How, let's say a B series trans, would one measure clutch slippage? I know that one way is to see an increase in RPM vs actual speed, but is there a more accurate way of measuring this? I'm looking for a better way to log this event.

With all of these aftermarket transmissions out there what are people doing to measure vehicle speed? What are you guys doing if your spool or LSD doesn't have a VSS provision? I thought I remember someone (Dave F maybe) posting a hall sensor setup....

What do you need to do to capture turbo RPM? I mean, I know how to setup a sensor, but would I monitor shaft speed or would a small magnet being placed on the wheel somewhere be better or even do-able without throwing off the balance of the assembly?

What about wastegate position? I know Tial offers nice gate sensor rigged heads, but are there other options or ways to do so?

I'm trying to capture as much data as possible. I like to know what is going on and learn from all of this.

Thanks for the help fella's.

 

we have our case on our tranny setup for a hall sensor IF we ever do this. i had libertys do the machining for it since the tranny was there already. of course this is just to measure shaft rpm (which corresponds to wheel speed) vs engine rpm. we dont have anymore inputs so this is not an option for us right now.

 

I havn't tryed this, but i'm puting it out there.

turbo speed. inductive sensor (hall) if you can find one that is fast enough, detects metall (electric conductors) so you could use the compressor blades for triggering witout any balance issues. and sensor would be wery close to flush in kompressor housing. and you get these sensors down to 3mm dia.

Speed. if you have abs rings on your axles together with a indutcive sensor you get a correct speed. you could also sligthly modify mainshaft. (crown) and place the sensor in the transmission housing. leaves out the gear calculations. or just find a sensore for harsh enviroment and put it inside the transmission triggereing on mainshaft 1st gear teeth.

a set of abs rings on inner side and outer on the axle would let you se phase diffrences an would let you caltulate actual torque that is actualy beeing but to the ground. (you would have to know how much the axle twists for a given torque)

the wastegate possition could be messured with slide potensiometer or mayby a delta pressure sensore. the valves possition would have to be calibrated for delta pressure vs mm. and for each wastegate spring change ( many oem use these sensors for egr feedback so finding a used one should not be hard)
with the delta press the exhaust backpressure pushing on the actual valve of the gate is left out.

 

Bothwell had a small sensor in the compressor of their turbo on the sunfire to capture rpms.

the Liberty i recieved (and i belive Miller and Ryan) have a threaded hole in the top of the gear housing case, for threading a sensor in to measure input shaft rpm. inside the trans there is an aluminum hat looking piece, which i belive has a magnet embeded in it for this reason. (input shaft rpm VS engine rpm)

on my car and Steve(HR-1320), we use a 2 piece shaft collar,with a magnet to measure output shaft rpm. this can be calculated into mph with tire size/gear ratio, ETC.

 

this is what i was trying to explain as well

 

That's with the billet housing though correct?

 

no they do the machinging for the sensor on the case, near where the mount bolts onto, not the bellhousing. ill snap a picture of it later today.

 

All of which you have mentioned above are readily available and easy to find sensor setups.

The clutch slippage one as mentioned above is straight forward and is easily done. Shaft speed vs. engine speed is as accurate as it gets.

Wheel speed, when using the factory speed sensor isnt an option isnt all that hard, just machine a 2 piece collar that goes on the half shaft with 2 magnets. Utilize the block for mounting the pickup and there you go. If you have a logger that is capable of writing math channels you will be in good shape as you will be able to convert the rpm to mph with a little of work.

Precision offers a turbine shaft sensor setup built into the turbo if you are interested.

The wastgate position sensor is something i am still not really sure why is needed. I mean i just dont understand what kind of feedback you are going to get from logging that.

 

Shane Tecklenburg of FAST Motorsports has some nice wastegate position setups.

http://www.fastmotorsports.com/produ...wastegates.htm

Clutch slippage should be measured through input shaft speed, as stated above.

Garrett also has turbo speed setup that will easily work with Motec and measures off the compressor wheel. I believe it's an optical sensor?

Wheel speed is easy, you either need a magnet or ferrous metal pickup somewhere in the driveline and a sensor to read it. The pulses per rev and such can easily be configured to give you speed.

 

take note of the bold letters, (tepid)

gear housing = outer part of case.
bell housing = inner par of case

 

sorry i forgot to get a picture of where libertys tapped my case. ill be sure to do it tomorrow.

edit: here is a crappy angled picture, this is all i have right now. you can see it kinda about where the tranny mount bolts up to the case