hawaiian_evo

iTrader: (13)

^^^^so CONCLUSION: GM 3 Port FTW ^^^^^

Robevo RS

iTrader: (16)

yes sounds like it,, wasn't as easy as i thought... We have to work around some ego issues ... LOL

Some one said it need some resistor installed with the GM 3 port., also. /Inline install /
"Using the GM 3 Port without any Resisitor could pottentially overdrive the ECU driver output for the boost solenoid."


So here are the clear choices for it /but not for me, which set up is the right one./:


"Both the GM and the Prodrive have a resistance of about 24 ohms. The stock BCS has a specified resistance range of 29 - 36 ohms. Should be safe to use a 5 ohm resistor, and a 5 ohm resistor gives 95% of the performance of a 1 ohm resistor. No resistor is probably ok too because the circuit current is still very low with no resistor. And razorlab says he's got a few customers that have been running the GM with no resistor for over a year."

"Thats what I am using in my GM 3 Port Setup. I used three 1/2 Watt 15 Ohms resistor in parallel to produce an Req of 5 Ohms and 1.5 Watts in power. That gives the 29 Ohms min as per Service Manual and provides a lower voltage drop and therefore faster response for the solenoid activation. A 5 Ohms produces 11.1 Volts and 10 Ohms produces 9.5 Volts at the soleloid coil based on a battery Voltage of 13.5 Volts. Power rating of a single 1/2 Watt 10 Ohms resistor is 312.5% and three 1/2 Watt 15 Ohms in parallel is 72%. Both assuming 100% DC which is not the case for the GM 3 Port.
"

"Running 2 10 ohm/1 watt resistors in parallel to form a 5 ohm/2 watt resistor from Radioshack HERE would be the best solution. There would only be roughly 0.6 watts passed thru each 10 ohm resistor."


so which resistor set up would be the best for the 3 Port GM. That would be a final step for the GM 3 port solenoid question.

Since im not an expert for me all three can be good. But im sure one of those has some advantage over the others or vice versa. Im sure this question was asked before too, but i couldn't find it... LOL
DO you have any idea?

Robevo RS

iTrader: (16)

how dare you... LOL

fostytou

iTrader: (15)

Really, you can stop digging at me... I've done no harm to you.... But I will say that this has been answered repeatedly in multiple threads also (in fact, you even copied some of it right in your post).

Since I'm great at taking abuse, I'll continue to answer your questions.

No resistor is needed. It is ideal to make the resistance match that of the factory solenoid, however many / most people run without it and have not had a problem. Using the resistor will slow the response of the solenoid slightly, but may not have any negative effect... so if you'd like to ensure you are 100% within factory spec then you can use one, otherwise no need.

GST Motorsports

iTrader: (8)

No resistor needed with GM

- Bryan

Robevo RS

iTrader: (16)

Thank you for the answer.
But i would like to go a closest to the factory specs. i try to be as safe as i can . I dont need anything failing in racing, and as you said the magic word "may" , just doesn't do it for me. I got enough trouble in racing because the "may" word was there . Sadly in racing the "may" suddenly becoming "sure" . And about that, i could have tell you stories for days. Related either tuning or mechanical.
So can you help out which would be, probably the ideal choice between those?
I got to be picky, since i spend a lot on racing and really bug everyone when , we have to stop the race because something $20 thingy wasn't installed or was left out. Specially when one race cost couple grand and countless hours logistic and work of many people. Im just one end of it.

Rob

fostytou

iTrader: (15)

While I think its highly unlikely that you will run into a problem considering the amount of time / units in use without one... but if you wish to do one a single 5 ohm 1w resistor should be fine. The unit is very low current. if you want to do 3 x 15 ohm .5w (1.5W total) (1/Rt = 1/r1 + 1/r2 + 1/r3 or 1/5 = 1/15 + 1/15 + 1/15) that provides extra paths for current, but also extra connections to fail. 2x 10 ohm 1w resistors provides the most current capacity at 2w and the same resistance, but again, more than 1 connection can fail (but also more than 1 path for current to flow). If a single one of the connections for the multiple resistor pieces fails, then you *may* still have a working solenoid, however it will run at a reduced rate and lower boost.

You could also use a single 1ohm 1w resistor to prevent damage if for some reason the solenoid failed and shorted itself, this would *help* prevent damage to the ECU while not having much of an effect on performance, but I would think that is an incredibly rare circumstance (and this protection does not even exist in the factory setup).

I personally think it would be more reliable (from a less soldered junctions / working parts point of view) to keep a backup solenoid if failure tolerance is that important to you. I know you can't always change that in the middle of a race, but you would be better off with that than having only one unit that failed (and no backup to test).
Alternatively, you could keep an MBC and a vacuum plug with you for a reliable backup.

Robevo RS

iTrader: (16)

Great !! Thanks for the advice!

So the that will be the winner set up :
GM 3 port solenoid with a 5 ohm 1 watt resistor, with an extra GM soleniod in hand JIC.

Thanks again. !!
Rob