Project S13 - Supersprint/Time Attack

[nismoman 1]

UPDATE!

 

Pic of my S13 at Winton Raceway added.

 

Some new Personal Best times:

 

Oran Park GP 1:20.65

Wakefield 1:04.8  1:03.8

Eastern Creek (SMSP GP) 1:41.6   1:40.9

Winton Raceway (National) 1:30.3

 

 

Car Spec Goals

Was - 200 rwkw's with about 1000kg kerb weight - CURRENT SPEC - 255rwkw's and 1050kgs.

 

Set up:

SR20DET (internally stock)

GT2871R S15 Comp cover, 52 trim, 0.64 rear housing AKA GTRS

Camtech Stage 1 Camshafts

Nistune ECU

E85, 1000c injectors

FMIC

Turbo back side exit exhaust (no cat)

Stripped interior

CAMS approved bolt in 6 point roll cage

Fixed bucket seat with 4 point harness

G4 Coilovers, Lovells Springs

17 x 9 wheels +17 offset with 245/45 Kumho V70A semi slicks and V710 also

R32 Front and rear brakes

5 stud conversion

 

 

OK people,

I'm building a track only S13 silvia for supersprints, hill climbs and the like and I want to put in a roll cage.

I considered the jap cusco type but decided against them because

1. they don't pass CAMS specs and

2. they don't look that safe anyway. (too many bendy parts in the a pillar struts)

 

So.. anyone out there who has a cage in their car, give some info or pics.

For example:

Type - bolt in or weld in?

Material - mild steel or chrom moly?

Number of points? 4-6?

Type of bracing? Side intrusion bars? Horizontals?

How much it cost?

Where to get it done?

 

Cheers

Mark

[Hi Octane Racing 0]

OK people,

I'm building a track only S13 silvia for supersprints, hill climbs and the like and I want to put in a roll cage.

I considered the jap cusco type but decided against them because

1. they don't pass CAMS specs and

2. they don't look that safe anyway. (too many bendy parts in the a pillar struts)

 

So.. anyone out there who has a cage in their car, give some info or pics.

For example:

Type - bolt in or weld in?

Material - mild steel or chrom moly?

Number of points? 4-6?

Type of bracing? Side intrusion bars? Horizontals?

How much it cost?

Where to get it done?

 

Cheers

Mark

 

Hi Mark,

 

As you are located in sydney I suggest you give Bond Roll Bars at Mulgrave( near windsor ) ( 4587 9672 ) a call. He does alot of Rally and Circuit car Roll Cages. We were going to get him to do our GTR Race Car cage but we couldnt get the car down to Sydney with enough time to get it done and back up there and finished.

 

If you check out our thread for our race car and have a look at our cage. It was built by a guy who does V8 Supercar Cages. It will give you a good idea of what a full circuit car cage is like as the rest of the car is stripped in the photos.

 

Cheers

-Nathan

[phunky_monkey 3]

Hey Mark,

 

I just spoke with Allan at Bond Roll Bars the other day in regards to a 180sx cage. He said if he was able to get a car in to use as a mould (I'm in Melbourne), then these would be the prices for the cage:

 

Rear half cage - 869

Harness bar - 121

Side intrusion - 121each

Front legs - 800

 

He would send all this to Melbourne for me, then I'd have my own person weld it in.

 

Hope this helps.

[neil_se 12]

Bond Rolls Bars for sure, i know they've done a fair number for S13s and are well priced too.

[teq 0]

why don't they pass cams spec?

I just got a safety21 cage and im planning on bolting + welding it in my track car, $800 delivered for 6 point full cage

 

edit: just read up on the cams specification myself, there's no reason why my safety21 cage couldn't be taken to a cage builder and rengineerd to meet cams specification, I think all it would need is

 

* Triangulation in the roof section anywhere (in the main support, behind the drivers seat) and;

* A pillar reinforcement, meaning that the bars that go from above/behind your head down past the A-pillar, to your feet area, would need some kind of reinforcing bar that would be in a spot chosen by the cage builder to provide adequite reinforcement, I think it would likely end up going from somewhere around the level of the steering wheel down towards the door sil beside the seat, making it a bitch to get in and out of - but its a track car so its all about safety anyway

 

It, like everything else in our chosen sport, would just cost more money

Edited September 5, 2007 by teq97

[nismoman 1]

Bond Roll Bars are sounding like the winner then.

