GS wheels/tires

[enobiko]

They are, but you have to use stock springs. You can also do different bump stops, but you have to size them to end up with the same amount of travel.

The Bilstein's replacement struts are a street setup (B6 and B8) and aren't what you want for autocross. B16 is a coilover and put you in ST.

I didn't know that about the bump stops... I'm not sure that would help, in any case, I don't think I've hit my bump stops.

The Bilstein B4 are basically stock, the B6 is for "sport", the B8 is for lowered springs, so B8 wouldn't work in GS. But... I was thinking of B6 when mine need replaced... not what I'd want for autocross?? I'd think they would be better than stock. What makes the Koni Sport a better shock for autocross? And, would that also reduce the usefulness for street/Daily Driver?
I have an Eibach RSB, and haven't noticed any negatives for street/DD use. I only have done one AutoX with it, another is coming up on the 18th. Also, zero toe-in on all corners, no negatives that I've noticed. I may need to use more tire pressure with these street tires, but I was overdriving my tires on a very tight course. A little slower entering the tight stuff would have been faster, instead of running wide and scrubbing speed.

 

[GTIfan99]

I didn't know that about the bump stops... I'm not sure that would help, in any case, I don't think I've hit my bump stops.

The Bilstein B4 are basically stock, the B6 is for "sport", the B8 is for lowered springs, so B8 wouldn't work in GS. But... I was thinking of B6 when mine need replaced... not what I'd want for autocross?? I'd think they would be better than stock. What makes the Koni Sport a better shock for autocross? And, would that also reduce the usefulness for street/Daily Driver?
I have an Eibach RSB, and haven't noticed any negatives for street/DD use. I only have done one AutoX with it, another is coming up on the 18th. Also, zero toe-in on all corners, no negatives that I've noticed. I may need to use more tire pressure with these street tires, but I was overdriving my tires on a very tight course. A little slower entering the tight stuff would have been faster, instead of running wide and scrubbing speed.

The konis have adjustable rebound The Bilstein's don't. Konis sports high speed dampening is really good too, good for typical broken surfaces we run on.

 

[xXDavidCXx]

I get that fsb can help reduce camber loss on a McPherson strut, and I experienced just that with my AS STI back in the day, but there's a guy on the forums that finished 2nd at nationals twice with a mk7 and experimented and found a big rear bar was better on these cars if you can only do one bar.

Sam Stranos who is a suspension manufacturer calculated and felt a big rear bar was better for street. He's the guy that recommended the fsb on the GD STI. 32mm of Stranos goodness.

So what information did you use to determine the front sway is part ofthe standard GS build? I don't know anyone running a front bar in GS.

If going STH, front and rear bar are the way to go, but I haven't seen anything indicating that on the mk7 a front bar is more beneficial than the big rear bar.

It's just my gut feeling after all the STH design and research I've done. I know nobody has done it. I would do it if I were to race in GS.

Also, just because one-front runner in STH didn't use a bigger FSB, does not mean there is only one way. What were his spring rates? It can be done without bars with correspondingly stiffer springs. (Side note. I think the top time in STH may have been influenced by a down cone that was never attributed to any car, but I pointed it out on my run, the winner ran before me )

The primary reason I hear for getting a rear bar is
1. It's the "first" mod everyone else does
2. It's easy
3. It's cheap
4. I gEt MaD oVeRsTeEr

None of these reasons are good considering the alternatives allowed in SCCA.

I believe the real problem with the GTI is front grip. Not too much rear grip.

So, we need to reduce the amount of front body roll since the OEM front roll couple is heavily front biased, as in most of the body roll comes from the front suspension. and 60% of the car's weight is over the front axle, aka 1000 lbs per corner static.

Also, if anyone watches a stock GTI with good tires drive a sweeper or a quick transistion, you may notice the rear tire picking up off the ground. Three wheeling.

What a siffer rear bar does, is allow the rear inside tire to lift higher. The issue is, if the tire is already off the ground, going higher is not helping. But what changes is how soon the tire lifts, not if it lifts.

This sooner lift can cause unpredictable and abrupt changes in rear grip and handling.

