Traxxas Revo Racing Thread

[atmo]

Alright the best set-up I've found is about 400-450k I'm sorry I am doing this in my garage and I don't have a lab so these are estimates. I mixed close to have and half 300-500 and then added alittle more of the 500k and mixed it of all things in an empty pill bottle stirred as best as possible to make my mixture "it's thick" but this time I'm using nothing but diff silicone oil. 40-450?-40 and she hooks-up. There is no drag and I even work on my shift point and set it to shift within the 1st 15-20 feet and you can hardly here it shift. My front tires are still balloning but she pulling like a scaulded ape. The on power transfer evens out around the 20000rpm mark and levels out with a smooth power distribution to both front and rear. The straight 500k seamed to make it front wheel drive almost and the power transfer doesn't level out until around the 25000rpm mark.

[IAMI]

Yes pulling like a scaulding ape, but it must turn in like a train.

[atmo]

She turn on a dime thats where the rear brake comes in

[atmo]

Yes pulling like a scaulding ape, but it must turn in like a train.
__________________
Like she on rails!!!

[Skytrekin]

I have a question about suspension tuning. I have read Slaydens suspension page on tuning. The track we are racing at is extremely bumpy in straights and corners. Not a smooth area anywhere! And I am having trouble keeping the back down on acceleration or any kind of speed, on any kind of straight away. Read very bumpy! I have one step up in spring size from stock front and rear and 60wt shock in rear 50wt in front using stock pistons inside. A arms level at rest. Running center diff with 300k and 10k front and back. Revo weighs 9lbs even w/empty tank.
Im gonna try the arms angled up for more height (more preload in springs) Help plz.

[IAMI]

Skytrekin, upper or lower holes on the rear upper a arm hinge pins? (roll center) Lower holes makes it stiffer, upper holes softer.

Also, I run on very bumpy tracks and have found a softer setup to be best overall. Stock springs (white fron, green rear) and 40wt shock oil all around and P2 rockers. Rear drivelines level with pushrods in in middle holes on, lower a rms. Front drivelines level to slighlty above level, pushrods in middles holes on lower a arms. I adjust front ride height slightly depending on how rough the track is and also to adjust steering.

Are you running the swept back a arms?

[twisted]

[Todd Hodge] The suspension mounts offer a lot more in the roll center adjustability. By running a lower roll center, pins closer to the chassis, you will gain more roll in your chassis, which results in less use of the tire. By running a higher roll center, pins higher, you have a car that now drives flatter and places more of a load on the tire for traction. Generally speaking, a lower roll center will have less traction where a higher roll center has more traction. You can easily see this with foam tires, a place where we never use high roll center since it will make the car traction roll due to the increased traction capabilities of the higher roll centers.

[Skytrekin]

I have the stock a arms and the pins in the upper holes and pushrods in the inner most on the lower arms. I tryed last night with the suspension tuned up (more spring preload) and it seemed to handle the bumps better. Maybe more suspension to work now? I also adjusted the camber and toe, it made a big difference in corners and tracking for the better. Im running velocitys with bowties and a proline wing and a 3.3 I just wish I could nail full throttle down the straight with out flipping or crashing.

[Revo Boy]

Pick your truck up by the rear and roll it while you adjust the brake bias. Then do the same with the rears. You might have to back them off some at your disc. i'm running about 20% front to 80% rear with a soft brake set-up. I'm not real heavy on my brakes just enough to slow me down but I don't like to use them as a pivot for turning.

hi guys, im having probs with my rear breaks still. i cant get the rear sharp enough im still getting more front breaks. if i screw my rear break adjuster in more i get break drag, lots. how are you lot doing your rear breaks?

any help will be great

Rb

[twisted]

throtle control is a major role in going fast. knowing when and where to lay the power down will result in lower lap times.

also on another note, having the suspension to soft could casue the skids to slap the ground and make the truck hard to drive.finding a good suspension set up for your driving style will be key.

good luck.

[IAMI]

Sky, soften the suspension. Go back to white front springs and green rear springs with 40wt all around. Put your pushrods in the center holes on lower a arms. Adjust ride height like I said above.

As I said before, I race on the most extreme blown out surfaces you can imagine. Until you make some major changes like those I have listed, you will not begin to feel the differences, good or bad.

[Skytrekin]

Thanks alot! Im gonna try those settings.. have a race tonight so I should be able to tell a difference one way or another!

[Skytrekin]

Well tonights race was intresting, Not enough MT to make a class so I had to run with the truggys. Anyway.. went back to stock springs and 40wt all around pushrods in middle holes drivelines level. The back end would hit the ground and send it flying in the air wrecking me most of the time. I tryed it smooth with a gradual throttle, but with any kind of speed and going over the bumps the back end would hit the ground and upset the truck.
Im not sure if I like the center diff either. The front tires balloon like crazy on acceleration and thats with 300,000 in the center diff. I had to loosen the slipper some just to try and keep it on the ground. Resorting to pre cd setups.
I think im gonna go back to stiffer springs and 60wt maybe even #3 pistons in the rear.

