Lemon's X47 track ST

[Fusion Works]

Wish we got the two door cars here. They look really cool. Reminds me of my old Honda hatches.

 

[lemonjs]

Tomorrow I'm booked in to have a full alignment and corner weighting. Last time I had an alignment was in 2023 and it was set up more for the road than for the track. The car rarely sees the road nowadays so a full track/race alignment is what I'll be getting. Last time the camber was limited by the slop in the strut bolts as the tiny hole in the strut tower prevented adding camber with the coilovers.

Today I widened the hole at the top to allow for more camber. I have seen some people on the UK sub that have opened the hole up almost to the bolts which allows access to the bolts on the camber plates, but I did not like the look of how little material there is. I decided to open it to 60mm so that the edges of the raised area still exist to add the extra strength.

How it looked before:


I made a small jig so that the hole saw wouldn't jump around:


I used a cheap 60mm hole saw. I was worried that it would go blunt trying to cut through but it had no trouble whatsoever:


Unfortunately I still can't access the bolts on the camber plate without dropping the coilovers out. Although the hole would probably only need 10mm more or so wider, so I may consider this in the future:


I maxed out the camber plates just to see what the maximum camber would be:


All back in and painted:


Oh lordy that's a lot of camber! I have no idea what it is at the moment, but if I end up with a similar amount of camber after the alignment I may need to add some spacers as the wheel now sits in way to far:


I'll follow up with what the alignment ends up being. I'm thinking 3-4 degrees of camber and a little toe out, but I'll leave it to the alignment guy to have the final say.

 

[Fusion Works]

Just cut the shock tops open enough to mount the camber plates on top of the tower. Then you can dial in what caster you want, within reason. Plus it makes the springs easier to change.

 

[lemonjs]

Finished with the alignment. The guy knew quite a few people that race in the Airtec Fiesta ST240 championship and asked them all what they run. They were all running upwards of -5 degrees on the front which sounds crazy to me! In the end we settled on the following:

Front:
-4 deg camber
1mm toe out

Rear:
-2 deg camber
2mm toe out

15mm rake between the front and rear jacking points.

According to the corner weighting scales it was 1090kg with half a tank of fuel, so the cage has added a fair bit!

This is so much more aggressive than my previous alignment, but still less than the guys are running in the championship. The rear camber and toe was achieved using washers, again this is what the guys are using in the championship. I removed the rear dust shields and had no trouble with the ABS which others have reported.

I’ve booked an evening session at Brand’s Hatch in a week’s time to see how I feel. Don’t want my first experience with this setup to be on the ‘ring!

 

[lemonjs]

I was at Brands Hatch again for an evening session to test out the new alignment. I'm sure you guys in the US are used to these sorts of temperatures, but it was 35c (95f) which is outrageous for the UK and not something that any of us are used to! I could only manage 5-6 laps at a time before throwing in the towel.

The car felt absolutely incredible in the corners with the new alignment, I have never experienced anything like it in a FWD car. However, this came at the cost of exit corner speed and braking performance. I had to really go easy on the power existing corners and the wheels kept locking on braking and the ABS kicking in constantly. I think I'm going to dial the camber back 1 degree all around and see if that finds a happy medium.

 

[Fusion Works]

I was at Brands Hatch again for an evening session to test out the new alignment. I'm sure you guys in the US are used to these sorts of temperatures, but it was 35c (95f) which is outrageous

That is Tuesday, quit whining and get back out on track.

Car looks good at attitude. If you could get 10deg+ of caster you could dial back the negative camber some and get better braking and corner exit. Remind me again what you have for springs and sway bars?

 

[lemonjs]

That is Tuesday, quit whining and get back out on track.

Car looks good at attitude. If you could get 10deg+ of caster you could dial back the negative camber some and get better braking and corner exit. Remind me again what you have for springs and sway bars?

Haha could have done with that encouragement on the day!

I have MeisterR Clubrace which are 8kg front and 5kg rear. Mine is an early 2013 model so has the 21mm front sway bar and softer beam (not sure if this applies to US cars), and no rear sway bar.

 

[Woods247]

Funny how we are all particular about our car setup. I run a big bar in the back and lockout the suspension on my beam. That’s probably why it’s super sketchy without aero at high speeds but it’s the only way I can predictably flick the car whenever I want when under 100mph. My front is setup soft too. Different tracks would benefit from tweaks but I mostly care about how it handles at my home track, which is fast and flowing.

 

[lemonjs]

Funny how we are all particular about our car setup. I run a big bar in the back and lockout the suspension on my beam. That’s probably why it’s super sketchy without aero at high speeds but it’s the only way I can predictably flick the car whenever I want when under 100mph. My front is setup soft too. Different tracks would benefit from tweaks but I mostly care about how it handles at my home track, which is fast and flowing.

I have another track day booked next week. I’ll experiment with going super soft on the front and see how it feels!

