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TIMSGT6 X 5

Chassis prep for track car

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As I have now stripped my driver GT6 in prep for a respray I am moving on to assemble and set up a track car.

For Ontario Time Attack I would like to keep the car as streetable, in the spirit of grass roots racing.

Some issues I encountered with the other GT6 can now be dealt with.

First is the pedal box. There is so much travel on the pedal for braking I'm not certain it can be set for true toe/heel shifting. I totally agree with Dave P on going to a cable throttle to isolate the engine from body movement re the old hinge type throttle.

What solutions have come up? And do I even need to be concerned about toe/heel?

2nd is releiving the running gear of the rotoflex. Intent is a modified Datsun half shaft utilizing the original unmodified hub and bearings/shaft  with an adapter flange welded to the stub and the Datsun outer joint. This will allow the shock to be reset back to the frame instead of the inner fender well.

At this point it may be advantageous to move the radius rod to a frame supported bracket?

I will be running the original motor and transmission, and assume the tranny may be suspect and prone to failure?

Not sure about going to PI on this one, a lot of penalty points added because of that mod.

Thinking a TR5 cam and properly set up CD175s plus headers with bespoke head mods.

  Suggestions and pitfalls to avoid?

Cheers  Tim

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Judging by your experience I'm going to have breakage problems by keeping the original hub, shaft, vertical link configuration coupled by flange to the shortened Datsun axles?

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IMO, the ONLY point of the conversion is to eliminate the stock hub.  That's what breaks, not the rotos.

 

After you weld a Datsun flange to the stock shaft how are you going to assemble/disassemble it?

 

A lot of your pedal issues will go away when you ditch the rubber brake lines for braided hose.  Less ballooning.  And toe/heel is vital but it's not a precise balance of the pedals, it's more of kicking the throttle and the gears snick together when the speeds pass thru their matching period.  Easier to do than explain.

 

BTW, your trannys and diffs will last a lot longer with the Rotos in place...

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Food for thought. My idea of removing the Roto was to allow the shock to be moved to the frame, and to get my alloys off the 1" spacer I have. New rules will not allow sidewall protrusion more than 13MM from the fender lip.

Bad news about the tranny and diff though , I am supposing the directness of the connections transfers directly back to the drivetrain, no rubber cushion.

Have the 2 GT6's you picked up been abandoned by their intended owner from Illinois? My wife is exerting pressure for a Feb 12th or so trip somewhere warm.

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The idea on the adaptation is to cuttoff the roto outer connection to within a 1/2 " of the hub and weld an adapter flange on it to accept the flange on the Datsun U-joint with studs or through bolts. I will have to re-think this mod as I do not want wheels careening off the car, Mosport is a very fast and lethal track.

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Hey Amigo, If ya want to bring the wife to warm Vegas we'll make you welcome.  If you want cars we can work on that too.  There's lots of rustfree ones in the Mojave.

 

As for the racer, I too used the argument that I could race it on weekends and still drive it to work.  I actually believed that at the time and fortunately the female mind swallows that crap as well.

 

If you are at all competitive that fallacy will quickly go out the window.  First time you get passed by ANYTHING that night is laying awake thinking of where to lose weight, improve braking or enhance horsepower.  If you've really got the bug it's all three.

 

So don't fool yourself up front, just the wife, if you wanna go racing then commit.  Otherwise it takes longer and costs more money before you finally go to Racers Anonymous for the twelve point bit.... 8)

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My idea of removing the Roto was to allow the shock to be moved to the frame.

 

See a mod marketed by the TSSC, and others.   Bracket to bolt on to the rear chassis cross-assembly, that provides a shocker mount.

You could fabricate and weld sucha bracket of course.  It allows the donut to stay. http://www.tssc.org.uk/index.php?option=com_virtuemart&page=shop.browse&category_id=62&Itemid=59

 

Have a look at Sideways and CT sites for threads on other ways to substitute the donut, or contact Nick Jones, who is the guru.

 

John

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Thanks John,

I have considered that, but still need the shock in the original frame mount to clear the offset rims. I am reluctant to change any Roto as the supply of quality ones(affordable) is dubious, mine are all compromised now with age. I have 4 sets of Datsun shafts. The hub issue is a puzzle, maybe make up new stubs with different diameter and larger thread, use higher tensile steel and moderate heat treatment. Would take about 5 minutes on a CNC lathe, would only cost me the material.

I'll have a look at the components bearing in mind the issues Steve S has pointed out from experience.

Cheers  Tim

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The advantage of the TSSC mount John mentions is shocker length.  The frame mount requires very short shocks and further compromises the limitations inherent in the rear suspension travel.  Again, my opinion.

 

Make the suspension work rather than chain it down to a minimal sweet spot as most racers attempt.  IMHO.

 

 

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