After market anti-roll bars

[gavin_t 184]

Afternoon all

 

I am considering changing the anti-roll bars on my GT86 to move the balance a bit more away from understeer in high speed/long corners.

I have come across the Litchfield anti-roll bar kit and wondered if anyone has first hand experience of this or other options?

Litchfields website doesn't state the thickness of the bars etc but I have sent an email to see if they can provide any further data.

 

The kit comes as a front and rear combo but as I am looking to move my bias to oversteer I wondered if it would be best to leave the front unchanged and just change the rear? as stiffening the rear should provide what I am after.

 

Opinions and reviews of your setups welcomed

Thanks

[surrey86 352]

What's the rest of your suspension setup? Geo, spring rates, etc.

[Lauren 2259]

The Litchfield handling kit will make you cry. I would not advise upping the anti-roll bar diameter. Better to add negative camber. A decent enough set of coil overs is a better option. You will reduce traction with the bigger ARB's, and weight transfer. This is the opposite of what you want to achieve. 

[Church 209]

+1 to more front camber as better way to reduce front understeer as one that will both add front grip & enhance track tire wear vs thicker rear rollbar, which will reduce rear grip and do nothing on evening tire wear. Changed grip front:rear balance both ways, but different results in other areas

[Kaltorak 111]

I took the add front camber route, it's the only change I've made to the geometry. 

The cars great now, the push in high speed corners is gone, definitely more risk of a spin though. 

[gavin_t 184]

Cheers all

 

Current chassis setup is

 

Tein flex A with the normal 7kg front and rear springs

adjustable drop links and camber arms

 

Running zero toe front and rear

-2.5 degree of camber up front

-1.5 degree of camber on the rear.

 

So I feel I already have a good degree of camber on the front. Anymore would compromise other aspects IMO.

 

I was thinking either stiffer roll bar on the rear or stiffer rear springs would be the answer.

 

I had heard some positive things about after market roll bars from Will and Jeff at the last club trackday the other week which was why I was researching that avenue plus some been offered for sale in the for sale section.

@Lauren have you heard bad press about the Lichfield items?


Thanks
Gavin

[Kaltorak 111]

Then I'll bow out and shut up 😊

If you're still understeery with that much changed that's a toughy.

[Lauren 2259]

20 minutes ago, gavin_t said:

I was thinking either stiffer roll bar on the rear or stiffer rear springs would be the answer.

 

I had heard some positive things about after market roll bars from Will and Jeff at the last club trackday the other week which was why I was researching that avenue plus some been offered for sale in the for sale section.

@Lauren have you heard bad press about the Lichfield items?


Thanks
Gavin

I've been in a car that had the 'Litchfield Handling Kit'. It was awful and confirmed that they do not know what they are doing. It really is terrible. I had 5/6kg springs on TEIN (streetflex - precursor to Flex A). Try a 6kg spring on the front and add negative camber. Or go 5/6kg on the springs. Personally and I can only go on my experience, increasing the ARB size is not the way forward. I like my car to dip under braking and I like to move the weight around. Anything that reduces that is not helping me. You need a little bit of roll to achieve that. The answer for you is to reduce your front spring rate in proportion to the rear. I thought Flex A shipped with 6/6kg post 2014 after we did the development work on it? 7/7kg was only what the earlier kit shipped with and that precedes Flex A. We thought it was too much. 

[Deacon 1357]

@gavin_t your Flex A's will be 6/6kg not 7/7kg. There's a lot of misinformation on here about the effects of spring rates - valving is way more important and Flex A's are valved to be quite soft.

As you said, we spoke about ARB's at Bedford. I'm more than happy with the whiteline set up in terms of handling, etc. My only grumble is the quality isn't the best (as per all whiteline stuff it seems).

[gavin_t 184]

@Lauren my error they must be as @Deacon said and 6/6. They were the ones I bought from will and am sure they were the stock springs.

So the answer may be to soften the front then rather then stiffen the rear to get the difference that way?

With the damping I found on track fully stiff rear and two from fully stiff on the front gave the best feel from the flex a kit. Agree they are quite soft but I like everything else about them as they seem a good do it all compromise. 

Corners where you can trail brake in etc the setup is ace but a long corner like clearway at brands for example once you are sustaining the turn that's when it tends to wash out at the front. 

 

@Deacon it turned out the roll bars for sale I mentioned were the Litchfield ones. They were just in white line packet in his photos. Shame the Lichfield stuff gets bad press as they seem to do well with other models.  

 

 

[Deacon 1357]

1 hour ago, gavin_t said:

@Lauren my error they must be as @Deacon said and 6/6. They were the ones I bought from will and am sure they were the stock springs.

So the answer may be to soften the front then rather then stiffen the rear to get the difference that way?

With the damping I found on track fully stiff rear and two from fully stiff on the front gave the best feel from the flex a kit. Agree they are quite soft but I like everything else about them as they seem a good do it all compromise. 

