13 replies to this topic

[Tim Wood]

It shows in USRA rules 2020 the height in rear from the tech block to the top of the spoiler is 1 1/2" and you have to have at least 1/8" rear bumper. Am I reading this correct. that seems to be low for rear of body. Thanks, Tim

[Rotorranch]

1 1/2 is what I measured on my old cars.

[Jason Holmes]

Tim

 

Yes 4" is 1.5" and 4.5" is 1.625 rear spoiler height 

 

jason 

 

That's the way it's been for Yearrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr's 

[Fast Freddie]

Keep in mind that they are now measuring the body height on a relieved tech block like ISRA.  That means a body cut to exactly 1 1/2 in and mounted on the chassis no matter what the tire size will remain 1 1/2 in when teched in.  Just don't go over the 1 1/2 or it will be easily noticed and failed at tech.

[Tim Wood]

Keep in mind that they are now measuring the body height on a relieved tech block like ISRA.  That means a body cut to exactly 1 1/2 in and mounted on the chassis no matter what the tire size will remain 1 1/2 in when teched in.  Just don't go over the 1 1/2 or it will be easily noticed and failed at tech.

Fred, Thanks for the clarification with the tech block. 

[Jason Holmes]

Tim

 

Shoot for 1.45 all will be good when you tire up it will be 1.77 min-1.9+ 

 

jason

[Tim Wood]

Tim

 

Shoot for 1.45 all will be good when you tire up it will be 1.77 min-1.9+ 

 

jason

Thanks  Jason 

[Fast Freddie]

OK Jason, why would you not want to shoot for the maximum height allowed?  Since tire diameter no longer affects the body height.  Just asking, maybe you 're giving everyone a free performance tip, could that be it?

[Tim Neja]

So the body height in ISRA is measured from the chassis--independant of the tire diameter?  That's far simpler and makes sense.

[Fast Freddie]

It would have made even more sense 20 years ago when I bitched about it then.  Body height should measure the height of the body not the height of a ready to race car. Many manufactures would put cut lines on a body that would never pass tech because the old rule didn't allow for tire diameter, now it does.  HOORAY!!!!!!!!!!!

[Jason Holmes]

Fred 

 

If you can hit it dead nut have at it I gave him 5 thou that's really not that much nail that 1.5 and if your a 1 thou over to your pits fix it and remember if there is a mid race tech and you have just tweeked you body and it springs back you get to fix it under green so for me I'd play it a little on the safe side and Tim and myself are good friends and I sure he knows what I was trying to pass along

 

jason

[Fast Freddie]

I think you missed my point Jason but that's OK I forgive you.  I was just saying that I'm finally glad the USRA has conceited to measuring the body height correctly and I'm sure that there isn't a single racer out there that would push the envelope and try to hit the 1.50 inch height dead nuts.  How about you?

[Richard Matthews]

1st time I have looked at Slotblog since before Covid. I intentionally sandbagged 1/16" on rear spoiler  due to the Drag created on the long straightaway. Wish I saw this earlier. 

[Richard Matthews]

Just realized this is a 2020 post, Doh!