Post your ITB Setup

[Jjm4life]

Originally Posted by MrBonus

Damn, that thing is a work of art.

thanks a lot. im hoping it runs as good as it looks

[wallra]

here is my 964

[MrBonus]

Originally Posted by ToySnakePMC

Love seeing updates and pics on this thread - one of my favorites. Planning to sneak by the shop and see Mr B’s air cooled toy sometime this coming week.

Sweet! It’s running and waiting for fine tuning on the dyno.

[thetorch]

1969 911T

3.4 liters
Rasant throttle bodies, crank and cam sensor
Modified 964 intake
Motec M84

[PeteKz]

Side question: I have the complete carburetors (40IDTP.3C), throttle linkage, air filter box, etc. system from a 1969 911. I have listed it for sale in the local PCA region, to clear it out of my garage. I have CIS on my 3.2 engine in a 1973 911T, which I like, but sometimes I wonder about installing an ITB FI system. Would there be a good reason to keep the air filter box from the 1969 carb setup for future ITB system? Or should I just sell the whole carb setup complete and buy what I need if/when I go to ITBs?

[MrBonus]

Originally Posted by PeteKz

Side question: I have the complete carburetors (40IDTP.3C), throttle linkage, air filter box, etc. system from a 1969 911. I have listed it for sale in the local PCA region, to clear it out of my garage. I have CIS on my 3.2 engine in a 1973 911T, which I like, but sometimes I wonder about installing an ITB FI system. Would there be a good reason to keep the air filter box from the 1969 carb setup for future ITB system? Or should I just sell the whole carb setup complete and buy what I need if/when I go to ITBs?

My Clewett system came with its own filters and hats. My exact same carburetors will be sold with their air filter and hat setup.

[rswannabe]

Originally Posted by PeteKz

Side question: I have the complete carburetors (40IDTP.3C), throttle linkage, air filter box, etc. system from a 1969 911. I have listed it for sale in the local PCA region, to clear it out of my garage. I have CIS on my 3.2 engine in a 1973 911T, which I like, but sometimes I wonder about installing an ITB FI system. Would there be a good reason to keep the air filter box from the 1969 carb setup for future ITB system? Or should I just sell the whole carb setup complete and buy what I need if/when I go to ITBs?

The 40mm carb manifolds, linkages, and air box would all be usable with a set of 40mm PMO itb’s. They won’t work with any itb’s other than PMO though. The linkages and airbox can also work with 46mm pmo itbs. I run just that setup on my 2.8 short stroke motor in my ‘69. I’m a fan of running the old airboxes, but I’m in a minority there I think.

You could sell the whole setup and just buy what you need at the time if you ever go to itb’s.

[Showdown]

RHD ITBs running Megasquirt.
Otherwise stock engine for now (Melissa/M1 cams to come…?)
Plenty of custom fabricated/modified bits and pieces.

[Hulley]

Originally Posted by Showdown

RHD ITBs running Megasquirt.
Otherwise stock engine for now (Melissa/M1 cams to come…?)
Plenty of custom fabricated/modified bits and pieces.

Looks great, Julian, love your build!

[r_towle]

Originally Posted by Clay Perrine

I recently purchased a 935 Style flat fan for my 4.0L 964 motor. So now I can't use the factory intake or throttle body assembly. So I decided to go ITBs, coil on plug, and MS3Pro injection.

I found two sets of BMW K1300S Motorcycle throttle bodies that came like this:



I cut them apart into individual throttle bodies, removed the studs and tapped the stud holes to M6x1.0.

I already had a set of MFI throttle bodies that were so corroded that they could not be saved. So I removed the throttle shafts and linkage from the MFI throttle bodies. I opened the slots on the shafts, and the BMW throttle butterflies fit perfectly. I had to cut the end off the shaft from one of the BMW throttle bodies and weld it onto the MFI throttle body shaft so I had a TPS drive. I pressed the cross shaft bearings out of the plastic MFI stacks for reuse as well.

Using a sheet of plywood, I built a jig to hold the throttle bodies in place with the fan so I can build the linkage and wiring harness before tearing apart the current Motronic setup.

Some time spent with Fusion 360 and a purchase from Send Cut Send, and I now have this:









I still have to make the correct length linkage to go from the crossbar to the center throttle bodies. And to do that I have to buy a M5x0.8 left hand thread die. I considered drilling the throttle bodies for idle air bleed screws, but I can compensate for that with the MS3Pro programming.

This setup is going in my 914 chassis, so it will actually go in with the crossbar at the flywheel end of the motor. I am going to make a throttle cable mount that will attach to the 4-6 side throttle bodies so I can hook directly to the crossbar with no additional linkage.

Clay,
Where did you get the fan shroud?

[ChrisHoover]

Originally Posted by chrisbalich

There's been a lot of discussion about power increases (expected vs realized) and about drivability.
But I just got back from a 60 car rallye in the mountains of WV and I can assure you all of the ITB/EFI guys got markedly better fuel economy than the CIS guys. Doesn't sound that important until you get to the bottom of the mountain on Monday morning to tank up and head home and find there is no gas at the station. I wasn't worried as I knew my 1/2 tank would easily get me to the next station. My friend next to me in a CIS car was worried. (we did both make it to the next fuel station)

The main reason I’m interested in ITBs is fuel economy. My 1966 2.7l weber 40 gets 16 mpg. Any idea how much an improvement ITBs will offer?

[na2ub]

Where is everyone running their O2 sensor into the engine compartment? I have a ‘79 with no prev O2. Through the engine tin? Thanks! Gratuitious pic of my almost ready to install engine.

[rwest]

Doug,

I ran my O2 alongside the left hand heater hose by undoing the hose and feeding either end through the hole and then it’s just the wire thickness alongside the hose.

[SiracHaile]

What is everyone using for cylinder head temperature sensors and mounts.

I’ve seen the one on Turbokraft but it’s very expensive. Any other alternatives?

Thanks

[Showdown]

Check out Chris’ Low Budget Dream Car Build thread; he fabricated one fairly easily (I think it was last winter or spring) and thus far it’s proven to be quite effective.

[MrBonus]

Just got my car back from Erik at Sport Purpose Garage who installed and tuned my Clewett ITBs with Masters ECU. 160 WHP but way, way better road manners and torque, especially at partial throttle. Super super happy with how this turned out versus my old Webers.

If you're looking for someone to install and tune one of these setups, I'd highly recommend him. Super communicative, works very fast, and does fantastic, clean work.

[Mixed76]

That's a very clean setup.

Sent from my Pixel 7 using Tapatalk

[cmpski]

There is a lot of beautiful eye candy on this thread!
Here is my POLO 4 banger built in 2011. It has 23,000 miles on it now.
The latest ones being built by tuners like Jerry Woods and others are now getting 230 to 250 hp. See the second set of numbers.
The upper graph is of an engine speced close to mine. Mine has had head work done to my 993 heads with titanium valves and the dynoed engine has stock 993 heads. Dean guessed this engine makes maybe another 10 to 15 hp.
I've tried to keep a period look in my 67. Here is a newer vintage look product from Jenvey.
https://store.jenvey.co.uk/heritage/heritage-ida-pair-throttle-body

[OSC911]

Lost for words, that is absolutely beautiful.

[Jim2]

Never get tired of seeing pictures of your engine. What displacement is your engine, and the 249 HP engine in the second graph?