Do you have more details on the stubs? Are they just drop stubs?
He was recultant to give out much info at all othen then that its not holden size bearings
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#26
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Posted 03 July 2013 - 09:15 PM
He was recultant to give out much info at all othen then that its not holden size bearings
#27
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Posted 03 July 2013 - 09:22 PM
Do you have more details on the stubs? Are they just drop stubs?
He was recultant to give out much info at all othen then that its not holden size bearings
#28
ls2lxhatch
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Posted 03 July 2013 - 09:44 PM
McDonald Bros have a full tubular front end for the LJ at around $4500 inc shocks, no brakes.
McDonald Bros also list a LX tubular k-frame 11-2027 for $4500 inc shocks. No brakes, no stubs although I expect that they use HQ stubs.
http://www.mcdonaldb...doublewish.html
Edited by ls2lxhatch, 03 July 2013 - 09:45 PM.
#29
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Posted 03 July 2013 - 11:37 PM
The issue with many of these off the shelf type Kframes (like the McDonald LJ Torana unit) is that these set-ups are aimed more towards the drag racing market than getting the ultimate cornering grip by designing in the appropriate geometry.
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#30
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Posted 04 July 2013 - 04:39 AM
The issue with many of these off the shelf type Kframes (like the McDonald LJ Torana unit) is that these set-ups are aimed more towards the drag racing market than getting the ultimate cornering grip by designing in the appropriate geometry.
who made the tubular one you posted a pic of in your original post?
#32
Posted 04 July 2013 - 07:03 AM
Yep minimal caster, little to no camber gain, steering rack positioned more for clearance than good steering geometry, no power steer. I'd venture to suggest that the straight line market is a lot bigger in Aus so it makes sense but doesn't help the case here. They're a bit expensive for a starting point that still needs to be modified.The issue with many of these off the shelf type Kframes (like the McDonald LJ Torana unit) is that these set-ups are aimed more towards the drag racing market than getting the ultimate cornering grip by designing in the appropriate geometry.
I kind of like the idea of the CRS ones with the forward outriggers (move the engine back a bit and run a rear steering rack?) but does anyone else think this might cause problems with chassis rigidity? I suppose that's a moot point if you have a roll cage.
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Posted 04 July 2013 - 10:17 AM
This one?
Zagari Engineering SA
https://www.facebook...gariEngineering
yeah thats the one, be awesome for header clearance.
#34
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Posted 04 July 2013 - 10:47 AM
It is my understanding that Mc Donald Bros k-frame has the same basic geometry as the factory k-frame. The main difference between the stock k-frame and the Mc Donald Bros k-frame is the coil over shock.
The upper and lower control arms on the Mc Donald Bros k-frame can be used on a stock k-frame with the QA1 Pro Coil shocks. If you want power steering the Axistr power steering kit should bolt up to the Mc Donald Bros k-frame as it uses the stock rack.
It is basically the A9X suspension with a coil over and more camber adjustment. This is fundamentality what the OP is proposing to achieve within the class rules modifying a stock k-frame.
SOME class rules don't allow a fabricated subframe but are free for suspension arm pick up points, and other rules do allow a change of subframe.
At this stage I'm looking at the original subframe just modified and strengthened due to this been allowed in more areas.
Edited by ls2lxhatch, 04 July 2013 - 10:58 AM.
#35
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Posted 04 July 2013 - 11:37 AM
Last time I spoke to them, Mcdonald Bros still had not built an LH=LX K frame. They were still in "prototype" stage. That was the case for a good 6 months or more. Not sure I could justify the big price tag though for what looks to be minimal gain.
As said above, these all look like they are built for the drag racing community in mind more-so than guys who like to turn corners.
#36
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Posted 06 July 2013 - 07:57 PM
As has been stated certainly seems a drag orientated industry, most people i have had to deal with locally have not got a clue about these things called corners, it's just something that interrupts there straight line hp race.
This CRS x member, worries me how it is "engineered" with out the rear outrigger mounts, they have deleted something that a few of us are thinking of ways to strengthen it. Jst look at the TCM cars this is an area of extra bracing. I have supported my engine with a brace between the guards when I removed the x member, never again will I do it after seeing the flex on those rails.
