, or whether a both carbs fed into one big chamber.

Also, 4th & 5th gear are very similar - is it possible to modify 5th to get a lower RPM at 70 mph (already have the differential from an automatic transmission) or is there a trans swap that works well?

THanks,

Paul

ps - Will there be an "attach image" button coming soon?
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seabeelt
Patron 2019
Patron 2019
Posts: 1614
Joined: Tue Feb 19, 2008 4:22 pm
Your car is a: Fiat Spider - 1971 BS1
Location: Tiverton, RI

Re: Waffle Manifold

Post by seabeelt »

Waffle is a good manifold for the IDFs. Auto tranny is about as good as you are going to get for lowering the rpms at highway speed
Michael and Deborah Williamson
1971 Spider -Tropie’ - w screaming IDFs
1971 Spider - Vesper -scrapped
1979 Spider - Seraphina - our son's car now sold
1972 Spider - Tortellini- our son's current
vandor
Posts: 3996
Joined: Sat May 23, 2009 1:23 pm
Your car is a: 1971 124 Spider
Location: Texas, USA

Re: Waffle Manifold

Post by vandor »

With the waffle and the IDF you have a separate runner for each cylinder, the best setup for performance.

There is not an easy solution for a longer 5th gear, unless your transmission if from a 1968-70 Spider.
Those had a 0.91 5th gear, 1971-85 had 0.88:1. Even the latter is barely more than 10% difference from 4th, so yes, these cars do rev higher on the highway than modern cars. If you have an automatic rear end, is the speedo reading lower than your actual speed?
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
BluePaulie
Posts: 9
Joined: Fri Aug 03, 2012 3:35 pm
Your car is a: 1978 spider 1800

Re: Waffle Manifold

Post by BluePaulie »

Thanks for the info.

ps speedo is correct, which makes me wonder about the rear end, but there is a receipt for the work. It runs at 3200 rpm @ 60 mph. which I think is lower than some of the other posts I've seen.
Paul
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