[atmo]

Skytrekin My track has become blownout with some heavy rains and alot of use. My current set-up extended chassis 19mm
P2 F-50wtan/R-50wblack
30-400-30
Camber 1.5 Front/rear
Toe front 1.0 positive
Toe rear 1.0 positive I know this is different but at mid to high speed it grabs better with more stability and with the center diff at low speed/RPMs I'm using more of my front wheels.
Upper front Lower rear-4clips front
I'm running CrimefightersMt with proline grey with offset and BowtiesMt with panther greens offset. I've had my picco in lately with the center diff and extended chassis. It has tamed it down and made it a good controlable motor.

Bmoney How was the 500k set-up?

[IAMI]

Skytrekin,
Glad to see you tried it out.

[bmoney]

Bmoney How was the 500k set-up?[/QUOTE]

Well it wasn't really to bad though some would say it defeats the purpose of having the center diff. I am going to try a mix closer to 400 I had some engine troubles(bad oring) so I didn't get to do alot of testing. The truck pulled really well out of the corners and I still had split braking which is what I am looking for. I only made the main so I got a whopping 11 laps on it.

[spencer!]

How is everyone liking all the tekno stuff and the center diffs.

[redman2]

I must say Roy and Craig know how to set up a Revo, I'm running their set up at my locals and the same tracks they do and its working great, dropping lap times like crazy!

[bmoney]

How is everyone liking all the tekno stuff and the center diffs.

The techno stuff is awesome as is the center diff/split braking.

[dudewittarevo]

I must say Roy and Craig know how to set up a Revo, I'm running their set up at my locals and the same tracks they do and its working great, dropping lap times like crazy!

More info on these setups?? Thanks!

[IAMI]

dudewittarevo,

Check pages 4, 5 and 6 of this thread for pictures and setup of my REVO.

For that matter, read through the whole thread. Lots of great information from everyone on here.

[revoskoooter]

hi guys, im having probs with my rear breaks still. i cant get the rear sharp enough im still getting more front breaks. if i screw my rear break adjuster in more i get break drag, lots. how are you lot doing your rear breaks?

any help will be great

Rb

try putting the brake arms to the farthest point away form each other

moving the front brake arm to a new position on the servo horn should do it

[atmo]

I used the star servo arm. One for my throtle one for the front and one for the rear. It seemed to work best for my set-up.

[spencer!]

What do yall guys think about the progressive 2 rockers compared to the progressive 1s because i honestly could not be happier with the progressive 1s

[kojak61]

I have a revo with stock gearring and a TRX 2.5R. The track I race has a double triple coming out of a turn. I want a quicker acceleration out of the corner. What gearing should I run? The track is a very technical track.

[Revo Boy]

hi mate, do you have foc? if not then get a foc and also go with 40/15 gearing and drop the close ratio gears in matey

Rb

[kojak61]

Yes, I already have FOC.

[TOPS]

Just passing along a little info I have found.... alittle long but nice read...

Toe is the angle (inwards or outwards) that the tires point when the wheel is straight ahead. Toe-in means the front of the tires point inward, and toe-out means they point outward. Zero toe means the tires are parallel to each other. The biggest effect toe has on the handling of the car is on stability. When a car hits a bump or enters a corner, forces on the tires act to steer the car off to one side, making the car unstable and difficult to control. Toe-in counteracts this, improving stability. Toe-in also causes understeer during initial corner entry. Interestingly, toe on the rear wheels has the same effect on handling as toe on the front. Toe on the rear wheels is useful for tuning the handling of the car as it is exiting corners.

Front Toe "IN"
Slower steering response
More straight-line stability
Too much will casuse greater wear at the outboard edges of the tires

Front Zero Toe
Medium steering response
Minimum power loss
Minimum tire wear

Front Toe "OUT"
Quicker steering response
Less straight-line stability
Too much will cause greater wear at the inboard edges of the tires

Less Rear Toe "IN"
Less straight-line stability
Less traction out of the corner
More steering
Higher top speed

Intermediate Rear Toe "IN"
Intermediate straight-line stability
Intermediate traction out of the corner
Intermediate steering
Intermediate top speed

More Rear Toe "IN"
More straight-line stability
More traction out of the corner
Less steering
Less top speed

****

Caster
------
Caster is the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side. If the pivot axis is tilted backward (that is, the top pivot is positioned farther rearward than the bottom pivot), then the caster is positive; if it's vertical to the lower pivot point then the caster is zero.

