How The Hood Stacks Up

[Guest larryNorCal]

I would like to ask if anyone has any experience with any of these chassis? These are the manufacturers that have a chassis with a front end set-up like the new Hood chassis.

 

1) Daxcars - UK, "Patented Camber Compensation & Anti-Roll Suspesion

System" Chassis??

http://www.daxcars.co.uk/start.htm

 

2) Fraser - New Zealand, "Widetrack, Inboard Shock Absorber" Chassis

type??

http://www.fraser.co.nz/

 

3) MK Sportscars - UK, new car, tube chassis some square, some round.

http://www.mksportscars.co.uk/newcar.htm

 

4) MNRacing - UK, tube chassis some square, some round.

http://www.mnrltd.co.uk/index2.html

 

5) PRB - Australia, Pushrod front bolted to a composite monocoque

chassis.

http://www.prbaustralia.com.au/

 

6) RAW Engineering - UK, pushrod front, tube chassis.

http://www.rawengineering.co.uk/

 

7) Robin Hood Engineering - UK, new car, tube chassis mostly round,

with some "U" channel & square tubing?

pics here: http://www.freewebs.com/rhocareast/robinho...rs.htm#75650694

- any I missed?

 

Here is a list of all of the seven manufacturers that I could come up with:

Birkin, Caterham, Challenge Motorsport Engineers, Dax / DJ Sportscars, Deanfield Motorsport, Donkervoort, Elfin, Formula 27, Fraser, GTS Tuning, HKT, Leitch, Luego Sports Cars, MAC#1 Motorsports, Madgwick Cars?, MK Sportscars, MNRacing, PRB, RAW Engineering, Robin Hood Engineering, Rotus, Shaw Speed, Stalker V6, Sylva Striker, Tiger, Toniq R, TRV Motorsport, Vindicator Cars, Westfield, YKC Sports Cars, Image Sports Cars. - any I missed?

 

Again, out of all these great 30++ manufacturers, only the 7 above seem to be making a chassis with a pushrod style front suspension. Why? Ok, companies like Caterham & Westfield can claim some sort of heritage dont-change-what's-not-broken mantality. They are selling history. You would think at least Donkervoot would try something. I can see why companies like RAW & MNRacing make them, probably because it is technically better for racing?

 

Looks like it's a great time to be a newbie at this! RHE! When are you going to get some of those Hoods on a boat bound for the States?!

[Guest ScotMac]

Why are you waiting for RH to ship to the US for you? You know that you can ship it yourself?

 

When i shipped my l/w, it was only about 500gbp's. The dollar was stronger then, but even now $1000 for shipping a car across the pond isn't that bad. Any retailer that takes them across the pond for you will charge a premium. Look at coveland and their l/w prices!!! They are charging *double* what RH does ($4000 vs $8000).

 

BTW, yes i agree that inboards are a better setup....but not that much better.

 

-sm

[Guest manglemender]

Others may feel free to correct or augment this post.

 

The inboard shocks design is something that has comparitively recently passed over from racing car design to kit cars and apparently offers some advantage.

 

Caterham do use this design on the new CSR models but for me, the Dax camber compensation design is where it's at right now on the front end suspension.

 

Looking forward to hearing about your build and experiences getting your hood on the road over the pond.

 

Nick

[Guest ColinDenyer]

I wanted to keep something simple that was a so a basic rocker/pushrod seemed to be the best way not to out trick myself. Stiff & easily adjustable is better than complex & fragile. I hope i am right

 

 

 

BTW, yes i agree that inboards are a better setup....but not that much better.

 

 

 

Scotmac why not that much better?

 

Edited August 31, 2006 by ColinDenyer

[Guest Dan_Beeston]

I agree the extra linkage allows more options for tuning spring rates and spring rate ramps, together will an aerodynamic advantage (if you are working on a whole aero package, which sevens certainly don't have!)

 

One thing people haven't mentioned is that in a standard outboard coil-over setup approx half the mass of the spring/shock unit counts towards your unsprung mass. With inboard units it is just half the pushrod mass reducing unsprung mass considerably, in turn reducing inertia of the road wheels allowing them to react faster to surface changes/undulations. With optomised roll-centres and anti squat/anti dive it is possible to run very low spring rates to maximise grip without compromising stability etc.

 

If you hunt hard enough you can find some interesting pull-rod setups, often with the shocks mounted horizontally on the floor of the car to reduce the centre of gravity. Using a pull-rod even more weight can be removed as you are only concerned with the tensile strength of the rod, there is no tendancy for it to buckle as with a too-weak pushrod.

 

Of course this is all conjecture, the opinions in this post belong soley to the author, the facts to everyone. The destinction is for the reader to draw..........

[Guest timswait]

BTW, yes i agree that inboards are a better setup....but not that much better

I'd agree with that statement.

Advantages:

Aerodynamic: marginally less drag from a pushrod versus a coil over in the air flow.

