Test and tuning at the lake.

[fourload]

Me and my friend spent 5 hrs yesterday on the Great Sacandaga tuning his RTX,(reverse,1800 mi,96 studs)with a stalker radar gun.The conditions were good with the temps in the low 30s.The track was 1.5 miles long.It was hardpack on the starting line near the beach and mostly ice in the middle where we would wind up the top ends.Hookup was excellent on the starting line.The night before I cleaned Joe's clutches set his offset and locked down his secondary.We also put a new belt on.We then tried to make his suspension settings like mine to eliminate as many variables as possible.(limiter strap.transfer rod,ride heights,track tensions and front carbides).My sled was set up the same as it was in my 134 dreameter post.Sleds also had 1/2 tank of fuel.
First we dragraced two times.The results were the same.I took the holeshot and took him by at least 4 sleds thru the midrange then I would pull him several more to the 1.5 mile cone.My speedo 133 his 125.
Now we break out the radar gun and he shoots and I drive.My GT goes thru at 118.6 and his RTX goes thru at 111.9.After these runs we only tuned his RTX to see if we could get his to run like mine.Here are my notes: 1-stock RTX-111.9,rpm-10600
2-stock RTX with white sec spring @60-113.2,rpm-10700
3-stock RTX with o-p-o primary and white spring @60-112.4,RPM-10900
4-RTX with my clutches ulmer stage2 lightened up slightly with windage plates-116.1,rpm-10800.My GT would pull 10900 with this setup...
5-RTX with my clutches and no windage plates-114.9,Rpms seemed slightly lower than in 4.
6-RTX with my clutches and windage plates back on.I also added my midheight windshield.-117.6.There is no way a big guy can get out of the air with that low bandaid windshield......
7-RTX back to stock ,even the suspension.We also put his 1800 mile worn belt on for fun.-109.6,RPM-10700.Sled sat higher,doolys put back on too.
8-My wifes vector GT with 400mi and 96 studs-103.1,115- dreameter.
I hope this post helps you guys.Looks like I am done this year with the weather heading this way.

 

[HAMMER]

For those with ADD (attention deficit disorder)............

1- 111.9, rpm 10600
2- with white sec spring @ 60, 113.2, rpm 10700
3- with o-p-o primary and white spring @ 60, 112.4, rpm 10900
4- with my clutches, Ulmer stage2 lightened up, windage plates, 116.1, rpm 10800
5- with my clutches, no windage plate, 114.9, rpms seemed slightly lower than in 4
6- with my clutches and windage plates back on, mid-height windshield, 117.6
7- back to stock, suspension, 1800 mile worn belt, 109.6, rpm 10700

 

[Tork]

Nice report,
Glad that you took the time both to test and to share the results.
Particularly interesting on the windage plates.
Looks like they made 1.5 MPH

 

[fourload]

Nice report,
Glad that you took the time both to test and to share the results.
Particularly interesting on the windage plates.
Looks like they made 1.5 MPH

All the small things really add up.

 

[vice108]

Great job Fourload and thanks for sharing.

 

[Bossman]

Pardon my ignorance but what are windage plates.

 

[RedRX1]

Plates that mount on the outside surface of the secondary clutch. They enclose the ribs in the casting and create a smooth low drag surface.

 

[vice108]

Plates that mount on the outside surface of the secondary clutch. They enclose the ribs in the casting and create a smooth low drag surface.

Plus they are cheap! You've gotta love that.

 

[welterracer]

Where do you get the windage plates..

I also noticed you got a 2mph increase with the white secondary spring.. (gotta love that)

 

[suprfst]

And 1.5 mph with mid hieght windshield.Nice info by the way.

 

[byoffcr]

what gearing were you running? Nice reort.

 

[yammiman]

I'm interested in the windage plates also - one other question, have you tweaked you Ulmer clutch kit or is it just the way it was sent to you?

 

[yammiman]

P.S. - looks like the speedo is off by 10.5% - that is a tad less than some of the other reports I've seen - great info - too bad you didn't have a Proline kit to throw in the test!

 

[fourload]

yammiman,I lightened up the arms some and run the wrap at 80.It runs just below 11000 on the long run.Stock gears too.I don,t think you would get as high of a top end with the 23 top gear on ice but I think it might run faster in hardpack or snow in a shorter distance.It will also probably spin more if you don't have the traction.I know the rx1 is a different animal but the 23 top gear definately slowed mine down last year on the lake about 3mph.It probably was quicker however.Its all a trade off.....

 

[SledFreak]

Where did you get the windage plates from? How much are they? Also, I always new the higher windshield was good for 1-2 mph. Is your windshield the same one used on the Attack?