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Offroad Reports

Rausch Creek
Off-Road Park

Wheeling in the
Valley of the Ferns

1.jpg (70086 bytes)
Tellico North Carolina

Paragon Adventure Park
◦ Rock Krawl ◦

Thousands more photos here..»


Jeep Project CJ-7

An ongoing Budgeted Rebuild/Build up of a Rock
Crawling Machine.

Jeep Central
From Jeep History to Tech Specs and Projects.  This section is all about Jeeps.
Jeep Technical Info
Engine Swaps

Installing 23,000 Volt Offroad Lights

What are HID Lights?

Onboard Air
Converting a York
AC Compressor
to Pump Air

Warn 9500i Winch Installation

HEI Ignition
Installation & Review

Lockers, Limited Slips &
other Differentials Explained


Jeep Dana 300 TeraLow - 4:1 Gearset for the Dana 300 Transfer Case

Jeep Trans Swap
T-18A Transmission Rebuild & Short Shaft Conversion

Black Diamond Suspension Lift install for CJ-7

Ramp Travel Index
RTI / Ramp Travel Index What it is and how to calculate it, with and without the ramp.

Offroaders Guide to Gearing up for Offroad
From Basic Equipment to Well Equipped.  An extensive list guide to help you prepare your vehicle for the offroad.






The term RTI stands for Ramp Travel Index.  Ramp Travel index is a measurement of a vehicles suspension, frame and tire compression and the resulting flexibility of all components of the vehicle to achieve a score.  This standardized test uses a ramp to find the extreme flex point of the vehicle.

The RTI test is a good indicator of how well a vehicle will do in many situations offroad while traveling over an obstacle.  Ideally a vehicle will do better if it is able to keep all wheels on the ground for maximum traction.  If a vehicle's suspension is too stiff (less flex), it generally will lift a wheel or possibly two wheels while attempting to get over an object resulting in a loss of contact and traction at those lifted wheels.  Loss of traction is especially apparent with vehicles equipped with open differentials.  In situations requiring a lot of flex locking differentials and some limited slip differentials will help maintain momentum with the opposite wheel of the axle (front or rear), however good flexibility results in more wheels on the ground, better traction and better stability of the vehicle as the suspension conforms to the terrain.


At many shows and offroad events, you may have seen 4x4's taking a shot at the ramp.  While the ramp itself is fun to challenge, it does have it's useful points as a valid test.  The ramp can tell you a lot about your overall flex and is very useful in evaluating suspension, examining the length of your shocks and finding contact and interference points of components and other things all of which can give you insight into a vehicles capabilities on the trail under extreme flex.   Several factors make up the score on the RTI ramp.  These factors include the ramp itself, the length of the vehicle's wheelbase measured centerline of front axle to centerline of rear axle, and the distance traveled up the ramp without lifting a tire off the ground.  In most cases the ramp used is a 20 degree ramp.  Some events use a ramp with a more extreme angle such as a 23 degree ramp.  The test proceeds as the vehicle attempts to climb the ramp as high as possible with a single front or rear tire without lifting a wheel off the ground.  The distance the vehicle can travel up the ramp without loosing contact with the ground is measured from the leading edge of the ramp itself to the point on the ramp just below the center of the hub of the wheel on the ramp.  The distance is measured up the ramp and on the ramp, not to the actual hub of the wheel.  That number is the divided by the vehicles wheelbase and then multiplied by 1000 to calculate the average.  For example if a vehicle with a 81 inch wheelbase traveled 59 inches up a 20 degree ramp then the RTI would be calculated as: 59 divided by 81 x 1000 = 728 (rounded down).  This method of multiplying by the vehicle's wheelbase allows vehicles of different wheelbases to compete with each other on the same ramp.

