ST-Line build for Sundae Cup

[FauxT]

Will be looking for info on what year ST Suspension bits swap onto a 2019 St-Line. Fun little car. The actual ST must be a blast.

 

[FauxT]

Ok. So googled and searched. Would like verification. 2014-2019 Fiestas in the US share the same platform. So a 2016 rear axle from an ST would fit on a 2019 Line. Any links to what swaps would be great. I couldn't find much. Coming from Hondas where just about everything interchanged. I don't want dive in head first 😁

 

[PapaJim13]

Actually most if not all of those suspension parts also fit my 2013 fiesta as well. I have brakes, lowering springs, and Bilstein B6s on and they fit right in. Also running an ST exhaust from a 2014, fits but with slight bumper cutting. B6s a 2011-2013 is very compatible with 2014-2019 models. I know I share the same suspension with the 2014+ base Fiesta models and I thought the ST line did as well.

 

[WannabeST]

ST to ST line (and other base models like mine) all have interchangeable suspension bits. In the rear the ST twist beam is stiffer than the base and has pads and rotors vs drums on base models. The SE rear beam has a touch more negative camber from factory apparently too. The shocks and springs are stiffer on the ST model but they are interchangeable with the base. I have swift springs that were designed for the SE and they fit my base shocks just fine. Same in the rear, there was no issue. Even the spring pad is exactly the same.
In the front end, the front knuckles on the ST have a different tie rod mounting point, it is closer to the center of the knuckle for better steering input. I've read some posts that say brakes from an ST and base are interchangeable but also read some that say they are not. When I have time, I would rather just do the whole knuckle with brakes. Bigger pads and rotors will add more un sprung weight but I think the added life span from better heat dissipation will be worth it.
fun fact; Hawk makes endurance brake pads for the base model brakes but not for the ST brakes. But there is overall more pad options for the ST brakes.

 

[daloonie]

Front brake calibers alone are not interchangeable. The ST brake calibers are bigger and requires a mounting bracket as well.
But mounting holes for the bracket is excactly the same.
I changed to 278mm front rotors and ST brackets and ST calibers on my 1.0 EcoBoost. Works perfectly fine with stock lines that are identical.
Rear axle with drums are not compatible with rotors unless you can weld on mounts for brackets. So a complete rear beam is the easiest way to convert to rotors. New ST handbrake cables is required AFAIK.
You can upgrade rear rotors to 280mm ST170 brakes with stock ST calibers and an ST170 bracket.

 

[FauxT]

Thank you all for the input. Lots of good info to get started. Seems like everything interchanges if you go far enough back. Stoked to get some bits and start swapping.

Ran into a slight setback. Dang low profile tires and potholes. I have a bunch of Honda and AE86 rims, but none bolted up. I assumed one would. Had to put on some universal Welds I had sitting around for the time being.

 

[Intuit]

The bubble lense on that camera makes it look even sillier LoL. Just need the BIG'OL fart-can exhaust to go with it. 😉 Buy hey, you do what you have to. Good use of the available resources. 👍

What brand of tire blew-out? Some are much more susceptible than others. The stock Bridgestone on the ST were pretty resilient. But the suspension was also engineered around a hard low-profile tire.

 

[FauxT]

The bubble lense on that camera makes it look even sillier LoL. Just need the BIG'OL fart-can exhaust to go with it. 😉 Buy hey, you do what you have to. Good use of the available resources. 👍

What brand of tire blew-out? Some are much more susceptible than others. The stock Bridgestone on the ST were pretty resilient. But the suspension was also engineered around a hard low-profile tire.

Nexens. It was a serious pothole. Entire rim went in. Used to driving my truck with big ol side walls.

They are rediculous but better than a donut. 8" wide with 0 offset. Until I can get adapters/centric rings for my other rims.

Interesting note about the suspension needing low profile tires. I was thinking of going down a rim size to get more sidewall.

 

[SteveS]

For track use many use a 16" wheel for access to more tire choices and for the sidewall. It's also a lighter wheel/tire combo.

 

[WannabeST]

For track use many use a 16" wheel for access to more tire choices and for the sidewall. It's also a lighter wheel/tire combo.

16" wheel is probably one of worst sizes to go with for tire options lol.
15" or 17" wheels have easily like 3x the tire options

Also he's building his car for sundae cup, so the only tire options are the RT660 and 615k, but the RT660 is the go to if you want to be anywhere near the front. Considering we are at a 1:25 power to weight ratio, 15x8 is the ideal size. 16 or 17" would just be adding extra un sprung weight, rotating weight, and potentially longer gearing (we are already at a gearing disadvantage vs the fits)
I believe the KE motorsports are the lightest 15x8 4x108 I have seen online so that would be the ideal wheel. Using conversion spacers wouldn't leave enough space for a wheel with a different lug pattern.
You would be better off getting wheel re drilled.

