Thoughts on interior

[Shaman]

I have the points from the cage and fire extinguisher to allow tearing out the interior of my car, but I don't really want to do that. I like driving it around on the street with all the comforts (except for A/C).

What are your thoughts, for those of you who have done it... is it worth it? Did your car become dramatically faster in corners?

[Marsh]

The plastic interior is a comfort?

I kind of like the look and sound of an empty car. I would gut more of my car if I could. Mind you I would keep the stereo.

[Nabs]

which brings you this question...how much can you strip to keep it street legal? ie. what can i take out legally?

[Shaman]

I'm talking about carpets, panels, etc. The stereo would have to go because it's integrated into panels, and probably weighs 50+ pounds (8 speakers, two subwoofers, big 500W amp, etc)

If there's not much racing value in doing it, I won't bother. It becomes a question of "where do you stop". I could put lexan windows in it too, but it's going to end up like a tin can that every pebble rings off of.

What I want to know is "will it be a second a lap faster".

[Bad Karma]

Mass is ALWAYS the enemy on the race track. HP to weight ratios only matter in acceleration, but overall vehicle mass applies to all factors that are important on a race track (acceleration, braking and cornering, all of which we could say are really different forms of *acceleration*).

Anyhow, on the street, it all depends on how often you drive the car, and what you would consider *harsh* or not.

My BMW is completely stripped out, and I don't actually mind the drive on the street, though to be honest, I don't drive it on the street much. This is mostly due to a race stiff suspension, and the PITA of crawling over a roll cage to get in....

I don't mind not having a stereo (though I could really use A/C on some days...), as the noise from the car more than makes up for it. It's great to hear the diff lock up around some corners, and while I have a rather mild exhaust on my car, without any sound-deadening material in place anymore, it's a decent sound inside the car.

Overall, my car is about 350 NET lbs lighter (including the install of the full roll cage...) compared to it's stock weight. This is without replacing any windows with LEXAN, and I still have the full door panels / power windows. I figure eventual replacement of the hood / doors with fibreglass units (including removing all power windows / glass, except windshield) will net me another 150-200 lbs.

I figure I can get my car to about 2600lbs, plus me.

Now, a couple of major areas this benefits. One, tire wear. Lighter cars tend to have MUCH better tire wear than heavier cars, so you can save a little $$$ in track tire consumption.

Secondly, you'll gain the ability to carry more speed through corners, as you'll no longer be carrying the mass you once were (assuming you can drop at least 50 lbs from the car, preferably more). Also, by carrying more speed through corners, you'll have less of a need to brake as hard for each corner, etc, etc.

Of course, I probably wouldn't want to drive my car for 2 or more hours anywhere to get to the track, hence the reason it's now a trailer queen.


Pat

[Dave]

a second a lap faster is a lot to ask for from gutting your interior. I would think you might get a few tenths faster if you lightened the car up by a 100 lbs. If there's more like 200 lbs to drop on that big fat fire chicken, then maybe half a second is reasonable. It never hurts to lighten a race car...easier on brakes and tires.

I guess it's a matter of how often you use the car on the street versus how much you really want to shave a few tenths off your lap times. With all the horsepower you've got, I don't think it's going to make a dramatic difference to your power-to-weight ratio so gutting your interior seems less important to me than it would in a little hatchcrap like mine. The strength of my car is lightness, so I've gutted as much weight as I can within the limits of available prep points. It's definitely louder/less comfortable on the streets, but I only ever drive it to the track and back so it's not a big deal to me. If I had to drive the car more than that, I'd probably line the interior with a sound deadening material which is easily removable at the track or something.

[Bad Karma]

As I've said before, MASS is always the enemy. On a HP friendly track like Mosport, losing the weight might not make as much of a difference as it would at SMP, or TMP.

I'm not sure what your T-Bird weighs, but I've heard upwards of 3800 lbs stock. I'd have to think a lot of that can come out of the car.....but at the expense of daily driver comfort (those doors have to weigh a ton....).

Being a *bit* of an outsider to the Solo 1 community (outside of the constant badgering by Chris, Nick and Rob to attend an event or two....), I'm not sure what you've done to your car.

Weight reduction is always one of the last things to look at to find time, especially since it's easier to shave seconds off your laptime via suspension / brake mods, than by losing weight. Only after you've upgraded your suspension, would I really worry about weight savings.

Now, if you've done the suspension, the weight savings is a good way to go.

Here's a rough idea of what weight I managed to strip out of my car (all parts being weighed after removal, and starting weight of 3120 lbs).

Power sunroof / headliner. Total weight, 52 lbs, right above my head.

Manual, heated, leather seats: 57 lbs EACH. Two race buckets at 14 lbs each.

Back seat, 10 lbs. Carpet, 25 lbs.

Sound deadening material (incredibly dense stuff): 140 lbs

A/C system (including condenser, collector, pumps, plumbing etc): 96 lbs

Stereo and stock amp / speakers (54 lbs).

Cruise control (9 lbs).

Airbags and wiring harness (18 lbs).

Total 518 lbs gross weight removed.

Added in 135 lbs of roll cage (Chromoly, not mild steel, so lighter weight), two race buckets (28 lbs total).

Net weight of the car, roughly 2765 lbs....

None of this includes wheels / tires, which dropped about 8 unsprung lbs per corner (from stock wheels to BBS RKs).