So I believe the best choice is to try and limit front camber loss with the front bar, use rear toe out to get the rear tires to follow the front tires using a larger scrub radious and enjoy drama free grip filled corners.

I think drivers are overly scared of rear toe changes and tire wear. Which I find ironic when a set of tires will last maybe a season depending on the # of events and how much wear the front tires get due to lack of camber and driver induced, and OEM alignments.

Other benefits of the FSB:
1. Better turn in
2. Better slolom response
3. Reduced rear tire pressure, possibly better tire wear, may need to reduce rear camber

Possible negative side-effects
1. Too much front bar does lift the front inside tire on track out and limits power down without a differential. With the VAQ it heats the inside brakes a lot.
2. The correct alignment reqiures some testing

I would love to co-drive a few events with a local GS GTI to prove my theory correct.

 

[GTIfan99]

It's just my gut feeling after all the STH design and research I've done. I know nobody has done it. I would do it if I were to race in GS.

Also, just because one-front runner in STH didn't use a bigger FSB, does not mean there is only one way. What were his spring rates? It can be done without bars with correspondingly stiffer springs. (Side note. I think the top time in STH may have been influenced by a down cone that was never attributed to any car, but I pointed it out on my run, the winner ran before me )

The primary reason I hear for getting a rear bar is
1. It's the "first" mod everyone else does
2. It's easy
3. It's cheap
4. I gEt MaD oVeRsTeEr

None of these reasons are good considering the alternatives allowed in SCCA.

I believe the real problem with the GTI is front grip. Not too much rear grip.

So, we need to reduce the amount of front body roll since the OEM front roll couple is heavily front biased, as in most of the body roll comes from the front suspension. and 60% of the car's weight is over the front axle, aka 1000 lbs per corner static.

Also, if anyone watches a stock GTI with good tires drive a sweeper or a quick transistion, you may notice the rear tire picking up off the ground. Three wheeling.

What a siffer rear bar does, is allow the rear inside tire to lift higher. The issue is, if the tire is already off the ground, going higher is not helping. But what changes is how soon the tire lifts, not if it lifts.

This sooner lift can cause unpredictable and abrupt changes in rear grip and handling.

So I believe the best choice is to try and limit front camber loss with the front bar, use rear toe out to get the rear tires to follow the front tires using a larger scrub radious and enjoy drama free grip filled corners.

I think drivers are overly scared of rear toe changes and tire wear. Which I find ironic when a set of tires will last maybe a season depending on the # of events and how much wear the front tires get due to lack of camber and driver induced, and OEM alignments.

Other benefits of the FSB:
1. Better turn in
2. Better slolom response
3. Reduced rear tire pressure, possibly better tire wear, may need to reduce rear camber

Possible negative side-effects
1. Too much front bar does lift the front inside tire on track out and limits power down without a differential. With the VAQ it heats the inside brakes a lot.
2. The correct alignment reqiures some testing

I would love to co-drive a few events with a local GS GTI to prove my theory correct.

Guys in GS did try it, they chose rsb.

I had zero issue with turn in with my GS setup and a little toe out in front. Zero rear toe allowed lower rear tire pressures. I ran as low as -1 in the rear, and the car was too loose in slaloms. Zero rear toe and -1.8 camber in the rear was perfect. It allowed nice rotation in corners and perfect in the slaloms.

I 100% agree it's optimal to do both , but if you can only choose 1, on this platform, the RSB is the way to go.

 

[xXDavidCXx]

Guys in GS did try it, they chose rsb.

Their choice. Did they try a rear toe out alignment?

I had zero issue with turn in with my GS setup.

I said FSB helps turn in, not that there is no turn in

I 100% agree it's optimal to do both , but if you can only choose 1, on this platform, the RSB is the way to go.

Agree to disagree

 

[GTIfan99]

Their choice. Did they try a rear toe out alignment?

I said FSB helps turn in, not that there is no turn in

Agree to disagree

Then spend two years building a GS car and half a dozen alignment variations and prove me wrong. I built 2 GS mk7's.

I've greatly appreciated your input on my STH build and tire pressures on these cars in general, but I'm talking from my experience and repeating what the fastest mk7 in the country found during his 3 years of development.

You can disagree if you like, but you have no basis to do so.

