3.6 ITB Project
 

Noticed a few threads lately about various ITB installations so I thought I'd show mine.

I'm a turbo guy and this is the first non-turbo car I've built. The car itself is a partnership with my race partner who is 74 but remains a hardcore Porsche nut. This ITB motor was destined for our RSR replica race car but the project stagnated a number of years ago. The motor had been overhauled but needed ITBs, injection, exhaust etc etc.

A couple months ago we picked up a local track rat roller figuring it would be an opportunity to complete the motor and tune it. If the day comes that the RSR replica is completed the motor will be complete, tuned, and ready for installation.

I'm a fabricator of sorts and my objective as usual is to spend as little money as possible by building whatever parts as I can. The ITBs are hand built using donor components from junk yard throttle bodies, throttle shafts, butterflies, shaft bearings, return springs, levers, ball socket joints and cross shaft are donors from some old MFI TBs which had corroded bodies.

The TB id is 49mm and tapers down to 44mm at the port. Overall length of the TBs is 12". The motor is a 964 platform mildly ported, some cam which Dema Elgin suggested, and stock pistons, rods etc. Won't be twisting this one very high with the stock rods and bolts.

Injection and ignition will be controlled with SDS EFI and though I'm expecting to use throttle position input as opposed to manifold pressure, I'm going to try to tune using MAP but won't be surprised if the results are poor due to lack of vacuum signal. I built manifold vacuum ports along with a small accumulator but don't know if this will be effective.

Headers are 1.75" OD primary shorties connected to a *cough* bursch muffler with a 2.5 superflow can. The partner wanted a modified factory 2 in/ 2 out but I talked him out of it in an effort to save my hearing.

Anyhow, here are some pictures I grabbed with my phone.


http://forums.pelicanparts.com/uploa...1341975407.jpg

Here's a shot of the car, a local friend built it and ran it for a few years before selling it. Big torsion bars, sway bars, polybronze, 930 brakes, fuchs/BBS 17x8 and 17x10.
http://forums.pelicanparts.com/uploa...1341975891.jpg

http://forums.pelicanparts.com/uploa...1341975937.jpg


http://forums.pelicanparts.com/uploa...1341976146.jpg

Here I mocked up the installation on my work bench so I could figure out how to orient the lever arms and return springs.
http://forums.pelicanparts.com/uploa...1341976571.jpg

This is prior to welding on the velocity stacks, and no butterfly shaft. Straight shot to the intake valve!
http://forums.pelicanparts.com/uploa...1341977023.jpg

http://forums.pelicanparts.com/uploa...1341977536.jpg

Only a few items remain before it runs, wiring, vacuum hoses, install O2 sensor, breather hoses, oil, gas. Hopefully by the end of the week.

Back to work.










.

looks great, Al, you seeing this??

I'm seeing and I'm really liking it..........love the DIY aspect...very nice work. What are the t'bodies originally from? . My experience leads me to believe that your MAP signal should be ok, using the accumulator. If you get low or no MAP signal......check for vacuum leaks......and then check again.

Please keep us posted regarding the tuning using the SDS unit. I have been using Megasquirt and EDIS with very good results, but I'm always interested in alternatives. We EFI/ITB/DIY guys have to stick together and compare notes.

Here' a link to my you tube channel for a peek at my various EFI projects....and others.

koz77911's channel - YouTube

Nice................

regards,
Al

ps: James, where have you been hiding...............stop by and check out my new ride.

PSS: Jamie...are you checking this out?

Very cool.

That looks like MFI linkage welded onto the existing arm. Very cool.

Are those welded to a factory 3.6 injector base? They look the same but I thought they were plastic.

Argh...must......not......look. :)

That car is really nice and the color is stunning. Love the ITB's. What did you get the ITB's from?

Jim...mad skillz..............Awesome project.

regards,
Al

'I am a fabricator of sorts'

understatement of the year.

looks very cool - love the color on the car too.

Nice, I need to hone my skills on the Bridgeport and do something similar. :).

There has to be an EFI'd motorcycle out there with the right TB size?

From another "fabricator of sorts", love your ideas and workmanship.

A few more hours in today, might even run tomorrow! Looking back, this project was a bit of a haul and I didn't really get my head wrapped around it until the last couple weeks when I could see the light at the end of the tunnel.

Bill, I haven't looked at your project lately, is it running yet? I recall your project looked well executed.

Tippy, fire up that machine or send it my way! BTW, I did some searching for TBs and didn't find much suitable other than what Al discovered. My partner already bought a box full of these Hyundai TBs so I felt compelled to try and make use of them. He was hinting at just making some adaptors to connect up to the factory plastic 964 stacks but he didn't realize that the TBs were simply too big at 53mm. I put my head to it in order to see if I could make use of the parts and realized after I built one unit, the other 5 were simple since the process was established. However I discovered the details are what took the most time.

