My Megasquirted KA-T S13 Project

[krazydriver]

So it's been a long time, but she's nearly done.

As some of you may know i megasquirted my car last year in preparation for a decent turbo setup. I've taken a while to install everything but have really changed ALOT on the car. She's not running yet, but should be by the end of the week.

So here's the specs:Factory blockT3/T04e 50trim/63AR shooting to run ~7lbs of boost.All the normal BOV, WG, stuff.

For engine management i've got a walbro 255 in the back, Tomei 555cc injectors, and megasquirt with an LC1 wideband for tuning purposes.

My thanks go out to alot of the sponsors for hooking me up with some great deals. Marty at Injected Performance for my fueling and wideband, Andy at 240sxmotoring for helping me figure out my oil cooler setup(which i forgot to take pics of), The great crew at FRsport for a TON of parts, and excellent customer support from the guys at Phase2motortrend when one of my gauges was DOA.

So here's some fun overview pics.

Now one of the fun parts of megasquirt was.... i don't need most of the factory engine harness anymore.So here's the megasquirt engine harness, which i tucked inside the intake manifold for a cleaner look.It's only about as big around as a quarter.Here's an awesome 5 gallon bucket, about half filled with unused factory wiring stuff.

I removed AC from the car, so i used the holes from that and the factory wiring harness to get everything into the cabin.Left is the LC1 wiring, middle is megasquirt and my gauges, and the right is power/abs wire that ran through the engine harness.

And the glory shot of the gauges.Pillar is oil temp and pressure, and the column has boost, coolant temp and the wideband gauge.

All i need to finish to start the car is to dump some oil in it, and finish mounting the battery in the trunk.But i want to finish removing all the cruise control/factory ecu wiring that i don't need first. So if i finish it up, maybe tomorrow night i can get her to run!

[480sx]

Whew, good luck man! You gona put the dash back in?

Also, so you resolved the MS false starting spark with the Ka dizzy issue? What was your fix, and does it ever kickback anymore when starting?

[krazydriver]

yeah i got the false starting spark fixed.Had to do with a false signal trigger method that MS2 has.for the ka dizzy YOU MUST change the trigger method from simple to advanced. I got decent results with a 1ms time mask, and 10% mask.

If i get the front harness stripped out, rewrapped and taped together and the car starts properly tomorrow, the dash will be going back in. If i have electrical issues, i'll just trace circuits from my awesome secondary fuse box i put in and find where the problems are. So either way the dash will eventually go back in.

[480sx]

i'll just trace circuits from my awesome secondary fuse box i put in and find where the problems are.

So your trigger angle is in the 100's? Where is your dizzy rotated in relation to normal stock position?

I went the easy/expensive rout and bought the relay board/box from DIY autotune. Made wiring soo easy, its got all the fuses, relays, and connections you need to wire ms.

I messed with advanced settings a lot, it was the only way i could get the kickbacks manageable. Guess i never got the magic numbers in.

I hate not having a MS powered car to check this stuff out on.. Thats gona have to change .

[krazydriver]

We have ignition!!!!

Far better then the first time i put megasquirt in. Instead of three times cranking, this time it fired up on the first shot... which was quite surprising considering my guesses for idle setup, and the fact i kinda guess tuned for 555 injectors...

Either way, she runs for about 8 seconds then sputters out. So i definately need to richen it a little, as well as play with the idle screw some because 2k is NOT where i want to be idling at.

As far as all the glorious rewiring. everything is fine EXCEPT i don't have backup lights.... which might be a problem because i need to get the car inspected within 2 weeks.

[480sx]

Lol GUESS TUNED! You make it sound like you got lucky or something. Come on mannn you got ms hah, theres no guess tuning for 555 cc injectors. Plug in your engines displacement + injector size and the software generates a baseline map. Its really rich all over the map, but thats to be expected.

Your dying out problem is def because its to rich if you used the baseline map. I had to lean out the lower bins of the map considerably before i was ever able to get a steady idle.

The first thing you want to do is get the car happy with cold starts, and save that tune. Make soo many copys of your tunes, do it every time you mess with MS and date the file names. I lost my best tune on MS, it was really frustrating when it happened. Also, i really wish i had kept a dated log book of how the car acted every time i messed with anything. You will notice sometimes you'll mess with the bins(or idle enrichment, accel enrichment, ect ect) and the car will run great one day, then the next day it will be a PITA to start, or have problems. It would be nice to go back and see what you did that day that had the adverse effect.

[krazydriver]

Lol GUESS TUNED! You make it sound like you got lucky or something.

Granted yeah i did use the megatune autocalc tune feature. But i changed it so much before starting the car that i'll call it a guess tune.

and yes you bring up a very important part about megasquirt. Keeping track of different settings. Last time i had the car running within 2 day i think i'd built up like 15 different files. So dealing with boost i'll be sure to have lots of fun now.

On a side note though..... i'm REALLY pissed with the backup light issue. There's no power going to the connector.. so okay maybe i pinched it/accidentally broke it. But the freaking reverse sensor itself doesn't appear to be functioning properly.

