Riviera Blue 420R - DPR Motorsport build

[bushhpd]

A few photos attached of my new arrival to the garage - 420R in Riviera Blue with lots of boxes ticked from the spec sheet!

Huge thanks to Dave and the team at DPR Motorsport who advised on spec, built the car, dealt with IVA, have set the car up perfectly for a mix of road and track use, and were absolutely fantastic throughout - would thoroughly recommend them to anyone else.

[TheDeadPrussian]

Congratulations on a great looking car!

I have one in build with David and the DPR team currently - very similar spec'. Hopefully it will be ready for collection in a week or two...I'll post some photos once complete.

Enjoy!

[griggsy2]

Looks great! Congrats!

[tomwoodis]

Lovely. Hope you enjoy it.

Can I ask about the nose cone? I see it has cut outs in it. I thought that style was what they put on the 620R variant. Is this now an option on the options list? What, if any, difference does it make on a car that hasn't had a super charger fitted? I'm interested as I have a SuperSport R (effectively a 360R) built a few years ago and back then none of the models had the cut outs.

Tom

[bcr5784]

tomwoodis said:

Can I ask about the nose cone? I see it has cut outs in it. I thought that style was what they put on the 620R variant. Is this now an option on the options list? What, if any, difference does it make on a car that hasn't had a super charger fitted? I'm interested as I have a SuperSport R (effectively a 360R) built a few years ago and back then none of the models had the cut outs.

Tom

According to Caterham the ducted bonnet (sidestrakes and remodelled wings) introduced on the CSR were intended to reduce front end lift. I imagine it helps with cooling too.

[bushhpd]

TheDeadPrussian - is that the Riviera blue one with orange rollcage and stripes? - saw it at DPR on Friday - looks good!

Tom - yes, this is the 620R nosecone. My understanding is there is no mechanical/engineering benefit of having it on a non-supercharged car, other than looks! It's now on the "Caterham Signature" options list now for all new cars.

[tomwoodis]

Thanks for the update. Must admit I've never found myself out on track suffering from front end lift. Sounds like I'll have to find something else to spend some money on instead 😀

[bcr5784]

tomwoodis said:

Thanks for the update. Must admit I've never found myself out on track suffering from front end lift. Sounds like I'll have to find something else to spend some money on instead ??

According to an article at the time the CSR mods halved front end lift from 100lb to 50lb at 100mph see https://en.wikipedia.org/wiki/Caterham_7_CSR, Those are BIG figures on a car with only 600 or 700lb on the front axle in the first place.

[tomwoodis]

Interesting, thanks for that. As you say that's a fair bit. I've also heard murmurings that running with a number plate on the front helps to reduce front end lift when compared to not running one at all, any truth in that do you know?

[bcr5784]

Don't know, but it was common in the 70's before aerodynamics got a bit serious, to have an air "dam" on the front to (sic) cause the air to flow over rather than under the car to reduce drag and lift as I suppose the Caaterham number plate might constitute a vestigial air dam, but how effective I've no idea.

I know that back in the day scrutineers were very particular about the size and placement of number plates on academy cars - but whether that was based on any real knowledge of the potential benefits, I have no idea.

Edited by bcr5784 on Tuesday 29th August 20:16

[TheDeadPrussian]

bushhpd said:

TheDeadPrussian - is that the Riviera blue one with orange rollcage and stripes? - saw it at DPR on Friday - looks good!

That's the one! I should have it in a week or two.

[bcr5784]

Because the 7's aerodynamics are so dire, it's a subject rarely scrutinised. Arguably for the same reason it's the one which should be focussed on. Everyone would doubtless agree an aero screen is better than a windscreen, and cycle wings better than clamshells. But by how much? How much worse is a full roll cage than a track day one? How much does a half tonneau gain you - and how much better is a solid one than a fabric one? How much does a ducted radiator gain you - or strakes or CSR mudguards. Is it worth fitting your front cycle mudguards back to front?

[anonymous-user]

bcr5784 said:

Because the 7's aerodynamics are so dire, it's a subject rarely scrutinised. Arguably for the same reason it's the one which should be focussed on. Everyone would doubtless agree an aero screen is better than a windscreen, and cycle wings better than clamshells. But by how much? How much worse is a full roll cage than a track day one? How much does a half tonneau gain you - and how much better is a solid one than a fabric one? How much does a ducted radiator gain you - or strakes or CSR mudguards. Is it worth fitting your front cycle mudguards back to front?

