Alfa Romeo Forums banner

1 - 20 of 29 Posts

·
Registered
Joined
·
4,501 Posts
Discussion Starter #1 (Edited)
I love this! (It's like Christmas around there when the crates arrive...) One day it is a new Glenwood engine for somebody and the next its GiroDisc brakes!

Last week I cleared some new Alfetta/GTV6/Milano/75 suspensions for the shop and started the process of helping them inventory it all. Existing orders will ship this week (there is plenty for inventory too!)

Give them a ring!
 

Attachments

·
Registered
Joined
·
14 Posts
JJ: I personally like the Rs-racing sway bar but what about weight? My 30 mm bar with uniball ends weights over 8 kilos!!! Thats a huge amount of weight to be added in the front of an already noseheavy construction... Rons bars uses 10mm solid steel arms, something i think is way overkill.
Have just ordered a hollow bar for my racecar and will save about 5 kilos with new cnc-milled arms and uniball ends. Prising is just about the same as the RSR.
Any thoughts?
 

·
Registered
Joined
·
3,771 Posts
JJ75,

Where did you buy this stuff from? What else do they offer for these Alfas?
 

·
Registered
Joined
·
4,501 Posts
Discussion Starter #4
...my thoughts...? I think that you are paying way too much value to the whole "oh my - these cars are nose-heavy/they plough/bigger bar=under-steer/weight of the bar argument and not considering the value of Ron's R&D - the value of that bar - the impact on the handling!

Body-roll is the enemy and if you can eliminate it (or at least control it to a large degree) you can control camber-changes mid-corner and-and-and... Things start to fall in to place with the car! Ron spent all of that time developing this suspension, running them daily, driving different versions, testing on V6 and TS cars, racing with it - before making production runs, and then on the next season, more driving, testing and further adjustments!

I know that you have his bar, but it's always funny to see the critics/hear the skepticism - its usually people who don't have his full suspensions that have the most opinion about it.

I would think that if it was too much bar, (buying batches of 20-30-40 at a time) - he would have corrected it by now, don't you? (He has literally sold hundreds and hundreds of these things the world over!) Hollow or not, I firmly believe that the bar is right for the car based on 20K miles on the street and days and days and days on the track with various setups!
 

·
Registered
Joined
·
4,090 Posts
My view: If you can get a lighter sway bar without structural weakness that provides the same "stiffness" (antiroll), it can only be better.

I'm no expert in materials, but with a hollow sway bar, I assume you need a larger diameter sway bar to get the same effect. This reminds me of the discussion of hollow torsion bars.

Jes
 

·
Registered
Joined
·
79 Posts
Yes, the torsional stiffness is (Do^4-Di^4) - where Do is outer diameter and Di is inner diameter. If you know the thickness of the tube you can easily get the diameter which will be equivalent to a 30mm bar. Obviously mass is linearly proportional to thickness whereas torsional stiffness is of the 4th power, so a hollow bar of equivalent torsion will be lighter. Of course one should stay within certain limits for wall thickness as a huuuuge thin walled bar may have serious torsional stiffness, but will bend the second it becomes part of a car's suspension system :) Having said that I really doubt that anyone assumes Ron doesn't know that
 

·
Registered
Joined
·
4,501 Posts
Discussion Starter #7 (Edited)
:D :D :D ...what the books tell you...

I don't particularly agree and I don't necessarily disagree at all - in fact - I am ashamed to admit that I don't even have the book-knowledge to participate in the conversation. I can't even solve the formula and I may lack the practical experience to participate in a scientific conversation about the torsional differences in rigidity between hollow and solid bars etc etc - that much is common knowledge amongst my friends!

I do know enough to tell you that there is NO single formula that can be applied blanket to all cars! Theory and practice don't necessarily always run parallel - it's just not that simple - !

If it was, women would come with a manual! :confused: :)
 

·
Registered
Joined
·
3,771 Posts
The RSR bar is quite heavy but I don't see how a hollow bar would be able to be used with out special sway bar mount brackets. I think the 30mm bar is already at the limit of the bracket's diameter, I think utilizing a much larger bar would become quite complicated, quite quickly.
 

·
Registered
Joined
·
14 Posts
JJ wrote:
...my thoughts...? I think that you are paying way too much value to the whole "oh my - these cars are nose-heavy/they plough/bigger bar=under-steer/weight of the bar argument and not considering the value of Ron's R&D - the value of that bar - the impact on the handling!


I have driven my 75 V6 for three years with RSR suspension and sway bar. Have driven most of Rons V6 demos at the ring and the experience is that all V6`s with RSR have a lot of understeer.
The last 2-3 seasons I have spent a lot of time testing the 116 chassis on track with different setups, and the best improvement by far has been lightening the front end.
I am not saying that the thickness or design of the RSR-bar is wrong, offcourse not, but I think there are lots of room for improvement.
The RSR-bar is a very "simple", and keeps labour at a minimum.