Less Castor (vertical = 0 castor)
More OFF POWER steering into the corner
Less steering out of the corner
Less straight-line stability

More Caster (laid back more)
Less steering into the corner
More ON POWER steering out of the corner
More straight-line stability

Benifiets of castor: (more positive castor/laid back more)

Maximizes tire contact pacth during roll, braking, and acceleration
Improves turn-in response
Increase directional stability
Improved steering "feel" and self-center
Increases dynamic negative camber during turn in

Castor Vs Camber:

Camber doesn’t improve turn-in, positive caster does.
Camber is not good for tire wear.
Camber doesn’t improve directional stability.
Camber adversely effects braking and acceleration.

****

Shock Absorbers
---------------
The purpose of the shock absorbers is to dampen the oscillation of the springs. The dampers not only dampen spring oscillations, but they also affect handling during transient conditions (such as the entry and exit of turns), but not steady-state conditions.

More Dampening
Slower shock action = could be unstable on bumpy tracks
Slower chassis weight transfer
Generally less traction

Less Dampening
Faster shock action = less chance of tire leaving the ground on bumpy tracks
Faster chassis weight transfer
Generally more traction

****

Springs
-------
The purpose of the springs is to control wheel movement and keep the tire in contact with the road over bumps and irregularities. Stiffening the springs front and rear will reduce body roll and make handling more responsive, but cause a loss of traction over bumpy surfaces. Likewise, softening all of the springs will give more grip on bumpy tracks, but increase roll and reduce responsiveness. You can also use the springs to affect the car balance. You can reduce oversteer by stiffening the front springs or softening the rear. Likewise, you can reduce understeer by softening the front springs or stiffening the rear. However, be advised that changing just one end also affects fore/aft weight transfer. By softening the front springs, you'll also get more dive under braking. Softening the rear will give you more rear weight transfer under acceleration, which can give you more traction on the rear wheels in straight-line acceleration. Read and understand about "anti-roll bars" before you come to the conclusion that you need to change your springs, springs should be one of the last, if not the last thing you should change to effect how the car handles other than during a bump condition.

Using Softer Front Springs
More steering
Slower steering response
Used on bumpy tracks
More 'diving' under braking
Used more for tight technical tracks

Using Harder Front Springs
Less steering
Faster steering response
Used on flat tracks
Minimum 'diving' under braking
Used more for large fast tracks

Using Softer Rear Springs
More traction out of the corner
Slower steering response
Used on bumpy tracks
More front lift under acceleration
Used more for tight technical tracks

Using Harder Rear Springs
Less traction out of the corner
Faster steering response
Used on flat tracks
Minimum front lift under acceleration
Used more for large fast tracks

****

Downforce
---------
Downforce is the aerodynamic force pressing the car down on the track and improves cornering grip. This downforce is dependent on forward speed, and increases as you go faster. Increasing the downforce all around increases cornering speed, but also increases drag, which gives you slower straightaway speed, and you may also need to increase ride height and/or spring stiffness to prevent bottoming. Likewise, decreasing downforce gives you lower cornering speeds but higher straightaway speeds, and allows you to run softer springs and/or a lower ride height. Also, you can also use downforce to fine-tune balance at high speeds. To reduce understeer, increase front downforce or reduce rear. To reduce oversteer, decrease front downforce or increase rear. Keep in mind that these adjustments are dependent on forward speeds and has less effect as speeds drop, so you can use this to give the car different handling characteristics for different speed ranges.


****

Differential Settings
---------------------
Differential's are used to allow the wheels on the same end of the car to rotate at different speeds during cornering.
If diff's are set to tight or are "locked" the tires will fight each other as the car is turning.

Front Diff Looser than Rear Diff
Steering response increases
If rear diff is to tight, the car will understeer into the corner, and will cause loss rear end sliding out of the corner.
Could cause oversteer while entering the corner (depending on other settings)

Rear Diff Looser than Front Diff
Steering response decreases, stability in turns in increased
Could cause understeer or "push" while entering the corner (depending on other settings)

***

Tires
-----
The tires are perhaps the most important part of the car. You can gain the biggest improvements by installing tires with more grip. Tires are available in many different compounds: hard - soft. Soft tires have more grip than hard tires, but wear out faster. You are also able to mix types front and back. You can reduce oversteer by using hard tires in front and soft tires in back. This gives the rear tires more grip than the fronts, making them less likely to slide out. Likewise, you can reduce understeer by putting soft tires up front and hard tires in back. If you car feel's like it is "loose" or "unstable" you may actually want to try a harder compound, by using a harder compound the tire will have less bounce, less side flex, and will typically offer a much more stable foundation.

