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K&N Cold Air Intake
- Thread starter Les
- Start date
Les
I chose K&N cone filters for the HS4 SU's on our 77 MGB because they are the only ones that will fit on the rear carburetor and clear the brake booster. To get maximum benefit from these filters a short stub stack should be used to assure air intake with minimum turbulence. These filters are designed to accomodate stub stacks within the filter body. Peter Burgess' book "How to Power Tune MGB 4-Cylinder Engines" states that the improved air flow provided by the K&N's will require adjustment to the air/fuel mixture. He suggests changing from the standard FX needles to the No. 6 needles. I found this to be true. The No. 6 needle is "richer" and offsets the "lean" condition caused by the improved air flow provided by the K&N's. This has proven to be preferable to simply enriching the mixture. It has not effected fuel economy and provides the full range of power available from the SU carburetors. I can refer you to the parts sources I used if you need them.
I chose K&N cone filters for the HS4 SU's on our 77 MGB because they are the only ones that will fit on the rear carburetor and clear the brake booster. To get maximum benefit from these filters a short stub stack should be used to assure air intake with minimum turbulence. These filters are designed to accomodate stub stacks within the filter body. Peter Burgess' book "How to Power Tune MGB 4-Cylinder Engines" states that the improved air flow provided by the K&N's will require adjustment to the air/fuel mixture. He suggests changing from the standard FX needles to the No. 6 needles. I found this to be true. The No. 6 needle is "richer" and offsets the "lean" condition caused by the improved air flow provided by the K&N's. This has proven to be preferable to simply enriching the mixture. It has not effected fuel economy and provides the full range of power available from the SU carburetors. I can refer you to the parts sources I used if you need them.
Jim,
Thanks for the info, I would have never thought to change any of the fuel supply components to rebalance the air/fuel ratio. With the exception of just using a aftermarket supplier of K&N, any suggested vendors ? Also, what would you think of using one of the crome air intake tubes that those guys are putting on their imports ?
https://www.knfilters.com/typhoon/Typhoon.htm
If I could find the room and a way to attach them to the carbs, I think it might work.
Thanks,
Les
Thanks for the info, I would have never thought to change any of the fuel supply components to rebalance the air/fuel ratio. With the exception of just using a aftermarket supplier of K&N, any suggested vendors ? Also, what would you think of using one of the crome air intake tubes that those guys are putting on their imports ?
https://www.knfilters.com/typhoon/Typhoon.htm
If I could find the room and a way to attach them to the carbs, I think it might work.
Thanks,
Les
Les
The reason for the Typhoon Cold Air System is well stated in the first paragraph of this section of the K&N web site. The engine compartment of modern cars is crammed with equipment. Most MGB's do not suffer from this problem and can perform well without direct access to cold air. Some performance improvement can be realized by ducting cold air to SU carburetors; however, the cost of such a system would likely produce more power if the dollars were spent on the air flow within the cylinder head. I f you are curious about the cone filters and stub stacks, they can be found at Advanced Performance Technology. Web address is www.aptfast.com
The reason for the Typhoon Cold Air System is well stated in the first paragraph of this section of the K&N web site. The engine compartment of modern cars is crammed with equipment. Most MGB's do not suffer from this problem and can perform well without direct access to cold air. Some performance improvement can be realized by ducting cold air to SU carburetors; however, the cost of such a system would likely produce more power if the dollars were spent on the air flow within the cylinder head. I f you are curious about the cone filters and stub stacks, they can be found at Advanced Performance Technology. Web address is www.aptfast.com