Wheels

[Gulbrandsen_Racing]

Maybe G_Racing can let us know the width of his rims...and I'll look up the width of the rims Al had on his black 360.

cheers

James

I've got 215 tyres in front, and the tire-sides are completely straight.
So i would believe they are 7.5" wide.

[IvanAE86]

I just got some nice tyres to go with my 13x8j ET4 Rota RB's (smoor/minilite lookalikes).
The tyresize is a bit unorthodox for a volvo 360...23/57-13 Michelin slicks...roughly equivalent to about 270/50-13 tyres according to some websites. although I'm not too sure about that.
They stick out about 5 cm's on each side
I'll try to get some pics of it.. looking like some kind of ridiculous dragracer with those wheels at the moment. Luckily I have some old toyota celica wide arches to get the whole thing to look proper.

[SteveP]

Looking forward to seeing it!

[340GLT]

I want pics!!! lol
Adam

[jtbo]

I wonder, what to do to make such wheels turn enough, they certainly are not turning as much as standard wheels ???

Putting wide tires to back will make under steering just worse, but maybe if it is used just for acceleration?

[IvanAE86]

A friend of mine took some quick phonecamera pics this weekend when we were test fitting them. I'm trying to get those pics sent to me, but he's a bit lazy sometimes. The front wheels turn freely all the way around, but I had already cut and modified the front wings/wheelwells to better accomodate the 15" wheels I had before.
The biggest problems as I see them at the moment are the lack of suspension travel in front (dutch 360 cup springs, leave about 5 cm's of travel) and the fact that they stick out so much at the rear means I have to cut as much as possible off of those arches as well, although I only got the tire to scrape the arches during hard braking in reverse gear.
Never got to test anything though, was supposed to go to Spa-Francorchamps with it yesterday but we had a front wheel bearing, radiator, waterpump, timing belt and power steering tensioner break all in the course of a single weekend. A kind of divine intervention there.

[jtbo]

That was great info, I was wondering one day how can it be when doing my mod that V360Cup car has so little travel, but it is so in real life too, maybe I just put even more stiffer springs to mod so it won't bottom out at Eau rouge, it is annoying as grip is lost at front, otherwise could do that with full throttle

I'm pretty sure that you can get car bottom out in real life too, specially in places like eau rouge, those G-forces kind of multiple cars weight so better make sure tires wont scrape before making high speed test, body wont handle forces of hitting tire wall doing 160kph too well, I'm sure

Damn, sounds almost like some evil spell cast to your car, so much broking down at once

[IvanAE86]

You need to keep in mind that the cup springs (well the ones I have, they use many different ones but these where developed by the 2004 or 2005 champion) are designed to work with 14" wheels with 185/60 toyo trampio semislicks. In practice the 15" 195/55 advan A032R's left me with even less travel, but this was never a problem after cutting the wheelwells and front arches out to max size. The car does hit it's bumpstops on every speedbump it hits on the street, so I think I'm opting for some stiffer rates in front one day. Just need something to get the rear end stiffer, otherwise I will just be adding understeer. Needs some kind of anti-roll bar I think..

About the evil forces at play, who knows. Much of the breaking happened while trying to fix stuff to be honest. Steeringpump tensioner was rusted beyond repair but had to come off so I broke it, timing belt broke because the darn nut of one of the waterpump studs had fallen in. It was lodged between the belt and crank gear and the belt was overstretched in a half-baked attempt to remove the crank pulley without air tools.
In the end we found out the B21ET waterpump wouldnt fit anyways so we spent a sunday wrenching for nothing.

Still waiting for those pics BTW...you'll be the first to see 'em guys.

[john.d]

...pics...pics...pics...!!!!

what do you mean by the term 5cm trave IvanAE86; 5cm in the damper before it goes on the bumpsteers or 5cm before tyres go on the arches; have yoy measured yoyr ride hide at front; i mean the distance from the center of the wheel to the edge of the arch. on mine it is 34.5cm

[IvanAE86]

I'm talking about travel from the top of the tire to the top of the wheel arch (I ground of the outer edge). Cant measure it anytime soon I'm afraid. I slightly shortened the bumpstops by the way. The 5cm's isnt exactly a precise measurement...I just feel by hand how much travel is left up there with the car on the ground, and it isnt much.
If I had to estimate what springrate the cupsprings have I would probably guess around the 3 or 4 kg/mm mark.. less stiff than the spring I use on my AE86, which are around 6 kg/mm. The front is really darn heavy on the 360 so it might just feel like a low springrate because of all that weight pressing on it. Wish they'd made that boat anchor B200 a bit lighter (at least it's pretty reliable most of the time).

Still no word on the pics... cant get that friend of mine to answer his phone.

[jtbo]

Stock GLT spring has approx 4,5 active coils, that means 6,5 coils total when you count those two at both ends too.