[WDRacing]

When she's up and running I'd be interested in a final price that covered just the MS and sensors required to get it to run properly. I'd be doing what Nate did and just buy the prebuilt box. Mostly cause I'm lazy and have heard nothing bad about any of the prebuilt boxes.

I just wanna compare prices to other systems like SDS.

WD

[krazydriver]

MegaSquirt-II Programmable EFI System PCB3.0 - Kit w/ BLACK CASE : $253.00Prebuilt MS2 with pcb3.0 is $410.USB to Serial Adapter : $20.003/8" NPT Aluminum Weld-On Bung for IAT or CLT Sensor : $9.00GM Open Element IAT Sensor with Pigtail : $22.25

Sub-Total: $304.25 with kit. $461.25 Prebuilt.

Total that in with a wideband, $130+ and that's all you need.You can use the factory coolant temp sensor and TPS. Megasquirts map sensor is on the board so you don't need that.

Honestly the cost isn't bad. There might be better engine tuning solutions. But i really wanted the full DIY approach.

[480sx]

Path of least resistance ftw!

I would also add a few minor things into that cost analysis. You really should get a bunch of different colored wire at different gages for your project. When i wired everything up, all the sensor output wires had a different color wire. I then made a wiring diagram of my engine so if i ever had any problems i could just go back to my diagram and figure out what does what. You dont know a nightmare till you have an electrical issue with 20 different strands of black wire. If you really want to go baller, you can pickup the bulk wire that DIY autotune sells for their kits. Its colored, and each wire is labeled as to what you should use it for.. Pretty sweet, but out of my price range and unnecessary.

Im telling yah, if you really want to make your life simple pick up the relay board for MS. Its going to add 88(was 70) dollars to your full MS price if you get a prebuilt one(however with how easy it would be to solder this thing up you could get away with the kit and a radio shack soldering iron). However, at basically a 100 bucks you really have to think about how lazy you really are, its not needed at all but ensures a clean and reliable wiring job. Check it out

http://www.diyautotune.com/cat....html

You hook all your engines wires to it(the board is labeled, ie. CLT, CLT GND, ect), then run a constant 12 volt, a GOOD ground( i would suggest running multiple grounds), and your 12 volt ignition to the relay board. Then you simply run the connector wire from the relay board to the MS unit in your car.
Modified by 480sx at 9:30 AM 4/26/2008

[krazydriver]

^ I'd really thought of doing the relay board and the wiring kit. But i have a friend who works in a place that makes electrical devices, so he snagged me a ton of wiring, and reusing the factory relays is pretty easy. So that's what i ended up doing.

On a positive note, I've replaced my starter that died on sunday so now she runs again. In doing so i managed to snap one of the connector posts off of my oil pressure sender, so idk what i'm gonna do for that. Along with a slight leak around my turbo drain return bung into the oil pan.

FYI, wideband tuning a 2.5' open downpipe is absolutely pointless. Open DP the wideband never gets hot enough to read properly + with NO backpressure VE is greatly increased. So it's kinda fun listening to the engine and how it idles to figure out what's going on.

My pre-inspection (Return to the roadworthy) list is down to only 7 things.1. Tune Idle/Cranking for megasquirt2. Fix oil Pressure3. Fix my backup lights4. Finish putting the fenders + bumper on5. Tuck the megasquirt wiring into the dash nicely.6. Put the dash back in.7. Fix the slight oil leak around the bung. (Honestly not sure what to do, going to try more silicon). Any tips on this would be appreciated.

[krazydriver]

Everything is finished. Car looks sick and runs pretty decent.Tomorrow i'm going to shoot by the local shop and get it inspected.

let's all hope it passes!Once it does, then i can REALLY start tuning it.

[BACARDI_DWB]

Question for you. since you have gone with megasquirt, did you loose your dash fuction? like your spedo/odometer/tach and other devices or did you leave the wiring in for that? i am a newb when it comes to info that the ECU processes (meaning does the ECU process the SPEEDO and the TACH, or is it done all directly thru the transmission and dash?)

and what manifold is that?
Modified by BACARDI_DWB at 5:28 PM 5/13/2008

[krazydriver]

Only ECU controlled dash gauge is the tach, and it is REALLY simple to wire up megasquirt to control that. Speedo and other gauges are run off a seperate harness and the megasquirt install doesn't play with that at all.

The manifold is a JGS.http://www.jgsturbo.com

[BACARDI_DWB]

so you are telling me that megasquirt is managing your stock tach? that is awesome if that is true!! i was worried about that.

[krazydriver]

yeah megasquirt runs the stock tach.Here's the wiring diagram from the MS2/extra documentation. That pic makes it look scarier then it really is.

[BACARDI_DWB]

That is awesome information. I am going to be doing a project where i am pretty much stripping a 240sx for my datsun truck (ka motor, wiring harness, ecu, cruise controll, transmission, and gauge cluster) and i wanted to make sure that later on after i go megasquirt (doing upgrades in stages due to $$$) that i can still use the gauge cluster that i am going to fabricate into my truck.