Unsprung mass: You save half the mass of the damper from being unsprung (or do you? Thinking about it when a bump is applied through the suspension it still has to move the inertia of the lower half of the damper -hmmm have to think about it) Even if you do, it isn't very much in comparison with the mass of a wheel, tyre, heavy Sierra upright, brake disc and caliper.

More freedom of adjustment to find the 'perfect' set up.

 

Disadvantages:

Overall mass increased: marginally!

More complex.

More potential for slack and friction in linkages.

Already got more than enough settings to play with/confuse yourself with on a standard double wishbone set up.

 

Overall if I was starting with a blank sheet (as RH I presume did with the new Hood) I would go with pushrod (or maybe pull rod) suspension, but it wouldn't be a decisive factor in which kit to buy.

My gut feeling on the Hood as an overall design is that it is the best car RH has come up with to date, but it still doesn't quite meet the standards of some of the other players, although the price which I've heard bandied about does.

[Guest Dan_Beeston]

Unsprung mass: You save half the mass of the damper from being unsprung (or do you? Thinking about it when a bump is applied through the suspension it still has to move the inertia of the lower half of the damper -hmmm have to think about it)

 

Good point, I hadn't thought about it like that. Perhaps the vehicle dynamics benefits come more from mass centralisation? (lower polar moment of inertia in yaw = better turn in)

 

Even if you do, it isn't very much in comparison with the mass of a wheel, tyre, heavy Sierra upright, brake disc and caliper.

 

Another good point, these sort of setups are generally favoured in racing where featherweight uprights/brakes/wheels and no cycle wings are used. On the hood it's probably marginal

[Guest ScotMac]

Good discussion (thanks everyone, especially Colin), and it brought out much of the reasons for my statement about inboards.

 

I was thinking of doing inboards on my l/w, and decided it probably wasn't worth the trouble.

 

As has been said, i think you can discount the aerodynamics on a 7, and the unsprung weight is marginal win, if going w/ sierra uprights. So, the major benefits are adjustability and spring rate.

 

Note, i have almost decided to buy the new mk II raceleda replacement sierra urights from mnr...though the price is bit steep ($1400). The weight savings is tremendous....and thus DOES make the inboards more attractive. Robin hood should include then on the HOOD. Could probably negotiate a deal w/ Bruce (Raceleda).

 

Has anyone noticed that Coveland has jumped on my idea for pinto/mustang II uprights w/ the l/w. Still a good possibility, especially w/ wilwoods front end kit (uprights, hubs, calipers, discs) costing only $652, *and* available in the states.

 

Can you tell i am not happy w/ my current sierra uprights??

 

Cheers, -sm

[Guest larryNorCal]

Why are you waiting for RH to ship to the US for you? You know that you can ship it yourself?

When i shipped my l/w, it was only about 500gbp's. The dollar was stronger then, but even now $1000 for shipping a car across the pond isn't that bad. Any retailer that takes them across the pond for you will charge a premium. Look at coveland and their l/w prices!!! They are charging *double* what RH does ($4000 vs $8000).

 

In the early stages before deciding to go with the RHE new chassis, I talked to some other seven manufacturers and was told pick-up only, no crating service. I thought it would be hard to get a shipping co. to go crate a kit in their parking lot. So I was happy to hear Coveland is bringing kits over. But they don't return calls or emails. I can't imagine they are charging DOUBLE. Are you sure you were not looking at Pounds for the RHE price? Coveland charges $8000 USD for the lightweight, and RHE charges $?,??? USD + VAT + Crating + Import Tax? + Insurance + Shipping. If buying direct is cheaper I will do it.

 

I am not sure what the new chassis will cost, or their kit with this chassis. I will want to do some stuff different from the kit probably so I hope they offer a custom kit option. If RHE will crate my components for shipping to the US then I will definately try that.

 

does anyone know if I have to pay the VAT if I am shipping it to the States? Last time I was in Europe they had some sort of "Tax Free" thing for tourists, maybe I need to visit the factory!

I wonder if I have to pay import taxes as well here in the States......?

 

 

 

My gut feeling on the Hood as an overall design is that it is the best car RH has come up with to date, but it still doesn't quite meet the standards of some of the other players, although the price which I've heard bandied about does.

What standards are you talking about? Colin (one of the chassis consultants/designers) is talking about this new design being stiffer than a Caterham or Westfield. What are the other considerations?

[Guest ScotMac]

In the early stages before deciding to go with the RHE new chassis, I talked to some other seven manufacturers and was told pick-up only, no crating service. I thought it would be hard to get a shipping co. to go crate a kit in their parking lot. So I was happy to hear Coveland is bringing kits over. But they don't return calls or emails. I can't imagine they are charging DOUBLE. Are you sure you were not looking at Pounds for the RHE price? Coveland charges $8000 USD for the lightweight, and RHE charges $?,??? USD + VAT + Crating + Import Tax? + Insurance + Shipping. If buying direct is cheaper I will do it.

