Classification question for 1957 Corvette

[Dynoroom]

Quote from: J_Rod on April 26, 2009, 06:54:47 PM
my dad did a resto mod with his 57 corvette. between the two of use we have 3 corvettes. When I drive his vette the front end gets real light and gets loose (I guess thats the terminology for it) and I am wondering what I could do when I build my 57 to prevent this condition.

Put lots of weight iin it.

I think Rich is right you might fit in the Modified Sports class.

Good luck with your project.   

I would suggest something else than using weigh to cure an aerodynamic stability issue. This, in my opinion, is asking for problems. 
I feel a better course of action is to determine what is causing the lift at speed and modifying the car (MS class allows almost unlimited front end mods) accordingly to eliminate the problem. Add weight for traction if needed, and balance the car with weight forward accordingly.just not to keep the front from taking flight!

*sorry, didn’t mean to be a D**K, BV701.

~JH

In modified sports you can do almost anything you want. Similar to lakester & streamliner. Just remember "almost" anything you do will add drag. If running at Bonneville & "if" HP is not the issue, add weight. JMO, and where BV701 "might" get some of his.....

[RichFox]

thanks for all of the replies, I have yet to get started on the fabrication of the car. Have a few projects ahead of this one, need to finish my model a and do an engine swap on my mustang. I am planning on attending Bonneville for speed week as a spectator and get an idea of what horsepower and suspension and aero everyone is running. I do like the idea of making the car more aerodynamically correct because my goal is to get in the 200mph club my first time competing at speed week

Good luck with that. There are some pretty stiff records on Mod Sport. And most of them are using smaller cars. No reason not to try anyway.

[J_Rod]

I figure I am starting with a little something might as well make purist cringe to see a hacked up corvette. Setting a record would be great but I would leave happy if I averaged a speed of 200.1mph

[RichFox]

No record, no 2 club.

[Stainless1]

Hey J, put a blown busa motor in it... 200 is a hat....

[Jonny Hotnuts]

Insert Quote
Hey J, put a blown busa motor in it... 200 is a hat....

He will need 205 or 205….200 wont get him there.
And ya better get crackin' if you intend to go after H/MS with a blown busa!
(hopefully they wont be 205 for much longer!)

In modified sports you can do almost anything you want. Similar to lakester & streamliner. Just remember "almost" anything you do will add drag. If running at Bonneville & "if" HP is not the issue, add weight. JMO, and where BV701 "might" get some of his.....

Curious why you would say this…..is it because the vette in question has really good lines (this is true) or are you saying the auto manufactures always build their vehicles with the best possible Cd and therefore can not be improved upon?

I see many things that can be done to this vehicle to improve the Cd & loose its frontal lift. He can also push a little more air down the sides and limit the air under to help reduce lift (among other things). This will also in turn decrease the wetted area and lower the Cd….not to mention getting rid of the radiator and adding a radiused belly pan.

Still think that adding weight to prevent flight is a bad idea. With future increasing speeds eventually the added weight wont be enough and then its back to adding even more weight if it hasn’t already had to be scooped up off the salt after a bad landing.

[McRat]

I figure I am starting with a little something might as well make purist cringe to see a hacked up corvette. Setting a record would be great but I would leave happy if I averaged a speed of 200.1mph

I know a guy putting a Cummins diesel in a C3 Corvette.  I heard there is now a bounty on his head ...

[J_Rod]

haha, i threatened to put a nissan engine in it, but I am going to stick with what I know and thats the small and big block chevy and pontiac 326-455.

[Jonny Hotnuts]

i threatened to put a nissan engine in it

Its a good thing you dont do the Nissan swap. An engine like the RB26DETT 2.6L (can make over 1000hp with a stock crank) clearly would make that car go too fast, better play it safe and stick with the sbc.

(*The RB and the toyota 1JZ GTE are 2 of my all time fave motors.)

 

Post some pics once you get the project going.

~JH

[Dynoroom]

In modified sports you can do almost anything you want. Similar to lakester & streamliner. Just remember "almost" anything you do will add drag. If running at Bonneville & "if" HP is not the issue, add weight. JMO, and where BV701 "might" get some of his.....

Curious why you would say this…..is it because the vette in question has really good lines (this is true) or are you saying the auto manufactures always build their vehicles with the best possible Cd and therefore can not be improved upon?

I see many things that can be done to this vehicle to improve the Cd & loose its frontal lift. He can also push a little more air down the sides and limit the air under to help reduce lift (among other things). This will also in turn decrease the wetted area and lower the Cd….not to mention getting rid of the radiator and adding a radiused belly pan.

