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Discussion Starter · #1 ·
I am about to install the FC04 17x8 45mm offset with the Evmods BC Coilover kit on a 2017 Bolt. I have read through the tire threads and am not sure I have seen anyone with this particular combo that is running a 235 wide tire, such as a 235/45-17. I would like to know if this particular combination will clear with a lowered vehicle say 3/4"-1" front and rear. Has anyone tried this yet? It is going to be tight from what I can tell.

35421

Before anyone mentions it, I know this will reduce mileage, bring a stiffer ride, give cute kittens fatal cancer, and that the Bolt is not a go-kart. Blah blah.

Thanks in advance.
 

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I'm in the same boat as you. I'm using that exact wheel and tire at the moment, and have a set of BC Racing coilovers to install, I just haven't gotten around to it. Based on how close the tire is to the OEM strut, I'm concerned with tire to strut contact with the BC Racing setup. The BC Racing struts do not have the flat spot at the sidewall bulge that the OEMs have. I'm anticipating having to use eccentric camber bolts at the knuckle and max the camber +ve to create more clearance there, and then use the camber plates at the top of the strut to gain that all back and then some.
 

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How does the diameter of the BC (Swift) spring compare to the Bolt spring?
BC springs (and Swift) are the standard 2.5" ID coilover size, so approx 3.5" OD. I haven't measured the OEM spring, but it's probably close to double that.
 

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Discussion Starter · #8 ·
OK I measured the OEM spring and it is close to 6" in diameter. The spring perch on the strut is even larger than that. So I do not expect strut rubbing to be an issue at all since the BC will result in considerably more clearance.
 

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OK I measured the OEM spring and it is close to 6" in diameter. The spring perch on the strut is even larger than that. So I do not expect strut rubbing to be an issue at all since the BC will result in considerably more clearance.
The area of concern for rubbing is the actual strut body. The spring and perch are completely above the tire so there's no risk of interference. The OEM strut body actually has a flat spot formed in to it to provide more clearance around the sidewall of the tire. The BC struts do not have this. I haven't measured or directly compared the mounting bracket (that clamps on to the knuckle) but unless they changed the offset of the bracket I think there might be some clearance problems. But like I said before, I think we can get enough clearance by setting the camber to max positive at the knuckle, and then use the camber plate to bring it back to negative overall.
 

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Discussion Starter · #10 · (Edited)
That and I am going with a 225 section width instead of 235 so I'll get a tiny bit more clearance. If there is light rubbing on the inside I'll add some spacers to move it out assuming the studs are still long enough, and pull/roll the fenders a bit if need be.

At any rate it is all on its way so in a week or two I will know how it all works out. I will report back after installation and a little driving time.
 

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Actually the Bolt handles pretty decently. I took it to the track a few weeks ago, and on stock Eco/run-flat tires could keep up with Miata's/M3's in the corners. Because you have pretty good torque (260 ft-lbs right?) you can really power out of the corners. It really failed in the straights when I got into low propulsion mode (occurred around 55-60% charge). It only takes 25 minutes (about 1 1/2 sessions or 9-10 laps on a 2mi course) of aggressive driving to go from 85% to 60% charge so your speed won't last long.

Here's my video snippet. On the first long straight after the initial loop, I get to about 87mph and take the corner at at least 60mph.

I imagine with R-compounds or some nice street/track tires it can handle quite a bit. I went off the track a few times pushing the tires past their limit - it definitely wasn't the Bolt suspension that was lacking yet.

The car is remarkably stable - I was never surprised by any handling issues, and the tires always gave me plenty of warning so I could correct my speed if taking a corner too fast. On the later sessions I was really pushing it and could always feel when the car wouldn't be able to take the turn at the speed I wanted, so it was never a big deal to let go and go off-track. No damage or issues whatsoever. I imagine this stability is in big part due to the battery weight being so low to the ground.