From all indications the McDonald bros x member wld seem to be the best suited from info we have to go off
This CRS x member, worries me how it is "engineered" with out the rear outrigger mounts, they have deleted something that a few of us are thinking of ways to strengthen it. Jst look at the TCM cars this is an area of extra bracing. I have supported my engine with a brace between the guards when I removed the x member, never again will I do it after seeing the flex on those rails.
From all indications the McDonald bros x member wld seem to be the best suited from info we have to go off
#37
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Posted 07 July 2013 - 04:49 AM
Not being into drag racing I haven't brought much off them (McDon's) except LX diff bracket kit and adj trailing arms. When I spoke to them some time ago they said they wanted to look at building an LH/LX Kframe for the drag racers along similar lines of the LJ unit they sell, but that was well over a year ago and I don't think they ever actually finished it.
99% of their stuff is aimed at the drag/pro-street drag market as going fast around corners is not something they understand. He did say the current tube arms they sell for the LX/LH wouldn't be able to be used on their new LX/LH Kframe as it was going to be different. I asked him for arm ratio's, arm length, track, caster adj limits, bump steer, roll centre measurements or if everything was going to be just a copy of the standard and he said he didn't know. He asked his brother but at that stage he wasn't sure (and he was building it). They had absolutely no idea about building in good cornering geometry. They have had the price for the LX Kframe up on their web site for a while, but he said that was mainly done to gauge peoples interest.
The short spindle, arm length, arm length ratio, track, shock/coil mounting position etc just limit what you can achieve with using a standard set-up. Even if you spent the $4500 odd dollars for these (Mcdonalds,CRS) what is the point if its only equal to an A9X setup? Doesn't offer enough to warrant that sort of expenditure imo. Now if your picking up substantial lap time then its easy to justify spending money.
Look closely at the cars that are built to corner well and those designs can help give you a basic idea of what you must aim for to improve your cars ability to corner fast and thus use your tyres full ability.
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#38
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Posted 07 July 2013 - 12:55 PM
The front end of a torana was the same design as GM USA had on their cars in the late 60's.....
If you want to go fast around corners - rip it all out and expect to do some pretty funky fab work. factory angles are HORRIBLE for track work.
#39
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Posted 07 July 2013 - 08:36 PM
The front end of a torana was the same design as GM USA had on their cars in the late 60's.....
If you want to go fast around corners - rip it all out and expect to do some pretty funky fab work. factory angles are HORRIBLE for track work.
Absolutely a clean sheet of paper is the only answer to dramatically make positive changes to your torrie lap times. The torrie chassis (i.e. half assed folded wafer thin sheet metal) is poorly designed and has little rigidity. This overhead chassis design meant Holden had to make the Kframe far too bulky to be able to give back some strength, but in doing so they further restricting room in an already tight engine bay. The H series Holdens always had the better basic over/under chassis design which allows far more scope for positioning your arms without restricting pivot points selection and arm lengths.
The idea is always to keep your centre of gravity (cog) as low as possible and get your roll centres to respectable levels in relationship to your cog. As above getting maximum negative camber gain with real suspension travel can really help the car carry so much more speed into and out of a corner with driver confidence. Even the yanks are discovering that going around fast around corners is possible with the correctly designed chassis and geometry to suit.
#40
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#41
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Posted 08 July 2013 - 03:46 PM
It seems to me that the main market for fabricated suspensions is street rods and street cars. Basically people that want height adjustable or air bag suspension that looks good.
Very few cars are seriously raced on either a circuit or strip compared to the number of show and street cars.
I can't see any significant benefit in fitting the McDonalds Bros tubular suspension arms on a drag car as they weigh the same if not more than the factory suspension arms. I expect the same will be true of the McDonald Bros k-frame.
Very few cars are seriously raced on either a circuit or strip compared to the number of show and street cars.
I can't see any significant benefit in fitting the McDonalds Bros tubular suspension arms on a drag car as they weigh the same if not more than the factory suspension arms. I expect the same will be true of the McDonald Bros k-frame.
