Advice about Gt/Gts track racing

[SeanDezart]

Power and torque figures are enough to put a big grin on any drivers face..........If you want more info then let me know.

Yeah, how much power and torque ? 150 alreadys puts a grin on my face !

And you don't get out of it that easily - copy and paste the

and

at the beginning and end of each text to be quoted ! If I can do it.........

 

[speedshot]

hi there sorry for the delay but i have been away on a course. The car is currently running in the Gurston down hillclimb championship in the over 2000cc Marque sports class. The turbo set up that Janspeed were tyring to develope was never succesful and did not compete in a race. They always raced the car with a normally aspirated engine. The engine set up now is

3.1ltr dry sumped......

Thanks ben, for the substantial informations.
Was it the turbo setup, which is shown in many images with the turbo sucking through a single SU carb? A friend of mine and me were often discussing this set up (we are mucking about flow benching, head set up a.s.o.) and our conclusion is, that the sucked mixture of air and fuel is isolated again due to the radial acceleration inside the turbocharger. The heavier fuel droplets are separated at the outside. This causes indifferent saturation depending to the revs per minute,espacially at higher revs.
What was the engine setup during the races in the group 5 and later in the group 4? The same 3.1 stroker as you were describeing during all the time?

 

[ben240z]

hi joris. The engine that janspeed ran was a 2.8 built on a block that was aquired from nissan which has extra wall thickness and webbings to add strength. They were trying various heads, the 12 valve and they also had a crossflow head. The car raced with the 12 valve head as far as I know and the turbo developement work was done tried on both heads. However due to them trying to use too larger turbo and high boost the heads were forever lifting and blowing head gaskets so they never made a race. I believe that the turbo system they were trying was an injection set up with the turbo blowing through a single throttle body but dont quote me on that. As far as your explaination of the turbo and SU setup you are way over my head there but it sounds a good explaination. I have never worked with turbo's so can not help on that. The car started in the group 4 series and then moved into the group 5 when janspeed got involved in 1975. It was driven by Rob Janssen in the early days and then by Han Tjan and occasionally by the circuit director of zandvoort. At the time it was run by nissan holland dealer team in conjuction with Radio Nordsea. In about 1975 when janspeed got involved the Radio Nordsea link was dropped but nissan holland still were involved. The car came back to england in 1977 and then did a few races over here before being sold by janspeed. They were concentrating more on the datsun sunny and 100a cars as they were having more success in the smaller engine classes that the unlimited class that the 240 ran in. Cheers ben

 

[speedshot]

So to summarize. The car competed in group 4 with the 2.8 liter without the turbo before 1975 and later in the group 5 ditto? Before 7/1975 the 2.8 liter set up wasn´t homologated for group 4!? What changes made it neccessary to change from group 4 to 5? Especially changings in the engine set up or only suspension and special body panels?

 

[ben240z]

So to summarize. The car competed in group 4 with the 2.8 liter without the turbo before 1975 and later in the group 5 ditto? Before 7/1975 the 2.8 liter set up wasn´t homologated for group 4!? What changes made it neccessary to change from group 4 to 5? Especially changings in the engine set up or only suspension and special body panels?

The car was homolugated as far as I know for group 4 as a 2.8ltr, and then the group 5 homolugation allowed for the body kit and would have allowed the turbo. The car always raced in normally aspirated form. The turbo only ony was tried in testing or they did use it on a practice session for a race but then had to revert back to normal for the race due to head gasket problems.
I will find the homolugation papers and see what they say about the mods that were allowed in each group but it may take awhile as they are filed away during building work on the house. regards ben

 

[speedshot]

I will find the homolugation papers and see what they say about the mods that were allowed in each group but it may take awhile as they are filed away during building work on the house. regards ben

Ben, I´m allready having the original homolugation papers of the Z and so it would be very interesting to see what was written down in your FIA car passport.
Hopefully you have found an end for your building work on the house. I know that the work on a house is never finding an end. So be dilatory in searching. Thanks.

 

[speedshot]

What rim- and tire-sizes were used at LeMans 75 and 76?

 

[Albrecht]

Joris,

Front = 9.5j or 10.5j x 15 ( they had a choice )

Rear = 10.5j or 12j x 15 ( they had a choice ).

BIG negative offset.

I have no firm data on tyre sizes that they used.

 

[speedshot]

Joris,

Front = 9.5j or 10.5j x 15 ( they had a choice )
Rear = 10.5j or 12j x 15 ( they had a choice ).
BIG negative offset.
I have no firm data on tyre sizes that they used.

Thanks for the advices,
do you have pieces of evidence like old news clippings or original articles from car magazines? I would need to substantiate to the FIA.
Regards