Just wondered if anybody had their LS1 Fbody up to 200 mph or close, and how much rwhp it took to do that or what your mods are if you haven't dynoed it. Thanks!

 

IT has more to do with aerodynamics and torque at higher rpm's that just horsepower.

 

I've already established good high speed aerodynamics and suspension with the land speed racing I did this year; now I need to do some more engine building to reach my goal of 200 mph. This is on salt so I will need more HP than people that do it on pavement. Torque is a big no-no on the salt since traction is poor on this surface. Right now I'm just trying to establish if it is practical to do this normally aspirated or if I should just go to a forced induction setup. It has already been done both ways with dedicated race cars, but my goal is to have a 200 mph capable daily driver.

 

Cal,

I think you took our driveshaft "critical speed" discussion a little too far....

I believe the last time I worked it out (based on Cd and frontal area) you need 377hp to overcome aerodynamic drag and enough extra to cover rolling resistance. There is a dyno sheet on my website showing a 3,4,5th gear dyno run. That will give you an idea about tires (it's a start, but by far not complete). I hope this helps!

Kevin

I'm sure NataSS will drop in here.

 

Thanks, Kevin. Yeah I'm kinda hoping NataSS will jump in here, I know he's done it on pavement. I'll have a look at your website. I know of one fbody that's in the 230 mph range with 650 hp, but drag is not a linear relationship so it's hard to judge.

 

Kevin, I just looked at your dyno sheet, amazing how much power we loose in 5th gear! Are you saying that is to be attributed to the higher rolling resistance at the higher tire speed? Or is this mainly loss due to running through the overdrive gears? I'm betting both make a significant contribution.

 

It is the spread between the gear ratios. You drop WAY out of your powerband when you jump to 5th and when you go to 6th its not even worth trying to waste the fuel

 

The general concensus is about 550FWHP to hit 200mph with a reletively aero'd car. BUT a properly set up chassis can do you wonders. I have seen a 3rd gen camaro with only 390rwhp hit 192mph.

Once you hit a certain point the amount of power it takes to go 1mph grows at an exponential rate. I'll have to dig up the formula on that one.

To give you an idea. Todd Carpenters 96 camaro has a crusing speed of 215-220mph. It took him close to 800hp to do that. He also covered 90 miles in a hair over 26 minutes. Now Alan Blaines 95 camaro has seem close to 200mph with just under 400 hp. So with 2, almost identical cars and drag cd's, you can see how much extra HP it takes to overcome the air to go about 15mph faster. Close to double if not more. Both of those cars are N/A cars.

As for rolling resistance, most of the REAL fast guys are running at least a 275 wide tire or bigger just for traction through the corners at HIGH speed. For being on the salt I would go to a skinney tire since you dont have to worry about any side loading of the chassis.

I would HIGHLY recommend a CF driveshaft from ACPT or someone else. Your DS speeds start getting into the straosphere when you get close to 200mph.

Now there are guys that do these runs in thier Mallet vettes breathing through a twin screw that can hit 200mph but look what it cost them to get into that car. And I am pretty sure they arent daily drivers.

As for being able to do this with a daily driver. That willbe a feat in itself. It is going to take only the absolute best parts that money can buy and ALOT of TLC. Most of the guys that run in the UNL. class in ORR are running NASCARS, NASCAR motors or something to the equivelent. Those guys can show up, run 50-90 miles WOT at 8500rpms, 6 or 7 times a year and only have to put new bearings in the motor inbetween seasons. The rest of them usually end up doing a complete teardown after every event.

Most blown cars dont fare to well at high speed. Especially when you start encroaching on the 200mph barrier. Thereare 2 guys running HIGHLY moddified cobras in the UNL. class and they cant get cblower belts to stay on the motor to save thier ***. And most of the turbo guys wont even try to go 200mph. Something about burning holes through manifolds or something.....go figure.

 

He shows up almost on cue.....Hi nata..

My dyno sheet is from the top of 4th gear to the top speed limiter. It is in the powerband, it's a dyno.

If you notice, there is horsepower loss in 3rd (due to accelerating the weight of the engine and such at a higher rate due to more mechanical advantage to turn the wheels) and 5th, due to a lack of torque multiplacation (and rolling resistance). 4th gear is "the way" to go. The C/F driveshaft is a good idea or the Lingenfelter I'm running is rated for enough RPM to do the trick.

