How good is the suspension?
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Robin Fairservice
- Posts: 322
- Joined: Mon Feb 13, 2006 9:11 pm
- Your interest in the forum: Learning about Jowett cars
- Given Name: ROBIN
- Location: Prince George, BC, Canada
Re: How good is the suspension?
Obviously some TNF'ers have a good taste in cars!
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Chris Gibson
- Posts: 11
- Joined: Mon Dec 28, 2009 1:45 pm
- Your interest in the forum: No Jowett now. Previous Javelin owner. Still willing to help Jowett owners.
- Given Name: Chris
- Location: Doncaster, United Kingdom
Re: How good is the suspension?
Returning to suspension, I have been looking for alternatives to the Panhard rod that would provide a more transversally linear movement to the rear axle.
The system adopted by the Lotus Seven Mk 2 would appear to offer some advantages. This car had the rear axle mounted on similar trailing arms to the Javelin but lateral location was achievd by triangulating the lower arms with rods from their chassis pivot points to a point below the differential in line with the lower axle pivot, in effect an A shaped stabiliser. As the Javelin lower pivots are in line with the lower part of the diff. casing two axle mountings would be required one each side of the casing, either welded to it or bolted using the rear cover bolts.
One disadvantage is that the roll centre is lowered to the point below the diff. leading to increased body roll. This could be countered by an anti-roll bar attached to the lower trailing arms. I have a drawing of the above arrangement which I can email to you as a pdf, I haven't figured out how to insert it here.
I am no suspension expert. The last paragraph was gleaned from a copy of ‘Racing and Sports Car Chassis Design’ by Mike Costin (of Lotus, Marcos and Cosworth fame) and David Phipps. They cover many Lotus suspensions but unfortunately not the Seven.
On another tack, Javelin aerodynamics was investigated by The Autocar in a May 1982 issue when they tested several vehicles in the MIRA wind tunnel. They also collated aerodynamic information from many current vehicles tested in various tunnels.
The Javelin fared well with a drag coefficient (Cd) of 0.41, but the coeff. of lift at the rear was higher than expected at +0.17, suggesting that the tail was too steeply raked leading to air separation. Whilst it may not look very good I guess a rear spoiler should improve things.
For comparison the Cd figures for the 1955 long nosed Le Mans winning D type Jaguar was 0.49 and a 1962 Lotus Elite was 0.35. These results ignore the frontal area which affects the total drag on the vehicle. Even by ’82 standards the Javelin was good, beating most Fords, Morrises, Peugeots, Renaults and Volvos.
While finding this info I also came across a copy of Automobile Engineer that analysed the Ferguson R5 flat 4 engine, but I’ll keep that discussion for another time. If only you could persuade our esteemed President to part with one from the Coventry Motor Museum!
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The system adopted by the Lotus Seven Mk 2 would appear to offer some advantages. This car had the rear axle mounted on similar trailing arms to the Javelin but lateral location was achievd by triangulating the lower arms with rods from their chassis pivot points to a point below the differential in line with the lower axle pivot, in effect an A shaped stabiliser. As the Javelin lower pivots are in line with the lower part of the diff. casing two axle mountings would be required one each side of the casing, either welded to it or bolted using the rear cover bolts.
One disadvantage is that the roll centre is lowered to the point below the diff. leading to increased body roll. This could be countered by an anti-roll bar attached to the lower trailing arms. I have a drawing of the above arrangement which I can email to you as a pdf, I haven't figured out how to insert it here.
I am no suspension expert. The last paragraph was gleaned from a copy of ‘Racing and Sports Car Chassis Design’ by Mike Costin (of Lotus, Marcos and Cosworth fame) and David Phipps. They cover many Lotus suspensions but unfortunately not the Seven.
On another tack, Javelin aerodynamics was investigated by The Autocar in a May 1982 issue when they tested several vehicles in the MIRA wind tunnel. They also collated aerodynamic information from many current vehicles tested in various tunnels.
The Javelin fared well with a drag coefficient (Cd) of 0.41, but the coeff. of lift at the rear was higher than expected at +0.17, suggesting that the tail was too steeply raked leading to air separation. Whilst it may not look very good I guess a rear spoiler should improve things.
For comparison the Cd figures for the 1955 long nosed Le Mans winning D type Jaguar was 0.49 and a 1962 Lotus Elite was 0.35. These results ignore the frontal area which affects the total drag on the vehicle. Even by ’82 standards the Javelin was good, beating most Fords, Morrises, Peugeots, Renaults and Volvos.
While finding this info I also came across a copy of Automobile Engineer that analysed the Ferguson R5 flat 4 engine, but I’ll keep that discussion for another time. If only you could persuade our esteemed President to part with one from the Coventry Motor Museum!
]
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Last edited by Chris Gibson on Mon Jul 26, 2010 4:16 pm, edited 1 time in total.
I have a Javelin in need of full restoration.
Also member of Doncaster Traditional Car Club.
As a student I previously ran a Javelin and my father owned Jav. & Jupiter (in Eire)
Also member of Doncaster Traditional Car Club.
As a student I previously ran a Javelin and my father owned Jav. & Jupiter (in Eire)
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Alastair Gregg
- websitedesign
- Posts: 757
- Joined: Sun Aug 27, 2006 10:43 pm
- Your interest in the forum: E2 SA 922 HKY 770
D7 CB 6079 CVG 166
E2 PD 22113 MVU 377 - Given Name: Alastair
- Location: Corrie, Isle of Arran.
Re: How good is the suspension?
The 1970's Audi boasted 0.26 drag co efficiency.
Compliments of the Season,
Alastair Gregg
Alastair Gregg