What's Your Fastest on Dirt?

[MonsterAir]

What's the fastest you've done on dirt or grass? Tell us car, engine, gearing, tires ect....

I'm going to give it a shot tomorrow. Will post results and vid.

 

[MonsterAir]

Ventured out into the crappy weather for a few speed passes. Wet and soggy ground I only hit 46.4mph. Speed got better as I loosened the diff so hoping to pass 50 when the ground dries up and I can dig in better.

 

[looker2756]

On the Big oval track at the old Hostile Racing compound in NewYork, we were clocked at 54 mph on the straightaways.
That is the fastest I remember being on radar at on dirt.

 

[kansasdirtovalracer]

How big was the hostile track. We are building a big track and have been told it's too big

 

[looker2756]

It was HUGE - I believe it was around 650' driving line

 

[looker2756]

The LSRC track I believe is around 430', and still quite fast.

 

[kansasdirtovalracer]

Our track is planned with around a outside edge of around 450'

 

[looker2756]

450' should be a great track.

 

[MonsterAir]

That looks like a lot of fun! Can only imagine the wear on tear on the motors tho.

 

[kansasdirtovalracer]

That's a concern of mine as well

 

[MonsterAir]

That cross over figure 8 looks awesome! That has to be less wear and just as fun. Could always incorporate that into the track seems like you have the room if guys are already complaining about the size.

 

[looker2756]

We don't see any additional wear on the engines at all.
As long as the tune is correct, they just keep on cranking out the RPM.

 

[MonsterAir]

Took the buggy out today for some runs. Finally broke 50mph-

 

[MonsterAir]

Anyone have any opinions/suggestions on the pipe I'm using? It's a FG tuned exhaust, seems to be a decent all around pipe but doesn't excel at either end. Some of the guys I race with you can really hear when the motor gets on the pipe, mine not so much.... Ya think a jetpro would get me closer to 70 or is that asking a lot out of a exhaust change?

 

[looker2756]

I think a JetPro would get you more top end RPM, and that would equal higher top end speeds, but probably only a 4-5 mph gain.
Usual gain in RPM is like from 17,000 to possibly around 19,000.
Really depends on what the top RPM would be with the pipe you have now.
Most FG pipes are not at all top end oriented, but create decent performance throughout the entire power range.

 

[MonsterAir]

Yes that's how I feel my pipe is, doesn't excel anywhere but good performance throughout..... It's amazing what just a couple extra inches in the diameter of a tire will do for speed! Made a few speed runs on asphalt today with a set of grp onroads and couldn't pass 53. Which was annoying the crap outta me being I hit 52mph on the grass just a few days ago. So I threw on my offroad tires which are a tadd taller and first run broke 70! Freaking 17mph difference! Can't wait to try a different pipe with the taller tire in rear and grp onroads up front, 80mph now sounds possible for me!

 

[looker2756]

Looks like you have got a good handle on what you are doing, and what your next move should be.
70.6 is Very fast, and with more RPM, I can definitely see it going faster yet.