 

RH charge(d) 2000gbp's for a LHD LightWeight. So, w/ the strong gbp, that is about $4000. That leaves you $4000 to crate, ship, insure and pay import tax (note VAT is not required, since shipping out of UK). RobinHood will crate the l/w for 50gbp's, the shipping is about $1000, importation costs (taxes, etc) are about $300. So, that is about $4000 + $100 (crate) + $1000 (shipping) + $300 ~= $5400. Which leaves you about $2600 to insurance it, based on the coveland price!!! Can't imagine that insurance would be much more than $600, so you save $2000.

 

Note, all of these are based on my ACTUAL costs for importing my l/w myself. Note also, for mine, you can add another $1000, because i went to the UK myself to pick it up and take it to the shippers, Obviously not necessary, but based on RH customer service, i thought it was prudent, and i had a airfare voucher i needed to use (expiration).

 

I am not sure what the new chassis will cost, or their kit with this chassis. I will want to do some stuff different from the kit probably so I hope they offer a custom kit option. If RHE will crate my components for shipping to the US then I will definately try that.

 

As i mentioend, RH crated up my l/w for 50gbp's.

 

does anyone know if I have to pay the VAT if I am shipping it to the States? Last time I was in Europe they had some sort of "Tax Free" thing for tourists, maybe I need to visit the factory!

I wonder if I have to pay import taxes as well here in the States......?

 

No, you don't have to pay VAT. RH still owes part of mine. My recent strategy is to simply order parts from them, and then take the price of the part off the VAT they owe me. They DO require proof of shipping, so keep all your shipping paperwork.

 

Yes, you must pay import taxes. You also have to pay DMV usage taxes.

 

-sm

[Guest larryNorCal]

Thanks for ALL the info Scotmac, sounds like I will be buying direct, maybe when the time comes you can refer a good shipping company as you are from the UK. Now maybe I can afford a Raceleda front end kit & those fancy shocks you were talking about!

[Guest larryNorCal]

No, you don't have to pay VAT. Yes, you must pay import taxes. You also have to pay DMV usage taxes.-sm

 

It sounds like we have it a bit easier getting a RH on the road here in the states. I don't know all the details, but as far as I know the DMV just checks that all the lights are the right height and things work properly (turnsignals, etc). I hear only 500 kitcars per year in California are allowed to be registered, and you have to have an appointment for 9:00 AM the first day they take applications because they are all gone in around 45 minutes the first day. but with this status, NO SMOG! and no SVA.....

[Guest ScotMac]

It sounds like we have it a bit easier getting a RH on the road here in the states. I don't know all the details, but as far as I know the DMV just checks that all the lights are the right height and things work properly (turnsignals, etc). I hear only 500 kitcars per year in California are allowed to be registered, and you have to have an appointment for 9:00 AM the first day they take applications because they are all gone in around 45 minutes the first day. but with this status, NO SMOG! and no SVA.....

 

It is called SB100 (also SPCNS). I have one of the 500 for 2006. It MAY be a waste, if i can't finish the car *soon*. Maybe i'll sell it, since they could register the car in my name, and transfer it to themselves, since the the SPCNS registration stays w/ the car.

 

Yes, our DMV and police inspection is VERY easy. Amounts to simply lights and brakes.

[Guest larryNorCal]

It is called SB100 (also SPCNS). I have one of the 500 for 2006. It MAY be a waste, if i can't finish the car *soon*. Maybe i'll sell it, since they could register the car in my name, and transfer it to themselves, since the the SPCNS registration stays w/ the car.

 

Yes, our DMV and police inspection is VERY easy. Amounts to simply lights and brakes.

 

you are going to sell your lightweight because you cant finish it in time?

then buy the new chassis?

[Guest ScotMac]

Thanks for ALL the info Scotmac, sounds like I will be buying direct, maybe when the time comes you can refer a good shipping company as you are from the UK. Now maybe I can afford a Raceleda front end kit & those fancy shocks you were talking about!

 

No problem...but Dan is the resident (LA area) UK expert, not me. I am from Washington, and have lived in california for 16 years!!! ;-)

 

In fact, i would like to know who Dan or anyone else recommends for a shipper. I would NOT recommend my shipper, tho the price was OK. My shipper was AllSeas, and if you look back thru my posts, you will see the damage they (or possibly the California warehouser) did to my l/w crate, body panels, and grp.

 

Note, also, even though i arrived at RH at 5 pm, the day i was scheduled to pick up, the l/w was not yet crated, and the crate was not yet made. RH did do VERY well in recovering from this problem (3 workers stayed late to build the crate and load the contents). But, if you are not going to make the trip to the UK, as i did, then i would be VERY diligent in making sure that RH is ready for when the shippers show up to make the pickup. ie, call them many times in the proceeding days. Note, AllSeas WAS willing to do a door-to-door ship, for not much more (i believe around another $200).

 

-sm

 

 

you are going to sell your lightweight because you cant finish it in time?

then buy the new chassis?

 

No, i am might need to sell my SB100/SPCNS Certificate of Sequence (allowing the smog'less reg).