Although you can't "cheat" on the ramp, you can optimize your score on the ramp and in the process improve your vehicles ability to flex and maximize traction over terrain.  One of the easiest things that you can to do to improve your score somewhat, which translates into improved traction offroad, is to air down your tires.  Airing down means to reduce the air pressure in the tires to the point where the tire is more likely to conform to the terrain.  Airing down to approximately half the recommended maximum PSI of the tire will allow a small gain on the ramp.  More noticeably, "airing down" will improve offroad driving in the form of better traction, a smoother ride over harsh bumps and allowing the tires to conform over obstacles resulting in better grip.  How much you air down may depend of several factors.  Some people air down as low as into the single digits however this can result in bead separation.  As a result bead locks are sometimes used to secure the tire bead to the rim.  Also smaller tires with a short profile aired down too low can suffer damage to the tire and rim such as tire pinch on the rim or a bent wheel rim.  Generally speaking extreme low pressures are usually reserved for large tires equipped with bead locks and in many cases bias ply tires are the preferred tire as they are more durable at low pressures.  Another factor for how low you go is whether you are equipped to air back up when you leave the trail ... or the ramp.  Obviously if you are not able air up, don't air down.  It is important to always bring your tire pressure back up to the recommended PSI for highway driving to avoid damage to the tire or loss of control while driving. 

Another factor that can improve your ramp score and improve the offroad ride with leaf sprung suspensions is to grease between the leafs in the leaf spring pack.  Without grease leaf springs in the pack tend to bind together and resist flexing.  Vehicles equipped with sway bars can greatly improve ramp travel by disconnecting the swaybar from the axle or suspension.  The swaybar is designed to limit wheel travel from one side to the other.  Most vehicles have a front swaybar, some have one in the front and in the back.  Many aftermarket vendors sell swaybar quick disconnects.  Disconnecting the swaybar will again, not only improve your ramp travel index score but also improve your articulation off-road resulting in better traction and a better ride offroad.  Always be sure to re-connect your swaybar(s) before hitting the road again.  With leaf sprung suspension, another aftermarket product designed to improve articulation is compound shackles such as the Revolver Shackles and obviously better suspension all together will improve RTI as well as off-road performance.

100_3522.jpg (109832 bytes)Measuring your RTI Score
Without a Ramp

If you want to find out your RTI score but you don't have a ramp, you can find out what your RTI would be if you were on the ramp.  Given that the RTI score is simply mathematics it can therefore be measured and calculated without a ramp.  At it's core the RTI score is a measurement of how high a tire can travel vertically before another tire is lifted off the ground.  The challenge is to safely raise one of the tires until one of the other tires almost comes off the ground but still has contact with the ground.  How the tire is safely raised depends on your resources but some people use a forklift with the tire resting on a strong pallet or they use a floor jack with the tire resting on a flat surface on the jack. Be sure to do this safely.  Placing jack stands under the vehicle as it is jacked is one way people secure the raised vehicle.  The main objective is to raise one wheel as high as possible before lifting a tire off the ground. Once the vehicle is raised to that point, measure the distance between the bottom of the tire and the ground. 

If using a fork lift you would measure where the tire meets the pallet to the floor.  With this measurement you calculate the score like this:  Since a 20 degree ramp rises at .345 inches per inch of travel, divide the height of the lifted tire by .345 (for 20 degrees).   Then divide that number by your vehicles wheelbase.  Multiply that number by 1000.  The result is your RTI score on a 20 degree ramp.  While the ramp is a true measurement of your RTI this calculated method is pretty close.  The calculator below does the math for you and allows for different ramp angles. 


RTI Calculator

Enter the Numbers:

What angle do you want the score for?
20 degrees is the normal testing angle.
How high did a tire go before ANY tire lifted?
vertical height in inches
Vehicle's Wheelbase



Your RTI score is   Degrees Tested:  
On the ramp ...
you would have traveled inches up a   degree ramp

How do you stack up? Compare your score to the Ramp Travel Index Summary below as reported by Four Wheeler Magazine some years ago.