Car is down to 1:40:xx's on the big track at Mosport, which isn't bad for a 172 HP car. I think I could shave that down 2 more seconds with bigger *cajones*.


While you've got the HP to make up for weight in a straight line, it also moves your braking zones much farther back than smaller, lighter cars, and your ability to carry speed through corners is affected. I'm always a fan of reducing weight in a track car.

How far you go is simply a function of what you're willing to put up with on the street.... which is why I trailer my car....sigh.


Pat

[Dave]

Pat, what kind of car do you have? Wish I could have found 518 lbs to take out of my little Civic rust bucket! Sounds like you might have a big Bavarian brick given the curbweight and horsepower number. Love them German brakes...

**edit** oops, just saw your earlier post with Bimmer reference. What model do you have and why aren't you bringing that thing out to some Solo 1's? Is it strictly a regional road race car or lapping day car?

[Shaman]

Let's do the math:

Racing seats: 25lbs (power seat delete too)
Passenger seat out: 40lbs (26 w/Forza)
Complete interior/stereo strip: 110lbs
Airbags: 30lbs
CD stack: 8lbs
Momo wheel: 6lbs
Lightweight wheels: 12lbs unsprung
Front + rear bumpers: 39lbs
Relocate battery back to front, lightweight battery: 25lbs+
Antenna, bracket, motor: 10lbs
Power windows: unknown
Lexan window replace: 95lbs
Heater core (never use it): 9lbs (w/fluid)

By my calc, that's 280lbs+ I can take out of the car without getting crazy with a drill, changing out the glass and keeping both front seats in the car. That would put my car at approx. 3100lbs w/cage, giving me a power:weight ratio of 1:5.5 or thereabouts. Worth it? Not sure, but I am riding my motorcycle to work everyday instead of the car now, so...

It's also possible to get the carpet in 2 pieces for track removal, not sure how simple that would be, and get carpet that only weighs about 10 pounds for the whole car with the sound deadening taken out. I dunno... I've thought about it a lot but it's a big decision. I'd leave the doorskins in... unless I can find some manual windows... they're good for 20lbs if they're out.

I have a feeling that lexan windows would bump me to a "mod" class, must get out the book.

BTW, a lot of the beemer stuff is heavier than mine. My A/C all told was about 40 pounds, and there's around 70 pounds between carpet and deadener.

[Bad Karma]

Dave,


It *started* life as a 1994 BMW 325is. All of 189 HP at the crank (172 to the rear wheels...just dyno'd a couple of weeks ago with the TAC boys).

Yes, they are a bit of a pig to begin with, and a LOT of that is in the sound deadening material. Packing that box out to the trash was a heavy pig...most of the *usable* stuff that came out of the car I still have.

As to Solo 1, well, mostly, I just haven't bothered. I've stopped by and watched a couple at the DDT, which to be honest, I can't be bothered to run after spending most of my time on the *big track*. My own personal bias against the DDT, nothing more than that....

I also spend several weekends a year at the track, so in order to keep more than just half my house and other worldly possessions, I need to spend some time at home.... ;) I have 8 track days scheduled in September without attending ANY Solo 1 events... It's tough enough to get *permission* for all of that....

I've been meaning to attend an event or two at Cayuga, but with the issues they've had, it's been impossible to set aside any time to do so.

I've also heard that the track time at a Solo 1 weekend is minimal, compared to that of a BMW Club weekend. I can probably get between 8-9 hours of solid, ON-TRACK time at a BMW Club weekend over three days, though that number drops a little as an instructor compared to a student.

I haven't checked your schedule to see if anymore events are happening at TMP this year, but I *may* attend one, just to see how well I might actually do. I'm just too lazy to drive all the way to Shannonville.....especially just to run on Nelson.

I'll get around to doing some Solo 1 events, most likely next year. Rob and Chris never seem to stop hounding me, so eventually I'll probably give in....

Have to go put those Turbo'd Nissan's back in their place....

(Sorry Adam, couldn't resist. Your heat problems just reminded me of a conversation online we'd had about the reliability of turbo-charged cars vs V8s....).


Pat

[Shaman]

Incidentally, I have 13 points in ASP, if you don't count the roll cage and extinguisher which let me take the interior out.

I am going to have to study the manual carefully to see what is legal in my class before doing any of this stuff, I don't have many points to spend.

485rwhp/chrome moly suspension pieces put me as close to the limit of ASP as it gets. And I will still drive the car on the street no matter what happens, I won't go to 100 octane fuel and all that crap just to be in the top few in class. Showing up with a 650hp production-based car that I can only drive on the track doesn't interest me.

[rpr]

As for legality, I was stopped for RIDE once, and all I had in my interior was a gauge cluster and seat, and they cop had no problems with it. As long as everything works (speedo, horn, signals, lights, etc) it would appear to be ok. However, I have not read the HTA on that, so don't come crying to me if you get a ticket... :)

[Rob McAuley]

Come on Pat! We'll be at the Pro Track at Shannonville on Sept 14 and Fabi on the 15th.

Even if you run, you'd still qualify as a novice next year.

If you'd run at Cayuga, you'd have a Dodge Daytona to run against in BSP and another to proposition in BMod.

Go for it with the clock running!

[Bad Karma]

But Rob, I'd only be in BSS1, the same as Christian and Victor.

But, I think I have only 1 point left before I'd be bumped up to B/SP or B/Mod. So much for the LTW flywheel idea....


Pat