I had the Eibach Pro Kit installed. I am very curious to see how the BC coilovers work out for you guys, as I'd like to do more track days with my Bolt and stomp on more of these gas-guzzlers.
 

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Discussion Starter · #12 ·
Looks like about a 1:50 lap time? I don't know Thunderhill well but if that is faster than a fast Spec Miata, like I think it is, that's a good lap time, especially on all-seasons. The way those tires were squealing you would definitely pick up a few seconds from summer tires IMO. Hoosier A7s would be a hoot!

I'm glad that Miata pointed you by. His lines needed... um... improvement.
 

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lol yeah he was definitely a newbie, I was in the novice group. Just sayin' I think the Bolt can do a lot more than people are giving it credit for!!

I would love to one day get another Bolt for daily driving, and then gut this one out and put on super-stcky tires as a track-only car. Maybe one day manufacturers will offer battery upgrades as the technology improves... solid state anyone?
 

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Discussion Starter · #14 ·
I agree, I think the Bolt could do alright as a track day car. I do a lot of racing here and might take the Bolt to a track once I get all of the suspension and tire stuff in place just for kicks. It won't be as fast as my track only car but should still be fun.
 

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I agree, I think the Bolt could do alright as a track day car. I do a lot of racing here and might take the Bolt to a track once I get all of the suspension and tire stuff in place just for kicks. It won't be as fast as my track only car but should still be fun.
awesome!
 

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Discussion Starter · #16 · (Edited)
EV track day and race cars are coming, no doubt. The National Auto Sport Association (NASA) is already working on amending the rules for EVs and for now are placing EVs in the Unlimited classes.

The big issue with track EVs will be keeping the batteries cool so it will be interesting to see what aftermarket solutions are developed for that.

Several years ago I saw someone bring an AWD Tesla S to the track for HPDE and remember talking with them about their lap times. They had trouble running a good lap because the battery pack kept overheating, which is typical. An HPDE session time is about 20 minutes so imagine driving an EV as hard as possible for that long. Time Trial and wheel-to-wheel races are also about 20 minutes.

Time Trials AKA Time Attack are where EVs will probably do best at first. The fastest people in those classes only stay out for one or two hot laps since at that point the ultra sticky tires start overheating, or they have caught up to traffic from the rear of the field. So an EV would only have to do a couple of laps to be competitive.
 

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EV track day and race cars are coming, no doubt. The National Auto Sport Association (NASA) is already working on amending the rules for EVs and for now are placing EVs in the Unlimited classes.

The big issue with track EVs will be keeping the batteries cool so it will be interesting to see what aftermarket solutions are developed for that.

Several years ago I saw someone bring an AWD Tesla S to the track for HPDE and remember talking with them about their lap times. They had trouble running a good lap because the battery pack kept overheating, which is typical. An HPDE session time is about 20 minutes so imagine driving an EV as hard as possible for that long. Time Trial and wheel-to-wheel races are also about 20 minutes.

Time Trials AKA Time Attack are where EVs will probably do best at first. The fastest people in those classes only stay out for one or two hot laps since at that point the ultra sticky tires start overheating, or they have caught up to traffic from the rear of the field. So an EV would only have to do a couple of laps to be competitive.
I looked under the Bolt hood and it seems like there's still a radiator/fan and plenty of coolant reservoirs, I wonder if people will try to start upgrading the coolant systems in the future. I wonder if the "Low Propulsion" warning had more to do with battery temps than the SOC? Maybe recording ODB II readout next time can reveal some info.

I wonder how Formula-E cars can squeeze out so much performance for so long, I know they completely change cars partway thru the race, but even then it seems insane when you describe the current limitations of prod. cars. Then again Fx cars are insane compared to prod. cars regardless..
 

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Discussion Starter · #18 ·
I created a separate Bolt racing discussion here
 

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Discussion Starter · #19 ·
I have ordered the wheels, tires, and BC/Swift suspension setup and will post the results when I have them.
 
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