Still think that adding weight to prevent flight is a bad idea. With future increasing speeds eventually the added weight wont be enough and then its back to adding even more weight if it hasn’t already had to be scooped up off the salt after a bad landing.

The reason I said this is because the fact is the faster you go the more lift you WILL generate. If you run in a class where aero mods are not legal (I used Gas Coupe as an example) weight is the best answer. In Mod Sports you can do some things but most will add drag. If you have enough power no big deal..... if not well.
Weight is not a bad idea at Bonneville unless you are running small engine classes and going less than 225 mph IMO.

Note: in gas coupe a radiator is required (not it's use however) belly pans are not legal either......

[J_Rod]

i threatened to put a nissan engine in it

Its a good thing you dont do the Nissan swap. An engine like the RB26DETT 2.6L (can make over 1000hp with a stock crank) clearly would make that car go too fast, better play it safe and stick with the sbc.

(*The RB and the toyota 1JZ GTE are 2 of my all time fave motors.)

 

Post some pics once you get the project going.

~JH

I'll post some pics when I get started on the car indefinitely. As for the RB series engines, I know first hand those are awesome. My cousin was stationed in Okinawa and imported 2 Skylines to the states as kit cars. Ended up selling them though to pay for school and a few hot rods.

[Milwaukee Midget]

I figure I am starting with a little something might as well make purist cringe to see a hacked up corvette. Setting a record would be great but I would leave happy if I averaged a speed of 200.1mph

I know a guy putting a Cummins diesel in a C3 Corvette.  I heard there is now a bounty on his head ...

I say pop-rivet the purists.

A - They didn't dig the car up - you did.
B - Corvettes have a long and glorious racing history that you are simply building upon and adding to.
C - For all the hoyty-toyties who own concourse '57 'vettes, you've only increased the value of their little trailer queens by taking yours out of the beauty pageant, and therefore, their owners should THANK YOU.
D - Most importantly and above everything else -

and this is important -

yours will go faster.

 

Chris

[Jonny Hotnuts]

The reason I said this is because the fact is the faster you go the more lift you WILL generate.

An aerodynamically balanced front end, one that generates an amount of downforce equal to the amount of lift pressure generated from ground effect should be able to remain somewhat weight natural at any speed.

Clearly a vehicle with an inverted wing or nose with high angle of attack without significant air allowed under the vehicle would generate increasing down force the faster it goes.


I have never heard of any concept that says a vehicle automatically generates lift the faster it goes. To me lift at speed is based on design factors that are for the most part controllable


I would like to know your reasoning for saying vehicles will generate progressive lift with speed.

As for the RB series engines, I know first hand those are awesome. My cousin was stationed in Okinawa and imported 2 Skylines to the states as kit cars.

In 91 the Jun Blitz team ran a Z34 with the VG30DETT nissan motor to some insane number....something like 260 and change. This record still stands….and you have to get to A and AA motors before anyone else gets close and it was done with a little “E” motor.

I have always felt these motors were as close as you could get to a 3.0 busa motor, but if your heart is set on a SBC run with it.
http://www.junauto.co.jp/democar/jb-z32/index.html?en

[J_Rod]

yeah, heart is set on sbc because I have 4 of them laying around and figured I would use what I have and save a little $$$$ because its gonna get expensive quick.

[Dynoroom]

The reason I said this is because the fact is the faster you go the more lift you WILL generate.

An aerodynamically balanced front end, one that generates an amount of downforce equal to the amount of lift pressure generated from ground effect should be able to remain somewhat weight natural at any speed.

Clearly a vehicle with an inverted wing or nose with high angle of attack without significant air allowed under the vehicle would generate increasing down force the faster it goes.


I have never heard of any concept that says a vehicle automatically generates lift the faster it goes. To me lift at speed is based on design factors that are for the most part controllable


I would like to know your reasoning for saying vehicles will generate progressive lift with speed.

As for the RB series engines, I know first hand those are awesome. My cousin was stationed in Okinawa and imported 2 Skylines to the states as kit cars.

In 91 the Jun Blitz team ran a Z34 with the VG30DETT nissan motor to some insane number....something like 260 and change. This record still stands….and you have to get to A and AA motors before anyone else gets close and it was done with a little “E” motor.

I have always felt these motors were as close as you could get to a 3.0 busa motor, but if your heart is set on a SBC run with it.
http://www.junauto.co.jp/democar/jb-z32/index.html?en

We are talking apples and oranges. With a production automotive body you will generate lift. The faster you go the more you'll have. Thats why they put spoilers on them. Weather its a Camaro or a Audi TT (they had a recall to add the spoiler)
I stand by my staments.
Add weight to keep from adding drag if you are running any production type class. IMHO.