High Butterfly Air Filtration

[letsrollbabe]

Does anyone have any documentation or pics of air filtration systems used on high butterfly systems from the 70s? These would have been on rally cars and could have been on Weber 46s or MFI inducted engines. Matt Blast sent me pics of a 73 911 (known in the northeast as the 'Bruno' car) that was sent back to the factory in the 70s to be retrofitted as a high level rally car, and it is likely that the factory fitted an SCRS type of filtration system, long before it was used on the SCRS and other rally 911s in the early 80s. The system is a stock early 70s MFI metal filter housing with short intermediate stacks bolted to high butterfly throttle bodies. There may have been other rally cars from this period with this type of system, so please search your data bases and post pics. There was at least one 'custom' filtration system on a 2.5L ST engine that is shown in the attached pics, plus a 78 Martini rally car using a 72 style oil console.

[Flat Six, inc.]

I wish someone would do a good reproduction of the SC/RS filter housing...they were cool. In the meantime, I've fitted these screens available from Pegasus...

[Flat Six, inc.]

Stolen from the interwebs....

[Flat Six, inc.]

More stolen pic...

[popowitz]

I wish someone would do a good reproduction of the SC/RS filter housing...they were cool. In the meantime, I've fitted these screens available from Pegasus...

Elevenparts has a reproduction.

http://elevenparts.com/index2.php?f=rare&p=racing

[letsrollbabe]

Back in the 90s a company called Race Force in the SF Bay area offered reproduction systems as shown in this ad. They also offered many rare Sports Purpose parts from Porsche, but alas, they are no more. This system is a hybrid of the early MFI air filter housing with larger velocity stacks (50 mm bore), with short (approx. 2") intermediates which fit the top of high butterfly throttle bodies. I have acquired the velocity stacks and intermediates for this system (thanks to Gordon Ledbetter) and plan to try it on my factory high butterfly TBs for the Kremer ST to see how it performs.

I suspect that most private rally teams used the stock S engines of the day with their inlet housings, but there must have been a few HB twin plug engines used for rally work which needed filtration protection in off road work. The factory retrofitted the 'Bruno Car' in the early/mid 70s with a single plug high butterfly engine which is the only time I have seen a documented factory effort utilizing a single plug ignition with HB induction and with a stock inlet filtering. There must be other cars that were modified or built like by the factory....

[Mr9146]

Just run 'em open...

[boba]

While these photos below are slides and not High Butterfly they are similar to prototypes in development which will be able to be fitted on High Butterfly, carbs, and pre-'72 MFI. The first prototype will be for HB.

[mrg3.6]

Not used him before, but I see that Ben Coles also supplies the split stacks in the UK:

See item 51 - http://www.bencoles.co.uk/

Martin

[Flat Six, inc.]

Cool!...lots of great parts....