Corners where you can trail brake in etc the setup is ace but a long corner like clearway at brands for example once you are sustaining the turn that's when it tends to wash out at the front. 

 

@Deacon it turned out the roll bars for sale I mentioned were the Litchfield ones. They were just in white line packet in his photos. Shame the Lichfield stuff gets bad press as they seem to do well with other models.  

 

 

The Litchfield bars are Eibach. I'm sure they'll be fine. The Litchfield handling kits main problem was just using lowering springs with oem dampers

[Shad 20]

13 hours ago, gavin_t said:

Corners where you can trail brake in etc the setup is ace but a long corner like clearway at brands for example once you are sustaining the turn that's when it tends to wash out at the front. 

I don't know a great deal about what these cars respond to in terms of setup, but it sounds like you already have a good amount of camber on the front, especially for a road tyre. How about corner weights and rake? From my own experience of Brands I find as soon as the car is over the crest at Clearways it's much more settled, but before then it can be a mixture of oversteer and understeer. If you get the line just a tiny bit wrong, there's very little grip. Make sure you're not getting back on the throttle before the apex too as that's a sure fire way to generate understeer, something I've struggled with for years.

I used to feel like I had understeer issues for a long time with the Caterham in high speed turns, Abbey and Copse at Silverstone in particular. Almost all of it was down to my technique. See if you can get some time with an instructor next track day and they might have some useful pointers. We're never too old to learn new things!

Not sure if this will be useful or not but this is a clip from a few years ago at Clearways. Notice how I didn't brake deep enough into the corner and found room to open the throttle again, create some understeer, then off the throttle to tighten up... it's a bit of a mess. This is not the fastest way! But I'm then patient with the car as we go through the corner and over the crest so the exit is decent.

https://youtu.be/jolTdf_TNE8?t=73

In contrast, this is the approach to Copse at Silverstone and you can see I'm braking much deeper and keeping more weight over the front wheels to help that turn in - trail braking properly. I could go deeper still but not by a lot. Once you get to that point and you apply some throttle it will help continue rotating the car. In this instance I still felt I had too much push on the exit but that's just how the car works.

https://youtu.be/X5y5O9EyiLE?t=78

Anyway it sounds like there are plenty of knowledgable people here so if you want to share any onboard I'm sure we can see if there's anything easy (and free!) you can change first

[gavin_t 184]

Cheers at @Deacon for the info.  

What are your views and before and after changing the roll bars?

 

@Shad thanks. I was using brands as just an example but find the same on many other corners also. 

Although I 100% agree that seat time and expert knowledge is worth its weight in gold. The instructor sessions I have done at brands and Snetterton are probably some of the best money I have spent. So much quicker and smoother once I have had my current technique torn to shreds and started again 😂

[Deacon 1357]

3 hours ago, gavin_t said:

Cheers at @Deacon for the info.  

What are your views and before and after changing the roll bars?

 

@Shad thanks. I was using brands as just an example but find the same on many other corners also. 

Although I 100% agree that seat time and expert knowledge is worth its weight in gold. The instructor sessions I have done at brands and Snetterton are probably some of the best money I have spent. So much quicker and smoother once I have had my current technique torn to shreds and started again 😂

No regrets - I found the Flex A too soft for on track and the ARB's definitely help. I found them a definite improvement and would happily fit them again.

[Lauren 2259]

I'd concur with what @Shad says. If you are trying to push on through high speed corners, you can expect understeer. This is always going to happen if you try and accelerate through long corners. Trimming the throttle or holding  a balanced throttle is what you need to do. Either will quell understeer. I think this is more a technique issue and I would say it's better to change your technique, because I don't think changing ARBs will help here. 

[gavin_t 184]

Cheers all. @Lauren I agree just seems on a balanced throttle the car has a nice neutral yaw and feel in slower stuff but in the faster stuff seems more understeer biased even when employing the same driving techniques and not pushing on too much too early. I am not expecting perfection as I am only on a little v105 road tyre. More the balance I would like to adjust. 

If I pass by that location soon I may pick the bar up to try as it's cheap and I can self fit and take back off if it doesn't feel right. Other option is to adjust the spring rate to 5kg on the front to adjust the balance that way. 

[Church 209]

Oh, rear ARB stiffening can "help" with changing car behaviour there .. but with "cost", making car TOO oversteery in other corners, and even in these high speed ones .. it's not like changed bias will increase cornering speed in such, it's just that now car will loose grip with both ends or rear first. At same or even slower speeds, when understeer during turn happened before. Stiffer roll bars change grip, true, but with making load transfer between sides happen sooner, so quicker to overload outside tires and quicker to loose grip.

Quick setup is a bit understeery. Stock simply was way too much understeer biased, but that is already fixed by that extra front camber. One can make handling worse if overdoing too much in other direction.