Floors, chassis and sumps. Newbie questions
Discussion
Half thinking about a Caterham at some point in my future, likely something relatively modern (Sigma or Duratec engined), and probably R spec (or an S with some mods leaning towards an R spec as it might do a few track days).
A couple of questions:
1) Chassis size: On paper an S3 chassis would fit me better at 5ft7 tall, so the only benefit I can see for an SV is a bit more packing space for weekends away. Is the boot space difference material? Is the theoretical downside of the extra size and weight of the SV really a material consideration in reality?
2) Floors - most cars I see in classified ads have lowered floors, which probably puts me lower than I need to be. This puts the seats brackets a couple of mm closer to scraping the floor and more likely to scrape. Any advice in this regard? Is it so immaterial that a lowered floor car won't be an issue and if I feel too low, I should just put spacers under the seat?
3) Slightly nervous of trashing a wet sump. Even leaving aside the potential occasional track day use, is a dry sump a sensible idea on lumpy roads? This is probably less critical than 1 and 2 as it is easier to fit later. I'm mindful that my (very leisurely driving) father put a hole in a sump in a hire Caterham a few years ago.
A couple of questions:
1) Chassis size: On paper an S3 chassis would fit me better at 5ft7 tall, so the only benefit I can see for an SV is a bit more packing space for weekends away. Is the boot space difference material? Is the theoretical downside of the extra size and weight of the SV really a material consideration in reality?
2) Floors - most cars I see in classified ads have lowered floors, which probably puts me lower than I need to be. This puts the seats brackets a couple of mm closer to scraping the floor and more likely to scrape. Any advice in this regard? Is it so immaterial that a lowered floor car won't be an issue and if I feel too low, I should just put spacers under the seat?
3) Slightly nervous of trashing a wet sump. Even leaving aside the potential occasional track day use, is a dry sump a sensible idea on lumpy roads? This is probably less critical than 1 and 2 as it is easier to fit later. I'm mindful that my (very leisurely driving) father put a hole in a sump in a hire Caterham a few years ago.
pixelmix said:
1) Chassis size: On paper an S3 chassis would fit me better at 5ft7 tall, so the only benefit I can see for an SV is a bit more packing space for weekends away. Is the boot space difference material? Is the theoretical downside of the extra size and weight of the SV really a material consideration in reality?
I'm 5ft8 and the SV felt massive and uncomfortable. I couldn't reach the pedals properly, the gearstick was too far back. It's not so much an extra space issue, it really changes the whole way of fitting the car. If Caterham only made the SV I wouldn't own one. The only way to know is to sit in a few. The chassis size is one thing, but the seats make a big difference too. I've got the leather seats, and I'd probably be too low in the composite ones. Worth sitting in several and seeing what works, and then hiring one for a few hours to see how it goes. I've heard people say some seats give them back ache. I've done lots of long drives in mine and the combination works for me.pixelmix said:
2) Floors - most cars I see in classified ads have lowered floors, which probably puts me lower than I need to be. This puts the seats brackets a couple of mm closer to scraping the floor and more likely to scrape. Any advice in this regard? Is it so immaterial that a lowered floor car won't be an issue and if I feel too low, I should just put spacers under the seat?
I think you'll be fine, mine has lowered floors, and the height is great. My wife is 5ft4 and she does need a cushion to sit on in order to see properly though.But yes, I think some steel spacers could be used if you needed to. I've thought about putting some on mine to give me a little more clearance when adjusting the seat (the lowred floor has a crossbar right in the way).
pixelmix said:
3) Slightly nervous of trashing a wet sump. Even leaving aside the potential occasional track day use, is a dry sump a sensible idea on lumpy roads? This is probably less critical than 1 and 2 as it is easier to fit later. I'm mindful that my (very leisurely driving) father put a hole in a sump in a hire Caterham a few years ago.
On the Sigma I've never heard of anyone using a dry sump. On the Duratec the r400/420 have a dry sump as standard I think. You do become aware of it as you drive, I've heard of people taking out their sumps on very cambered roads. I guess it's always going to be a bit of a risk. It's been a long time since I looked at this but I think the Duratec sump is a little lower to the floor than the Sigma one? Trackday wise, there are lots of Sigma cars being used on trackdays, including in Caterham's various race series and I don't think any of them are dry sumped.Edited by framerateuk on Monday 23 March 15:03
That's really helpful info, thanks.
It sounds like I need to spend some more time sitting in a few cars but that an SV isn't really a sensible option.
Noted re the sump. I'm probably more bothered about damage on the road than oil sloshing about on track (where I probably wouldn't be pushing hard enough). The kind of roads I drive around are exactly the kind with horrible cambers and massive ridges: the sort of stuff that would make me very twitchy with a vulnerable wet sump.
It sounds like I need to spend some more time sitting in a few cars but that an SV isn't really a sensible option.
Noted re the sump. I'm probably more bothered about damage on the road than oil sloshing about on track (where I probably wouldn't be pushing hard enough). The kind of roads I drive around are exactly the kind with horrible cambers and massive ridges: the sort of stuff that would make me very twitchy with a vulnerable wet sump.
