RexDiablo

Yeah! We`ve been discussing it but i mean we have to build it more serious with wider ramps, and a platform around the whole thing! It sist on snow now so when it melts the rig will move so we have to wait with making it permanent..

stburgpete

You have got to post the test video. Good or bad everybody I am sure would have some good input.

bill12690

iTrader: (4)

oh, and one more thing, i didnt reaqd every post but im assuming this is only for tuning? or will there be some way to get hp/tq measurements also?

RexDiablo

We are going to post the video! If it works it will be a fairly easy way and cheap to tune your car!

We are "never" going to get a true HP read out of that thing, but we are looking for a way to get a hp curve / torque.. Like a crank angle sensor from my 13b rotary engine mounted on a rotating point of the wheel. Then make a software to calculate the acceleration and make some sort of usable output. Havnt thought so much about how to get it working but if anyone got an ide it would be appriciated!

BLWNLT1_T/A

iTrader: (12)

What are the speed rating of those tires. I would hate for one to come apart while WOT tunning

Outlaw 03

The diff. should reduce the amount of wheel torque (or speed) by the gear ratio at the input shaft. To simplify if the gear ratio is 2:1 (we know it's not but it make the math easy) then 1 turn of the input shaft = 2 turns of the wheels or in this case 2 turns of the wheels = 1 turn of the input shaft. Meaning the brake force at the input shaft would be multiplied (by the gear ratio) compared to a brake at the wheels. So the input shaft brake will do more work with less effort.

This is a cool project!!!

JFM-jr

iTrader: (23)

This is awesome!

LilJayV10

iTrader: (39)

I think that looks safer than hanging it off a damn cliff. Freakin white people.

RexDiablo

Im not good enaugh in english to get my arguments right but i see what you mean. The main problem is still the heat beeing generated by the brakes and if the output on the wheels from my track car is 350KW i have to waste 350KW in heat on the brakes. Doesnt matter if the gear ratio is 2:1 or more/less, i still have 350kw than i need to waste.

The tires are, actually, very close to 2:1, in that case the truck wheels will have half the speed of our cars. Im not affraid of having to high speed on the truck tires as i dont think we need to pass 200km/h (truck tires are rated to 100km/h with VERY high load)

01ssreda4

iTrader: (96)

This is a confusing post and everyone in here is now dumber bc they read it. 2 turns dont equal 1 input shaft turn. Its nowhere on that half of the spectrum. Multiple turns of the wheels wouldnt equal one turn of the input. It would be the other way around. Multiple turns of the input would yield fractions of a turn on the wheel.

And yes breaking the input would work. You could weld on a brake rotor from a car/truck and actuate a caliper to stop it. It would have a huge advantage bc its breaking before the internal gearing.

DynoDR

iTrader: (1)

This same thing was going all over the forums about 5-6 years ago. Do a search for "redneck dyno" and maybe you can find something on it.

RexDiablo

We were supposed to try tuning HerskerHans`s turbo ls1 silvia but the weather stopped us! Besides that we finnished the truck air brake controller. Not very complicated! Fixed airflow regulator into the brake actuators and adjustable leak out of the actuators! I will post a diagram soon!

It does not matter where the brakes are! It is basic physics... actuall the first law of physics that "energy can not appear or disappear". If the output of my car is 350KW.. 350kw is what i need to brake and turn into heat =)

If someone can explain this so everyone understands, please do, as i dont know how to explain it understandable..

Tried to search, didnt find anything..

ccsanders01

iTrader: (1)

what is the gear ratio of truck rearend

RexDiablo

I got no idea! We can measure it but it isnt nothing we need to know.. If we need more brakes we`re adding eddy current brakes since the truck the axle came from had a ED brake. Its easy and brakes about 150kw alone

WarShrike

iTrader: (5)

Hmm, how about this way? Water Dyno, chassis dyno style:
http://www.youtube.com/watch?v=ogfX2mH_tok

Via Jalopnik: LINK

01ssreda4

iTrader: (96)

No it isnt. Braking at the wheel and braking the input of the rear axle are two completely different things. That general rule of physics isnt practical in every situation. It just doesnt apply directly all the time like you are trying to make it out. Good luck anyway.

sxracerb25

iTrader: (6)

+1. The energy isn't "disappearing" from the driveshaft to the wheel. It's being used to rotate the axles and wheels and such. Exactly why there is more horsepower at the flywheel than the wheels.

RexDiablo

True! You loose around 10% from the engine to the wheels. I still have to waste alot of watts =)

EDIT: Nice with inputs! We`ve been discussing the energy losses etc with alot of people and nobody seems to agree hehe.. Just one way to find out!

SSPerformance

iTrader: (76)

one word ....WOW being that i have a 224x Dynojet in my shop i WHOULD NEVER DO THIS.... very good way to get some one hurt or KILLED

BlwnLs1GTO

iTrader: (12)

So, if you did'nt have a Dynojet you WHOULD DO THIS??