Have fun!

 

the optimum way to do it would be to throw a richmond 4 or 5 speed in the car. In ORR we do use 5th gear for the cruising gear. Even the guys that run close to or over 200mph in Fbodys w/ the six speed.

A couple things I would also recommend for making an assult on 200. trans cooler, diff cooler and an oil cooler.

 

200 mph. In the 1/8th or 1/4.

 

Some time we're going to have to talk Nata, I've got all sorts of questions. I'm trying my best to get the car done by spring and make it out to do at least the entry class to get my feet wet and work my way thru the Silver State over the next couple years.

 

Go ahead and shoot the questions here. Maybe someone will have some good info to add.

One thing about running in ORR is that it is its own little monster. To set up a car to run at high speed in these events is totally different than setting it up for anything else. But that only when you start talking about tech speeds above 165mph. Anything under that and a decent road race set up usually works fine. Alot of it has to do with the amount of time that is spent on the throttle.

 

Nata, thanks for showing up on this thread and providing a lot of much need information!

Air drag is proportional to the square of velocity, this means it takes 4 times the horsepower to double your speed. So if it takes 125 rwhp to push a fbody to 100 mph, it will take 500 rwhp to go 200 mph (in theory!)

And going fast on salt has it's own unique problems; one being a lack of traction (it's like racing on smooth dirt) and another is higher rolling friction. I think it may be easier in some ways than the open road racing, since the track is only about 5 miles long, and I would only be using about 2 miles of it. So hopefully I would not need the additional cooling for the rear and the tranny.

Some of the guys at Bonneville that are running over 200 mph with fbodys are adding a lot of weight to their cars to keep them from floating. I heard one of them had 250 lbs added to the front end, and another 150 lbs just in front of each rear wheel! Huge wings don't work, they just raise the front end up by lever action using the rear axle as the fulcrum. One guy said the nose of his car raised about a foot higher than normal for the whole run!

Nata, just wondering, have you had your car dynoed? I see you have some good heads and a X1 cam; that sounds a lot cheaper than a forced induction setup if that will get me to 200 mph.

 

Any chance you could go into more detail on how he set up his chassis to go that speed on only 390 rwhp?

 

Yeah the salt flat guys have to use ALOT of balast. One thing you should look into doing is a complete front air dam to increase the down force on the nose of the car. but that requires totally re-routing the airflow to the radiator. This is something i am currently in the process of doing.

The car made 420RWHP and 400RWTQ on a basically stock bottom end other than new bearings and ARP rod bolt upgrades. So it is still stock pistons, rods and crank. To made a real solid push at 200mph IMHO this is not enough. If I tried to spin the motor that hard at the revs required I am pretty sure the bottom end would come apart. I am now researching a solid roller 427 N/A set up that would more than handle the abuse I would be dishing it.

Trying to hit 200mph isnt cheap and it sure as hell isnt easy. I once thought that I would be able to do it on a minimal budget and have a car that was still somewhat streetable. Alot of the ORR guys tried to tell me I was living a pipe dream.......they were right. Well, the budget has gone through the roof and the car is streetable but it beats the hell out of you.

The X1 cam and heads set up is nice but there are some issues with it that I am in the process of fixing.

 

Moser 9 inch rear end with LCA that ran all the way up to the middle of the doors, a REALLY trick set of edelbrock shocks that were revalved, custom springs, TOTAL air managment around the car, re-routing of the entire airflow to the radiator, custom upper and lower control arms, a roll cage the gods would have been proud of. there was so much time put into this car it was unreal. and it even looked good for a turd gen. He recently sold the car though . I'll try to dig up some pictures of it.

 

What purpose does it serve to have LCA's that long? The rest makes sense.

BTW, what kind of cage do you have? I noticed from the pic in the seat thread that your roof rails come down behind the dash. The roof rails that are available for my Wolfe bar go right through the dash and are a PITA to install.

I used to have a '85 IROC, and I still like the look of those cars. Only problem is most people that have them now don't take care of them. Mine still looked great when I sold it with over 200,000 miles on it.

 

My cage is a custom build. .120 wall chrome moly. and there is still more that needs to go in. the link in my sig has more pictires of it.

the LCA being that long has alot to do with stability of the rear end and movement of it. It is a set up alot like a NASCAR long LCA set up.

 

Tom Heinz car? (Spelling on the last name)....