Yeah i get that.
Speedbumps are a pain, although the bolts on the lowered floor tend to bottom out before the sump does.
We had to avoid a large rock in the road once, where in most cars you'd probably try to place it centrally, with the 7 you're making sure you give that sump some clearance!
We did 10 days in Scotland and several trips around North Wales and it's all been fine. I run the small 13" wheels all round so my ride height is probably on the low side too.
You could always run higher profile tyres to give extra clearance when on the road. I've thought about it just from the comfort aspect as the 13x6 ZZS give a very hard ride.
Speedbumps are a pain, although the bolts on the lowered floor tend to bottom out before the sump does.
We had to avoid a large rock in the road once, where in most cars you'd probably try to place it centrally, with the 7 you're making sure you give that sump some clearance!
We did 10 days in Scotland and several trips around North Wales and it's all been fine. I run the small 13" wheels all round so my ride height is probably on the low side too.
You could always run higher profile tyres to give extra clearance when on the road. I've thought about it just from the comfort aspect as the 13x6 ZZS give a very hard ride.
I have both 14" and 13" wheels for my Caterham. The 14" are heavier and you feel it in the steering and less acceleration, but the extra 12mm grand clearance is rather nice at times.
I also run 60 profile Toyo R888R tyres on both sets, and the taller, (slightly) softer sidewall works well with the Caterham suspension and helps ride out the bumps a little.
Sump wear is common, but only catastrophic if you collide with something big and heavy. You can fit a sump guard, but that simply transfers the impact forces to the chassis which may not improve the situation. Getting the car flat-floored and set to a ride height you are comfortable is the best way forward, You will need to have adjustable-platform suspension (not all cars come with this) and then get it set for your weight and driving style (about £300).
I also run 60 profile Toyo R888R tyres on both sets, and the taller, (slightly) softer sidewall works well with the Caterham suspension and helps ride out the bumps a little.
Sump wear is common, but only catastrophic if you collide with something big and heavy. You can fit a sump guard, but that simply transfers the impact forces to the chassis which may not improve the situation. Getting the car flat-floored and set to a ride height you are comfortable is the best way forward, You will need to have adjustable-platform suspension (not all cars come with this) and then get it set for your weight and driving style (about £300).
Thanks both.
Interesting to hear that you are changing between the 14” and 13” wheels. I had wondered about that as an option to give a little extra ride height. Does this affect the geometry so little that there is no real compromise in changing between the two?
On the floors point, if I do find a car with lowered floors and would prefer standard floors, is it possible to change them back at a sensible cost (as opposed to just shimming the seat)?
I’ve got lots of time to think about these things as it will be months before I’m even thinking about changing, but that gives me the summer to get my bum in a few different Caterham seats.
Interesting to hear that you are changing between the 14” and 13” wheels. I had wondered about that as an option to give a little extra ride height. Does this affect the geometry so little that there is no real compromise in changing between the two?
On the floors point, if I do find a car with lowered floors and would prefer standard floors, is it possible to change them back at a sensible cost (as opposed to just shimming the seat)?
I’ve got lots of time to think about these things as it will be months before I’m even thinking about changing, but that gives me the summer to get my bum in a few different Caterham seats.
With the wheels it depends.
If you have the same size wheel all round, you can switch and while the ride height changes, the rake stays the same. You'll only get issues if you have a staggered setup with wider rear wheels.
I'm sure someone can let you know how much they paid to have the floors changed. Caterham sell the floor panels for about £350 each, and then you'd have to get them rivited in.
If you have the same size wheel all round, you can switch and while the ride height changes, the rake stays the same. You'll only get issues if you have a staggered setup with wider rear wheels.
I'm sure someone can let you know how much they paid to have the floors changed. Caterham sell the floor panels for about £350 each, and then you'd have to get them rivited in.
The S3 or SV question is a personal thing. I think you’ll have to sit in a few & see how you get on. I’m on my second S3. I drove a friend’s SV last year & I was really surprised by how much bigger it felt.
From my perspective, it was too big. I wasn’t able to fully depress the clutch pedal, even with the seat as far forward as it would go & the intimate sense of ‘wearing the car’ that I get with an S3 was lost.
I’ve done a couple of month-long trips to Italy in the last few years & I didn’t have any issues with luggage space or the size of the fuel tank. My wife came along in the Seven on last summer’s trip (she took the plane the previous time!) & amazingly, we managed to pack so light, the boot was only three quarters full when we set off. I managed to bring tools, spare oil & coolant, a foot pump & a jack, as well as the full hood, half hood & a shower cap to keep the car dry overnight. It’s amazing what you can fit in a Seven when you apply a bit of thought to careful packing.
My current car has lowered floors, my previous one had the standard floors. I’d be fine with the standard floors & I have thought about swapping back. I’ve raised the driver’s seat, as I do sit a bit TOO low with the lowered floors & that does give you a small amount of stowage space below the seat, as well as a bit more space behind the seat, if you don’t have the seat fully back, so I guess there are pros & cons. The lowered floors do reduce the ground clearance, the bolts sometimes scrape on speed bumps.
