So why did my hood suck up?

[Sumner]

........................we are talking about a water tank for weight -  that would be easy -  but it would be over the rear axle -  so it should have no effect on the hood - (unless the weight lifts the front end -  if thats the case - I need new suspension!)

carl 'I'm still stuck on airflow into the engine compartment" Johansson

I would question the weight over the rear axle being a good idea.  Good for traction on snow, but not always the best bet for LSR.

I have some comments about it here:

http://purplesagetradingpost.com/sumner/bvillecar/bville%20-%20LSR%20Thoughts-Index.html

...........and there are past posts on here and other places if you do a search.

Congrats on getting through tech and making some passes.  You did good  .

c ya,

Sum

[Super Kaz]

Have Not yet LSR my Car's but I have had your Problem before !
I used to race a little 1700hp Turbo SS/O Mustang in the NMRA back in the day.
All of the Races were back East ,and "I Live in Vegas" so I didn't get much seat time. I left the car there and my tuner would tow it to the track and I'd fly in.
So  I had little time to Practice while tryin to Qaulify BACK THEN.
It used to be a 16 car field and 47 OTHER car's trying to qaulify!
SS/O Was the Biggest and Baddest Class  too Race as there were only 3 or 4 Pro 5.0 car's racing then.
NOT  A GOOD WAY TO RACE
I Never got to make a Good Clean pass,but went 8.20@ 170mph Lifting at 1000' because the Hood was Lifting off the car! I was on a 7 second record pass ,but had to get out of it.This Custom thing had Hood Pins but the rear part was "12inches taller then stock and sloped back too the windshield" would have Blown off if I STAYED IN IT I Couldn't see where I was going on a Track I had never raced at before.
It was a Very Scary feeling,but now I just race Motorcycles .
So  Now I have Nothing to worry about fly off but me .
Your answer has already been talked about so I'll let you figgure it out in the Posts.
Good Luck , Stay Safe,and Have FUN,
Kaz...........

[1212FBGS]

so did you determine your problem was caused by, and what did you to fix your problem kaz?

[Super Kaz]

so did you determine your problem was caused by, and what did you to fix your problem kaz?

Kent,
Yes and No. We just taped up the Nose of the car"Too Much Air Causing Lift''but I then went through and Ugly Divorse"LOST EVERYTHING ",and had to sell the car !
I been on the Motorcycle Racing Roller Coaster ever since !
I would Love to someday get my AA on my V-rod and my Saleen Speedster,but Time and Money will tell !
Goals and Desire don't go very Far without lots of $$$$$!
As you already know Speed Cost Money ,and I don't have anymore
Why do I always Pick the Most Expensive SPORTS??

Kaz.......

[code5coupe]

My guess is the high pressure at the windshield base is only about 5" forward due to the steep rearward angle of the shield. that hood is huge! kent

....and since the hood of your Corvette ends about five inches short of the windshield, the hood itself might not be seeing ANY of that "high pressure at the base of the windshield".

Since the hood is SO large, it would take only a very small pressure delta to lift it a large amount.
I.e. if your hood is 4ft by 5ft (and I'm betting that's conservative), and you have only a ONE-HALFpsi average difference, then you would experience over 1400lbs lift on the hood.
That could probably pop a latch.....

[Carl Johansson]

Hey Sumner,
Thanks,
I use your website alot to calculate gears HP needed speeds etc.  It is a great resource.  So Now I have to go home and jack up my car to determine the CG.  Then we can talk about adding weight and were to add it!

........................we are talking about a water tank for weight -  that would be easy -  but it would be over the rear axle -  so it should have no effect on the hood - (unless the weight lifts the front end -  if thats the case - I need new suspension!)

carl 'I'm still stuck on airflow into the engine compartment" Johansson

I would question the weight over the rear axle being a good idea.  Good for traction on snow, but not always the best bet for LSR.

I have some comments about it here:

http://purplesagetradingpost.com/sumner/bvillecar/bville%20-%20LSR%20Thoughts-Index.html

...........and there are past posts on here and other places if you do a search.

Congrats on getting through tech and making some passes.  You did good  .

c ya,

Sum

[JackD]

Ya see, these guys are not rocket scientists but most often do better in this sport.
Remember they are talking about PSI and you have more than most on that hood with lift to match.
It sounds like you have a good handle on the CG / CP thing, but remember to keep any added weight as low as possible.
Ignore all that and you need to learn to land a Vette, the fly part will be automatic.

[Sumner]

...............................It sounds like you have a good handle on the CG / CP thing, but remember to keep any added weight as low as possible.
Ignore all that and you need to learn to land a Vette, the fly part will be automatic.

........and here I was going to tell him to add it to the "headliner"  ,  man Jack you can spoil all the fun  ,

Sum

[Sumner]

...............I then went through an Ugly Divorce"LOST EVERYTHING ",and had to sell the car !............

..........As you already know Speed Cost Money ,and I don't have anymore
Why do I always Pick the Most Expensive SPORTS??
Kaz.......

Well I think you found the one thing that is more expensive than "speed"    , and your not the only one  ,

Sum

[JackD]

"Understanding the difference between tongue in cheek and just parking it in the hole created by the missing teeth is not quite the same." (me)

[RidgeRunner]

# 23

     Kaz     Because they look so fun and feel so good....................

     Sum     Yup................................

[Bob Drury]

Carl, the new issue of Circle Track magazine (July 2007) has a excellent article on this very subject and aero in general.  By the way, I have found this magazine to be a great source of information on engines, general chassis info, and current safety issues over the last ten years.  It is a great technical racing magazine.  Just remember, if you use their suspension advice, be sure to put a lot of clockwise "crank" into the wheel...................

[KEVIN]

Being that this is a production car and you can't mess with the areo package, what if you left the headlights up? Would that spoil some of the lift?

[Carl Johansson]

Being that this is a production car and you can't mess with the areo package, what if you left the headlights up? Would that spoil some of the lift?

Absolutely -  it would also spoil quite a bit of the speed.  The hood lift is not a big problem -  it's very manageable -  a properly working hood latch cured the problem.  Putting in safety pins insures that it will not be a problem again.  I''m just trying to see if I can turn the information and cause into a way to pick up a little speed!

Carl Johansson

[bvillercr]

When we first built our car, we had a big bulky hood built for us.  The air enter at the front of the car and was tight at the window.  The hood blew off at Bonneville at over 200.  We built a new hood ourselves and left a nice gap at the window and no problems since.