My brothers whacky idea (he's an engineer)

[93rev2sev]

But im sure it's possible. Or just buy a g-tech?

Figure out how to hotwire the ABS sensor output from one of the rear wheels, and read the signal inside the car. You can record it to a wave file, and then calculate acceleration/velocity/position vs time directly. Then it will be easy to calculate HP, torque, etc. You can also then do some coastdown testing to estimate the drag forces acting on the vehicle. Then, the only thing we will have to guess is the rotating inertia of your drivetrain and engine.

Anyone got an idea as to how I can do this?

 

[JoesSHO]

Like you said before- buy a G-Tech.

Good thought, but you can run a G-Tech on more than one car, and it sounds like too much to mess with for what you will get out of it, but that's just me.

Oh those engineers!

 

[SHO M0nk3y]

Like you said before- buy a G-Tech.

Good thought, but you can run a G-Tech on more than one car, and it sounds like too much to mess with for what you will get out of it, but that's just me.

Oh those engineers!

Well the main propose of an engineer is to make thing complicated.


Well it does sounds like a cheap way of doing it.

 

[Shoaz]

Well, I'm an engineer and I bought a G-Tech.

The way you suggest can be made to work, but it'd be a ton of work. You'll be way ahead with teh G-Tech, IMHO.

 

[93rev2sev]

Yeah, when I told him the car felt down about 20HP he spent 45 minutes running a bunch of calculations(based on timed runs compared against a couple of other cars) and then sent me an e-mail stating..."it looks like your car is down apprximately 20HP"

Gotta love Engineers!

 

[SHO M0nk3y]

I am going to go a hard and ask, whats a G-Tech?? Been around here for a while but have never heard of it??

 

[93rev2sev]

www.gtechpro.com

It's an accelerometer. It will measure how hard you accelerate, brake, corner ect. Also will tell you reaction time, 1/4mile times, horse power, it's much cooler than my brothers whacky idea.

 

[NiNeTy Fo SHO]

But your brothers idea would be much m ore accurate than the g-tech. I g-tech bases everything off of an accelerometer...which depending on how its mounted and how accurate it is, will give you a reading. Tapping into the abs sensor gives you the direct information from the wheels. It like dynoing a car (measure force at the wheel) versus what the manufacturer tells you the car should have.

I am an engineer too.

 

[AREA 91]

My Kenwood CD player has a built in "G Tech".

 

[93rev2sev]

My Kenwood CD player has a built in "G Tech".

Really?!?! does it render the engine speed through RFI? Or is there an actual accelerometer built in? Whats the model number?

 

[Shoaz]

But your brothers idea would be much m ore accurate than the g-tech. I g-tech bases everything off of an accelerometer...which depending on how its mounted and how accurate it is, will give you a reading. Tapping into the abs sensor gives you the direct information from the wheels. It like dynoing a car (measure force at the wheel) versus what the manufacturer tells you the car should have.

I am an engineer too.

I'd disagree. Non-skidding wheel slip under acceleration can be as much as 10%, and a good accelerometer will be immune to that. FWIW, the G-Tech monitors engine rpm pretty accurately via the ignition noise on the power supply, so I don't see any downside to the G-Tech.

 

[93rev2sev]

I'd disagree. Non-skidding wheel slip under acceleration can be as much as 10%, and a good accelerometer will be immune to that. FWIW, the G-Tech monitors engine rpm pretty accurately via the ignition noise on the power supply, so I don't see any downside to the G-Tech.

He has a formula for that, also but you are right. G-tech FTW!

 

[NiNeTy Fo SHO]

I'd disagree. Non-skidding wheel slip under acceleration can be as much as 10%, and a good accelerometer will be immune to that. FWIW, the G-Tech monitors engine rpm pretty accurately via the ignition noise on the power supply, so I don't see any downside to the G-Tech.

I figured that would all be taken out by using the rear tires on a FWD car. I figured the rear tires would have no problem keeping up with the acceleration of the car. I could see this being a problem on higher hp cars, especially ones with rear wheel drive slightly lifting the front tires.

Learn new things everyday.

 

[SHOtime2511]

My Kenwood CD player has a built in "G Tech".

 

[93rev2sev]

good point 9t4sho. I would have to say you are right.

 

[sho'd]

i wanna know what cd player you have, i want one.

 

[JoesSHO]

www.gtechpro.com

It's an accelerometer. ...it's much cooler than my brothers whacky idea.

You should still hit a track to know for sure what your numbers are- on my Mustang, the GTech showed some consistently more favorable numbers at times vs. actual measurment... But still uber cool

 

[JoesSHO]

I'd disagree. Non-skidding wheel slip under acceleration can be as much as 10%, and a good accelerometer will be immune to that. FWIW, the G-Tech monitors engine rpm pretty accurately via the ignition noise on the power supply, so I don't see any downside to the G-Tech.

ENGINEER FIGHT!!! :laugh_ti:

 

[NiNeTy Fo SHO]

ENGINEER FIGHT!!! :laugh_ti:

You better watch out, I will break out my pocket protector and TI calculator and drop some integration along with some differential equations on your behind.

 

[sho'd]

is this similar to the cd player you have?? has g-analizer
http://www.abtelectronics.com/product/22357.html