Speaking to an F1 aero designer who has driven my R400D on track a few times, the phrase 'polishing a turd' came up.............

[bcr5784]

REALIST123 said:

Speaking to an F1 aero designer who has driven my R400D on track a few times, the phrase 'polishing a turd' came up.............

Yes and no. There's no way you are going to make a 7 style car good - or even average - aerodynamically. The fact that you can reduce front end lift by 50lb at (only) 100mph with (cosmetically) very minor mods shows that there is plenty of scope for noticeable improvement without a major redesign. I think the step from "dire" (aerodynamically) to merely "poor" would be a step worth making.

[anonymous-user]

bcr5784 said:

REALIST123 said:

Speaking to an F1 aero designer who has driven my R400D on track a few times, the phrase 'polishing a turd' came up.............

Yes and no. There's no way you are going to make a 7 style car good - or even average - aerodynamically. The fact that you can reduce front end lift by 50lb at (only) 100mph with (cosmetically) very minor mods shows that there is plenty of scope for noticeable improvement without a major redesign. I think the step from "dire" (aerodynamically) to merely "poor" would be a step worth making.

If that's true; I think everyone would be doing it if it was.

[Smitters]

REALIST123 said:

bcr5784 said:

REALIST123 said:

Speaking to an F1 aero designer who has driven my R400D on track a few times, the phrase 'polishing a turd' came up.............

Yes and no. There's no way you are going to make a 7 style car good - or even average - aerodynamically. The fact that you can reduce front end lift by 50lb at (only) 100mph with (cosmetically) very minor mods shows that there is plenty of scope for noticeable improvement without a major redesign. I think the step from "dire" (aerodynamically) to merely "poor" would be a step worth making.

If that's true; I think everyone would be doing it if it was.

Have a look at Woog Automotive on fb to see what said turd looks like.

[bcr5784]

Smitters said:

Have a look at Woog Automotive on fb to see what said turd looks like.

I rather like it, (but I'm no aerodynamicist) but the head/side lamps look a bit out of place and the rear wings look far too big, as they do on all 7s, which must increase frontal area, and the huge rear tyre clearance (especially with 13" wheels) both looks naff and must be bad for drag, Combine that with inboard front suspension a la CSR or Freestyle and we might be getting somwhere.

But the proof of the pudding would be in wind tunnel figures.

Edited by bcr5784 on Thursday 31st August 15:36

[anonymous-user]

Smitters said:

Have a look at Woog Automotive on fb to see what said turd looks like.

Well, I don't bother with Facebook but I've seen it on their website. A little more than a 620 type nose, I would suggest!!

As said it would be interesting to see some tunnel results but that wing doesn't look that effective in terms of generating downforce itself and without knowing what, if anything, they've done downstream it would be hard to see how effective it might be overall. The more I look at it the less I like it.

Personally, the freestyle/CSR suspension development would seem to be a better bet for improving performance. Combined with a good damper set up it should be possible (I know it is) to get a well balanced car.

[bcr5784]

REALIST123 said:

Personally, the freestyle/CSR suspension development would seem to be a better bet for improving performance. Combined with a good damper set up it should be possible (I know it is) to get a well balanced car.

There would still be 50-100lb of lift at 100mph. That really is dire. Enzo Ferrari once (very foolishly) said aerodynamics were for people who couldn't make engines - he got that upside down. Let's face it you shouldn't need 210bhp to make a 11cwt car go fast enough to be interesting on track (my wife's Ibiza with 150bhp will comfortably see off a 420 on top speed)

[Smitters]

REALIST123 said:

As said it would be interesting to see some tunnel results but that wing doesn't look that effective in terms of generating downforce itself and without knowing what, if anything, they've done downstream it would be hard to see how effective it might be overall. The more I look at it the less I like it.

I said that - as in, how does it partner with other aero-management further down the car. I got quite a turbotoaster-esque response of equal parts nonsense and obfuscation. Methinks he's simply invented a flamboyant way of burning money.

In all of this, I realise I haven't said anything about the OPs car, which looks fantastic. I must admit, it's essentially the spec I ended up with when doing one of those "dream build" exercises to see what chopping my car in for a brand new Caterham, exactly as I wanted it would cost. It will be great fun I'm sure - coming to a track near me hopefully!