• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!

Weight reduction for autocross question

Messages
367
Likes
486
Location
Anchorage
#1
Hi all,
So, I have heard a couple different opinions on reducing weight, and would appreciate everyone's thoughts and experiences on the subject, specifically this: if reduction of front end weight reduces traction to the point of being counter productive.
Some have suggested that any weight reduction is a net benefit, but other (such as this author) suggest that a very front heavy car is best.
Thoughts?
 


Messages
290
Likes
238
Location
Portland, OR, USA
#2
a) I dont think you can get enough weight off the car to really even notice (in HS, full gut/body removal is another conversation).
b) My opinion is that any minor weight reduction is good as that's less weight to try and turn/accelerate.
 


OP
Pablo Pistoffo
Messages
367
Likes
486
Location
Anchorage
Thread Starter #3
a) I dont think you can get enough weight off the car to really even notice (in HS, full gut/body removal is another conversation).
b) My opinion is that any minor weight reduction is good as that's less weight to try and turn/accelerate.
That makes sense. I'm in STH, and was looking at the options available. I was thinking about a battery relocate to the spare tire well or maybe a lightweight battery, but the balance issue raised by the linked author is making me reconsider. Seats would be another option, but they'd be a pain as I daily the car during the summer.
 


Messages
290
Likes
238
Location
Portland, OR, USA
#4
That makes sense. I'm in STH, and was looking at the options available. I was thinking about a battery relocate to the spare tire well or maybe a lightweight battery, but the balance issue raised by the linked author is making me reconsider. Seats would be another option, but they'd be a pain as I daily the car during the summer.
Yeah I looked at a light battery, before being told thats specifically in street class (not sure on STH). And the wire needed to move it to the trunk I think would partially offset any benefit of moving it. So I would do a light battery and keep it in the standard location.

A good seat make an amazing benefit to driver feel, but the recaros + a harness I would say is 90% of the way there. So then the only benefit is some weight. Do you have a real diff to take advantage of the power/class?
 


OP
Pablo Pistoffo
Messages
367
Likes
486
Location
Anchorage
Thread Starter #5
Yeah I looked at a light battery, before being told thats specifically in street class (not sure on STH). And the wire needed to move it to the trunk I think would partially offset any benefit of moving it. So I would do a light battery and keep it in the standard location.

A good seat make an amazing benefit to driver feel, but the recaros + a harness I would say is 90% of the way there. So then the only benefit is some weight. Do you have a real diff to take advantage of the power/class?
Yep, I'm running a Quaife (really the best mod for AX so far except for tires), and am just trying to figure out if there is anything else I can do that will have a decent cost/benefit for improved performance while staying in class. I have a Schroth Quick-Fit, but don't have Recaros.
 


Messages
290
Likes
238
Location
Portland, OR, USA
#6
Yep, I'm running a Quaife (really the best mod for AX so far except for tires), and am just trying to figure out if there is anything else I can do that will have a decent cost/benefit for improved performance while staying in class. I have a Schroth Quick-Fit, but don't have Recaros.
Yeah a guy in our club just did his Focus ST to STH, I really want the Quaife... but I dont think the diff is enough to overcome the PAX hit...

Seats could help with weight and driver connection, but your right pain the rest of the time.=\
 


OP
Pablo Pistoffo
Messages
367
Likes
486
Location
Anchorage
Thread Starter #7
Yeah a guy in our club just did his Focus ST to STH, I really want the Quaife... but I dont think the diff is enough to overcome the PAX hit...

Seats could help with weight and driver connection, but your right pain the rest of the time.=\
It really depends on your circumstances- I didn't trophy at all in H Street (we have a really small region, so it's a driver's class based system based on PAX), but took 3rd place in Open in '19 and 2nd last year.
I think I improved over time, but I had trouble making the car work for me in H street. I occasionally beat my buddy's raw time in his 718, which makes it all worthwhile.
 


