I have been looking the Sprint exhaust as part of my long term sprint conversion (now have axle and subframe). It just seems an odd design, I always thought the best exhaust system had a flow with minimal changes of direction, to reduce resistance. Both Sprint silencers seem to require the exhaust flow to do a 180 degree turn.
Was this done, because the Sprint needed large silencers that wouldn't fit any other way? Is there another reason for it? Would it be possible to redesign the system without these bottlenecks and still keep the car road legal?
Is there a reason for the sprints convoluted exhaust?
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cleverusername
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Re: Is there a reason for the sprints convoluted exhaust?
Sprint sports exhaust.
Re: Is there a reason for the sprints convoluted exhaust?
The sports exhaust has a free run down the n/s without being excessively noisy (from the divers seat at least) so if it has 2 silencers it'll be fine.
Tony
Tony
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cleverusername
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Re: Is there a reason for the sprints convoluted exhaust?
Wouldn't the fuel tank be an issue if you ran it down the n/s?tony g wrote:The sports exhaust has a free run down the n/s without being excessively noisy (from the divers seat at least) so if it has 2 silencers it'll be fine.
Tony
Re: Is there a reason for the sprints convoluted exhaust?
I think the standard system was designed the way it is for packaging.
The cross silencers are raised into the space under the front seats.
The front box of the sports system ends up much lower and is invariably crushed at some point in its life.This does nothing for its flow characteristics and makes them rattle and resonate.
The biggest issue is the over axle rear section though. The standard system is split into two smaller diameter pipes so that it can be flatly packaged against the body in this area, avoiding contact with the axle at large suspension deflections. It also goes over the axle inboard of the near side trailing arm bracket on the axle and then the pipes flick back out to the near side to avoid the tank well.
For the rear box of the sports system to sit nice and straight up the near side of the tank well the over axle pipe ends up in line with the trailing arm bracket on the axle. This means the hand brake cable mount hits and scrapes the pipe on big bumps or with the car loaded.
The rubber bobbin mounting system is also very poor and they tend to tear under tension.
The standard system may not be the ultimate design for flow, but it is at least fit for purpose.
The cross silencers are raised into the space under the front seats.
The front box of the sports system ends up much lower and is invariably crushed at some point in its life.This does nothing for its flow characteristics and makes them rattle and resonate.
The biggest issue is the over axle rear section though. The standard system is split into two smaller diameter pipes so that it can be flatly packaged against the body in this area, avoiding contact with the axle at large suspension deflections. It also goes over the axle inboard of the near side trailing arm bracket on the axle and then the pipes flick back out to the near side to avoid the tank well.
For the rear box of the sports system to sit nice and straight up the near side of the tank well the over axle pipe ends up in line with the trailing arm bracket on the axle. This means the hand brake cable mount hits and scrapes the pipe on big bumps or with the car loaded.
The rubber bobbin mounting system is also very poor and they tend to tear under tension.
The standard system may not be the ultimate design for flow, but it is at least fit for purpose.
1979 Carmine Dolomite Sprint
1974 Saphire Dolomite Sprint (Soon to be tastefully modified)
2005 Mystic blue BMW M3
2004 Mystic Blue 330d
2001 Peugeot 206 Hdi180
1974 Saphire Dolomite Sprint (Soon to be tastefully modified)
2005 Mystic blue BMW M3
2004 Mystic Blue 330d
2001 Peugeot 206 Hdi180
Re: Is there a reason for the sprints convoluted exhaust?
Bear in mind that the Sprint system is designed to push out 135bhp's worth of exhaust, compared to the original 1300 FWD's 58, and you can see why they had to think of something novel to get the gas out without changing the sheet metal on the floor.
As with everything on these cars, "Given the constraints they did a bloody good job".
As with everything on these cars, "Given the constraints they did a bloody good job".