 

teg97 - sounds like after you spent $800 initially, then more on getting it modified and engineered, you end up spending more!

 

Think I'll go for their bolt in roll cage package. That way I can remove it later if I decide to street register the car.

 

Nathan- Cheers for the info mate! That roll cage of yours look the best! I'm jealous!! Good luck at Tsukaba.

 

Regards

Mark

[Hi Octane Racing 0]

Bond Roll Bars are sounding like the winner then.

 

teg97 - sounds like after you spent $800 initially, then more on getting it modified and engineered, you end up spending more!

 

Think I'll go for their bolt in roll cage package. That way I can remove it later if I decide to street register the car.

 

Nathan- Cheers for the info mate! That roll cage of yours look the best! I'm jealous!! Good luck at Tsukaba.

 

Regards

Mark

 

 

No worries Mark, We have had plenty of stuff done through Bond Roll bars over the years and I have friends and family ( circuit and rally racers ) who have also had cages built by him and they are top quality.

 

Thanks for the support for Tsukuba

 

-Nathan

[teq 0]

yeah I'd say you're right

I'm doing all the welding/etc myself and the only money I should spend from here on in is complying it through a workshop which will make it legal, not sure how much that will cost.

 

for now though, while the car is still street registered, it's a good start and gives me peace of mind

[nismoman 1]

Bond Roll Bars here I come!

 

teq97 -Any roll over protection is better than none! After my brother hit the wall at turn 1 at Eastern Creek, I'm definitely getting a roll cage. Luckily he escaped unhurt but he was damn lucky! One more centimetre here and there, and he could've been mashed.

 

I figured if I'm hitting the race track, do it right and do it safe.

[OZ_HCR32 0]

why don't they pass cams spec?

I just got a safety21 cage and im planning on bolting + welding it in my track car, $800 delivered for 6 point full cage

 

edit: just read up on the cams specification myself, there's no reason why my safety21 cage couldn't be taken to a cage builder and rengineerd to meet cams specification, I think all it would need is

 

* Triangulation in the roof section anywhere (in the main support, behind the drivers seat) and;

* A pillar reinforcement, meaning that the bars that go from above/behind your head down past the A-pillar, to your feet area, would need some kind of reinforcing bar that would be in a spot chosen by the cage builder to provide adequite reinforcement, I think it would likely end up going from somewhere around the level of the steering wheel down towards the door sil beside the seat, making it a bitch to get in and out of - but its a track car so its all about safety anyway

 

It, like everything else in our chosen sport, would just cost more money

 

Have you actually spoken to a cage manufacturer about what you have planned? I suggest you do so. It may be better to sell your cage now.

 

Things to check is the diameter of the main hoop. Its probably smaller then what CAMS/FIA require. Most Jap cages uses thicker gauge steel to make up for the smaller diameter, so whilst beign an equivelant, its not recognised as beign equivelant unless you have the whole cage engineered. Here is the funny thing, no cage builder (never say never, but its a good rule) will re-work someone elses cage as they become the custodian of the burden/risk/insurance of the cage.

 

Also what you suggest with the front A pillar supports will not work as well as just not using the front legs and getting them made locally by a cage builder. The front legs have too mnay bends/points of failure. It basically has to go through the dash, going around the dash, in front, causes too many rigidity problems. It is very difficult for a leg with so many bends to pass the loading tests the FIA dictate (its in the CAMS manual) . I would have to check this years regulations but if it has too many bends then it has too many bends, no amount of gussets or bars will help it pass the loading test which is a factor of the cars weights applied from different directions to the top of the A pillar / roof line. The fact that when you comply striclty to the FIA/CAMS guidelines you dont have to prove the strength of the cage as it is implied to be strong enough if compying with the guidelines....thats a big bonus to many cage fabricators.

