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Type 73C Development
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Author:  Lazarus [ Mon Sep 20, 2010 2:35 pm ]
Post subject:  Type 73C Development

Sadly time was against us before Goodwood on saturday.We had identified the gearbox case as a weak link in the transmission, and had as a consequense made a new case with stiffening ribs inside.Unfortunately there was no time to fit it before this weekend.Tom ran carefully in friday's practice as he was running in the engine.Notwithstanding this "nursing" he achieved a place on the fourth row of the grid for saturday [ the T54 300 BHP 5 litre monoplace was on the last row of the grid ! ] His times were very good and we hoped for a glorious result, The reality was to be somewhat different though.The engine performs very well and in the "red mist" moment at the start,the gearbox case split in half,the gears simply pushing apart the main and layshafts explosively,so no problem with power then ! He has now only two weeks or so to machine the new case,assemble the box and test the car before the next meeting.....Development schedules really cannot be worked around future races,We must get the car right before the next outing.I will later [when my proper computor is working again] publish photos of the box with its split case. The rear of the car tends to lift under fierce acceleration,does anyone have any ideas about this?

Author:  Lazarus [ Thu Sep 23, 2010 7:33 am ]
Post subject:  Re: Type 73C Development

Lazarus wrote:
Sadly time was against us before Goodwood on saturday.We had identified the gearbox case as a weak link in the transmission, and had as a consequense made a new case with stiffening ribs inside.Unfortunately there was no time to fit it before this weekend.Tom ran carefully in friday's practice as he was running in the engine.Notwithstanding this "nursing" he achieved a place on the fourth row of the grid for saturday [ the T54 300 BHP 5 litre monoplace was on the last row of the grid ! ] His times were very good and we hoped for a glorious result, The reality was to be somewhat different though.The engine performs very well and in the "red mist" moment at the start,the gearbox case split in half,the gears simply pushing apart the main and layshafts explosively,so no problem with power then ! He has now only two weeks or so to machine the new case,assemble the box and test the car before the next meeting.....Development schedules really cannot be worked around future races,We must get the car right before the next outing.I will later [when my proper computor is working again] publish photos of the box with its split case. The rear of the car tends to lift under fierce acceleration,does anyone have any ideas about this?

as promised here are the photos of the T73c at Goodwood and the aftermath...

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Author:  Herman [ Sat Sep 25, 2010 9:57 am ]
Post subject:  Re: Type 73C Development

Quite some force... Engine power is not your problem at the moment, is it?

as for lifting the rear: Perhaps your tyres? (like in dragster races, or Bart Rosman starting at the "Paleis het Loo" sprint?)


Author:  Lazarus [ Sat Sep 25, 2010 10:14 am ]
Post subject:  Re: Type 73C Development

Herman wrote:
Quite some force... Engine power is not your problem at the moment, is it?

as for lifting the rear: Perhaps your tyres? (like in dragster races, or Bart Rosman starting at the "Paleis het Loo" sprint?)


Yes Herman,I think the engine is ok now ! But it took only 28 years ! The lifting of the rear is obviously a reaction of the axle against the reversed springs.Perhaps some stronger shockabsorbers would help.This last of Ettore's racing cars has great potential.

Author:  DJ Dirk [ Sat Sep 25, 2010 10:45 am ]
Post subject:  Re: Type 73C Development

yes, saw the car in the paddock
didn't looked at the track on friday so didn't see the car drive
and hadn't seen the car during the race wich i felt was a bit of a shame
and now i know why
that's a massive crack, still good you noticed it before setting off during the race because that could have been very dangerous

Author:  Lazarus [ Sat Sep 25, 2010 12:17 pm ]
Post subject:  Re: Type 73C Development

DJ Dirk wrote:
yes, saw the car in the paddock
didn't looked at the track on friday so didn't see the car drive
and hadn't seen the car during the race wich i felt was a bit of a shame
and now i know why
that's a massive crack, still good you noticed it before setting off during the race because that could have been very dangerous

Tom noticed it right away ! If you look closely at the photo,you will see a hole in the case at bottom right.The gearbox case has actually broken completely in half.The rear closing plate and bearing support went first.The oil obviously left the box in a hurry ! Strangely this is not too sad as it confirms our previous diagnosis of the transmission.Tom had already borrowed the original Bugatti gearbox patterns and made a new case with stiffening ribs inside and a thicker wall.[the original wall is as thin as 2mm in places.] Sadly he had no time before the race to change the case.The car will be raced again in two weeks with the new case.The story continues.But the engine is proving itself worthy of the great man.

Author:  Lazarus [ Mon Oct 04, 2010 9:33 am ]
Post subject:  Re: Type 73C Development

STOP PRESS.The Bugatti Type 73C chassis number 73C005,Driven by Tom Dark,came second in the VSCC race at Donnington at the weekend.Beaten only by the "E" Type ERA which has a massive 320 BHP.This is the first ever podium position for a Type 73C Bugatti.Despite having ruined its gearbox case at Goodwood a few weeks ago,the repairs were rapidly carried out and the result was very satisfying.

Author:  Herman [ Mon Oct 04, 2010 7:52 pm ]
Post subject:  Re: Type 73C Development

Not bad at all! What is the power output of the 73C?

Author:  Lazarus [ Mon Oct 04, 2010 7:58 pm ]
Post subject:  Re: Type 73C Development

Herman wrote:
Not bad at all! What is the power output of the 73C?

ADEQUATE !! As RR would say.lol

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Author:  Herman [ Mon Oct 04, 2010 8:05 pm ]
Post subject:  Re: Type 73C Development

Ah, that is easy, a lightweight driver! Who is the guy holding him?

Author:  Lazarus [ Tue Oct 05, 2010 5:44 pm ]
Post subject:  Re: Type 73C Development

Herman wrote:
Ah, that is easy, a lightweight driver! Who is the guy holding him?

Dam we hoped nobody would notice ! Tom Dark and son.

Author:  barttore [ Sun Oct 10, 2010 9:49 am ]
Post subject:  Re: Type 73C Development

See him go!
Image

Author:  Herman [ Sun Oct 10, 2010 10:33 am ]
Post subject:  Re: Type 73C Development

Good picture!

Author:  Lazarus [ Sun Oct 10, 2010 3:35 pm ]
Post subject:  Re: Type 73C Development

barttore wrote:
See him go!
Image

Fantastic shot.I am glad it was not me in this rain.

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