engine/diff change

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babyofo
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engine/diff change

Post by babyofo »

Hi All

We (I) are currently in the process of putting a 948 into Alexs A30, do we have to change the diff to the one out of the A35, or are both diffs the same?

Thanks
Ian.
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gazza82
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Re: engine/diff change

Post by gazza82 »

A35 will be 4.55, A30 is lower at 5.1 or 4.8.
"If you're driving on the edge ... you're leaving too much room!"

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Cars: "Project 757" '59 A35 2-door bought in 1971 & Subaru BRZ SE LUX Auto plus "family fleet": Alfa MiTo, Peugeot 206, (Ex '98 Alfa Romeo 156 2.0 TS)
WAC_Paul
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Re: engine/diff change

Post by WAC_Paul »

I have put a 4.22 in my A35 with a 948. It gives a lovely cruising speed.
Edosan
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Re: engine/diff change

Post by Edosan »

Definitely better with A35 diff, you'll just need to check on your speedo readings which will be incorrect after the change. Check how far out they are with a Sat Nav. Or you could put the A35 speedo in as well but you would need to change the speedo drive in the gearbox for this as well, very easy when the gearbox is out as you just need to remove tailshaft housing to get at it. :wave:
OVY871
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Re: engine/diff change

Post by OVY871 »

Because the 4th gear ratio is the same for both A30 and A35 at 1:1 the cruising revs will be the same with the new engine. But the new engine will be able to use a higher diff more comfortably making it a bit more relaxed on any trips.

To give an idea, a car with 145/80R13 tyres travelling at 3500rpm would be 47.2mph for the A30 diff, 50.7 for the A35 diff or 54.6mph for the 4.22 diff (Minor I believe?)

More notably though travelling at the 47ish-mph would be 3500rpm for the 4.88 diff but only 3000 for the 4.22.

Hope this helps you decide.
Neal Welch
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A40FARINAGURU
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Re: engine/diff change

Post by A40FARINAGURU »

OVY871 wrote:the 4.22 diff (Minor I believe?)
A40 Farina MK2 (1098cc) & wash your mouth out too :whistle:
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gazza82
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Re: engine/diff change

Post by gazza82 »

Small bore Spridget too I think but will check tomorrow. :study:
"If you're driving on the edge ... you're leaving too much room!"

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Cars: "Project 757" '59 A35 2-door bought in 1971 & Subaru BRZ SE LUX Auto plus "family fleet": Alfa MiTo, Peugeot 206, (Ex '98 Alfa Romeo 156 2.0 TS)
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Re: engine/diff change

Post by OVY871 »

Little list of them here :)
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