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Converting a 33 to a mac strut is not an easy task. The strut top mounting points are quite far in compared to a mac strut. If just slapped together, I would not be surprised if double digit negative camber was the result. Not only this, but the pivot angle on the strut top would likely be quite extreme over the full travel of the suspension. And on another note, (this next section is theory on my part, I may be quite wrong) the chassis was designed for suspension that directs most of its force vertically. If converted to a mac strut, the angle that it would be on would put a fair amount of force inwards. At a minimum, a strut brace would need to be fitted. Triangulating to the firewall would probably be advisable.

I believe the strut top mounting point is also too far forward to have any reasonable amount of positive caster.

There is one skyline I know of which has been modded to a mac strut. Have you ever heard the name Stewy Bryant? or Nisskid? When the biddies see him, they be froffin... ;)

This is his website: http://inertia-ms.com/

Have a poke around, you should be able to find a few pics of what he has done.

If you plan on having this car road registered, I suggest you stop now and rethink what you want to achieve.

But, if it's just a drift hack...angle grinder, welder, maths and common sense, you'll be swearing at it in no time.

The reason driftworks did it was for less weight and also more clearance when trying to achieve more lock (less arms etc in the way). Driftworks also used their special geo knuckles designed for S chassis which lowers the car 40mm I think without changing any suspension geometry.

  • 1 month later...

There is no good reason. None at all.

Well you've never added anything useful to this site, so why start now i guess eh?

Yes there is some unsprung weight savings with mac strut, but it's far from the reason why most people go down the path. For Drift one of the most important modifications to a car these days is the knuckle design, unfortunately for R chassis cars they decided to use a shitty cast item instead of the stronger and much lighter forged item the S chassis' use. More importantly than the weight to drifters is how much easier it is to cut and shut the knuckle while still keeping strength, as well as how much easier it is to change hubs etc, anyone who has had to change the hub on the front of a skyline frequently, quickly and with minimal tools knows exactly what i'm talking about, it's a head screw compared to dealing with the S chassis gear.

Clearance is also a bit of an issue with the R chassis front end at big lock, the sway bar links further out and the bulky upper arms can possibly create an issue with real large lock setups.

My biggest worry going away from the standard R chassis setup is simply strength, for a drift car, we use mostly the rear end to steer the car, the front end is more of a catalyst, so unlike grip cars which waste so much grip at each front wheel fighting both the rear end and in a lot of cases the other front tyre on the other side, drift cars are more efficient with the front grip they have and don't need to chase the same fractions of percentages of grip up front, so the geometry curves at the front are less critical, and the mac strut does a good enough job for most applications.

It's simplicity is a huge benefit, especially when you're not a race engineer or have access to a team of them, but most of all it's ability to make more lock easier is why the conversion has been done in quite a few R32's around the world, probably most famously the Bee*R R32 etc.

As far as my setup goes, there is very little that still resembles an S-chassis or R-chassis setup, however it does still use the S14 knuckle and strut, the lower control arms, tension rods and strut tower are all completely custom.

  • 2 weeks later...

Well you've never added anything useful to this site, so why start now i guess eh?

Yes there is some unsprung weight savings with mac strut, but it's far from the reason why most people go down the path. For Drift one of the most important modifications to a car these days is the knuckle design, unfortunately for R chassis cars they decided to use a shitty cast item instead of the stronger and much lighter forged item the S chassis' use. More importantly than the weight to drifters is how much easier it is to cut and shut the knuckle while still keeping strength, as well as how much easier it is to change hubs etc, anyone who has had to change the hub on the front of a skyline frequently, quickly and with minimal tools knows exactly what i'm talking about, it's a head screw compared to dealing with the S chassis gear.

Clearance is also a bit of an issue with the R chassis front end at big lock, the sway bar links further out and the bulky upper arms can possibly create an issue with real large lock setups.