Messages
15
Likes
6
Location
Seattle, WA, USA
#8
Yeah I looked at a light battery, before being told thats specifically in street class (not sure on STH). And the wire needed to move it to the trunk I think would partially offset any benefit of moving it. So I would do a light battery and keep it in the standard location.
Lightweight battery is legal in Street Touring, including STH. Most people avoid the (minor) extra weight and hassle involved in relocating and just go with a smaller/lighter battery in the stock location.

However, going to the 10/10ths level of weight reduction is something you usually only see in the pseudo-"spec" classes where everybody is driving the same car (like in STS where everyone is driving the same 89 Civic Si) and you're looking for any advantage at all, especially on a low-powered momentum car. I wouldn't go to too much effort for minor weight savings on an STH car.

If you're changing a sway bar, going with a hollow bar vs a solid bar can save a couple lbs, but again, not a huge improvement.
For some cars, like the MK7 GTI, 2 piece brake rotors are available that are significantly lighter than the massively heavy and huge stock rotors on the Performance Package. Not sure if anything is available for the FiST, or if it'd be worth it since the brakes aren't too big to begin with.

Some racing seats are light AND actually comfortable, but you need to find a shop with a showroom or make lots of friends at an event to try them out to see what would work for you. Personally I don't fit well in the stock FiST Recaros (so I got the standard seats, which aren't very supportive), but if I was doing an STH build on a Fist I'd look at seats, for sure. But then again, you're giving up your modern airbags for racing seats, which have their purpose on the street.
 


OP
Pablo Pistoffo
Messages
367
Likes
486
Location
Anchorage
Thread Starter #9
Lightweight battery is legal in Street Touring, including STH. Most people avoid the (minor) extra weight and hassle involved in relocating and just go with a smaller/lighter battery in the stock location.

However, going to the 10/10ths level of weight reduction is something you usually only see in the pseudo-"spec" classes where everybody is driving the same car (like in STS where everyone is driving the same 89 Civic Si) and you're looking for any advantage at all, especially on a low-powered momentum car. I wouldn't go to too much effort for minor weight savings on an STH car.

If you're changing a sway bar, going with a hollow bar vs a solid bar can save a couple lbs, but again, not a huge improvement.
For some cars, like the MK7 GTI, 2 piece brake rotors are available that are significantly lighter than the massively heavy and huge stock rotors on the Performance Package. Not sure if anything is available for the FiST, or if it'd be worth it since the brakes aren't too big to begin with.

Some racing seats are light AND actually comfortable, but you need to find a shop with a showroom or make lots of friends at an event to try them out to see what would work for you. Personally I don't fit well in the stock FiST Recaros (so I got the standard seats, which aren't very supportive), but if I was doing an STH build on a Fist I'd look at seats, for sure. But then again, you're giving up your modern airbags for racing seats, which have their purpose on the street.
Yeah, I think I'll keep it basically as is and just try to get as much seat time as possible. STH allows seats and mounts that weigh at least 25 pounds, which is something like 15 pounds each less than stock. I should probably just try and lose that off of me, and keep the airbags.
 


M-Sport fan

9000 Post Club
Messages
11,893
Likes
4,528
Location
Solebury, Pa.
#10
Are fixed caliper brakes allowed in STH as a mod (if the car comes from the factory with floating {slider pin} calipers, like ours do)?
 


OP
Pablo Pistoffo
Messages
367
Likes
486
Location
Anchorage
Thread Starter #11
Are fixed caliper brakes allowed in STH as a mod (if the car comes from the factory with floating {slider pin} calipers, like ours do)?
You can change calipers and brackets, so yes. My main challenge is that the main option for me, the small Whoosh calipers, aren't a known fit with my TD 1.2s. Living in Alaska makes it hard to ship potential wheel /tire /brake combos up and try them on, and I couldn't find any weight specs for them.
 