'96 Acura SLX: 506
'93 AM General Hummer: 385
'92 Chevrolet S-10 w/Rugged Trail 3.5-inch lift: 351
'81 Chevrolet K-5 Blazer: 653
'81 Chevrolet K-5 Blazer w/Rugged Trail 2.5-inch lift: 695
'92 Chevrolet K-1500 Blazer: 453
'92 Chevrolet K-1500: 421
'92 Chevrolet K-2500HD turbo diesel: 365
'92 Chevrolet K-3500 Crew Cab dually: 303
'94 Chevy S-10 ZR2: 420
'94 Chevy K-2500 Suburban: 401
'95 Chevy ZR2 Extended Cab: 336
'95 Chevy Blazer 2-dr:. 405
'96 Chevy K-1500 extended-cab: 376
'96 Chevy Tahoe LS: 433
'92 Dodge Ramcharger: 613
'92 Dodge Dakota Club Cab: 393
'92 Dodge W150: 526
'92 Dodge W250 Cummins: 372
'92 Dodge W250 Cummins w/Natl. Spring 3-inch lift: 406
'94 Dodge Ram 1500: 556
'95 Dodge Ram BR2500 Club Cab: 431
'92 Ford Explorer 4-dr.: 460
'92 Ford Explorer 4-dr. w/Superlift 4-inch lift :492
'92 Ford Bronco: 516
'93 Ford Ranger SuperCab: 416
'92 Ford F-150 Flareside: 471
'92 Ford F-150: 484
'92 F-350 Crew Cab w/Mac's Spring Shop 2-inch lift: 405
'94 Ford Ranger SuperCab: 406
'94 Ford Explorer Limited 4-dr.: 443
'94 Ford F-250 SuperCab: 383
'95 Ford F-250 SuperCab: 406
'95 Ford Explorer 2-dr.: 391
'95 Ford Explorer 4-dr.: 352
'97 Ford F-150 SuperCab: 441
'92 GMC Sonoma: 354
'93 GMC Sonoma Club Coupe: 334
'92 GMC K-1500 Suburban: 342
'92 GMC K-3500 Crew Cab: 338
'95 GMC K-1500 Club Coupe: 387
'95 GMC Jimmy 4-dr.: 371
'93 Isuzu Rodeo LS: 435
'92 Isuzu Trooper LS 4-dr.: 497
'93 Isuzu Trooper LS 2-dr.: 508
'93 Isuzu Trooper RS 2-dr.: 529
'94 Isuzu Rodeo LS: 454
'96 Isuzu Rodeo: 464
'75 Jeep DJ-5D: 556
'92 Jeep Cherokee 4-dr.: 399
'92 Jeep Grand Cherokee: 458
'93 Jeep Grand Cherokee: 448
'93 Jeep Grand Cherokee: 439
'96 Jeep Grand Cherokee: 422
'96 Jeep Wrangler: 357
'96 Jeep Wrangler w/Pro-Comp 2.5-inch lift:532
'97 Jeep Wrangler:532
'96 Kia Sportage: 471
'94 Land Rover Defender 90: 580
'95 Land Rover DIscovery: 588
'94 Mazda B4000 Cab Plus: 409
'92 Mitsubishi Montero 4-dr.: 391
'92 Nissan Pathfinder: 511
'96 Nissan Pathfinder: 466
'92 Oldsmobile Bravada 4-dr.: 411
'92 Range Rover County: 670
'93 Range Rover County LWB: 588
'96 Range Rover 4.0SE: 600
'92 Suzuki Sidekick 4-dr.: 379
'96 Suzuki Sidekick Sport: 440
'96 Suzuki X-90: 441
'93 Toyota 4Runner:441
'93 Toyota Land Cruiser: 593
'93 Toyota T100: 407
'95 Toyota T100 XtraCab:369
'96 Toyota Tacoma: 435
Offroad Tire Info
P-Metric Tire Sizes Conversion to Inches
Tire Terminology
Wheel Terminology
How to Pick the Right
Tires for your Truck
Truck Tire Info
Tires - What Hits What Fits
All Terrain  Mud Terrain
Tire Reviews & Info
Mud Terrain MT Tire Reviews
All Terrain AT Tire Reviews
Super Swamper Bogger
Super Swamper SSR
Super Swamper SX
Super Swamper Vortrac
Interco IROK TSL
Super Swamper LTB
Super Swamper TSL
Super Swamper TSL Radial
Super Swamper Narrow
Interco SS-M16 Swamper
Thornbird TSl Radial
Thornbird TSl Bias
Thornbird TSL
Parnelli Jone Dirt Grip
BFGoodrich Krawler
BFGoodrich MT T/A KM
BFGoodrich MT T/A KM2
BFGoodrich AT TA KO
BFGoodrich Mud King XT
Bridgestone Dueler MT
Cooper Discoverer ST
Cooper Discoverer STT
Cooper Discoverer ST/C
Federal Couragia MT
Firestone Destination AT
Firestone Destination MT
General Grabber MT
General Grabber AT2
Green Diamond Icelander
Ground Hawg Mud Tire
Hankook Dynapro MT
Hankook Dynamic MT RT01
Hercules Terra Trac MT
Hercules Trail Digger MT
Kelly-Springfield Safari DTR
Kelly-Springfield Safari MSR
Kumho Road Venture MT
Kumho Road Venture KL71
Kumho Road Venture AT
Dick Cepek Mud Country
Dick Cepek F-C II
Dick Cepek Fun Country II
Dick Cepek Fun Country Nylon
Dick Cepek Fun Country Kevlar
Mastercraft Courser MT
Mastercraft Courser HTR
Mastercraft Courser HTR Plus
Maxxis BigHorn Radial
Maxxis Creepy Crawler
Maxxis Trepador
Maxxis Buckshot Mudder
Maxxis MA-SW
Maxxis M-8080 Mudzilla
Maxxis MT-754 Buckshot
Maxxis MT-753 Bravo
Maxxis MA-751 Bravo
Maxxis MA-S2 Marauder II
Maxxis MA-S1 Marauder
Maxxis MT-762 BigHorn
Nitto Mud Grappler
Nitto Terra Grappler
Nitto Dura Grappler
Nitto Dune Grappler
Nokian Vatiiva MT
Pit Bull Rocker Extreme
Pit Bull Maddog
Pit Bull Growler
Goodyear Wrangler MT/R
Pro Comp Xterrain
Pro Comp All Terrain
Pro Comp Mud Terrain
Pro Comp Xtreme AT
Pro Comp Xtreme MT
Toyo Open Country AT
Toyo Open Country MT
TrXus Mud Terrain
TrXus STS All Terrain
Michelin LTX A/T²
Michelin LTX AT2 Press
Michelin LTX AT2
Mickey Thompson MTZ
Mickey Thompson MTX
Mickey Thompson Baja Claw Radial
Mickey Thompson Baja Claw Bias
Mickey Thompson Baja Crusher
Mickey Thompson Baja ATZ Radial SLT
Competition Claw
Dunlop Mud Rover
Federal Couragia M/T
Nitto Dura Grappler
Yokohama Geolandar
Dick Cepek's 2008 F-250 Super Duty Project Vehicle – Project CRUSHER
Mud Tire Reviews

