911SC -- 78-79 vs 80-83 (powerband)
05-22-2003, 08:15 PM
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911SC -- 78-79 vs 80-83 (powerband)
I've read the early 911SC had larger intake runners. Although Porsche stated the same power and torque for early and late US models, the early 911SCs seemed to have more top end "pull". Do these larger intake runners provide any performance gain vs the 80-83 runners?
Todd
1981 911SC
Todd
1981 911SC
05-23-2003, 04:18 AM
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I will second that - my '78 SC has the same 'power on' setpoint. It is still a good car though. Everone tells me that the best way to improve an early 'SC is to fit SSI heat exchangers with a Dansk single outlet rear box - this is supposed to give up to 20% more torque at low RPM's. At £1500 to buy the parts here in the UK, it is an expensive solution.
05-23-2003, 08:16 AM
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This is a very good question. Another difference with the earlier cars was the lower compression. The compression of 78-79 US and Euro was 8.5:1. US 80-83 was 9.3:1, but it had smaller intake runners. The ideal situation is to have the larger intake runners along with the higher compression. That is what one gets with the Euro 81-83 motor. That is the 930/10 motor with a 9.8:1 compression ratio. You can really feel a difference in those. A lot of the ones that I have driven felt as fast if not faster than 3.2's. But between any year US SC and 78-79 Euro or US, they feel about the same overall. The US 80-83 might feel a hair better down low, while the EURO and US 78-79 might feel a little better at top. These differences are minute though. What I don't like about the 80-83 US is the lambda sensor and frequency valve. I did away with that in mine and put in the fuel distributor, ignition distributor and warm up regulator from the 81-83 Euro.
05-23-2003, 08:21 AM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"><strong>Everone tells me that the best way to improve an early 'SC is to fit SSI heat exchangers with a Dansk single outlet rear box - this is supposed to give up to 20% more torque at low RPM's. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">When I installed SSI's on my 81SC, I felt the benefit in the higher RPM band, not lower. If I remember, the SSI benefit is in the 15-20 hp (+11%) range....+20% torque sounds optimistic.