#42
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Posted 08 July 2013 - 05:04 PM
I think you will find that pro-street/drag racers like something like the McDonald system because it is far simpler to have two sets of front coilovers (shock/spring) one for road use and one setup for front lift rear weight transfer (90/10). The difference in weight between something like a QA1 with spring and the torana spring/shock would have to be significant. In suspension a big gain is always made in keeping upsprung weight as low as possible. I have never physically seen the mcdonald tube arm but if they are heavier or as heavy as standard then that's far from a well designed. The standard lwr torana arm is a terrible design it is bulky, heavy and the mounting points (hence length) are far too close to the ball joint.
Edited by LXSS350, 08 July 2013 - 05:06 PM.
#43
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Posted 08 July 2013 - 07:28 PM
The stock components are not particularly heavy to start with so there is not a lot or room for weight reduction.
UCA with bushes and ball joint ~ 2.0 kg each
LCA with bushes and ball joint ~ 4.5 kg each
V8 Springs ~ 4.50 kg each
The McDonald Bros arms are made mild steel tube and plate. I would have expected the arms to be made from chrome-moly if they were trying to reduce weight.
UCA with bushes and ball joint ~ 2.0 kg each
LCA with bushes and ball joint ~ 4.5 kg each
V8 Springs ~ 4.50 kg each
The McDonald Bros arms are made mild steel tube and plate. I would have expected the arms to be made from chrome-moly if they were trying to reduce weight.
#44
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Posted 08 July 2013 - 08:41 PM
Weight is not the issue with the front suspension on any torana.
The geometries are the problem.
The RC and COG are up the shit technically speaking.
There are ways to package arms from bigger GM cars in the states but the problem is front track starts to get very wide past the guards. Even then the RC's are still fairly average because of the base loacation points.
#45
Posted 08 July 2013 - 08:44 PM
Interesting because I just bought a pair of lowering trailing arms from them and was quite surprised by the weight, I'm not game to drill into them to see what the wall thickness is but from hefting the things it seems like the tube is thicker than necessary. In this application they seem to be roughly the same or possibly ever so slightly heavier than a boxed factory arms. Luckily I bought them mainly for clearance not weight savings!
That's also an interesting comment because the only time I've raced my car (so far) is a few non-competitive runs down the drag strip. Its mainly a street car, but even in that purpose I find myself chasing a better setup. I guess we have more corners than you guys...?Very few cars are seriously raced on either a circuit or strip compared to the number of show and street cars.
#46
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Posted 08 July 2013 - 08:45 PM
They are heavy and very poor in my book. McDonalds being out of Mild steel is why its heavy. The weight to strength ratio is very poor with mild steel. I would never use anything less than 4130 chrome-moly which has a very high tensile strength and thus you can use thinner wall tube. If you cant produce a less than 2kg lower arm setup you have done something very wrong.
#47
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Posted 08 July 2013 - 10:09 PM
Weight is not the issue with the front suspension on any torana.
The geometries are the problem.
The RC and COG are up the shit technically speaking.
There are ways to package arms from bigger GM cars in the states but the problem is front track starts to get very wide past the guards. Even then the RC's are still fairly average because of the base loacation points.
The track is easy to overcome by going inboard, but in a torana (as we found) it means ditching the F150 sized Kframe with its very poor suspension mounting and then re-doing the chassis to the far more conventional under/over and thus giving it real strength not 10c worth of half assed folded bits of sheetmetal. That way you can dial in lots of negative camber gain over real suspension travel (its a car not a go cart) and then design your cog and rc's as low and matched as possible.
Those who know the C2 know they are torana small. If you look at the C2 pic you can see how he did his mounts to be able to get good geometry within the narrow track (limited by body) and then he was able to pull 1.15g in the skidpan something a std C2 could never do.
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#48
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Posted 09 July 2013 - 09:24 PM
someone else's version
And their website:
#49
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Posted 10 July 2013 - 12:17 PM
Those who know the C2 know they are torana small. If you look at the C2 pic you can see how he did his mounts to be able to get good geometry within the narrow track (limited by body) and then he was able to pull 1.15g in the skidpan something a std C2 could never do.
What's a C2?
#50
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Posted 10 July 2013 - 04:26 PM
second generation Corvette
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