 

[SteveS]

16" wheel is probably one of worst sizes to go with for tire options lol.
15" or 17" wheels have easily like 3x the tire options

Also he's building his car for sundae cup, so the only tire options are the RT660 and 615k, but the RT660 is the go to if you want to be anywhere near the front. Considering we are at a 1:25 power to weight ratio, 15x8 is the ideal size. 16 or 17" would just be adding extra un sprung weight, rotating weight, and potentially longer gearing (we are already at a gearing disadvantage vs the fits)
I believe the KE motorsports are the lightest 15x8 4x108 I have seen online so that would be the ideal wheel. Using conversion spacers wouldn't leave enough space for a wheel with a different lug pattern.
You would be better off getting wheel re drilled.

I was replying to a comment which is now gone asking why he was considering a smaller wheel than 17". I was implying the same thing you said, but not going as far as 15" because I wasn't really knowing what was allowed in terms of downsizing wheels. But then again, I guess the ST-Line probably didn't even come with 17s anyway.

 

[WannabeST]

I was replying to a comment which is now gone asking why he was considering a smaller wheel than 17". I was implying the same thing you said, but not going as far as 15" because I wasn't really knowing what was allowed in terms of downsizing wheels. But then again, I guess the ST-Line probably didn't even come with 17s anyway.

woops, that comment you mentioned was the missing context I needed then.

 

[M-Sport fan]

I believe the KE motorsports are the lightest 15x8 4x108 I have seen online so that would be the ideal wheel. Using conversion spacers wouldn't leave enough space for a wheel with a different lug pattern.
You would be better off getting wheel re drilled.

The KE Motorsport Pro T12s in 17x8 are also one of the lightest and strongest of all of the 17s as well.

But yeah, of course, not nearly as light as their 15x8s, and I don't know if the SC rules allow a 17x8 or not.

 

[WannabeST]

The KE Motorsport Pro T12s in 17x8 are also one of the lightest and strongest of all of the 17s as well.

But yeah, of course, not nearly as light as their 15x8s, and I don't know if the SC rules allow a 17x8 or not.

17" is allowed, but no one uses them due to the extra mass.
As long as you are on a Falken tire, and it isn't wider than 205 it should be legal.

 

[Intuit]

Wonder how much Falken paid to limit the event to their brand of tire... 🤔 ...and no 215...

 

[WannabeST]

Wonder how much Falken paid to limit the event to their brand of tire... 🤔 ...and no 215...

Tire brands do this all the time. Almost all pro level competition has a tire sponsor. I believe Maxxis used to be the tire sponsor for sundae cup. Falken only sponsors club tr and sundae cup, not the event as a whole, the other classes are open to any brand. The event organizers typically enjoy it because of A- the money they receive, B- all drivers on an equal tire makes for better competition and C- it guarantees sales and is good advertising for their tires. I believe they started this when the Rt600 first came out.
Falken usually brings out their big rig and will help you out with any tire issues or setup recommendations too.

 

[WannabeST]

🤔 ...and no 215...

The rulebook "technically" does allow for a 215, BUT only if your competition weight is at least 3100 pounds. I believe they did this to accommodate newer vehicles that just weight a ton more these days. you still need to adhere to the 1:25 power to weight ratio. So one size up in tire is no where near worth the extra 500-600 pounds you would need to move around a corner. A couple people have tried this and are usually around 2 seconds off pace from what I've seen. That's a lot considering the podium is normally under a second a part from each other. 225 would probably be a more fair tire size at that weight in my opinion, but I don't make the rules, I just follow them.

 

[M-Sport fan]

Tire brands do this all the time. Almost all pro level competition has a tire sponsor.

Not just 'pro' level, but WORLD level competitions.

Both the World Rally Championships and Formula 1 both have a requisite single tire manufacturer supplying their donuts, which just so happens to be Pirelli at this time for both.

That tends to change (every 4-5 years or so for the WRC, which is going to Hankook in 2025, but now going on 13 years for Pirelli in F1, until the 2027 season), when their contracts with the sanctioning governing bodies within the FIA have expired.

 

[Intuit]

Even though part of the equation is having more sidewall and a heavier tire, I just enjoy not having the spinnies every time I decide to step on it with stock power. If I were boosted beyond stock levels like the lot of folks here, would want no part of 205 on everyday streets.