M-Sport fan

9000 Post Club
Messages
11,893
Likes
4,528
Location
Solebury, Pa.
#12
^^^You could ask O.D.D. Racing about their 15" wheel Wilwood 'kit', albeit much more coin than the whoosh setup, and yeah, just because it fits inside most popular 15x6/6.5/7 gravel rally wheels for our cars does not necessarily mean it will fit inside of 15x8 1.2s.
But, they might know. [dunno]
 


kevinatfms

Active member
Messages
592
Likes
516
Location
Germantown
#13
With 225's and an LSD id think you would have more than enough traction to start with. Maybe a lighter exhaust? Titanium shaves some crazy weight and remove the mufflers/resonators(its gonna be painful to drive though on long distances). 2pcs rotors and fixed calipers(maybe Wilwoods?). Carbon hood/hatch and fenders?
 


OP
Pablo Pistoffo
Messages
367
Likes
486
Location
Anchorage
Thread Starter #14
With 225's and an LSD id think you would have more than enough traction to start with. Maybe a lighter exhaust? Titanium shaves some crazy weight and remove the mufflers/resonators(its gonna be painful to drive though on long distances). 2pcs rotors and fixed calipers(maybe Wilwoods?). Carbon hood/hatch and fenders?
Sadly I can't swap out hoods, hatches or fenders in STH, and it is my summer daily, so I'd like to keep it somewhat livable. After the slight upgrades I'm doing this spring, I think I may just work on technique and fine tuning the suspension. Maybe going on a diet lol.
 


kevinatfms

Active member
Messages
592
Likes
516
Location
Germantown
#15
Sadly I can't swap out hoods, hatches or fenders in STH, and it is my summer daily, so I'd like to keep it somewhat livable. After the slight upgrades I'm doing this spring, I think I may just work on technique and fine tuning the suspension. Maybe going on a diet lol.
Hows the body roll? Maybe look into a front sway bar and some poly filled rear beam bushings.
 


OP
Pablo Pistoffo
Messages
367
Likes
486
Location
Anchorage
Thread Starter #16
Hows the body roll? Maybe look into a front sway bar and some poly filled rear beam bushings.
It's actually a lot better with the FA coils- I have the rear beam and front sway PowerFlex bushings I need to install this spring, along with new lower control arms that I had poly bushings pressed into, as well as an intake update and an exhaust cutout.
 


Messages
182
Likes
82
Location
Paramus, NJ, USA
#17
Hey man, I'm right there with you in STH. Quiafe Diff. Light weight battery was a big move. Losing that 10-13 lbs off of the corner my fat ass sits in helped corner balancing the car. I'm in the same boat as you. I don't really want to go race seats quite yet. I'm trying to find info on Aero allotments. Need to find some info for my custom valved Feal Coils I'm working on.

But that's pretty much it. More suspension mods and grippier tires.
 


kevinatfms

Active member
Messages
592
Likes
516
Location
Germantown
#18
If anyone is interested, i have a set of drawings for a custom made set of delrin rear beam bushings. Got a set made and the gentlemen produced a set of drawings that any machine shop could duplicate for under $100.

They should be worlds better than the OE bushings and polyurethane that is currently on the market.
 


Messages
182
Likes
82
Location
Paramus, NJ, USA
#19
If anyone is interested, i have a set of drawings for a custom made set of delrin rear beam bushings. Got a set made and the gentlemen produced a set of drawings that any machine shop could duplicate for under $100.

They should be worlds better than the OE bushings and polyurethane that is currently on the market.
I went with Super Pro from Australia. Such a great improvement in the rear, but I can now spin the car if I'm going crazy on any AutoX run ๐Ÿ˜‚
 


kevinatfms

Active member
Messages
592
Likes
516
Location
Germantown
#20
I went with Super Pro from Australia. Such a great improvement in the rear, but I can now spin the car if I'm going crazy on any AutoX run ๐Ÿ˜‚
Im worried that poly will break down fast in this case. Those beam bushings are gonna take alot of abuse smacking curbs all day long. Add in that i hit a track event once a month and it will take its toll on them.
 


Similar threads



Top