 

[xXDavidCXx]

Then spend two years building a GS car and half a dozen alignment variations and prove me wrong. I built 2 GS mk7's.

I've greatly appreciated your input on my STH build and tire pressures on these cars in general, but I'm talking from my experience and repeating what the fastest mk7 in the country found during his 3 years of development.

You can disagree if you like, but you have no basis to do so.

If you didn't try my formula, you don't have a basis to tell me I'm wrong.

Also, I don't think you understand what disagree means.

 

[GTIfan99]

If you didn't try my formula, you don't have a basis to tell me I'm wrong.

Also, I don't think you understand what disagree means.

You have tried either. And others have tried fsb only and rsb only in multiple sizes.

You're welcome to disagree, your just doing so without actual basis to disagree other than your unsupported opinion.

 

[Roald]

I recognize that we've migrated a away from wheels and tires...but since we're here!


Typically the lots we run on have a ton of off camber turns. Is that normal? Most videos show nice flat lots, but ours is pitched up in the middle to facilitate draining to the outside or edges.
It has a really great surface, very smooth, no cracks, or weird bumps its a relatively new lot but it's basically pyramid shaped. And the other is SIGNIFICANTLY older and the surface is very loose/rough.

On both tracks that rear inside tire is up A LOT on FWD cars, but it was the loose/old track that really showed the issue with corner entry techniques and GS suspensions. What I notice is that, especially the hatches... on entry, you have front loading as the car pitches forward during braking, then the turn, but the momentum is still pushing most of the car, and it's weird shaped high CG rear portion. As a result, that back inside wheel comes up but the fronts are still down, however they're out of good/negative camber because they're still super compressed. The car mostly maintains this stance until straightened out at which point you have good camber and momentum and are moving toward the next gate and the whole thing starts over.

Ideally you would be braking earlier, and attempting to accelerate or at least not dive into the apex to change that suspension loading, but you're still going to run out of camber because of the cars geometry.
At which point keeping the rear under control and flat would be a big benefit.

Is the issue with RSB that folks are generally driving them incorrectly on FWD?
It makes sense that the FSB would keep the fronts in positive camber by connecting them more.
It also seems reasonable that rear camber would help to push the rear inside down or at least resist roll more.


I'm curious as to what the group that tested their GS setups and chose RSB found when running FSB. What were the drawbacks that were actually experienced?
Doing a RSB in a FWD is counter intuitive. Basically any suspension article for AutoX recommends a FSB. So what is really happening that makes RSB function...differently/better? Is it the softer suspension? Keeping the rear flatter actually does translate to keeping the front planted and in contact?

Im genuinely curious and am trying to understand this. I didn't grow up racing in anyway, but I am pretty handy and mechanically inclined. So I'm trying to make up for lost experiences at 35.
Am i getting it in any way?


Really it seems like the solution is "stiffer suspension" which is beyond GS, but man I really want to do it. Point a guy towards a good STH suspension?

 

[GTIfan99]

I recognize that we've migrated a away from wheels and tires...but since we're here!


Typically the lots we run on have a ton of off camber turns. Is that normal? Most videos show nice flat lots, but ours is pitched up in the middle to facilitate draining to the outside or edges.
It has a really great surface, very smooth, no cracks, or weird bumps its a relatively new lot but it's basically pyramid shaped. And the other is SIGNIFICANTLY older and the surface is very loose/rough.

On both tracks that rear inside tire is up A LOT on FWD cars, but it was the loose/old track that really showed the issue with corner entry techniques and GS suspensions. What I notice is that, especially the hatches... on entry, you have front loading as the car pitches forward during braking, then the turn, but the momentum is still pushing most of the car, and it's weird shaped high CG rear portion. As a result, that back inside wheel comes up but the fronts are still down, however they're out of good/negative camber because they're still super compressed. The car mostly maintains this stance until straightened out at which point you have good camber and momentum and are moving toward the next gate and the whole thing starts over.

Ideally you would be braking earlier, and attempting to accelerate or at least not dive into the apex to change that suspension loading, but you're still going to run out of camber because of the cars geometry.
At which point keeping the rear under control and flat would be a big benefit.