The hollowbar is 1 1/4"(31,75mm) with 0,25" wall. 466Lbs at 5deg of twist(arm lenght suited for the 116). Bar is ordered with very light arms, new swaybarmounts and rod-end links. Pricing for everything is about the same as the RS-bar with rod-end link.
 

·
Registered
Joined
·
4,501 Posts
Discussion Starter #12 (Edited)
I have driven my 75 V6 for three years with RSR suspension and sway bar. Have driven most of Rons V6 demos at the ring and the experience is that all V6`s with RSR have a lot of understeer.
That's bizarre!

My stock street 3.0 12 valve Milano/75 has only had the battery moved to the trunk and the A/C pump removed (in terms of front-end lightening) and it is tuned to mild over-steer! I fact, I have been thinking about ways to dial in more grip at the rear, because at times it feels like I have TOO MUCH over-steer (but not until I get some new tires will I be able to make that determination!) Right now it may just be worn rubber at the rear making it so loose!) The car used to be VERY neutral with proper rubber and NEVER under-steered!

I run the full RSR setup with 125kg per side up front, 70kgs at the rear, 30mm front bar, 27+mm torsion bars and a 24/25mm non adjustable (non-RSR) rear bar! My car right now has nothing but over-steer. On SLOW entry in to some corners there is a VERY MILD push, until a bring in some throttle and then the rear comes! As soon as I enter the corner with more speed - there is no - and I mean NO - push!

Maybe it is that Shankle rear bar that does the trick!? I did notice that the under-steer went away when I added the rear bar! Ron is pretty specific that his rear bars (even-though they are 4-way adjustable) go a LONG way towards increasing the car grip at the front to match the rear!
 

·
Registered
Joined
·
3,771 Posts
John, slight correction - I think you mean you want more grip at the rear, not the front if you are oversteering too much (CAN I HAVE YOUR CAR!!!???).

I think having a 25mm rear sway bar a la shankle vs the stock 22mm bar or whatever it is is a very large factor between these two cars being described!
 

·
Registered
Joined
·
14 Posts
Last summer I joined Rons 75 experience for the 4th time. He was developing the rear sway bar at that time and I got many hours in a V6 with the rear bar.
The car had lot of understeer, absolute no compare with his demo car(caronfiber hood TWIN SPARK) that is a fantastic drive. Thats my experience with the RS setup for the V6. It is to be said that I have not ran any of RONS cars this season.

My personal car has the 125/70 springs and 30mm front bar,stock torsion bars. Added 27mm torsionbars 2 years ago and the understeer got even worse, so I ended up with the stock once again..

Greg: Please explain... Have you done any calculations?
 

·
Registered
Joined
·
296 Posts
iam going to run one of Ron's bars up front!! then junk everything that i don't need up front to save weight, battery is going in the boot, fibreglass wings and bonnet aswell (when i can afford it! project bit by bit!)
 

·
Registered
Joined
·
296 Posts
sorry to barge in un announced!!

nose weight is an issue, but i'll agree with JJ, bodyroll plays a big part in how precise these cars (well most anyway according to the Jag i used to have) steer and take corners! bodyroll tends to over exagirate the motion momentum!
 

·
Registered
Joined
·
4,501 Posts
Discussion Starter #17
Corrected: yeah - I meant at the rear...

JJ75 - I agree - D1 (his Demo car # 1 with the CF hood and trunk and the long shifter), is brlliant - headed back again next month - gotta go and get my fix!
 

·
Registered
Joined
·
4,075 Posts
JJ75, Are you seriously are asking me if I have done the calculations to prove that at 32mm bar won't fit through a 31mm hole? Excuse me while I fire up the Univac to figure that out.

I don't have the exact measurements in front of me, but I am certain that the big front bar from RS racing is as large as it can be and still fit through the forward jacking point, at least on U.S. spec Milanos.

Handling is highly subjective so I tend to stay out of those discussions. However in this case I will chime in and say that I find handling with the RSR kit on a Milano to be very nuetral with driver input easily able to swing it toward oversteer or understeer.

Greg Gordon,
www.hiperformancestore.com
 

·
Registered
Joined
·
3,771 Posts
Hey John, how much more are the adjustable shocks than his normal shocks?
 

·
Registered
Joined
·
14 Posts
Greg, I misunderstood what you called jacking points.Easy modifications to make the hollow-bar fit. Offcourse the swaybar mounts should be reinforced, but thats a modification required even with 28mm solid bar.
 
1 - 20 of 29 Posts
Top