Downforce with a Sy

[Robert Lone]

I screwed up earlier and added this question on another forum. I'm not sure where it should be but here goes:

In the other post I asked about getting enough downforce on a Syclone to keep it planted at around 200mph (Bonnieville). My truck is geared tall enough to run that fast. I understand that I may increase drag with the ground effects, but I would rather be embarrassed with a top speed of 103mph with the truck planted than wow the crowd with a 175mph backflip. You understand my concearn (sp?).

Prolly a couple of years away from even trying this crap but I'd like to know if is do-able.

Q 1. How close to the ground should it be? (Build it too low and let the truck scrub off what it doesn't want?)

Q 2. What kind of materiels should be used (i.e. plastic, aluminum, fiberlass, etc.) and how much bracing might it need?

Q 3. Should the truck be lowered like the one GMC built for the flats?

We all need to dream,

even if it's a nightmare.LOL

Robert :tup:

 

[Maxtor]

Re: Downforce with a Sy

My truck has been somewhere between 175 and 185mph with stock sheet metal...... speedpro registered 5500rpm in 4th gear (700r4 trans) with 26" tires. The only lowering it has is a 2" drop in the back.

 

[Robert Lone]

Re: Downforce with a Sy

Cool! There was some question as to how many ponies it take to push a brick that fast. I wouldn't know since "it" happened several years before I bought the truck. Any idea on hp and how stable was yours at that speed?

Robert


("it"- mine has supposedly been clocked at 187mph)

 

[gkrcr882]

Re: Downforce with a Sy

From what I can tell, these trucks are pretty stable, as I reach 105 on the freeway sometimes. I have no idea what ours will top out at, but I think it helps that we're lowered 2" over stock:2cents:

 

[Norm]

Re: Downforce with a Sy

I'll through my #2 cents in on this. Back in 1987 I did a small block _v-8) swap in my 2 wheel drive sonoma ext cab. I wanted it for highwat cruising and liked going fast. The small block was done for reliability so wasn't really radical. The old speedometer onlt went to 85 miles per hour. I use to wral it all the way around and back to 50 mph . The truck would float at that speed. I tried it with the gate down,still floated. I took the gate off still no fiffernce and the a tonneau cover,which help a bit but I come to the conclusion it needed a spolier. I Found one off a Fiero. While it got a snicker from people while driving on the street it helped alot at 150. I know it's not Bonniville that's my daily driver at the time. ........Norm

 

[Timbo]

Re: Downforce with a Sy

While Syclones are probably a little more stable than Typhoons at speed, I will say that above 120, my Typhoon feels like it's floating, and I've never had the balls to take it above 145 or so.

 

[SY#2910]

Re: Downforce with a Sy

I recently ran a Lightning from a 60 mph roll and kept pulling away. Afterwards he said he let off at 140. :lol: I had him by about 8-10 trucks by then. I have no idea on what the top speed is now but it felt stable. I was driving in a straight line though.

 

[boostedbuick]

Re: Downforce with a Sy

check out the world record syclone from bonneville that gale banks built. Could give you some ideas

 

[Maxtor]

Re: Downforce with a Sy

Cool! There was some question as to how many ponies it take to push a brick that fast. I wouldn't know since "it" happened several years before I bought the truck. Any idea on hp and how stable was yours at that speed?

Robert


("it"- mine has supposedly been clocked at 187mph)

The only dyno sheet I have for mine was right after the motor was built, before some of the more recent upgrades (heads/turbo). It shows a max of 650hp and 750 ft. lbs of torque. Not sure how much HP is needed. It is a full weight (plus some) truck and was stable at that speed. I've never had it fast enough to feel it float.