Track car thoughts: power vs weight

Track car thoughts: power vs weight

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Discussion

Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
Hi all

I'm thinking of picking up an old Model 3 and building a track day tool out of it. There's a big aftermarket scene mostly US based but now with UK outlets for parts too so should be a fairly easy build and the mods look great.

My initial thought (and still no.1 plan) is to get the "Standard Range Plus" model which was the lightest variant, at around 1,600KG (possibly a bit less, data seems variable) and due to the battery chemistry still quite potent (perhaps 330i or 335i levels of power I suppose in BMW speak).

I am wondering though if I will quickly get bored of this after a few track days and I should just get a Performance model. Weight will be more like 1,850KG but of course all the power and built in track features that would be missing from the standard model. It's all wheel drive but you can also choose rear wheel drive from the track modes (if I remember correctly).

I'd be getting a high miler and you can get SR+ models for around £10-13k whereas Performance would be closer to £18k at the moment so quite a difference but bear in mind I would potentially spend £5-10k on suspension, brakes, wheels, tyres etc which would be the same either model which makes the difference a bit less in the total cost.




So, lighter and only decent power or a bit heavier and all the power?

Thanks for your thoughts!

PS: this would be my first track car.

bigothunter

12,303 posts

71 months

Thursday 13th February
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Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
Thank you, that aligns with my no.1 plan :-) 200-250KG seems a decent chunk to avoid carrying around the corners!

Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
I just dug up an old Carwow drag race 11.7s 1/4 mile for the performance vs 13.8s for the SR+... visually, watching it, really doesn't seem a colossal difference considering I'd be mostly enjoying the corners!

I perhaps have answered this for myself but starting the thread was a helpful for my thoughts.

There is a lingering concern that the smaller battery won't last as long during a track day, but the extra weight and power of the performance would presumably drain the larger battery quicker so I'd suspect the difference could be surprisingly close.

E-bmw

10,571 posts

163 months

Thursday 13th February
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I assume you have asked around to see which tracks near you that you would want to visit ACTUALLY allow EVs on track?

I ask because many don't.

GetCarter

29,944 posts

290 months

Thursday 13th February
quotequote all
Darinz said:
Hi all

I'm thinking of picking up an old Model 3 and building a track day tool out of it. There's a big aftermarket scene mostly US based but now with UK outlets for parts too so should be a fairly easy build and the mods look great.

My initial thought (and still no.1 plan) is to get the "Standard Range Plus" model which was the lightest variant, at around 1,600KG (possibly a bit less, data seems variable) and due to the battery chemistry still quite potent (perhaps 330i or 335i levels of power I suppose in BMW speak).

I am wondering though if I will quickly get bored of this after a few track days and I should just get a Performance model. Weight will be more like 1,850KG but of course all the power and built in track features that would be missing from the standard model. It's all wheel drive but you can also choose rear wheel drive from the track modes (if I remember correctly).

I'd be getting a high miler and you can get SR+ models for around £10-13k whereas Performance would be closer to £18k at the moment so quite a difference but bear in mind I would potentially spend £5-10k on suspension, brakes, wheels, tyres etc which would be the same either model which makes the difference a bit less in the total cost.




So, lighter and only decent power or a bit heavier and all the power?

Thanks for your thoughts!

PS: this would be my first track car.
No. Both way, way, way too heavy. Tracks are about corners, not power. +/- 600kg is a good weight with 500 BHP per tonne is perfect.

Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
I have seen the odd thing about that but must admit assumed it was just a few particularly stubborn organisers/owners.

Is there any source for that info you could recommend or would it be a case of asking individually?

I was looking at trackdays on MSVT and nothing about EVs in FAQs or anywhere really, so I must admit I assumed it wouldn't be a problem under their organisation.

Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
GetCarter said:
No. Both way, way, way too heavy. Tracks are about corners, not power. +/- 600kg is a good weight with 500 BHP per tonne is perfect.
haha, thank you for that opinion. I am talking about making a road car capable on track, to be clear not making a race car. 1600kg seems fine to me, 1850kg pushing it but with the power available and upgraded components I do not see an issue.

GetCarter

29,944 posts

290 months

Thursday 13th February
quotequote all
Darinz said:
GetCarter said:
No. Both way, way, way too heavy. Tracks are about corners, not power. +/- 600kg is a good weight with 500 BHP per tonne is perfect.
haha, thank you for that opinion. I am talking about making a road car capable on track, to be clear not making a race car. 1600kg seems fine to me, 1850kg pushing it but with the power available and upgraded components I do not see an issue.
I've owned three road cars that weighed less than 600kg (two of which had 500 BHP per tonne) which I used on track. It's not difficult. :0)

Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
Yes fair enough, I am also considering a Morgan and Lotus to be fair and appreciate I could achieve what you are suggesting with a Caterham however I would like it to be an EV, as much as an experiment as anything. Tesla has the best power to weight (at the low end of weight anyway) for an EV so that's where I've settled.

It helps that they are pretty cheap, I can build a very nicely prepped Model 3 for the price of a fairly tired, in no way ready for track Morgan. I haven't examined Caterham prices at this point.