 

[Fusion Works]

Lemon has to focus solely on Mechanical grip, so the goal is to make the front tires work as efficiently as possible. Unfortunately that will mean the car tries to kill you on the warm up laps, but will be magic once the tires have heat in them. If your springs are in the OEM location like the ST240, I would lean towards the rates used in that series, but I would add a rear bar and use a bit less rear spring. so 550-650 fronts and 800 rear springs, but I would drop the fronts down to the 450-500lb/in. So step one order some rear springs that are in the 550-600lbs/in and get a rear bar on the car. I would lean towards a 1.0in diameter bar, but I am a bit biased. You are also running a "super 200" type tire vs a true race slick.

Theoretically you would like to see 450lb/in ISH actual wheel rates. There will be some fine tuning on that rate for you car and application. The Fiesta Bspec rates aren't a terrible place to start. 450/550 with a 22mm bar. That will make the front tires work better. You are currently pretty soft for the track use the car is seeing now.

 

[hawyee]

I'm running a similar setup currently with 400f and 500r and eibach rear bar, and the black poly beam bushings. I think I need to go a little stiffer up front possibly but the car feels great on track. May also need some rear revalving as it feels very stiff on the street at full soft but still liveable.

 

[Fusion Works]

The OEM beam bushings are a pretty complex piece. They tune the way the beam reacts to lateral forces and helps it create some rear steering. While a twist beam looks pretty simple its fairly complex from a kinematics standpoint. I would currently recommend installing OEM beam bushings over the poly bushings.

 

[hawyee]

Hard to say what difference they made since they were installed at the same time as the stiffer rear springs, could be placebo but it seems more stable under heavy braking. Besides that I did not notice much of a change other than being harsher over bumps combined with the springs. The Airtec championship says they're allowed to use powerflex bushings so I'd be interested to see which of the top cars have them changed.

 

[lemonjs]

Really appreciate all the input here, didn't expect it!

Doing some conversions, my springs are:
Front: 8kg/mm or 448lb/in
Rear: 5kg/mm or 280lbs/in

This is much softer than the rates Fusion Works was referencing, and also reversed front to rear!

Stock 21mm front ARB, no rear ARB, and stock mounting locations for everything. I also have black rear bushings like Hawkeye.

I'm back at Brands Hatch tomorrow evening. I'll try softening the front as that's free, but will maybe look into stiffer springs or a rear ARB as a next step.

 

[Fusion Works]

On a FWD race car, you need the rear to "contribute" as much as possible to keeping the front tires happy. A pushy FWD is the worst kind of Race car. Race car rates and street car rates are not going to be the same thing for obvious reasons.

Your current spring rate bias is kinda typical of the typical FWD street mindset. Heavy weight up front, put heavy springs up front. Your current setup is another 25% more front biased than the OEM setup. So you have made the car a worse handling car, with the "upgraded" suspension you currently have. You will see your lap times drop and front tire life increase by going to a more rear heavy bias. (its not technically a "rear bias", because wheel rate is all we actually care about). Remember rear wheel rate is somewhere along the 15% less than the spring rate. Put a 8K rear spring on the car to test. You should be able to find those easily.

 

[lemonjs]

On a FWD race car, you need the rear to "contribute" as much as possible to keeping the front tires happy. A pushy FWD is the worst kind of Race car. Race car rates and street car rates are not going to be the same thing for obvious reasons.

Your current spring rate bias is kinda typical of the typical FWD street mindset. Heavy weight up front, put heavy springs up front. Your current setup is another 25% more front biased than the OEM setup. So you have made the car a worse handling car, with the "upgraded" suspension you currently have. You will see your lap times drop and front tire life increase by going to a more rear heavy bias. (its not technically a "rear bias", because wheel rate is all we actually care about). Remember rear wheel rate is somewhere along the 15% less than the spring rate. Put a 8K rear spring on the car to test. You should be able to find those easily.

This is really valuable information, thank you. I didn’t choose these spring rates, they are the default that comes with the Meister R coilovers.

Do you have a recommendation for whether to pick stiffer rear springs or add a rear anti roll bar?

 

[Fusion Works]

Personally I like a combination approach. Since you have no rules a stiffer bar and stiffer springs will work better than just stiffer springs. The sway bar comes into play in the turns and doesn't "overload" the tire like the stiffer springs. (this is all kind of a general information). The beam acts like a big sway bar on the back of the car, you are just adding to that. If you notice, Ford stiffened the rear beam on the Mk8 cars so they could get some ride quality back. I am currently running a stockish spring rates (I think I have a 200lb front spring and a 162 for the rear with a 1in solid rear bar. I can drop my rear tire pressures well into the 30s for normal road use and the car rotates nicely. (I run 32-33 hot front and slightly less hot on track with the race spring setup, 500/630 and the 1in rear bar)

 

[Woods247]

I’ll also mention I have the solid beam bushings along with DNA front LCAs. They definitely made my car more predictable and precise. @Fusion Works made me a set of bolts that lock the rear beam in place to that prevent it from slipping out of alignment after curb strikes or when I accidentally put two wheels off track.

 

[Fusion Works]

BTW, I made the mistake on my rear shock valving of using too much low speed rebound and the car wouldn't rotate as well as it should have even when I went to extremes on rear spring rates (think 1000+lbs). I am currently running an OEM FiST rear shock and am pretty happy with it. Will probably go back and revalve my track setup to more closely mimic the OEM damper in the low speed range.