EFI conversion: looking for a few things
 

Hi All,

I'm working on converting a Gen I car to standalone engine management and I need help with a few of the items I need. Having never had the need to buy them before, it's proving to be slight challenge. I simply don't know where to find some things and I also don't know how much to spend for them.

I'm trying to gather the sensors I'll need, one of which is the exhaust gas temperature sensor. I've found them in various places (Summit, DIY Auto Tune, ATP Turbo, etc.), but none of them seem to give me useful info - like temperature range. Given the fact that rotaries run hotter exhaust than most reciprocating engines, I didn't want to buy just anything. I've seen prices between $35 and $400, but most of them were between $50 and $80, so I pretty much just need to know a good brand that would work with a rotary.

I'm also having somewhat of a time finding injector pigtails. Again, I've found some, but based on the ones with photos, I don't think they'll fit. The rest simply don't have photos. I'll be using S5 T2 injectors, so I either need to know somewhere to get pigtails that will fit, or I'll need to know a model number to give to vendors I've found that ask me for one.

Any help/direction is appreciated.

Thanks,
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forgot to mention that i've already ordered an intake air temperature sensor, but am looking for a coolant sensor that will fit the stock threading.

one thing that i have NOT found yet is a fast idle solenoid.

on a slightly off-topic note: i'm planning to mount the EMS one of the storage bins, but i'm a bit concerned about the length of tubing required to carry the intake vacuum signal to the MAP sensor. anyone have any experiences? advice?

anybody used the wideband shown at the bottom of this page?

why is it so cheap?

wait........what block? a carbureted 12A? GSL-SE 13B? I figured I'd ask because there's a huge difference there........
BTW, that's a replacement sensor for the Innovate LC-1 wideband unit---- as for other units out there, I honestly don't know exactly what sensor they use, but I believe it may be this one or even a variant of it. I personally use a PLX because it's a great unit and is pretty cheap at $245.

You can buy injector pigtails at any auto parts store. IIRC they run about $6 ea.

EGT guages are all going to have about the same range. Just move your sensor back away from the engine than the normal 6" from the header flange and the sensor will survive longer. You will really only find out the right temp for your set up with a trip to the dyno and some tuning time. Then you will know what is going on.

The fast idle solenoid is usual very application specific because of how they have to mount on the car. Find one that you can install where you want or just use a throttle body with an idle screw adjustment.

As for sensors, it depends on what ECU you're going to run. A megasquirt can deal with just about any sensor you can hook up to it. The GM ones are cheap and a lot of ECU companies use them here in the states.

That wideband sensor is just that, the sensor. Not the controller with it. Thats what you have to spend when you burn out the sensor for your DIY wide band or similar units.

neither ... or is it both? :D seriously, it's a streetport old school 13B.

yeah, i'm used to seeing them around the $300 mark. that's why i asked why it's so cheap, but i guess JGrewe answered that question. never used one before so i had no idea that it wasn't all i needed when it comes time for tuning.

okay. i'll give that a shot. i guess i underestimate the local shops when it comes to specialized parts i need. i developed the habit of going straight to the Internet.
:)

makes sense. thanks, i'll order one. do you think 12" is far enough?

well, i'm using a TB with an idle screw - the Autonomics TB. however, what do i do with the connection on the EMS harness (MegaSquirt)? won't it be looking for some sort of signal from one?

yeah, the IAT sensor that i got is actually a GM sensor.

so where does this controller fit in in terms of the wideband signal and the MegaSquirt? as i mentioned, i've never used one before so i may as well fill in the missing gaps of understanding.

on another note, i'll try to do some more research between Innovate and PLX.

thanks JGrewe.

12" would be fine, you could even go back farther if you want. Your "perfect" temp might be down around 1000-1200F but at least you will know what you are looking for.

The Fidle circuit is just a controlling circuit. It uses info from other sensors to tell the solinoid what to do. Leaving it unhooked is no problem.

The MS will take a signal from the wideband controller, not just the sensor itself. There is a lot of calibration calculations with a wideband, not just a 0-1V signal that comes from a narrow band. You just set up the MS to take the 0-5V signal instead which is done in the software, not hardware so don't worry.