Stock GLT springs are around 30kN/m, which is around 3kg

Cut one coil and you get 38,45kN/m, which is around 3,9kg

Cut two coils and you get 53,83kN/m, which is around 5,5kg

One coils is around 61mm high, so spring is 120mm shorter when cut two coils, that is bit more than 1/3rd shorter than original.

It is rather easy to calculate but when measuring springs, even small error sets numbers off greatly. 0,5 coils is already quite a lot for example.

Here is new version of my program, I just corrected some texts and added few for it to be more useful.
http://www.janiervast.com/tiedostot/Spr ... taller.zip
Unzip and run setup.exe, that will make JTbo folder to your start menu, where is then this spring calculator, I must change that too when I find out where I can change it

Problem with short range of motion and too soft spring is that you will lost grip when car touches bump stops and car does not know what to do. I get this with stock GLT springs, front jumps towards outer corner on one place of my home track, once got even my back hurt there because of that, it did hurt for next two weeks.

Oh yes, here is other program, very good for conversions like kg-nm etc:
http://joshmadison.net/software/convert/

[IvanAE86]

Does that calculator allow you to calculate springrate from coil diameter/thickness and those kinds of measurements? I cant test it cause I'm at work at the moment.
This is getting quite offtopic by the way

[jtbo]

Does that calculator allow you to calculate springrate from coil diameter/thickness and those kinds of measurements? I cant test it cause I'm at work at the moment.
This is getting quite offtopic by the way

Currently it is using these variables to calculate springrate:
Diameter of wire
Average diameter of coil
Number of coils
Also modulus of rigidity, but that is more like constant.

It should be not a big problem to make it calculate springrates from other data, just would need to know formula how to calculate things, putting it into program is not a big issue...

Oh yes, maybe bit OT, but still when you change big wheels you like to know spring rates and make them perhaps stiffer, so maybe semi on topic too

[IvanAE86]

I'm missing coil spacing (distance between coils) in that formula I think... or else a combined length for all the active coils. I would like a bit stiffer front suspension, the only problems you run into are that the free length of the spring will never pass any MOT (or equivalent) inspection, and that you need something to get the rear stiffer too.
What kind of springrate works well in your experience? I think the cup springs are as soft as they are so they dont turn the car into an even more understeering brick. The slicks I have mounted at the moment could use a bit more springrate though, but when I do that I want to stiffen the rear up too.
Has anyone here experimented with the stiffer leafsprings for sale in scandinavia (volvo300power shop)?

To go a bit further off topic...I measured a spare strut in my basement last week, it had a 52mm diameter.. this happens to be the exact same diameter thread (M52) that almost every german coilover manufacturer uses. Has anyone made coilover suspension for a 360 before? I know you can buy replacement springperches etc from H&R and whatnot, you just need to have the threads cut on the strut. After that it's a bit cheaper to experiment with springrates, and it will also allow you to use wider wheels in big sizes without rubbing the springperch.

[jtbo]

There is at least two different formula to calculate springs, what I have used does not use coil spacing or length of active coils, however I know there is such formula, but I have not managed to grab it anywhere.

When I was making program there was lot of discussion from subject and conclusion was that there is no more dimension needed, length of spring would be not affecting spring rate.

After several tests it seemed to be like that, but if program gives wrong results then of course I have been under false impression.
That is actually one of reasons why it still is Beta

I have not too much experience from different springs in my car, I have just had GL and GLT springs and GLT springs are certainly improvement, car won't bottom out as easily, but then again I replaced dampers same time so that can help a bit too

I have read quite lot from this and some race engineering stuff too. Also making this mod for rFactor has been great as spring rates seem to act there quite realistic so it is rather easy to test few things, however I have not yet tuned tires completely and those are still causing false information when testing springs, there is too much grip compared to street tires currently and that causes springs to feel even softer than they really are.

Anyway according to many race teams it is important to try to find softest spring rate that won't bottom out, in higher level series they will use different springs on different tracks, some can even change them depending from weather.
Bottoming out is very bad as when suspension bottoms out tire and bump stop are those that act as spring and there is no rebound damping which means kangaroo on track

Some Honda's have spring rate of 65-80kN/m (approx same weight car) I do know that those have quite short bump travel so I would try to look spring somewhere in that range for car that is as low as yours. Also I think rear should be no more than 20% softer than front to make it turn well as there is so much weight on rear too in these cars.

Of course 2Hz rule applies, you will need dampers that are enough stiff too or car will bounce out of grip.

But I'm sure you know lot of these already and many things better than I

Here was thread about 363cs with great photos, there is photo from rear ARB too, you could try install similar way?

I think that only coilover might be in Nev's car ? Or was it his car where they were going to?

That is quite good information that one could actually get that kind of coilover built, then also adjustable dampers could be easier to get into car.