Project_Kahn2.jpg (43446 bytes)
Project Kahn
2006 Range Rover
TD6 Vogue



Off-Road Lights
by LightForce Product Review / Installation.
from Off-Road Lights

ARB Air Locker Install
Jeep Wide Track Axles Swap


Do it Yourself
Detriot EZ Locker Install  in a 92 Toyota 8" rear

For all the Jeep
Fans out there!


From the
Department of Cheap   Tricks and Useful Tips

Ultra-Cool Hand Throttle for Free!

Jeep V8 Swap Tips

The Exploding Clutch

Radiator Protection using 6 bucks worth of material

Cracked Under Pressure - Fixing a smashed fingernail

A Cheap, effective alternative to undercoating

Home-built Saginaw Gearbox Brace for the cost of lunch!

Ammo Box Storage - Mounting Them for Quick Disconnect

Home-built Serious Skid-Plate protection for the Oil Pan for under 20 bucks!



Jeep CJ Axle Swap using
Scout II Dana 44 Axles


Building a Garage?
Need a Garage Plan?
Need a House Plan?

Knoebels Amusement Park


Ramp Travel Index
RTI / Ramp Travel Index  What it is and how to calculate it, with and without the ramp.


Reader's Rigs and Seriously Stucks!


Jeep Trans Swap Info
T-18A Transmission Rebuild & Short Shaft Conversion

Black Diamond Suspension Lift

install for CJ-7