Sway Bars

[Troy G.]

Did 1975 small block standard corvettes come with rear sway bars ? Or was it a special order or maybe a option ?

[Joe L.]

Re: Sway Bars

Did 1975 small block standard corvettes come with rear sway bars ? Or was it a special order or maybe a option ?

Troy-----


For 1975, a rear sway bar was installed only if FE-7 suspension or the Z-07 performance package was installed on the car. It was not otherwise available.

[Troy G.]

Re: Sway Bars

Thanks Joe,

I might add one if I can find NOS parts. So much for this car being all orginal. Will it matter if it is a big block or small block sway bar?

Troy

[John H.]

Re: Sway Bars

Thanks Joe,

I might add one if I can find NOS parts. So much for this car being all orginal. Will it matter if it is a big block or small block sway bar?

Troy

Troy -

It's not a great idea to add a rear stabilizer bar without compensating for it with a stiffer front bar; if you just add a rear bar, it will increase rear roll stiffness and the tendency for oversteer, particularly at the limit.

[Troy G.]

Re: Sway Bars

Thanks,
You guys are the stuff. We will leave it alone and spend the money on gas or NCRS membership!

[Duke W.]

Re: Sway Bars

IIRC the '74 FE7 suspension option was basically the same at F-40 from the sixties, which was the same as the '63 Z-06 setup - 15/16" front bar, 550/305 lb/in springs and no rear bar.

FE7 used the same springs, but increased the front bar size to 1 1/8" inch. Too compensate for the greater front roll stiffness due to the larger front bar, which would have increased understeer with no other changes, a rear 7/16" bar was added to rebalance the roll stiffness.

This setup would work okay in a big block, but it would understeer more than a small block due to the greater front end mass.

The F-41 suspension for sixties big blocks used the same springs with the 15/16" front bar and a 9/16" rear bar. Looking at the bars you can see that the big block has less understeer bias due to the greater front end mass, which naturally increases understeer.

F-41 (big blocks) involved the same substituition of parts as F-40 (small blocks) The difference is that the base big block suspension included a 9/16" rear bar, and this remained in place with F-41.

Duke

[Joe L.]

Re: Sway Bars

IIRC the '74 FE7 suspension option was basically the same at F-40 from the sixties, which was the same as the '63 Z-06 setup - 15/16" front bar, 550/305 lb/in springs and no rear bar.

FE7 used the same springs, but increased the front bar size to 1 1/8" inch. Too compensate for the greater front roll stiffness due to the larger front bar, which would have increased understeer with no other changes, a rear 7/16" bar was added to rebalance the roll stiffness.

This setup would work okay in a big block, but it would understeer more than a small block due to the greater front end mass.

The F-41 suspension for sixties big blocks used the same springs with the 15/16" front bar and a 9/16" rear bar. Looking at the bars you can see that the big block has less understeer bias due to the greater front end mass, which naturally increases understeer.

F-41 (big blocks) involved the same substituition of parts as F-40 (small blocks) The difference is that the base big block suspension included a 9/16" rear bar, and this remained in place with F-41.

Duke

An interesting note: 1969 ZL-1's were equipped with F-41 suspension and, as far as I know, a rear sway bar like all big blocks. However, the ZL-1 engine weighed slightly less than a base engine small block.

[Duke W.]

Re: Sway Bars

Yes, that is interesting. A dressed ZL-1 probably weighed about the same as the dressed base 350 - something on the order of 550 -600 pounds.

The '67 AMA spec list the "427 engine" option at 175 pounds, which is probably all on the front end.

Duke

[Lynn H.]

Re: Sway Bars

Did 1975 small block standard corvettes come with rear sway bars ? Or was it a special order or maybe a option ?

Troy,
ALL the Corvettes were small block cars in 1975, so any rear sway bar set up after 74 production would have been on a small block car.
Lynn