Is the issue with RSB that folks are generally driving them incorrectly on FWD?
It makes sense that the FSB would keep the fronts in positive camber by connecting them more.
It also seems reasonable that rear camber would help to push the rear inside down or at least resist roll more.


I'm curious as to what the group that tested their GS setups and chose RSB found when running FSB. What were the drawbacks that were actually experienced?
Doing a RSB in a FWD is counter intuitive. Basically any suspension article for AutoX recommends a FSB. So what is really happening that makes RSB function...differently/better? Is it the softer suspension? Keeping the rear flatter actually does translate to keeping the front planted and in contact?

Im genuinely curious and am trying to understand this. I didn't grow up racing in anyway, but I am pretty handy and mechanically inclined. So I'm trying to make up for lost experiences at 35.
Am i getting it in any way?


Really it seems like the solution is "stiffer suspension" which is beyond GS, but man I really want to do it. Point a guy towards a good STH suspension?

That theory is sound, and I've had success with it on other platforms, but this platform is so front heavy, has so little static camber, and such a conservative camber curve, you aren't keeping it out of the front bump stops under hard trail braking and there isn't much neg camber to preserve to begin with. It took a 32mm fsb to keep my GD STI front going into the bad part of the camber curve and the car was less nose heavy and had much stiffer springs from the factory.

Both my mk7 GS builds rotated well under braking with the big rear bar and zero toe out back without using big tire pressure splits to the rear. It took a lot of the pressure off the front tires, shown in reduced wear, but it still looked like this at turn in.

 

[Roald]

Thats crazy. It looks like your front inside is nearly up in that first photo. On that second one you can see the front left is in positive camber.
So the real answer really is to stiffen up that suspension as a whole and drop some lbs! HA! what is that X? class at that point?
For real any suggestions on a decent dd/autox suspension?

 

[GTIfan99]

Thats crazy. It looks like your front inside is nearly up in that first photo. On that second one you can see the front left is in positive camber.
So the real answer really is to stiffen up that suspension as a whole and drop some lbs! HA! what is that X? class at that point?
For real any suggestions on a decent dd/autox suspension?

Welcome to STH. Lol.

But seriously, there is no good option for a GTI in GS. The least bad option is the big rear bar and zero toe out back.

If you want to properly set the car up, you're looking at STH.

Then you have to decide how race car you want to go. I daily drive on crap roads daily, so I've gone pretty mild.

My next suspension mods will be offset LCA's and a front sway.

If I had to do it again, I'd have worked with redshift to build a custom coilover setup. 400/600 ish. In at about half those spring rates right now. 220/336. Those wit real STH setups are runnimg much higher spring rates. Car is flatter now, but still getting into bump stops, though I cut them an inch to delay that.

 

[SouthFL_Mk7.5]

I’m a proponent of a smaller aftermarket bar in back- especially for track days. But even for AutoX here’s the rear on my son’s car with a small 22mm Superpro bar out back set on full stiff. -2.2 camber up front , -2 rear, a smidgen toe out up front. Rt660 at 40psi all around hot.

 

[enobiko]

Finished the final SCCA Solo of the year on Sunday, came in 2nd in GS, 0.5 seconds ahead of 3rd place. I was very happy with my last run, 0.8 seconds improvement over my previous! First place went to Joe Blaha, who is the better driver (he's been to the National Championships for years, not sure how he placed). I was 1.9 seconds behind him, and felt good about it. He runs a much more track-focused car, mine's a DD, so that may have had something do do with it, but... he's the better driver. He was number 1 in PAX for the morning run, I'm not sure if the afternoon session bumped him down.
Mine is very DD focused, stock wheels, Michelin PS 4S, 40 lbs all around cold. I think a more track-focused tire is stiffer, and can run lower pressures. My two concessions to track times are the Eibach rear sway bar, and 0 degrees toe on all tires. Neither seems to interfere with daily driver use.
If you have the money and want track-day tires and wheels, others have valid advice, but this is my setup until the weather gets cold and wet/snowy. Honestly, even if I went with a set of track tires/wheels, replaced my shocks with Konis... I could reduce my deficit, but could not make up the 2 seconds to get me into first place. Attending a driving school would help more... I had fun, which was my goal.