 

The cost of FEA analysis on your custom front legs??????? As an ex scrutineer im just passing on some of my experience...of course this is all for nothing unless you actually want to get the car log booked with CAMS or CAMS start applyign the wording of their handbook to Level 2 Speed and Non-Speed Events.

 

But best of luck, will be interesting to see how you go with it all

[OZ_HCR32 0]

But to answer the original question...what is your budget. I would stay away from Chrome moly and stay with mild steel. A good 6 point weld in cage (if its for the track, bolt in if for the street/track) will work nicely. Incoporate a harness bar and side intrusion and tie it into your B billar and cost wont spiral too much out of control.

 

From there you can tie it into your A piller, you can tie it into strut tops (but it cannot protrude any further then the front or rear axle lines), along with some pretty crazy triangulation. If ytou are going to be doing tarmac rally stuff then you need a whole lot more cage then track work....so thats another thing to keep in mind when shopping for cages

[nismoman 1]

I'm on a tight budget. Now I know when it comes to safety you shouldn't hold back, but I still only have a budget of approx $1000. Which is why I'm going to go for the Bond (mild steel)bolt in cage with side intrusion bars and horizontal harness bar.

 

Anyone got pics of S13 roll cages?

[phunky_monkey 3]

http://www.drdrift.com.au/gallery/main.php?g2_itemId=362

[teq 0]

But to answer the original question...what is your budget. I would stay away from Chrome moly and stay with mild steel. A good 6 point weld in cage (if its for the track, bolt in if for the street/track) will work nicely. Incoporate a harness bar and side intrusion and tie it into your B billar and cost wont spiral too much out of control.

 

From there you can tie it into your A piller, you can tie it into strut tops (but it cannot protrude any further then the front or rear axle lines), along with some pretty crazy triangulation. If ytou are going to be doing tarmac rally stuff then you need a whole lot more cage then track work....so thats another thing to keep in mind when shopping for cages

 

 

curious why you'd recommend staying away from chrome moly, given that its lighter and stronger?

[OZ_HCR32 0]

curious why you'd recommend staying away from chrome moly, given that its lighter and stronger?

 

In a perfect world i would go chrome moly. But its important to firstly consider what the rules and regulations say. Should you want to adhere to them...then.

 

The main roll hoop and cage tube must be a certain diameter and wall thickness. This assumes mild steel and is what stipulated by CAMS/FIA. Now as you point out the point of chrome moly is that its stronger so you can go to a thinner wall thickness and hence lighter cage. BUT, there is the problem. You are no longer using the wall thickness as dictated by the regulations.

 

So this means you now need to prove that its an equivelant. So this means you need to engineer the cage. Now engineering a cage is very different to say engineering a car. Engineering a car is basically wives tales and empirical experience. Engineering a cage is a pure engineering exercise, and includes 3D modelling and Finite Element Analysis. (FEA). So the exact same cage in chrome moly will automatically cost thousands more as a result of the egineering exercise associated with it as now the cage mnaufacturer has to verify that its equal or exceeds the FIA guidelines. As they are assuming all the liability for the cages safety, the engineering exercise is often quite exhaustive and needs to pass the load tests i mentioned above.

 

So you have two basic choices...strictly use the FIA/CAMS guidelines to build your cage. Or the minute you change a single aspect of it, like material wall thickness with chrome moly then you have gone free design and the cage needs to be engineered.

 

So unless you have a serious competition car and going gung-ho with your cage then the engineering of the chrome moly cage can easily double the cost. So thats one aspect of it, but there is also the fact that chrome moly needs to be heat treated after its welded. So you would want to be sure its beign fabricated with approved weld procedures which have undergone tensile tests etc and radiography to ensure that the post weld heat treatment achieves the desired grain structure.

 

So, if someone is payign for my cage...go chrome moly. If i have cash to burn, go chrome moly. If you want a jap cage that will not comply with CAMS guidelines then go with a HKS Kansai cages etc. Otherwise, its easier to go mild steel

[SRS13 9]

Hi Mark, no sure if this is possible but could you go for a welded in rear section and bolt on front???

