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markm
11-20-2012, 12:01 PM
I have had to bring my 85 Olds Cutlass out of retirement this week because my mothers car was in body shop for a minor incident and I loaned her my Impala. After driving the Cutlass with front & rear sway bars and 14x6 chrome ralleys with 205/70/14s, my 56 with front and rear sway bars and 500 PS and 15x6 TTDs& 225/70/15s handles somewhat disappointing. Both cars have decent gas shocks and alignments by same guy who is best around. Is it the Cutlass lower stance and aero dynamics that makes the difference. I believe the weight to be close between the two, 307 Olds vs SBC in 56.

Maddog
11-20-2012, 01:45 PM
I would guess it's front steer(Olds) vs rear steer(Tri5) mainly and other components just more modern, like gear box in the Olds. The lower car will make a big difference also.

markm
11-20-2012, 01:57 PM
I would guess it's front steer(Olds) vs rear steer(Tri5) mainly and other components just more modern, like gear box in the Olds. The lower car will make a big difference also.

I acknowlege the ft vs rear steer thing but the funny thing is my first gen Camaro handles about the same as my second gen Z28, I cheated a little by installing a low milage 77 Z28 PS box on the 67 in early 80s. It was a bolt on deal and a fellow came by work that night and sold me a factory tilt for $15. Work was a junk yard in those days and the PS box was free.

chevynut
11-20-2012, 02:02 PM
See markm, you need a C4 chassis!!! I have heard from a lot of guys who have done bolt-on upgrades on Tri5s and are disappointed with the results. I don't understand why front-steer versus rear steer would make any difference. It could be spring rate.

Rick_L
11-20-2012, 02:57 PM
Why would you think that front steer vs. rear steer would make any difference?

There are only 2 factors on the front vs. rear steer to my way of thinking. One is Ackerman. You could really screw up if you used rear steer steering arms on a front steer car, and vice versa. Lots of cars don't have 100% Ackerman, it's not that sensitive unless you have reverse Ackerman! The onlly other deal is that the wheels naturally try to toe out as you go down the road, and front steer might be better when you drive really hard because the linkage is in tension. But I don't think you'd ever notice it in everyday driving.

The steering box shouldn't make a real difference, the CPP500 is the same technology and ratio as the Cutlass' Saginaw 800 box.

Some of it might be the sway bar rate, might be more on the Olds. And the higher center of gravity on the 56 if it's not lowerd will make it roll more with equal springs and sway bars. Some of the difference may even be where you sit in the car. You are higher up in the 56.

While the tire sizes you post aren't that different, it could just be the particular tires on either car.

All that said, I've never seen anyone rave about an 85 Cutlass' handling either.

Maddog
11-20-2012, 03:35 PM
A lot of it could be in the rear also, the Olds is probably a 4 link type coil spring vs the ancient leaf springs.

Rick_L
11-20-2012, 04:38 PM
Yeah but the 4 bar under a 85 Cutlass is pretty ancient stuff too. Either one is a dog if the parts are deteriorated.

markm
11-20-2012, 04:51 PM
[QUOTE=Maddog;6375]A lot of it could be in the rear also, the Olds is probably a 4 link type coil spring vs the ancient leaf springs.[/QUOT

You are correct, all I have done to rear is add a f-41 sway bar and a posi to the 2.14 geared 7.5 ten bolt.

Ok I learned something I always wondered about ft steer vs rear steer no big deal. I guess my Camaros prove that anyway.

Call me different but I really like the was a RWD Cutlass drives, last of the cars that I really like, never been a fan of R&P, ft wheel drive and struts.

frogman21758
11-20-2012, 05:43 PM
[QUOTE=chevynut;6365]See markm, you need a C4 chassis!!! QUOTE]

How did I know you'd say that Laszlo...Lol

chevynut
11-22-2012, 08:31 AM
Mark, what do you mean by "handles somewhat disappointing"? Is it the ride quality/stiffness, steering feel, body roll, braking, or something else?

There's a lot of variables that can affect these things. Spring rates will affect ride quality, caster and scrub radius will affect steering, swaybar rate and spring rate as well as CG will affect body roll, and there's a multitude of other things that affect "handling".

It's a well-known fact that you can't get any significant caster with stock tri5 suspension parts. That will make a big difference in the way the car tracks the road.

frogman21758
11-22-2012, 10:47 AM
As Laszlo points out there are many variables that determine how the suspension will handle. You can greatly improve the handling of your suspension by lowering the CG, adding the tubular control arms with added caster, adjustable coil overs, sway bars, rack and pinion and the like. However nothing can replace a suspension that was designed and engineered, start to finish, with the best technology today has to offer.....thus making the C4 suspension conversions that Laszlo does very attractive for a trifive conversion...particularly when the cost of an Art Morrison or the like is out of reach...

markm
11-22-2012, 04:01 PM
I the 56 is as good as its going to get because I think you guys are right to handle better I need to lower car and thats not going to happen. I am going to go with a 59 Impala wheel, which I hope 1.5 less wheel diameter helps. My 55 on the other hand will get a trip to the frame shop for crossmember spread. Tubular a arm do not fit the look that I am after 56 is a early mid 60s look and 55 is late 60s early 70s, I can tell you guys one thing for sure there is a big difference in the way a 500 box feels with a 13 vs 18 steering wheel.