I have a 420R with a dry sump & I’m not convinced there’s much of an advantage with regards to increased ground clearance. Although the sump does sit higher, the bell housing hangs down below it. Caterham have fitted a hard nylon wedge in front of the bell housing, to deflect the car upwards over any bumps you might be misfortunate enough to encounter & mine has a good few dents & gouges after nine years of use. I guess that’s better than a cracked sump, although I do know of a local 420 owner who cracked his bell housing a couple of years ago.
I’d agree that getting the car properly corner weighted & the ride height set to suit your local roads is the answer, but as has already been pointed out, you need a car with adjustable spring platforms to be able to do that.
Anyway, enjoy your ruminations & good look with your search! Caterhams are cracking cars, you won’t be disappointed.
From my perspective, it was too big. I wasn’t able to fully depress the clutch pedal, even with the seat as far forward as it would go & the intimate sense of ‘wearing the car’ that I get with an S3 was lost.
I’ve done a couple of month-long trips to Italy in the last few years & I didn’t have any issues with luggage space or the size of the fuel tank. My wife came along in the Seven on last summer’s trip (she took the plane the previous time!) & amazingly, we managed to pack so light, the boot was only three quarters full when we set off. I managed to bring tools, spare oil & coolant, a foot pump & a jack, as well as the full hood, half hood & a shower cap to keep the car dry overnight. It’s amazing what you can fit in a Seven when you apply a bit of thought to careful packing.
My current car has lowered floors, my previous one had the standard floors. I’d be fine with the standard floors & I have thought about swapping back. I’ve raised the driver’s seat, as I do sit a bit TOO low with the lowered floors & that does give you a small amount of stowage space below the seat, as well as a bit more space behind the seat, if you don’t have the seat fully back, so I guess there are pros & cons. The lowered floors do reduce the ground clearance, the bolts sometimes scrape on speed bumps.
I have a 420R with a dry sump & I’m not convinced there’s much of an advantage with regards to increased ground clearance. Although the sump does sit higher, the bell housing hangs down below it. Caterham have fitted a hard nylon wedge in front of the bell housing, to deflect the car upwards over any bumps you might be misfortunate enough to encounter & mine has a good few dents & gouges after nine years of use. I guess that’s better than a cracked sump, although I do know of a local 420 owner who cracked his bell housing a couple of years ago.
I’d agree that getting the car properly corner weighted & the ride height set to suit your local roads is the answer, but as has already been pointed out, you need a car with adjustable spring platforms to be able to do that.
Anyway, enjoy your ruminations & good look with your search! Caterhams are cracking cars, you won’t be disappointed.
A straight swap between 4 wheels of the same style and width, and with the same tyre height, does not cause me any issues. It is only the rolling diameter that changes and that adds height equally all round.
I had a damaged lowered floor replaced at Arch Motors two years ago. £500 for a drive in, drive out service of about 2 hours. Personally I think the lower seating position suits the car better - you sit in the chassis, not on it. The car is so small seeing all the corners is still possible and the 'feel' through the seat is superb.
I had a damaged lowered floor replaced at Arch Motors two years ago. £500 for a drive in, drive out service of about 2 hours. Personally I think the lower seating position suits the car better - you sit in the chassis, not on it. The car is so small seeing all the corners is still possible and the 'feel' through the seat is superb.
If you can get a dry sump, do so. I have an R300K with a wet sump that I managed to destroy by hitting a stone on the road. Repair costs with a new Caterham sump was over £600 and that was a good 8 years ago. Plus it’s never been oil tight since. Always a small weep from somewhere.
Any wet sump is going to take biffs, scrapes and wallops. I’m not sure about Sigma engines in 7’s but the R400 has dry sumps as standard.
Piers
Any wet sump is going to take biffs, scrapes and wallops. I’m not sure about Sigma engines in 7’s but the R400 has dry sumps as standard.
Piers
I'm 5ft 3 and have a lowered floor Sigma S3 with Tillets.
I have raised the drivers seat up on shims and have a Tillet insert; I am very comfortable with good visibility.
I've not had a big issue with speed bumps or uneven roads yet, you just need to slow right down and plan ahead if possible.
I use my Caterham as much as possible, as a daily when it is dry as well as popping to the shops. They are just great fun. As mentioned, pop along to a dealer and have a sit in some, I had to modify mine as the previous owner was much taller than me, but it is all relatively straight forward.
I have raised the drivers seat up on shims and have a Tillet insert; I am very comfortable with good visibility.
I've not had a big issue with speed bumps or uneven roads yet, you just need to slow right down and plan ahead if possible.
I use my Caterham as much as possible, as a daily when it is dry as well as popping to the shops. They are just great fun. As mentioned, pop along to a dealer and have a sit in some, I had to modify mine as the previous owner was much taller than me, but it is all relatively straight forward.
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