Alphabettispaghetti
Club Member
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Its arrived V2.0 :)
- Thread starter Alphabettispaghetti
- Start date
Surely roll hoop manufacturers will give the weight?
I've said this so many times. On the road the weight of a hoop or cage is not as important as the practicality issues. Make the decision on safety and car use. Also a stiff arb is only really necessary on a smooth track. Too stiff and it will stress the chassis mounts too. All above based on experiences.
I've said this so many times. On the road the weight of a hoop or cage is not as important as the practicality issues. Make the decision on safety and car use. Also a stiff arb is only really necessary on a smooth track. Too stiff and it will stress the chassis mounts too. All above based on experiences.
Alphabettispaghetti
Club Member
Thats where I got that weight from Rob, I gave them a call and had the answer 30 seconds later. you can see also that it doesn't impact the car's practical use either. I can't comment on earlier versions.
Also agree on having ARB's that are too stiff, thats why I've got the smallest I could find. the good thing about the rear is that it doesn't actually mount onto the chassis at all. i've tried cars without them on the road, even with £5k's worth of suspension, they still needed them, just not massive ones.
Ian
Club Member
Wow, thats a lot lighter. Thats not a bad penalty to suffer for the benefits, they far outweigh the minimal weight gain. Especially as the S30 can't have much strength in roof should the worst somehow happen.
Thanks.
Still wish there was weight I could remove from the car, but theres literally nothing that can be removed if you want a good road car.
Regarding anti roll bars if you are interested, this is not 100% because I guessed measurements and the chassis mounted bar has slightly different shape to the rear mounted bar. But it gives a good idea how much stiffer it would be over stock.
Allowing both bars being the same:
Stock 16mm bar has a Torsional Stiffness of 55.60 Lbs/in
Uprated 19mm bar has a Torsional Stiffness of 111.25 Lbs/in
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Alphabettispaghetti
Club Member
I think you need an arb at the rear if you are going stiffer at the front otherwise you may have too much understeer.
If you are worried about a few kgs then only drive with your petrol tank almost empty! Seriously does it make a big difference on the road if you have a full tank or a 1/3 full tank?
If you are worried about a few kgs then only drive with your petrol tank almost empty! Seriously does it make a big difference on the road if you have a full tank or a 1/3 full tank?
Alphabettispaghetti
Club Member
I think they key thing here is that the 'softened down' US market cars didn't get rears!
Ian
Club Member
Thats a big rear and IMO definitly too much, but again thats all personal preference.
Its absolutly a needed upgrade for cars that don't have any.
I also apologise for somewhat cluttering up your build thread with all this talk.
Thats for certain, you want to keep the balance, hence for me upgrading the rear means also moving a 1" think front bar.
Its just how I think. I want to cut weight wherever I can, do this in several areas and it adds up noticeably. Colin Chapman's philosophy of adding lightness. I wouldn't want to add 30+KG but I would add 12-15KG if the benefits in other areas are there, 12kg you would not notice, 30kg you would, at least on track and drag.
The lighter the car the more you notice extra weight. My other fun car comes in at 950kg and I really notice the effect of a passenger and also but to a lesser extent the difference between a full and near empty tank.
uk66fastback
Club Member
Being conscious of weight is fine, and in a racing or drag scenario it's obviously very important, but for a road car, unless you're driving everywhere flat out (as you mostly are when racing or taking it down the strip), what's the point?! Unless it's the 'challenge' of getting the car lighter ... or am I missing something else?
Alphabettispaghetti
Club Member
Alphabettispaghetti
Club Member
you know as a early car, they're so much lighter as the panels were hot rolled between Brazilian virgins thighs to create strength and purity.
Ian
Club Member
Just how my mind works, I could never be happy unless every detail has been thought out and executed in the best way I can, and at the same time creating a balance between stiffness, power, weight, ability on track and usability on the road. I don't like the thought of knowing I had added weight for no benefit, I want the end product to be as light as it can be while keeping it good to use as a road car. Obviously for a track car adding lightness is easy as you don't need any sound deadening, carpet, interior and you can remove a lot of unneeded systems to offset the weight of the full cage you would want.
I guess you could say I enjoy the challenge, might be weird to you, but everyone is different. Being a 78 chassis its already stiffer than an early chassis but with some extra weight, and while I've taken about 40kg out of her the engine, gearbox, wheel/tyre and driveshaft setup are heavier than original. I would like to offset this as much as possible.
Similar to why I am putting thought into changing my anti roll bar setup, for packaging reasons it makes sense for me to move to a rear mounted anti roll bar at the rear but rather than just blindly switching I have to think about the implications of running a stiffer bar at the rear, and therefore a stiffer bar at the front, how this affects the handling in relation to how I like my setups and the extra load of the chassis and mounting points.
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Alphabettispaghetti
Club Member
yes
Alphabettispaghetti
Club Member
maybe while you’re in the Far East you can get some copied along with exhausts and panels etc.
Good choice, their setup transformed my cars handling completely, I've been very impressed. The rear bar in particular makes a massive difference and mounts up so nicely!
Haha its not that kind of trip but it could be amazing if I found the right place. Avoiding Japan so that I don't destroy my budget in the space of one week!
Haha its not that kind of trip but it could be amazing if I found the right place. Avoiding Japan so that I don't destroy my budget in the space of one week!
Pondo
Club Member
This is something I’m going to try on mine, I’ve had the enjoyment of driving the car this summer but hoping to change out the poly bushings on the car this winter and have been thinking lately about fitting an arb to the rear as mine doesn’t have one as it’s a late ‘71, excited to see how this might alter the driving experience.