GetCarter

29,944 posts

290 months

Thursday 13th February
quotequote all
Darinz said:
Yes fair enough, I am also considering a Morgan and Lotus to be fair and appreciate I could achieve what you are suggesting with a Caterham however I would like it to be an EV, as much as an experiment as anything. Tesla has the best power to weight (at the low end of weight anyway) for an EV so that's where I've settled.

It helps that they are pretty cheap, I can build a very nicely prepped Model 3 for the price of a fairly tired, in no way ready for track Morgan. I haven't examined Caterham prices at this point.
Fair enough. You'll have fun whatever you buy/build... but you'll get overtaken by most everything with the extra EV weight. Regular road cars are mostly too heavy for track (I've also owned and taken 1500 kg M3's out onto track, and they are way too heavy).

BTW ...my daily drive is a hybrid with heavy batteries .. so I'm not an ICE bigot!

Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
Thanks, I am not worried about being overtaken :-) more interested in learning tracks and trying to get clean laps out that ideally improve in time over the day!

Yes, I spotted the RR in your profile and was slightly surprised but fair enough! My DD is a Merc EV that weighs far too much but does the job very well (barge). I was in the market for a Model 3 but after Elon's descent (along with removal of stalks) I decided a used Merc EV was more for me.

I will feel slightly gross even buying a used Tesla but will get a "no fascists on board" sticker of similar lol

Rotary Potato

455 posts

107 months

Thursday 13th February
quotequote all
Have you considered what that weight will do to your brakes and tyres?

Both in terms of their ultimate performance ... but also in terms of their longevity.

If you want to just drive round a track for a bit, then obviously that's fine - you can modulate how fast (or not) you go. If however, you're interested in pushing the car to its limit (in my eyes, the fun bit of track driving - whatever car you are in) you may well find that the limit of such a heavy car cannot be maintained for more than a lap or two, and that you are burning through consumables (brake pads & tyres) at an ungodly rate.

Obviously it's your time and money, and you'll spend them on whatever you fancy, regardless of what anyone says on here ... but I can't see how your current choices will leave you with something that is rewarding to drive throughout the entire day of a trackday.

Krikkit

27,247 posts

192 months

Thursday 13th February
quotequote all
Rotary Potato said:
Have you considered what that weight will do to your brakes and tyres?

Both in terms of their ultimate performance ... but also in terms of their longevity.
This is a very significant factor - if you get it to do more than a few laps you'll need very serious brakes and tyres to keep it all in check... The running costs will be significant.

1600-1850kg and hundreds of horsepower will be absolutely murder.

SpudLink

6,650 posts

203 months

Thursday 13th February
quotequote all
Krikkit said:
Rotary Potato said:
Have you considered what that weight will do to your brakes and tyres?

Both in terms of their ultimate performance ... but also in terms of their longevity.
This is a very significant factor - if you get it to do more than a few laps you'll need very serious brakes and tyres to keep it all in check... The running costs will be significant.

1600-1850kg and hundreds of horsepower will be absolutely murder.
It does seem like a very expensive folly. Even if you could take 500kg out of it, I don’t imagine it’ll be happy thrashing around track all day. Even for a single day.

Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
Thanks for the comments, potatoes et al!

Is 1600KG really that crazy for a track car? What about things like M3s, Giulia QF etc, they're at this weight with more power. Do they munch brakes and tyres in a single track day?

I am not sure how many track days I'm imagining a year but to be honest I find it hard to fit much in my calendar, I'd be surprised if I did more than 5 and probably more like 3!

I am intending to put good big brakes on it and good suspension, not just lowering springs or something.

Perhaps I have got sucked in by the PR bumf some of these outfits have put out (mountain pass performance, unplugged performance for example) who have highly regarded track spec'd Model 3s running around.

E-bmw

10,571 posts

163 months

Thursday 13th February
quotequote all
Darinz said:
Is 1600KG really that crazy for a track car? What about things like M3s, Giulia QF etc, they're at this weight with more power. Do they munch brakes and tyres in a single track day?
TBF while you compare it in weight to those, how many of them do you see on track?

The answer is, not that many, and yes, they do go through brakes unless the braking solution is expensive & then they are just expensive to keep up on pads etc.

Just as an example I used to track an e36 328 coupe until a handful of years ago, all up it was under 1500k.

4-pot AP front brakes cost £330 for pads and they lasted 5/6 track days if I was lucky, and that was around 2018 IIRC.

I could go down to £100 pads but they barely lasted one TD.


Darinz

Original Poster:

167 posts

72 months

Thursday 13th February
quotequote all
Wow - OK, maybe I should reconsider then. I hadn't considered the longevity of tyres/brakes I must admit, so while it could be very capable for a few laps, more than that and you're knackering the parts...

thank you for the food for thought all!

bigothunter

12,303 posts

71 months

Thursday 13th February
quotequote all
GetCarter said:
Fair enough. You'll have fun whatever you buy/build... but you'll get overtaken by most everything with the extra EV weight. Regular road cars are mostly too heavy for track (I've also owned and taken 1500 kg M3's out onto track, and they are way too heavy).
57 seconds around Brands Indy isn't slow.


SpudLink

6,650 posts

203 months

Thursday 13th February
quotequote all
Modern powerful saloon cars tend to make a few appearances at track days, do a few laps, then go home.

The saloons you do see often are E36 and E46 BMWs which are light and modestly powered by modern standards.