My biggest worry going away from the standard R chassis setup is simply strength, for a drift car, we use mostly the rear end to steer the car, the front end is more of a catalyst, so unlike grip cars which waste so much grip at each front wheel fighting both the rear end and in a lot of cases the other front tyre on the other side, drift cars are more efficient with the front grip they have and don't need to chase the same fractions of percentages of grip up front, so the geometry curves at the front are less critical, and the mac strut does a good enough job for most applications.

It's simplicity is a huge benefit, especially when you're not a race engineer or have access to a team of them, but most of all it's ability to make more lock easier is why the conversion has been done in quite a few R32's around the world, probably most famously the Bee*R R32 etc.

As far as my setup goes, there is very little that still resembles an S-chassis or R-chassis setup, however it does still use the S14 knuckle and strut, the lower control arms, tension rods and strut tower are all completely custom.

Charming. I was simply trying to dissuade someone (who is obviously new to all this) from committing wholesale butchery on their car for no good reason and without any proper engineering guidelines to go by. There are a raft of traps to fall into, strength and geometry issues for both the suspension components and the chassis being just the start.

Oh and by the way "grip cars" do not "waste grip". The whole purpose of the exercise is to generate and then use as much grip as can be found.

How did you come to the conclusion about so called Grip cars wasting energy "fighting" opposing wheels??

I'd assume or comes from the idea of locked diffs causing understeer.....

A sorted chassis has no such issues. The majority of the time its the driver not the chassis

Charming. I was simply trying to dissuade someone (who is obviously new to all this) from committing wholesale butchery on their car for no good reason and without any proper engineering guidelines to go by. There are a raft of traps to fall into, strength and geometry issues for both the suspension components and the chassis being just the start.

Oh and by the way "grip cars" do not "waste grip". The whole purpose of the exercise is to generate and then use as much grip as can be found.

lol sorry, i mixed you up with another SAU member who just comes in and talks shit unnecessarily constantly, it's been a while since i've been on here and the names are starting to mix together haha.

and yes, grip cars do waste grip, the rears fight each other around every corner with the diff resisting dissimilar radii, same as the front often depending on ackerman and scrub radius, although more importantly the front ultimately has to fight the rear and it's resistance to turn. All this is wasted grip, drifting wastes it's rear grip through spinning the rear tyres, however it uses it's front grip quite efficiently as doesn't have to fight the rear when turning, in fact the rear helps the front turn. This is why for sharp turns, where the radii differences are so great and there is so much conflict between every tyre on the car, drifting around the corner is often the fastest way, especially in low traction conditions (rally).

Your joking with you drifting around the corner is often the fastest way comment Arnt you??

Low grip gravel rally yes. Any thing circuit orientated your kidding yourself if you think drifting is the fastest way.

If a car is drifting its sacrificing forward propulsion to lateral slip and hence going slower than it potentially could.

Rally guys sacrifice this forward propulsion so they can go faster into a corner as they have more traction in a straight line, the longer they are straight the faster they can go. Due to the low grip they end up sideways, its a trade off for higher entry speed.

Your joking with you drifting around the corner is often the fastest way comment Arnt you??

Low grip gravel rally yes. Any thing circuit orientated your kidding yourself if you think drifting is the fastest way.

did i not just say that? lol

If a car is drifting its sacrificing forward propulsion to lateral slip and hence going slower than it potentially could.

Rally guys sacrifice this forward propulsion so they can go faster into a corner as they have more traction in a straight line, the longer they are straight the faster they can go. Due to the low grip they end up sideways, its a trade off for higher entry speed.

A good example was one time i was skidding in the hills, big rear grip, bugger all front, on a tight corner half way through the engine cut out (plug on the igniter module came off), the front just plowed as soon as the rear straightened, and off the edge i went. I was only able to make it through that corner with that speed under drifting conditions where i could use the rear grip to help steer the car, once i was left to grip up there wasn't enough front steer to keep me around the corner. This is an example of a poorly setup car, but the physics are still relevant.

Anyway this is off the topic, my point is that drift cars use the small amounts of front grip they have very efficiently, and therefore chasing huge grip at the front becomes less relevant, hence camber gain curves etc aren't as critical where the mac strut can some times fall down.

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