Individual Throttle Bodies

[Hjulenx]

I have started this post to track the progress of my individual throttle body project.

Some numbers:
-1981 Fiat Spider
-Rebuilt Head and Engine
-Vick's HC pistons
-IAP 80/40 Cams on both intake and exhaust
-Megasquirt v2.2 w/Extra code
-Ford EDIS Distributerless ignition
-40mm ITB kit from http://www.extrudabody.com
-Weber 300kPa Fuel Pressure Regulator
-Assorted Earl's Super Stock Fuel Fittings and Hose

Progress:
Before pictures

Head Disassembled

Head Removed

PBS Manifold

Extrudabody Kit Layed Out

Manifold Ported

Bench Setup 1

Bench Setup 2

Mounted On Head

Mounted on Head 2

In Engine Bay

In Engine Bay 2

Homemade Vacuum Log

[So Cal Mark]

all that nice fuel/air mix run through a stock cast iron manifold?

[mbouse]

well, i like it.

looks like you spent a lotta time in researching your equipment choices too. very nice. When can i see it in person?

[Hjulenx]

Mark,
I would love to have one of your headers, its just the wallet is a whee bit empty at the moment. Unless you want to supply a slight discount... I am located in Jacksonville, FL; if anyone wants to come by and take a look drop me a line, but I may put you to work.

The biggest issue with the intake manifold was space and I took the if it ain't broke don't fix it approach to it. It really is quite interesting to try and sandwich the fuel rail and fittings in there with the amount of space available. The angle is little harsh for flow on the PBS manifold but I couldn't get anything better by custom making anything myself. In addition, the head has not been fully ported nor have I installed larger valves, to as of right the the intake manifold/throttle bodies far out flow the head in terms of potential horsepower.

Once I get prove of concept, a good tune, and more money, I will fully port the head and maybe put large valves in. The deal is though that this is a fast road car and the modification was more for fun/just to see if I could do it then for massive gains in horsepower. I don't want to more the powerband TOO far north.

The fuel rail originally came 18 inches long put I had it cut down by my machinist to 13 inches to fit in the engine bay. Compression fitting hardline AN adaptors link the stock FIAT 5/16 fuel hardlines to the fuel rail via Earls Superstock hose.

I am slightly worried about the injectors being too big for a smooth idle (MS likes the idle pulsewidth to be about 1.6ms; I will likely be skirting just around there.) To help counteract this I am going to be upgrading to the MSII chip and ExtraII code which has higher resolution and better acceleration tuning algorithms. But then again, I won't know the fuel requirements exactly until I get to tuning. The 'vacuum log' you see if to balance out the manifold pressure pulsations that the ECU uses to tune the engine. Essentially, this creates an artificial plenum to dampen the pulses, though making it too large can introduce lag in the ECU's response. (I have since painted it black and placed it into the spot where the charcoal canister used to be.

The next thing I am toying about doing is making a fiberglass airbox...but I am getting ahead of myself.

[So Cal Mark]

don't misunderstand, I like the project alot! I understand about the wallet

[mbouse]

I'm not getting to Jacksonville any time soon, so you might have to stop by here on your way thru.

and... i am put out. I paint my cam covers and i catch the flames. You paint yours and notta peep.

[mdrburchette]

It's been a while since you've posted and it looks like you've been quite busy! I look forward to hearing how it runs once you've completed your project.

[Hjulenx]

I torqued down the head bolts today but I am having some problems routing the throttle cables. No bigger, but again a space issue close to the firewall. I am thinking about moving the FPR anyway so I am just going to pull the throttle bodies off the manifold to get that work done.

I have been lurking quite a bit. Finished up school and have 30 days leave before I start my temporary duty pushing papers at the recruiting office till October. So in order to keep myself off the streets and off drugs I decided to spend some of my bonus money. My work isn't going to be extremely labor intensive and I will probably only work a few hours a day until the move which equals more time for the girl and more time for the car.

[Hjulenx]

Good stuff today.

Got the timing belt set, exhaust hooked up, all fuel lines cut and run, fuel rail and injectors mounted. I also got the throttle linkage hooked up though I am not really that happy with it so I may redo it in the near future. (It has proved to be the biggest PITA of the project because of how the throttle bodies are set up.)

As soon as I get the coolant system bleed I can get the car running. I also need to hook up the throttle position sensor, run new wires for the fuel injectors, and redo the intake temp sensor wires. (Technically though, I can at least run in the cams and set the idle with what I have now.)

Still a lot can go wrong but so far so good.

[Hjulenx]

Car is running, though I am chasing down some leaks. (tightening coolant hoses ect)

The car is completely wired with the new Microsquirt engine controller, very nice IMHO and a good upgrade from my home built MSI ECU. The extra CPU power is key, and the Tau-X accel algorithms are really going to come in handle once I get there. The microsquirt requires an external Manifold pressure sensor, so I went to the local junkyard and got one for 5$.

I have two problems now that are keeping me off the road:

1. A fuel leak in one of the fuel rail fittings. This is caused by the firewall pressing up against the fuel fitting. This puts strain on the o-ring inside the fuel rail leading to a small leak.

2. I accidentally broke the brake line leading from the master cylinder to the right side front brake. The threads on the fitting are also damaged. Anyone got a new one?

[Hjulenx]

Youtube video (unexciting) of the car idling.
http://www.youtube.com/watch?v=H2lR_x2FvEY

[spiderrey]

this is exactly what my cars next step needs to be.already have the edis ignition . what throttle bodies did you use.if you dont mind, could you be more specific as to what was used and where its available. thanx so much reyy
as for the comment about why this guy didnt get flammed for painting his valve covers. the paint and color he used is something thats been done many times before,since we have all seen it before, its easily accepted.you went down a new road for this crowd, that runs the risk of a good flamming. personally, i do what i want to my car based on my idea of the ideal spider. luckily i havent been flammed yet, but alas, im not done yet. and the vision of my car wont change because someone dosent like it.

[So Cal Mark]

how do those foam filters flow? or are they just used when the engine is off?

[Hjulenx]

Rey,

I did A LOT of research into throttle bodies before I bought this kit...matter of fact I bought another one, and sold it because this one was so much better, and cheaper.

Its the 4 cylinder ITB kit from Extrudabody.com; Kit came with throttle bodies, adapter plates for IDF/DCOE manifolds; fuel rails, fuel rails mounts, filters, throttle position sensor, throttle stop, throttle cam wheel, throttle spring arm, air horns, and joints for joining the throttle bodies together. http://www.extrudabody.com/Products/ITBs.html I got the 40mm, the smallest size they have; which in my opinion is the largest you need or would want.

Mark,

The filters are "Uni filters" custom made for the extrudabody throttles. I don't know much of anything about filters, but these are reusable and fit which is good enough for me. More info here: http://www.extrudabody.com/Products/AirIntake.html

I am toying with the idea of making a fiberglass airbox myself and plumbing it to colder air....but I am not going to get too far ahead of myself.

[So Cal Mark]

nice project, keep us posted with updates. Does it have a similar sound to dual idf's?