Tires are to small:
Low forward traction
Low top speed
Car becomes twitchy

Tires are to big:
Very slow steering response
High chance of traction rolling
Tire distortion in turns
Less stable

Softer Front Tires:
More Steering
More wear
Less stable

Harder Front Tires:
Less steering
Less wear
More stable

Softer Rear Tires:
More rear traction
Less steering
More bounce on bumpy tracks
Less stable

Harder rear tires:
Less rear traction
More steering
Less bounce on bumpy tracks
More stable

****

Camber
------
( PLEASE READ ABOUT CASTOR BEFORE YOU ADJUST YOUR CAMBER )

Camber is the angle the tires make with the road and is measured in degrees. Tire grip varies with the camber angle, and ideally is maximum when the angle is zero. However, the maximum grip is found with a small amount of negative camber because of tire sidewall deflection (when the top of the tire is tilted inward it is called negative camber. Also, as the body rolls in a turn, the suspension movements themselves causes some adverse camber change. These combined effects mean that for maximum cornering power you need to have some amount of negative camber. However, too much camber will cause you to lose grip because the outside edge of the tire is being lifted off of the pavement, reducing the contact patch. So to summarize, as the camber angle increases from zero, cornering grip improves to a point, then falls off.

-2 deg. ~ -1 deg.
Front Camber
Quicker steering response
More overall side traction
Less chance of traction rolling

-1 deg. ~ 0 deg.
Front Camber
Less quick steering response
Less overall side traction
More chance of traction rolling

-2 deg. ~ -1 deg.
Rear Camber More overall side traction
More traction under braking
Less chance of traction rolling

-1 deg. ~ 0 deg.
Rear Camber Less overall side traction
Less traction under breaking
More chance of traction rolling

Ride Height
-----------
A lower ride height lowers the center of gravity, which reduces weight transfer during cornering, acceleration, and braking. The reduced weight transfer improves cornering. A lower ride height also lowers drag at high speed because you are presenting a smaller frontal profile to the airstream. Also, by lowering the front end and raising the rear, you can improve high speed stability and increase downforce by preventing high-pressure air from building up underneath the nose of the car. If the car is too low, it can bottom out, though this can be eliminated by stiffening the springs(which could cause problems elsewhere).

HTH
PEACE
TOPS

[nitrobasher]

Great info TOPS. Thats worth printing to keep in the pitbox. I have always wondered what to change to get more steering, stability, etc.. Thanks for posting that. Im sure it will help a lot of us out.

[atmo]

Great stuff TOPs When are going to get that ST-R back out

[TOPS]

Glad I could be of some help....

atmo, i'm still rusty, not racing in a while(or practicing) and all but, I smell a podium shot this weekend.... I'll be out the early getting some time in on the track....

You think you'll make the podium this weekend? Can be a tough class, that smt...


PEACE
TOPS

[atmo]

I'll be down in Dallas this weekend. I see you after the new track built. I'm going out to the track tomorrow and do alittle fine tuning

[Roarke555]

Hello guys..

I just broke my front arm and ordering RPM front A-Aarms, but I cannot decide if I should buy RPM rear A-Arms or Traxxas Suspension Arm Set Adjustable Wheelbase Revo ? I know, that ppl use them for Revo 2.5 , but I dont know if with Revo 3.3...

Thanks...

Roarke

[Bigmax]

80/20 brakes? Point me to an explanation on how it's done please.

[atmo]

20% front 80% rear. Pickup the front and roll it while have your truck and radio on. Hit the brake and start adjusting then do the same with the rear brake. After you get it to a good point set it down and push it while you hit the brakes and fine tune it from there. My rears will lockup on high traction while my fronts slow but do not lock up.

[spencer!]

Hello guys..

I just broke my front arm and ordering RPM front A-Aarms, but I cannot decide if I should buy RPM rear A-Arms or Traxxas Suspension Arm Set Adjustable Wheelbase Revo ? I know, that ppl use them for Revo 2.5 , but I dont know if with Revo 3.3...

Thanks...

Roarke

you will want the extended a-arms if you are racing

[Tornado_Racing]

Just wanted to drop by and say hey to all of you guys. It's been awhile since I was last on here but nice to see you guys are keeping the Racing Thread alive and strong.

Still doin' a ton of Oval racin' which doesn't leave much time for Off-road. I'll check back from time to time and good luck too you all!

Tony Moffre
Tornado_Racing

[Ian Bowers]

Hey Tornado, Nice to see you poppin in.

[lextek]

Just wanted to drop by and say hey to all of you guys. It's been awhile since I was last on here but nice to see you guys are keeping the Racing Thread alive and strong.

Still doin' a ton of Oval racin' which doesn't leave much time for Off-road. I'll check back from time to time and good luck too you all!

Tony Moffre
Tornado_Racing

Oval? That just makes you dizzy! Your input is very, much missed.

[claytm300exc]

Does anyone know the part number for that header Slayden was using for a side pipe, it looks like it should also easily fit my os .18.