Suspension set ups for Autox

I just bought a 18 1.8 and will be doing autox with it. Not seeing many people with suspension mods.
I want a compromise of lowered/stiff and every day driveability. Was thinking a Bilstein coilover set up. Is there djustable camber from the factory or will I need camber bolts etc?

Are you running with any specific organization and do you know what class are you aiming to be competing in? If you are looking to be competitive thats where you need to start. If you just want to do it for fun it isn't as important.

Factory strut has very little camber adjustment. You can go with after market control arms or camber plate to add more front camber. Rear camber is adjustable on these cars.

xtina said:

I just bought a 18 1.8 and will be doing autox with it. Not seeing many people with suspension mods.
I want a compromise of lowered/stiff and every day driveability. Was thinking a Bilstein coilover set up. Is there djustable camber from the factory or will I need camber bolts etc?

Click to expand...

I autocross a GSW 1.8t automatic. I have 30 plus events, mostly in this car. I compete in a tire width restricted modified class at my club. The class you choose to compete in may dictate your mods. I would study classing at your local club. I would drive the car bone stock, nannies disabled for a while before throwing money at it, especially if you haven't competed in autocross yet.

From an SCCA stock classing perspective, the 1.8t is behind the eight ball as there are more powerful cars, including the GTI, in its class.

I have similar objectives for daily driveability though I'm not a fan of lowering on this platform.

I have a thematic approach (again, permitted in my modified class).

Keep the front soft and concentrate on improving alignment (negative camber).

Firm up the rear to help the car rotate.

For front alignment, I have adjustable camber plates. They are a compromise for DD but if you keep the front soft and stick with 15" or 16" wheels, they are quite tolerable and add a lot of steering feel. There are other solutions to improve camber, but with less change and no adjustability. Note that all of this is verboten in SCCA stock.

For the rear, I have the gti 22mm swaybar, koni shocks, and bump springs to tune firmness. The rear can be tuned considerably simply by changing the amount of shaft travel before engaging the bump springs (as well as tone things down for the street).

The sway and the shocks are SCCA stock legal, the bump springs are not.

Wheels and tires are currently 195 55r15 for events and 195 65r15 for street.

Overall, daily driveability is firmer than stock but not bad at all. I would bet it's more pleasant than a GTI on 18s and summer tires, but haven't done the comparison.

I took this approach after about a dozen events in this car and getting feedback and instruction, and after reading Dennis Grant's "Autocross to Win" website. I am by no means a great driver but I'm steadily improving.

Finally, a while back before I bought this car, an experienced track person told me (for track) the hierarchy for getting faster is:

Driver -> Tires -> Alignment -> Shocks -> Springs -> Sways.

I think a lot of it rings true for autocross, though classing may dictate otherwise.

In SCCA "Street" classing(where GTI is most competitive in) Sway bar is probably the first thing you tackle after you are on the correct tires. And generally it will have the most effect. I would put dampers last but if you change spring rates you'd want to do dampers.

Odessa, interesting setup. i never thought about bump spring on the strut to increase rear rate. Would you provide any details on the spring rate or supplier of the parts?

I have been toying with shorter front bump stops (CSS p/n) on my stock setup when i eventually add camber plates (fixed or adj, tbd) to reduce the front roll rate and increase travel. Any thoughts?

-Jonathan

00Zero said:

I have been toying with shorter front bump stops (CSS p/n) on my stock setup when i eventually add camber plates (fixed or adj, tbd) to reduce the front roll rate and increase travel. Any thoughts?

Click to expand...

I don't understand this sentence. Shorter bumpstop will increase travel but it won't reduce rate.

00Zero said:

Odessa, interesting setup. i never thought about bump spring on the strut to increase rear rate. Would you provide any details on the spring rate or supplier of the parts?

I have been toying with shorter front bump stops (CSS p/n) on my stock setup when i eventually add camber plates (fixed or adj, tbd) to reduce the front roll rate and increase travel. Any thoughts?

-Jonathan

Click to expand...

these are 300lb springs from slade shock technology. they sell softer and firmer springs. hyperco, eibach and others sell them, though most are at much higher rates.

saw these and thought they'd be a fun experiment. koni yellows are currently set to 1/2 turn from full soft. I started out with minimal clearance, packed almost to zero. car was very lively and it could get away from less-experienced me rather suddenly. spun the car on three successive events. car rotated very easily, just a handful if I went into a slalom too hot. now running with about 5/8 clearance and it seems better overall and I can run them this way on the street without worry.

you could do something similar with fully packed and firm bump stop material, which I tried, or spring rubbers, which I haven't tried.