Thanks for the info

[jik]

just wanted to say thats an awesome set up and hope everything passes. nice work

[jbenz]

i loved megasquirt on my old car, real easy to work with

[krazydriver]

Well massive fail.....The night before i go to get it aligned/inspected/new tires...... an ugly short rears it's head.

Apparently my coil power wire had somehow grounded out to the coil trigger wire from megasquirt, so not only was the coil grounded like constantly, i think megasquirts ignition circuit is fried. So now i'm going to have to wait a couple days to test/repair megasquirt, run new wiring for the coil, and wait for a new coil to arrive...

Needless to say this really sucks.... Up until tonight, i WAS having fun driving around tuned to ~3psi.

[480sx]

Pick up two VB9's from DIY autotune man, iv burned through one of them myself. They are like 5 bucks and worth having an extra one lying around. If you burned anything out its most likely the VB chip.

[krazydriver]

Yeah the VB is discontinued. They new piece is a Bosch BIP#### MUCH better component.

Ordered them last night, so hopefully i'll have that by wednesday. New coil by tomorrow. Then either tonight or tomorrow i'll completely rerun the wiring for the coil.

Overall it could have been far worse. I know what the issue is, i know exactly where the wiring is, and everything else seemed to still be working. (Needless to say megasquirt is going on the stim for a full diagnostics) I'm still not sure why it would have shorted though, it's sheathed and isn't rubbing anywhere. Maybe there was a break in the wiring insulation that i didn't see when i put it in or something?

[480sx]

O rly.. Is it a direct drop in replacement for the VB? Hah, my MS unit was mounted upside down right.. The thing got so hot (after i left my ignition on all night.. wtf? must of had something wrong with my .MSQ, who knows) that it actually desoldered itself from the board. Also melted the little plastic retaining jobber they use to hold the chips to the board, im sure you know what im talkin about.

EDIT - Hey bud i saw your sig, i have atleast 5 TPS's if you want one ill hook you up. [email protected]

[krazydriver]

^ went and found the full part #. Bosch BIP373 full drop in. Best thing is the new part has a thermal cutoff to keep from smoking itself! Absolute sweetness eh?also gonna shoot you an email.

Yeah so the VB is completely fried. The nylon screw is actually MELTED into the VB... not just melted on it... like the plastics mixed and are one solid piece now.

Went over all the wiring, there isn't a short in the wiring. So... whatever happened the VB melted, this made it so it was constantly grounding. Took just a moment to fry the coil, and then with no current control that's why the fuse started blowing. I

'm going to look over all my dwell settings again to make sure it's not an issue with that, as well as rewire the coil power to come from the fuel pump relay. This way it won't have power until the engine is cranking. Then once i know the car runs, i'll just schedule inspection as soon as possible and hope it makes it that long. lol

[krazydriver]

Alright, spent ALOT of time stim testing and redoing stuff.

VB921 and coil fried because my firmware/msq was corrupted because when i switched from a beta firmware(which was known for corrupting the tune) to the 2.01 release firmware, instead of rebuilding the msq for the new firmware i modified the old one so i wouldn't get errors with megatune. Long story short for some reason this then caused the coil to ground constantly.

Stepping up to today, i've got the BIP373 wired up, i've rebuilt the msq for the 2.01 firmware, I've got the megasquirt sparking on the Stim.... BUT i still get no spark in the car. So i'm going to need to use a test light to verify that it is properly grounding the coil line, and possibly get yet ANOTHER coil because i'm fairly sure the one i'm testing with is dead.(really old coil from my friends junked car)

To some it up.... i'm not very happy with the car at the moment. If i can get the damned thing to spark again, it was running absolutely awesome. so

[1991h9]

Looks good man. I have a huge question to anyone. I`m looking in going ka-t, but i want a good intake manifold, something that looks kind of like an s14 or s15(sr20det), but just able to handle around 350- 400whp. [IMG][/IMG]

[240sxvaj]

JGS log style Manifold like in this guys set-up. Good price and good quality. if you using a t2 turbo then those ssautochrome and ebay works great. If you're having doubt about those T2 manifold then reinforce the welding.

EDIT: sorry i thought you meant exhaust/turbo mani.

***Thread Jack***
Modified by 240sxvaj at 5:05 PM 5/31/2008

[nelson8708]

Looks good man. I have a huge question to anyone. I`m looking in going ka-t, but i want a good intake manifold, something that looks kind of like an s14 or s15(sr20det), but just able to handle around 350- 400whp.

for a intake manifold you options are xcessive, Gato (O&J Performance), and custom for the most part. Not sure what you mean by looks like a sr20det?

[480sx]

If you want a good manifold, stick with the stock one. Its better than the aftermarket ones for anything less than 500 hp.

Also.. If you have a Q, just make your own post next time so we dont steal this guys thread.

[1991h9]

Thank you for the info, i guess i don`t need to upgrade it. Any sites though?