Do the ST bars come with the fixings needed as I’m not sure mine has the mounting points. I was having this discussion with my mate who’s building a MG Sebring style car and he says he’s taking his arb off the back of his.
Do the ST bars come with the fixings needed as I’m not sure mine has the mounting points. I was having this discussion with my mate who’s building a MG Sebring style car and he says he’s taking his arb off the back of his.
The ST kit comes with all of the mounting hardware and doesn't mount off the body at the rear. It provides new hangers around the diff which are mega, you can see them on Jasons car. I was in the same boat as mine is a 1970 car and has no mounting points whatsoever....
One of the best mods to make to a US market car imo!
Alphabettispaghetti
Club Member
Not much progress as i'm waiting on a few bits arriving and some time to do stuff.
Got a v5 and Reg number which is ace.
spent some time farting about deciding on wheel colour for its main wheels.
Thought I had decided, however still not sure.
Got a decent LHD dash.
Got some tyres, managed to get them at a more sensible price than normal, i'm very pleased as they look so good, have amazing 'performance' reviews.
https://classic.michelin.com/en/Classic-Tyre-range/MXV3-A
195/65/14.
Also decided on a gearbox. Thanks to Alan T ;
from a 1972 KGC10 model Skyline GT showroom option 5-speed.
Ratios 3.321, 2.077, 1.308, 1.000, 0.864 and 3.382 reverse, It is an FS5C71-B flanged output transmission with Servo type synchros.
Sold a load of spare bits to free up cash for all the above, met a couple of club members which was nice. Feels nice to de-clutter also.
A few bits being made, so I can properly put the running gear in, might actually get an engine in it next year.
Got a v5 and Reg number which is ace.
spent some time farting about deciding on wheel colour for its main wheels.
Thought I had decided, however still not sure.
Got a decent LHD dash.
Got some tyres, managed to get them at a more sensible price than normal, i'm very pleased as they look so good, have amazing 'performance' reviews.
https://classic.michelin.com/en/Classic-Tyre-range/MXV3-A
195/65/14.
Also decided on a gearbox. Thanks to Alan T ;
from a 1972 KGC10 model Skyline GT showroom option 5-speed.
Ratios 3.321, 2.077, 1.308, 1.000, 0.864 and 3.382 reverse, It is an FS5C71-B flanged output transmission with Servo type synchros.
Sold a load of spare bits to free up cash for all the above, met a couple of club members which was nice. Feels nice to de-clutter also.
A few bits being made, so I can properly put the running gear in, might actually get an engine in it next year.
Alphabettispaghetti
Club Member
Small update. The intrax are 'upside down' so adjusters at the bottom of the strut, I won't lie, less than ideal!
A great engineer on here made me some roll centre adjusters to my spec, this week I finally ordered the right bolts in the right length and thread to bolt bits together properly. I was really pleased to see I was 5mm out on some. However, great to have it all properly together.
Caliper brackets are not properly mocked up, Its nice and tight under the wheels. A little too tight for the watanabes, they'll need a 2mm spacer. to be honest I can't be arsed to change the whole setup in the chase for 'perfection'. The other wheels are spot on though.
My last rack was cracked, a replacement found from Murdocks friend. used all the best bits to make the best rack I could out of all of the parts. I've added new nipples, most racks nipples can be improved on. These nipples had gone hard from old lube blocking them up, the new rack with new nipples and lube feels lovely to touch. I was in the garage for about 3 hours playing with the rack, it wasn't the most fun i've ever had. Seems like decent racks are in short supply. I'd like a new one, I've got a cost however spare cash is in short supply.
damaged parts not used
Has anyone on here also rebuilt a rack and set it up to the FSM's spec? I've just ordered a spring weight to try and do it correctly. i'll then paint it.
So CV-19 has helped me make progress, took me 3 days to sort and empty the garage so I can get to the car. Once the slightly longer bolts arrive i'll torque all the front and rear running gear to spec, fit the rack and think about the fuel/brake lines. I won't lie, I hate doing hard lines as they never ever look quite right.
A great engineer on here made me some roll centre adjusters to my spec, this week I finally ordered the right bolts in the right length and thread to bolt bits together properly. I was really pleased to see I was 5mm out on some. However, great to have it all properly together.
Caliper brackets are not properly mocked up, Its nice and tight under the wheels. A little too tight for the watanabes, they'll need a 2mm spacer. to be honest I can't be arsed to change the whole setup in the chase for 'perfection'. The other wheels are spot on though.
My last rack was cracked, a replacement found from Murdocks friend. used all the best bits to make the best rack I could out of all of the parts. I've added new nipples, most racks nipples can be improved on. These nipples had gone hard from old lube blocking them up, the new rack with new nipples and lube feels lovely to touch. I was in the garage for about 3 hours playing with the rack, it wasn't the most fun i've ever had. Seems like decent racks are in short supply. I'd like a new one, I've got a cost however spare cash is in short supply.
damaged parts not used
Has anyone on here also rebuilt a rack and set it up to the FSM's spec? I've just ordered a spring weight to try and do it correctly. i'll then paint it.
So CV-19 has helped me make progress, took me 3 days to sort and empty the garage so I can get to the car. Once the slightly longer bolts arrive i'll torque all the front and rear running gear to spec, fit the rack and think about the fuel/brake lines. I won't lie, I hate doing hard lines as they never ever look quite right.