Forum: HoseHeads Sprint Car General Forum (go)
Moderators: dirtonly  /  dmantx  /  hosehead

Check out the video on youtube.

http://www.youtube.com/watch?v=CsEf96u2ZFw

The chassis dyno is awesome. It is cool how much more accurately you can set things on a dyno when everything is in the car as it is when you hit the track. Notice on the front view the slight hesitation when the RPM's drop and he gets back on the throttle. You can see the roll cage shake for a split second. You'd never be able to see that on a standard dyno, let alone make the right adjustments to fix it.

Sorry, while interesting to watch, I just don't think that a chassis dyno run on a sprint car serves much purpose, as no two dirt tracks are alike, differing in length, track prep and such.

A run on the dyno will give you a baseline from which to start, and may help you when troubleshooting engine performance issues, such a a stumble, but really won't do much to aid in the set up of a car.

It will allow you to tailor the fuel system for the most efficiency, but other than that...Sprint cars are about bars, stagger, air pressure in the tires, and much, much more..

Chuck.....

A run on the dyno will give you a baseline from which to start, and may help you when troubleshooting engine performance issues, such a a stumble, but really won't do much to aid in the set up of a car.

Maybe you are confused on what a chassis dyno is. It has absolutely nothing to with your car's setup. It is 100% for engine purposes only. The point is to Dyno the engine in the car to get an accurate reading of the perfomance at the real wheels just as everything will be when your car hits the track.

If you are looking for it to help you with your bars and shocks, you will be greatly disappointed.

Tailoring the fuel system for the most efficiency and power, and troubleshooting engine performance issues, I would say that would serve a huge purpose.

Just let him live in the past.............  And for God's sake, PLEASE don't show him a video of the 7 post shaker rig!!!

I never said that a dyno run was a bad thing - it's just that there is a whole lot more to a sprint car than you'll ever learn from a chassis dyno pull, IMO. Engine setup - absolutely; and I said so!

And I know what a seven post rig is, and does.... maybe we can get someone to build a "rolling dirt road" dyno to really test sprint cars.........

Chuck.....

Just wondering how they started the engine? It obviously wasn't a push start.... ;)

Phil Taylor

home-theater-systems-advice.com

can they spin the dyno?

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I thought I heard a starter motor spin up but wasn't quite sure...

Phil Taylor

home-theater-systems-advice.com

The rear wheels are started spinning by air like a air starter on a big rig.

I just cannot see how they can get an accurate reading without the top wing. ;)

On the first pull, check out the LR tire "growing".

bbbd is correct its an air starter , most shops like to have the cars share same gears and role out for the run .the post about set up is funny .when an engine losses power the set up is compromised and we tend to start chassis tuning a dead horse .a dyno session is the first tuning tool each spring . then the chassis can be tuned to the engine . its cool to watch the dyno #s change when you turn the front wheels side to side and the timing also changes . i suggest sitting in on a session if ever possible .c

At the beginning of the video, when I asked Joe if he's ready, I held down a switch on the wall that powers the rollers until he gives me the thumbs up when it starts and I let go of the switch.

As far as the tire growing, they've got a couple of balanced pavement tires they use. You should see it with dirt tires...very scary. It's great to use your own car, your wiring, plumbing..etc.

Best money I ever spent, $250 for a few hours. When I was done I put the hood on and never had to take it off before going racing.

Thanks for the clairification,quite usefull,but I'm looking forward to sprinter 25's Rolling Dirt Dyno.Include a cusion,a few ruts,a hole here and there and that could get exciting...K rail to launch off?

Scott Benic is a firm believer in the benefits of the Gaerte Chassis Dyno. Congratulations to those guys on a great week with the Sprint Bandits TNT Tour as well as their 30k win at Oskaloosa.

I understand what this dyno does, but what will it help at the track? What is usually the outcome of going to a dyno like this to the motor?

.

Like one engine builder told me " I bought a chassis dyno so when you call complaining how the engine I just sold you won't run. I can find out what kind screwed up wiring or plumbing you have on your car."