 

and hurry up and finish your car as I need motivation to start on mine again!

[teq 0]

yeah good point, can't I just use 44mm chrome moly instead of 44mm steel though?

from the reading I've done 44mm is required for CAMS, but most of the jap spec cages are 40mm chome moly

[NickRB20 1]

while we're on the topic of roll cages, how much does it cost to your car log-booked by cams, and what does the process involve?

[nismoman 1]

John, I think you mean "hurry up and finish your car so you can work on mine!"

Goal is to have it ready by start of November. So fingers crossed.

[Boxheadmr 2]

Becasue of the use if it is still registered then you won't need a cage but if you wanted one then a simple mild half cage from bonds will do you nicely. There are also some companys in Melbourne that do cages and suggest you speak with them. You can get a lot of the companies from the cams newsletter and ones in your area.

I am utilising a Bonds half cage that has the harness bar and is bolted in, stiffeness has improved greatly and i am curently considering my options about welding in the rear and putting in the front section whilst still maintaing rego as it appears i will need to have the front section bolted in so i can remove when driving on the street.

[SRS13 9]

John, I think you mean "hurry up and finish your car so you can work on mine!"

Goal is to have it ready by start of November. So fingers crossed.

 

Yep, thats what I meant... and thanks for offering

 

Dont cross your fingers, just work harder and faster.. and no more holidays - get your priorities straight

[180-SEX 0]

how extensive can a roll cage be while staying street legal ?

[OZ_HCR32 0]

how extensive can a roll cage be while staying street legal ?

 

Not very. It means registering your car as a two seater, removing all rear trim and seat belts etc. Then you have to be careful with the front legs etc to be sure not to hinder access/egress from teh car. Frotn hoop is not allowed to foul sun visors etc etc. So to be road legal it has to be a pretty simple cage that goes through the dash board

[3AM 1]

Hey Mark,

 

I just spoke with Allan at Bond Roll Bars the other day in regards to a 180sx cage. He said if he was able to get a car in to use as a mould (I'm in Melbourne), then these would be the prices for the cage:

 

Rear half cage - 869

Harness bar - 121

Side intrusion - 121each

Front legs - 800

 

He would send all this to Melbourne for me, then I'd have my own person weld it in.

 

Hope this helps.

 

yikes. I got my half cage there for my 180sx less than a year ago and it was $550, guess the demand has gone up.

[Boxheadmr 2]

main issue in NSW is the distance of the cage to your head, the front hoop sections are within a certain distance (i can't remember exactly how much).

[phunky_monkey 3]

Hey Mark,

 

I just spoke with Allan at Bond Roll Bars the other day in regards to a 180sx cage. He said if he was able to get a car in to use as a mould (I'm in Melbourne), then these would be the prices for the cage:

 

Rear half cage - 869

Harness bar - 121

Side intrusion - 121each

Front legs - 800

 

He would send all this to Melbourne for me, then I'd have my own person weld it in.

 

Hope this helps.

 

yikes. I got my half cage there for my 180sx less than a year ago and it was $550, guess the demand has gone up.

 

I spoke with Autosport the other day before I spoke with Bond and they said they no longer stock the Bond stuff due to the price increase...

[eeden1 0]

While on topic of roll cage.

What is the regulation on roll cage in a 4 door to be legal on the street. Do you need to wield the rear doors shut?

[SRS13 9]

Mark will give an update but he went with a Bond roll cage, not sure exactly what he paid but it is being made up now so hopefully pics in the next week or so.

[nismoman 1]

Yup. Ordered a Bond roll cage. 6 point bolt in cage. CAMS approved.

Basic cage - $869

Side intrusion bars - $242

Rear harness bar - $121

Total $1232

 

Will post up pics once arrived and installed.

In fact, I may start up another thread covering the whole build project of my budget "time attack" S13.

[phunky_monkey 3]

Please do mate

 

The cage is for a silvia right? And you didn't go for front legs?