XXO/BVGC '38 Chevy Coupe Build

[bucketlist]

I've been busy trying to get the changes done on the car, and looking for good aero mods. I want them to work, and at the same time, I want them to have the 'vintage' look.

I've settled on a modified version of fairings like the Lockhart car had.
,

I don't know if or how this would apply to LSR, but Forbes Aird discusses front wheel fairings in Aerodynamics for Racing and Performance Cars. Topic is stability at speed, CP needs to be behind neutral steer point for better stability in cross winds and to be self correcting if vehicle starts to get sideways. Additional side area at the rear is good, at the front is murder, and gets worse if the side area is steerable. Steerable front wheel pants banned by NHRA. This might bear looking into.

[38flattie]

Rich, Tom- Thanks!

Tony suggested http://www.jonesracingproducts.com/ , and they can take care of us! I'll order the needed belts today, and they will make them up!

The plan is to run a 53T on the crank, and we'll start with a 66T on the top, when on the dyno. We'll then work our way through a 59T, 53T, and a 48T, on the blower.

I'll also be taking a 46T, For Bonneville, to compensate for altitude.

I've been busy trying to get the changes done on the car, and looking for good aero mods. I want them to work, and at the same time, I want them to have the 'vintage' look.

I've settled on a modified version of fairings like the Lockhart car had.
,

I don't know if or how this would apply to LSR, but Forbes Aird discusses front wheel fairings in Aerodynamics for Racing and Performance Cars. Topic is stability at speed, CP needs to be behind neutral steer point for better stability in cross winds and to be self correcting if vehicle starts to get sideways. Additional side area at the rear is good, at the front is murder, and gets worse if the side area is steerable. Steerable front wheel pants banned by NHRA. This might bear looking into.

Yes, your concerns are well founded. However, if we can get a good design, that works, the endeavor will be worth it!

[RichFox]

I don't buy blower belts. But the belts I do buy I get from the same industrial supply stores that most race shops get them from. And then mark them up a bunch. Bigger choice in length also. If I was buying blower belts I would have to have a very good reason explained to me to change my supplyer.

[dw230]

Nah, you are Ok Buddy. As long as you have met one of the other four critieria. Wheel pants alone will not get you into the class.

Chauvin Emmons used wheel pants on the front of his Modified Roadster in the 70s. He didn't like 'em, steered the car. Those pants went to Ken Walkey for rear wheel fenders on his lakester. That car went to Keith Young, back to Ken. Sold to Roy Creel and now is used by the Stewart Family.

DW

[Rex Schimmer]

Wheel "pants" as DW calls them, probably need some real thought before designing. I would think that if you were going to rotate the pants along with the wheel/tire while steering you would want to make sure that the center of pressure of the shape was behind the king pin of your axle. This way any steering affect will try to straighten the wheel, kind of like caster. If the CP is ahead of the king pin then when you turn the pant shape wants to make the wheel turn more. Something to talk to Woodie about.

The other option, which I would think best, would be to make the pant wide enough so that it can be mounted ridged and the wheel would turn inside of it. This would make it bigger and you would have to restrict your steering angle but the pant would not want to steer the car.

Rex

[38flattie]

Rich, I tried the link you supplied, but they didn't have the belt I need.

DW, Rex, Thanks! I'll probably not have the fairings/pants this year, but would like some next year. Woody is doing some port work for us, and I'll probably get him involved on this.

Dale has the lifters installed, with the bronze bushed lifter blocks! That is not a job anyone would volunteer for!

[Jack Gifford]

... Steerable front wheel pants banned by NHRA...

I don't know current-era NHRA rules. Is that rule worded so that full wheel discs (both inboard and outboard) are legal? What about a fixed-to-a-spindle inboard disc whose periphery sits in close proximity to a wheel's rim?

[JonAmo]

Buddy,

RCD makes a belt you might be able to use.

Tom G.

1312-2000-075 is their part number.   

2000-8M-75 POWER GRIP RUBBER (250T, 78.7 X 3) BLOWER BELT    $259.00

RCD does have this belt and is manufactured by Gates. This is a Polychain HTD belt. This belt has a significantly higher power rating due to the Aramid Tensil cords an polyurethane material over other belts. This also has superior racheting power over the tooth then lets say a GT2 Belt.

On the blower setup is it possible to change the smooth idler to a toothed idler pulley? A toothed idler gives the best protection against cord damage and can lead to longevity of the belt. Do not get me wrong smooth idlers may work ok but the bend over the apex of the curve can lead to issues (possible not definitive).

Jon

[38flattie]

In order for us to run the pulleys we want on the dyno, we need 3 belts. The one we have is a 1760, and will work with the 46T, and 48T-one of which I THINK we will run at Bonneville.

The 53T will need a 1792 belt, and the 59T and 66T will need a 1840 Belt. The 53T-66T pulleys are only to break in the engine, and stage the boost up slowly on the dyno. It's probably being over-cautious, but it's what I have planned.

[dw230]

Jack G,

Wheel pants as discussed many pages ago in this thread are not addressed in the rulebook. Wheel disks, Moon type, both inner and outer are allowed. Inner disks mounted as descriped have been and continue to be allowed.

DW

[38flattie]

On the blower setup is it possible to change the smooth idler to a toothed idler pulley? A toothed idler gives the best protection against cord damage and can lead to longevity of the belt. Do not get me wrong smooth idlers may work ok but the bend over the apex of the curve can lead to issues (possible not definitive).

Jon

Thanks Jon! Putting a small, toothed idler may be the way to go. I didn't even think about wear "over the apex of the curve". This would also allow for a shorter belt, and therefore be a win-win situation!

[Tman]

On the blower setup is it possible to change the smooth idler to a toothed idler pulley? A toothed idler gives the best protection against cord damage and can lead to longevity of the belt. Do not get me wrong smooth idlers may work ok but the bend over the apex of the curve can lead to issues (possible not definitive).

Jon

Thanks Jon! Putting a small, toothed idler may be the way to go. I didn't even think about wear "over the apex of the curve". This would also allow for a shorter belt, and therefore be a win-win situation!

Jon kinda knows of what he speaks, he works for Gates!

[Jack Gifford]

DW- thanks for the wheel disc info.

[JonAmo]

On the blower setup is it possible to change the smooth idler to a toothed idler pulley? A toothed idler gives the best protection against cord damage and can lead to longevity of the belt. Do not get me wrong smooth idlers may work ok but the bend over the apex of the curve can lead to issues (possible not definitive).

Jon

Thanks Jon! Putting a small, toothed idler may be the way to go. I didn't even think about wear "over the apex of the curve". This would also allow for a shorter belt, and therefore be a win-win situation!

I would be carefull going to small, what are the dimensions of the smooth pulley in the system now? Specifically the OD dimension?

Jon

[38flattie]

Jon, The OD is 4.4"