More downforce less drag

[spacemanspif]

More info on the truck is needed. Has it been converted to rear wheel drive? Are you using a conventional radiator cooling system or an ice box? Have you already moved dead weight to the rear by putting the battery in the bed? Have you scaled it to know weight distribution of the vehicle?

I'm sure you've already done most of the race car mods but us knowing what you have will give us a better starting point.

[Leonel1995]

[IMG] subir fotos gratis[/IMG]This saveiro is AWD and it uses 4 slick 25x8x15 tires, also we tested M/T (mickey thlmpson) 4 26x10.5x15 but it had less traction, the track is without treatment, no glue, no vht.

[Leonel1995]

In my country we made 8.38 sec 1/4 mile at 288km/h (gps) 60' is around 1.50 sec, 1/8 mile around 5.6sec. With other saveiro stock chasis, now this is a street legal saveiro, and we are trying to low that number.
One of the problems to work underside, is that the truck have susp. travel, also with the air dam

[kach22i]

Originally Posted by Leonel1995

[IMG] subir fotos gratis[/IMG]This saveiro is AWD and it uses 4 slick 25x8x15 tires, also we tested M/T (mickey thlmpson) 4 26x10.5x15 but it had less traction, the track is without treatment, no glue, no vht.

Looks pretty good to me.

Click on the links in my signature to see my project.

Trading out the rear spoiler for a wing as you have is shown the lower drag option.

[freebeard]

I'm looking at this:

Initial acceleration, the charge a racecar makes off the starting line and through those sixty-foot timers doesn't require a ton of power to be quick. Contemporary 500” Pro Stocks will consistently go between .997 and 1.00 or so, and they have nowhere near the power of a Pro Mod blower car that will short .02-.03 slower. The blown Pro Mod has to do two things the Pro Stocker does not: move an additional 350 lbs. and deal with a power band that builds steam as the car moves out. The Pro Stocker uses mechanical leverage (gear ratio) and a manageable and relatively flat power curve to move its lighter mass forward very quickly. This allows the crew chief to manage that "thrust' in a way that will repeat and stay hooked, run after run.

http://truestreetcars.com/forums/drag-racing/22346-60-ft-times-interesting-read.html

1.5sec 60 foot time isn't that great for cars that run at the speeds you claim. Either the AWD isn't hooking up or someone is napping at the Christmas tree.

We don't know the weight yet. We don't know the sanctioning body. Would they tolerate this difusser:



Or this one?

[spacemanspif]

[QUOTE=freebeard;510812]

1.5sec 60 foot time isn't that great for cars that run at the speeds you claim. Either the AWD isn't hooking up or someone is napping at the Christmas tree.

60' time has nothing to do with R/T. Timers for 60' don't start until the R/T sensor is tripped (car starts to move). If he is really having traction issues, he may be nursing it off the line to try and keep traction. Remember, he said the track is not prepped at all. As much as drag racers would love to say that their car hooks well, it has just as much to do with track prep that will pull your shoe off your foot as it does suspension and tire technology.

I still can't really believe that AWD is roasting all 4 tires at mid-track but I've never driven a car with that kind of power. Drag radials and slicks won't help becuase they stick best when warm and (usually) AWD has trouble with warm up burn outs. I'm thinking tires need to be super soft summer high perf summer tires that grip when cold.

[Leonel1995]

https://youtu.be/rO8uSNzb0bQ
That vídeo is an example on a 1/8 mile track boost is controled all race, not mid track, in 1/4 mile too.
1.5 aprox without R/T (reaction time)(driver business) At 60'ft (18meters) the car starts with 30%power and reaches 90% power to the end of the track of 1/4 mile we control it to be driveable, imagine too muchas power and the car goes like soap on wet floor.
Wheight around 1100 kg at race
We do 2nd gear bournouts 4wheels smoke 60meters, pretty hot slicks, no bournout problem.

[spacemanspif]

Now that's movin! Great job building a truck like that that you can still drive on the street.

A front bumper should help keep the front end from lifting at speed. Also, consider fender vents to evacuate some underhood pressure which also causes lift. If you don't want to cut the fenders, cut the hood...back by the windshield but on the outer edges. If this wasn't a street car your best bet would be a 1 piece, solid front end with an a/w intercooler in the bed. I'd grab a sheet of plywood to make a 1 piece tonneau cover and pro-stock spoiler. Use the template feature on this site to see how far off the back the spoiler should reach. Pro-stock spoilers usually have "fences" on the sides which kind of channel the air flow and help to keep the vehicle going straight. It's a nice truck I wouldn't blame you for not wanting to ruin the lines or the body with speed holes or big wings off the back. I think you'll notice a big benefit by fitting it with a larger front bumber/air dam.

Are all 4 wheels given 100% of the power? Or is it biased to the front or rear?

[cRiPpLe_rOoStEr]

I've already seen some drag-racing Gols with the hood slightly tilted forward. That may help in case you don't wanna cut the hood or the fenders.

[RedDevil]

Are you allowed to fold the mirrors, replace them for smaller or delete them altogether?
Little details like that can help.