regarding front bumps, I found out accidentally (thanks to a buddy autoxer) that my vorshlag plates took away about an inch of strut travel. no big deal really but I'm almost riding on my bump stops now. I plan to cut them to add at least a 1/2 inch travel. this is just one reason why I'm not inclined to lower.

different plates have different tradeoffs. I believe the gc plates and the 034s do not have the strut travel issue, at least in certain configs.

overall I want my front to have plenty of camber and allow it to use it with softer springs and adequate travel. also think it's easier to add spring rate back (by packing bumps, spring rubbers etc) than take it away.

you could cut your bumps or get shorter ones. if you don't like the results then you can pack them back to where they were.

if you go with plates, research carefully. your springs and your strut sway link connection can limit adjustment. my stock springs prevent full adjustment and I'm planning a spring change (at roughly stock rate) to provide clearance for full adjustment.

RacingManiac said:

I don't understand this sentence. Shorter bumpstop will increase travel but it won't reduce rate.

Click to expand...

By increasing the front bump travel you engage the progressive rate bump stop later. That means more roll before the bump stops start adding to the spring rate, this would reduce the resistance to front roll, decreasing front roll rate.

I think my logic is correct but my terminology may be off. Correct me if I am wrong

-Jonathan

odessa.filez said:

these are 300lb springs from slade shock technology. they sell softer and firmer springs. hyperco, eibach and others sell them, though most are at much higher rates.

saw these and thought they'd be a fun experiment. koni yellows are currently set to 1/2 turn from full soft. I started out with minimal clearance, packed almost to zero. car was very lively and it could get away from less-experienced me rather suddenly. spun the car on three successive events. car rotated very easily, just a handful if I went into a slalom too hot. now running with about 5/8 clearance and it seems better overall and I can run them this way on the street without worry.

you could do something similar with fully packed and firm bump stop material, which I tried, or spring rubbers, which I haven't tried.

regarding front bumps, I found out accidentally (thanks to a buddy autoxer) that my vorshlag plates took away about an inch of strut travel. no big deal really but I'm almost riding on my bump stops now. I plan to cut them to add at least a 1/2 inch travel. this is just one reason why I'm not inclined to lower.

different plates have different tradeoffs. I believe the gc plates and the 034s do not have the strut travel issue, at least in certain configs.

overall I want my front to have plenty of camber and allow it to use it with softer springs and adequate travel. also think it's easier to add spring rate back (by packing bumps, spring rubbers etc) than take it away.

you could cut your bumps or get shorter ones. if you don't like the results then you can pack them back to where they were.

if you go with plates, research carefully. your springs and your strut sway link connection can limit adjustment. my stock springs prevent full adjustment and I'm planning a spring change (at roughly stock rate) to provide clearance for full adjustment.

Click to expand...

Thanks for the info. good to know about the vorshlag plates, I'm currently leaning towards 034 if the sportwagen can supprot the added -1.4degrees.

Good luck with the front spring change and let us know how it goes. If you can get a rear coil-over adjuster some 5-6k swift spring would go pretty good back there too, if my math isn't too far off

-Jonathan

00Zero said:

By increasing the front bump travel you engage the progressive rate bump stop later. That means more roll before the bump stops start adding to the spring rate, this would reduce the resistance to front roll, decreasing front roll rate.

I think my logic is correct but my terminology may be off. Correct me if I am wrong

-Jonathan

Click to expand...

Thats correct assuming you are on the bump stop a lot. At the same time too what is the logic for wanting less front roll rate.

RacingManiac said:

Thats correct assuming you are on the bump stop a lot. At the same time too what is the logic for wanting less front roll rate.

Click to expand...

Lower front roll rate should shift the roll stiffness to the rear, reducing understeer a small amount, but i would consider it a bonus in addition to more bump travel.


-Jonathan

For these cars where camber control is a at a premium and we don't have a whole lot of roll stiffness to start with, unless you have some specific limit to add rear roll stiffness I don't see the need to reduce roll resistance on one end to shift balance.

I understand your point, a rear sway bar or stiffer rear springs will be more effective. (I plan on a Clubsport S or 22mm rear come spring)

I figure, if I'm in there installing a camber plate and can add 15mm of bump travel and reduce understeer a littler bit more with out increasing stiffness, why not?

I assume it can't be too out of line if a softer front bumpstop was specked on the Clubsport S for the same reasons.

https://www.pistonheads.com/features/ph-features/golf-gti-laid-bare/33369


-Jonathan

Clubsport also have stiffer springs and damper tuning. And is lowered. It would make sense to allow for more bump travel for that car to absorbed the bumps as it will have less travel to start with.

springs

Jen I thought dampers can be changed but must use stock springs in the street classes