Amazing work, thanks for sharing!

Mind sharing where you are planning to install the O2 sensor?

Thanks in advance,
Ben.

Jim,
My 3.6 ITB project is sitting under a cover in a corner of the garage all ready to slip into my Carrera, however I have been sidetracked doing an engine-out fix of a few annoying oil leaks and a general clean-up on my 930 (and working for a living).
I love your method of spinning the velocity stacks. It's enough to make me want to start another ITB project!

I think you've made this project of yours look way too simple - like it's 5 minutes work to make up smaller butterflys, another few minutes to make and fit the internal sleeves, then maybe ten minutes with the die-grinder removing all the unwanted appendages on the ITBs!
Jim, you really have to stop making this stuff look easy. :rolleyes:

Bill, it sounds like you have your hands full with two cars on the go, I know the feeling,... now! I normally try and avoid having a second hobby car, there's enough projects to keep me busy with just one car (currently my turbo'd 993).

Contrary to the way it may appear, nothing went fast on this project, though motivation was certainly a big issue. Gone are the days when I used to work on these projects from 7 in the evening to 3 AM then get up and go to work at 6. Now I'm lucky if I can get my lazy butt off the couch and go into the shop on a week night. Burnt myself out abusing sleep.

I'm definitely more motivated during the summer and that's when I did the bulk of work on this project. One thing I'll say, it's deceiving which aspects absorbed the bulk of time hand building these parts. Lots of planning and head scratching to determine how to construct the parts, but not much time doing the actual construction. Final details also ate up many hours. Once again, the construction, machining and welding are something I do regularly.

Flatsix, I'll take a picture of the location where I stuck the O2 sender and post it up for you.



Happy to say, IT RUNS!!


My partner and I cleaned up a bunch of loose ends over the weekend and finally we were ready to run the motor at 7pm yesterday. Since this motor was fresh we pulled the plugs and turned it over on the starter until we had oil pressure for about 20 seconds. After a couple minor wiring snags we ran the fuel pump for a minute to get the air out of the fuel system. Hit the starter and the motor fired up after about three rotations, idling on it's own! We stood back and looked at each other somewhat shocked. All we had to do was turn up the idle stop screws a little. Having not worked with ITBs I presumed the motor would be idling rough and coughing but this was clearly not the case. One of the guys at SDS preprogrammed the ecu with values which he thought would get the motor running, certainly worked well.

We proceeded to calibrate the timing for the SDS computer then watched the AFRs which were fat, in low 10s, leaned it out a little and the idle picked up. Did a quick test with an old fashion unisync tool and adjusted the idle stops but haven't locked down any of the throttle rods yet.

After a quick shutdown to look for leaks we restarted and then of course cracked the throttles a few times, all I can say is Porsche music! It revs really fast. Tue or Wed I'll complete the sync of the throttles and lock all the rods then clean up a few loose ends with the wiring on the left frame rail. Install the air cleaners and drivers seat and it should be ready to drive and start tuning. I'll report back, and maybe add a video if I can figure out youtube.

Engine bay is done except for the air filters and the bit of wiring on the left frame rail. I managed to cut out some of the reverse light wiring and had to undo my wire wrapping to sort it out.

Thanks to the following guys for supplying various mechanical parts to put this thing together: Andrew15, Unclebilly, Haycait911.





http://forums.pelicanparts.com/uploa...1342503124.jpg

I need to clean the glue off the firewall and clean the frame rails, had lots of opportunity to do this while the motor was out but I guess it fell off the list. Also the wiring in the left front corner looks pretty busy but this will get cleaned up now that I've figured out what I did wrong with my reverse light wire. The panel in the left front holds a map sensor, high idle air bypass, two relays for the coil driver box and coils, and the air temp probe which is visible just forward of stack #3.

Looks like I also need to install a breather hose on the oil tank, forgot about this. Picture seems to make the engine bay look busy with wiring and plumbing but it's actually tidy when looking at it look.
http://forums.pelicanparts.com/uploa...1342503188.jpg

I mounted the ecu on the virtical panel behind the drivers seat. The PLX box operates the wide band O2 and is needed to process the O2 signal being delivered to the ecu. The relay provides power to the ecu and PLX. One in-line fuse for both devices as well. The hand held programmer for the ecu is connected via the white cable on the left. It will get removed once the programming is done.
http://forums.pelicanparts.com/uploa...1342504552.jpg

I have a load of pictures taken during assembly and various mods to things like headers and such. Lots of work I've forgotten about!

When I grow up, I'm going to be a fabricator of sorts...TOO!!!!

Mighty nice...