All "K" type thermocouples have the same range (more or less) the difference is the range of the gage or ECM that you hook it to. Mine reads all the way to 2000deg. And in my opinion moving the sensor away from the engine to lower the reading is just silly, why would you buy a precision measurement device just to purposely make it inaccurate?

Cause they are expensive and they burn out quickly on a rotary and usually at the worst possible time.

I don't think there are enough variables that affect the temp of the gas in a header over 6-10 inches to matter. The gas temp drops many hundreds of degrees over a couple feet but it would seem to have a pretty consistant drop within the system. I may be way off, I have not done tests with thermocouples at 6" and at 12" on the same engine to see if they react differently. I have had consistant temp readings from the dyno to the track with sensors in a spot they can survive longer.

Have you ever burnt out a "K" type thermocouple? We have run them at 1750 degrees for hundreds of hours. If you are actually burning the inconel sheith off the probe the exhaust temps are the least of your problems. All "K" types are capable or reading temps in excess of 2000 degrees.

I've had them fail.

jeez, you guys were busy yesterday. :) well, i know enough about both you guys to have respect for you. JGrewe, you and i have had e-mail conversations about some of your experiences, and 13B-RX3 i've seen your progresses both in threads and video.

both points are valid. a precision device such as this should also be used to gather accurate data. however, for what i need (which is it's aid in tuning the motor), as long as the same trends exist in the same proportions (with respect to fuel mixture and ignition timing adjustments) at 6 and 12 inches, then why not preserve it. based on the type of signal the wideband sends, if the correlation between tuning parameter and exhaust gas content is in the same proportion over the extra 6 inches, then it doesn't sound like it should matter. am i correct? oh and for what it's worth, i plan to use install a permanent EGT gauge on the car anyway.

so my next question goes out to 13B-RX3: is it safe to assume you run yours at 6 inches? have you had any premature failures that close to port?

JGrewe: the ones that you've had fail, what type of timeframe are we talking. is it long enough to compose a good tune in a safe (for the motor) manner or are talking about something that won't make it out of 1 dyno session? with this info i can advise the owner of the potential failure and see where he wants me to install it.

thank you both for your inputs guys. :)

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I run mine at 6 inches and i also use a exposed tip thermocouple. They react a lot faster than the enclosed tip. I only use the car for drag racing though, in a sustained high temp situation mine might fail as well.

Good luck.

I leave them in the car all the time so it gives me a window to see what is going on during a race if the car starts to act funny. Having the info that an AFR guage and EGT guage give you can save you a ton of money if you are trying to decide whether or not to continue that last few laps.

I would say the couple that have failed with me around were about 6 or 7 races old. So, maybe 12-15 hrs?

well, the car is pretty much a street car. if it does see track time, i doubt it will be an awful lot, but let me not speak out of turn because it's not mine.

which one do you run?

i just want to do what's best for tuning the car. i guess nothing risked, nothing gained and i'd much rather risk the sensor than the motor (not likely, but worst case scenario). so i think i'll go ahead and set it up at 6 inches. if it keeps killing sensors after the tuning is complete, then i'll move it (or get another header setup with it at 12 inches).

thank you both. with any luck, i'll have this thing running by December.

didn't see the point to starting a new thread since this is all for the same car, hence the resurrection.

i'm having a bit of a time finding fittings for the fuel rails i have (i bought them from ATP Turbo). i bought 2 sets of fittings 1/2 with a -8 AN (which was too big for the rail) and 3/8 with a -8 AN (which is too small. my question is how do you guys with aftermarket rails that didn't come in a kit get fittings to work. better yet, has anyone used the ATP Turbo rails? if so, what fittings did you go with?







also, just re-read the thread and wanted to add that anyone doing this from scratch, as i am, if you use S5 injectors, there are no aftermarket pigtails available (at least, i didn't find them after months of searching) so you can use junkyard pigtails from a Toyota Supra (MA-70), Corolla (95-ish) or Paseo. they fit the S5 injectors perfectly.

thanks for reading. :)


EDIT: not that it matters because the question still stands, but this is actually diabolical1 posting. i didn't realize that i forgot to log my brother out. this is his car, i'm working on.

thanks :)