IDS - IDA - IDT
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IDS - IDA - IDT
Can anyone explain the detailed differences between these carbs as I need to replace some Solexes.
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- Nurse, I think I need some assistance
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You can use any of the 3 versions of Weber carburettor (with appropriate jetting) to replace your Solexes.
Porsche originally used the IDA's to replace the Solexes for the 'S' models in early 1966 (the Webers were used on several Italian cars including the Lancia Aurelia V6's).
IDT's were a modified version of the IDA used on the 'T' models & incorporated different jetting & idle mixture screws with a different taper.
IDS's were introduced for the 'S' models sometime during 1968 & incorporated an extra 'high speed enrichment' circuit - this apparently gave no increase in performance but was meant to be a safety feature to prevent destructive detonation at high revs.
Whichever version you fit you will need to ensure that the manifold internal diameter matches the inlet ports (so probably better to start with 'T' manifolds).
Porsche originally used the IDA's to replace the Solexes for the 'S' models in early 1966 (the Webers were used on several Italian cars including the Lancia Aurelia V6's).
IDT's were a modified version of the IDA used on the 'T' models & incorporated different jetting & idle mixture screws with a different taper.
IDS's were introduced for the 'S' models sometime during 1968 & incorporated an extra 'high speed enrichment' circuit - this apparently gave no increase in performance but was meant to be a safety feature to prevent destructive detonation at high revs.
Whichever version you fit you will need to ensure that the manifold internal diameter matches the inlet ports (so probably better to start with 'T' manifolds).
Andy
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
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- Nurse, I think I need some assistance
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- Joined: Wed Nov 12, 2003 10:48 pm
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- Nurse, I think I need some assistance
- Posts: 16928
- Joined: Wed Nov 12, 2003 10:48 pm
- Location: Worcs/W Mids border
The original reason that Webers were fitted was to eliminate the 'flat-spots' that plagued the Solex-fed cars.
When Porsche went over to using Zenith 40TIN carbs instead of Webers for the 2.2 911T models, it was essentially a cost-cutting exercise.
The advantage that Webers have over both the Solex & Zenith carbs is the much greater availability of alternative jets, chokes, emulsion tubes, etc.
When Porsche went over to using Zenith 40TIN carbs instead of Webers for the 2.2 911T models, it was essentially a cost-cutting exercise.
The advantage that Webers have over both the Solex & Zenith carbs is the much greater availability of alternative jets, chokes, emulsion tubes, etc.
Andy
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
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- Nurse, I think I need some assistance
- Posts: 16928
- Joined: Wed Nov 12, 2003 10:48 pm
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- Bootsy
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Bit big for a Super 356 engine - now if they were 40s or 44s I could be tempted - I love 48 IDAs - lovely carbsLightweight_911 wrote:Will - I don't think those Webers would be much use to Peter as they're twin-choke IDA's for a 4-cylinder engine...
1972 911T | 1994 993 Carrera | 1999 986 Boxster | 1990 T25 Camper
Vintage Heuer, Omega, Zenith and other vintage watches - http://www.heuerheritage.co.uk
Vintage Heuer, Omega, Zenith and other vintage watches - http://www.heuerheritage.co.uk
To chip in a bit I'll paint with a very wide brush: Solexes are better carbs than Webers when set up correctly.
Why? Numerous reasons. Solex throats line up directly with the ports on a 911 engine. They have more tuning flexibility than Webers. Most interestingly, the flat spot problem is easily mitigated by a knowledable rebuilder like Duel or Harry Bieker.
I have talked to several folks racing their '65s w/ Solexes and all insist that the Solexes make more power. Think about it; with the more direct route for air, remote float bowls that keep the fuel from boiling in the carbs, no starvation problems from hard cornering, they are the carb of choice.
In talking to Harry Bieker, he insists that the flat spot issue was the result of a design flaw that caused the throttle shafts to wear quickly and improperly on these cars. He has rebushed hundreds of sets of these carbs and not only does this cure the issue, he has seen only a handful come back to readdress the issue. As far as the jetting problem goes, he reams the Solexes to accept 356 Solex parts, which removes the scarcity of parts issue.
Needless to say, I am hoping my set will be back from Harry very soon so I too can experience Solexes in all of their glory in my '65. I'll keep you posted.
Why? Numerous reasons. Solex throats line up directly with the ports on a 911 engine. They have more tuning flexibility than Webers. Most interestingly, the flat spot problem is easily mitigated by a knowledable rebuilder like Duel or Harry Bieker.
I have talked to several folks racing their '65s w/ Solexes and all insist that the Solexes make more power. Think about it; with the more direct route for air, remote float bowls that keep the fuel from boiling in the carbs, no starvation problems from hard cornering, they are the carb of choice.
In talking to Harry Bieker, he insists that the flat spot issue was the result of a design flaw that caused the throttle shafts to wear quickly and improperly on these cars. He has rebushed hundreds of sets of these carbs and not only does this cure the issue, he has seen only a handful come back to readdress the issue. As far as the jetting problem goes, he reams the Solexes to accept 356 Solex parts, which removes the scarcity of parts issue.
Needless to say, I am hoping my set will be back from Harry very soon so I too can experience Solexes in all of their glory in my '65. I'll keep you posted.
Kenik
>1969 911S
>1965 911
>1969 911S
>1965 911
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- Nurse, I think I need some assistance
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