Larry

+1

check out his pictures of the build at the bottom of his page. under RSR project, fantastic job Jim

+1

My favorite understatement from the Man-of-few-words Department:

"Spun the velocity stacks"



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I for one would like to know more about the flaring Jim:

1) did you make that die that is holding the tubing and helping set the flare?
2) is the die in two pieces and sized so it clamps the tubing?
3) is that a bearing on the end of your tool to roll the flare?

Thanks!
Chuck.H
'89 TurboLookTarga, 336k miles

Wow. Great skill here Jim.
Always impressed to see all the parts people makes themselves.

Man of few words.... and dirty fingers.

I've been messing around for years building stuff, but I never really deviate from metal working. I'm envious of people with other skills like woodworking and fine carpentry, they can contribute to a household. It's pretty hard to impress the other half with a velocity stack.

http://forums.pelicanparts.com/uploa...1342843803.jpg

http://forums.pelicanparts.com/uploa...1342843865.jpg

http://forums.pelicanparts.com/uploa...1342843883.jpg

http://forums.pelicanparts.com/uploa...1342843910.jpg

http://forums.pelicanparts.com/uploa...1342843927.jpg

Intake for some guys 8 cyl home built plane
http://forums.pelicanparts.com/uploa...1342843973.jpg

Sled intake (Snowmobile 460hp)
http://forums.pelicanparts.com/uploa...1342844046.jpg

Back on topic:

I ran the motor for while on Wednesday and started tuning but realized I have a loooong way to go before it's drivable. Very deceiving, it starts, idles, and revs beautifully, but then put in under load and the AFRs are all over the place. This is going to take a little while to refine as compared to the plenum style intakes I've dealt with in the past.

I've also had to spend a number of hours the last few days trying to find a better switched power source. The current power source I'm using is what I believe used to energize the DME relay in this car, but I discovered that once the alternator kicks in, the switched power source remains energized even with the key removed, effectively like it's being back fed by the alternator. Found another small blk/Red wire in the engine bay, it too is switched but also appears to get back-fed by the alternator. I don't have a schematic for the car so I'm trying my best to determine a suitable source from the key switch to energize my ECU relay. I posted another thread asking for some help from someone who might have a schematic (86 Carrera). I'm all ears if anyone can point me to a clean switched source on this car.


http://forums.pelicanparts.com/uploa...1342845020.jpg

Hey....I am very impressed. Mad skillz. Turned into a very clean machine. Look at that engine compartment. It is the business. (the UniFilter socks look great too!)

Congrats...now the fun begins.

regards,
Al

Al, not sure if you recall but I asked you for a referral on the filter socks on one of your threads. The Uni filters were priced right at $17ea versus about $50ea for some others I was looking at. Thanks for the advice.

Jim,
I do remember. The UNIs are priced right, look great on your intake set up and should work well.

A related follow up: One of my buddies has one of my EFI/ITB set ups on his engine and was asking my ideas regarding rain shields. We are located in the Pacific Northwest, so it's a reasonable and practical thought. Damn...i hate to be practical and I hate to mess up the clean, simple lines of the ITB filter set up, but I'm looking at making/sourcing some caps that will fit over the top of the UNI-Sox, to act as rain shields. Something discrete, that won't detract from the cool ITB set up.....and still allow plenty of air intake/filtered surface area. I've used the 906 rain shield repops and really like them, but this time I'm thinking more along the lines of a simple cap that covers the top and extends down the sides 1/2" or so...perhaps flared out a bit....to keep the majority of the rain out. What do you think of this idea?

Keep up the good work.

regards,
Al

Jim2 - are you running the coils off the DME harness along with the ECM? If so, I had the same problem of the engine continuing to run after key was off.

The fix; hook the coils to the original power wire and all was well.

Yes, the idiot light keeps the system running after key off explained to me by "scarceller".

Al, regarding rain shields can you tell me the outside diameter of your filter socks? (Somewhat accurate)

Tippy, I deleted the entire factory wire harness and relays pertaining to the motor and ignition, everything is now custom. My power supply for all aspects of the efi/ignition is taken direct from battery with relays switching each device. I just need to locate a clean switched circuit which is not back fed by the alt to activate my relays. Your note about the idiot light has been discussed and we feel it may be related to the back-feed issue. Anyhow, I did a search of Scarceller's posts and found your thread. It may well provide what I need as Scarceller says fuse 8 is switched and supplied the factory dme relay! I'll check it out tomorrow. - Thanks for the feedback, I feel like this may solve my problem. Sure sounds like you had a go round with your issue!

Just to clarify, I hooked the Ford EDIS coils hot to the factory coil power wire and all was good.

I like the fixture you made to make the bell mouth of the trumpets - mental machining note. :)