Raising not Racing !!

[Misho]

A friend's dad owns a 92 Cadillac STS. He thinks its too low and is causing him a lot of trouble and now he wants to raise it a bit. He asked me if that will cause any negative side effects?
Anyone has a knowledgable answer that could help me add insight to this guy and help him decide wether to go ahead or not ??

[Matra et Alpine]

A friend's dad owns a 92 Cadillac STS. He thinks its too low and is causing him a lot of trouble and now he wants to raise it a bit. He asked me if that will cause any negative side effects?
Anyone has a knowledgable answer that could help me add insight to this guy and help him decide wether to go ahead or not ??

Someone who knows the car's suspension will give a more detailed answer.

BUT, in general, raising a car makes it more suseptible to body roll when cornering.

On softly sprung cars it also makes them more likely to move in sidewinds.

You can get unusual bump-steer effects dependant on where the steering arm operates. Camber may change dramatically if dual wishbone.

Raising can also limit the amount of travel available going over holes. As the wheels cannot follow the surface you can have anything happen from nasty handling as it hits bump-stops or springs ( or other parts ) coming loose - this is common with springs on arms where damper is not 'coil-over'.

If you're not sure, then I suggest you find a club where members will ahve modified the vehicles already or consult a QUALIFIED engineer !!

If he's only raising it by 1/2 to 1 inch then none of the above are likely to be major issues.

[Misho]

Thanks, I appreciate your help.

I assume he meant raising it by about a couple of inches (5cm). Its a very uncommon car over here and I dont think there is such a thing such as a car club, or someone with previous experience on this issue and most of all, i dont think there is such a thing as a qualified engineer !!

[Matra et Alpine]

Thanks, I appreciate your help.

I assume he meant raising it by about a couple of inches (5cm). Its a very uncommon car over here and I dont think there is such a thing such as a car club, or someone with previous experience on this issue and most of all, i dont think there is such a thing as a qualified engineer !!

Do a search on the web for a club somewhere else and write to the secreatery.
Any club in the UK would certainly help with some advice !!
Can't speak for anywhere else

[henk4]

Someone who knows the car's suspension will give a more detailed answer.

BUT, in general, raising a car makes it more suseptible to body roll when cornering.

On softly sprung cars it also makes them more likely to move in sidewinds.

You can get unusual bump-steer effects dependant on where the steering arm operates. Camber may change dramatically if dual wishbone.

Raising can also limit the amount of travel available going over holes. As the wheels cannot follow the surface you can have anything happen from nasty handling as it hits bump-stops or springs ( or other parts ) coming loose - this is common with springs on arms where damper is not 'coil-over'.



If you're not sure, then I suggest you find a club where members will ahve modified the vehicles already or consult a QUALIFIED engineer !!

If he's only raising it by 1/2 to 1 inch then none of the above are likely to be major issues.

Very interesting, just wondering whether the same issues come up when you lower a car, actually i think not, because that's done very often without any problem. Creating more negative camber seems to be less problematic than positive camber.

[Egg Nog]

Just get some thick polyeurethane spacers made. I don't have any engineering background as these guys do, but I think it's probably the cheapest way to do this.

...or you could just use metal ones, but then you wouldn't get to say "polyeurethane"

+1 For this thread, it's brought up a lot of great information.

[Matra et Alpine]

Very interesting, just wondering whether the same issues come up when you lower a car, actually i think not, because that's done very often without any problem. Creating more negative camber seems to be less problematic than positive camber.

Neg camber is better, so you're right most times it's not an issue.
But all the other issues can come to the surface dependant on the suspension design.
Too much neg camber can make it difficult to keep rubber on the deck
Hitting bump stops is the major problem when you lower a car as when that happens you've lost progressive 'give' in the handling of the car and it will do odd things.
( My personal experience of this was at Brands where I took the dip before Hailwood hill with the suspension 'wound' up after taking the right hander too quickly. When I hit the dip the whole car just snapped direction and I ended up in the barriers. Spending time int he pits repairing the car I got LOTS of 'experience' of those who race there regularly that explained that hitting suspension stop IS a major problem there )
Racing cars have much more spohisticated damperes with much highre deamping as the reach minimum length.

[henk4]

Neg camber is better, so you're right most times it's not an issue.
But all the other issues can come to the surface dependant on the suspension design.
Too much neg camber can make it difficult to keep rubber on the deck
Hitting bump stops is the major problem when you lower a car as when that happens you've lost progressive 'give' in the handling of the car and it will do odd things.
( My personal experience of this was at Brands where I took the dip before Hailwood hill with the suspension 'wound' up after taking the right hander too quickly. When I hit the dip the whole car just snapped direction and I ended up in the barriers. Spending time int he pits repairing the car I got LOTS of 'experience' of those who race there regularly that explained that hitting suspension stop IS a major problem there )
Racing cars have much more spohisticated damperes with much highre deamping as the reach minimum length.

Well I wasn't really competition,suspension travel does play a role there as you had to experience. I was more thinking of road use. On another note, while writing this there is an automotive programme going on Romanian televison which just showed one of those US cars that have converted hydraulic suspension, which allows the car to move in almost any direction, even at different angles per side. Could be useful to increase the height of the Caddy. While at home I only have to shift one button in my Citroen and up it goes, at the expense of ride quality though.