Yeah. Me too. I'm pretty sure it's a hair under $5,000 USD for an ITB kit from a reputable manufacturer these days. And that includes the standalone, even.

Heck, wanna go super cheap? 3D print some standoffs, grab a pair of used Triumph ITBs off eBay, build yourself a Megasquirt, grab two Hall effect sensors off Aliexpress, 3D print up a holder for those sensors - use one for a cam sync and the other for a crank angle sensor. Now add a way to convert your push/pull gas pedal into a twisty type (reusing stock components, or once again 3D printing). A little bit of wire, maybe some connector pigtails off the same junkyard Triumph(s), and you've got pretty much everything you need. I'd guess you could get out of it for about $1000-1500 if you've got a 3D printer capable of printing CF-Nylon. There's plenty of ways to save money, just gotta be willing to sacrifice your time in exchange, and maybe learn some new skills in the process. (Me? I'd buy the kit!)

ITBs are not exactly difficult to tune, either. Shared vacuum port means you can use a single MAP sensor and don't have to go Alpha-N. Setting your base map will take about an hour, then you can drive down to the dyno, drop off your car, and let them do steady state tuning over the next ~3 hours or so for a 16x16 map. It's not like a Porsche flat-six is some bizarre exotic engine that requires special care. It's 1960s technology. Tuners have known how to work with ITBs on 911s since the first standalones entered the market.

If you’re the type who can stare at your engine and just love the beauty, then go PMOs. I did and no regrets. If budget, economy, easy starting and tuning are more important, keep the CIS. I have it on my track car and love the reliability.

Looks like the ITB kit from Rasant is around 13k, and Motec / wiring is another 19k. Add some tuning time and extras and I can see you at 28-30k pretty quickly. When I priced out my setup, I looked at home brew / Triumph, Borla, Jenvey or PMO units with a Vems, AEM or PE-LTD ecu. At the time, carbs and a 12 plug dizzy was about 6.5K all in, and most of the ITB / ECU options listed didn't come in too much more. This assumed, you'd build your own wiring harness and make all the other bits to connect it.

You can build an ITB/EFI kit a LOT less than those numbers.

RHD ITBs: $2400 with rain hats, ($2000 without)
Megasquirt: $659
Harness: $99
AFR sensor: $100
TPS: $30
Fuse panel: $20
FPR: $100
Fittings, hoses, wires, etc: $200
Temp sensor: $30

That’s a basic kit that doesn’t control timing, you can add that if you like or add it later.

Total cost $3639. So round up to $4k because I know I forgot some stuff and there you go. EFI/ITB for less than the cost of a set of core carbs.

The amount of money one spends has little to do with the performance of the EFI/ITB setup.

It’s also my understanding or so I’ve read that if I should switch to PMO’s that I would need my distributor recurved?

It's not necessary to recurve them becuase you switched to carbs, but it will improve the running across the RPM and load range.

Understood, and interesting.

How do you put this prescribed dinner table covered in random parts together to function as a system? Are you cutting into the factory harness? Now who is going to tune it for you? What software, what are your fuel and timing tables? My close amigo with 3.6 and ITBs was jaw on the floor when my low-life CIS 3.0 freight trained him on a highway pull... At that moment ...he knew, he needed a tuner. LOL And years later and another $6k on top of his $31k purchase, as mentioned, 43whp less than stock.

I'm simply trying to play devil's advocate for the sake of the OP.

Understanding Rasant offering is top of the line, https://rasantproducts.com/.

Trumpets?...12K 964 or GT3 Plenum style?...$14k Wiring Harness? Pick your flavor between $14k and $21K... Nevermind install and tuning SmileWavy

My personal thought process bottom line... a cobbled together ITB system or even something like Rasant at the highest level, is extremely unlikely to have more engineering knowledge, purpose, and precision than what came out of the Engineering staff in Stuttgart.

Your pricing is way high. Clewett and other ITB manufacturers cost under $4000. There are plenty of other affordable ECU options and a harness shouldn't cost that much to build and install.

I'm paying under $15,000 for my EFI ITB conversion from start to finish for what it's worth and that includes new fuel lines and a new tank.

Ditched my CIS for EFI, mostly because I found EFI way simpler to understand and troubleshoot. CIS was dependent on parts that are getting increasingly more expensive and hard to replace, and there were just more points of failure or wear that I couldn't wrap my smooth brain around. Plus, I didn't have a mechanic that wanted to touch it when it broke.

Cost definitely benefits the DIY versus someone who wants it to just work day one. Some of the off-the-shelf prices seen in this thread are more turnkey than mine was to be sure, but I'm a broke dumb enlisted dude in the military that can barely read and I figured it out just fine. My EFI/ITB setup with ignition cost a little over $3000 3 years ago. I spent maybe a month researching it all and did all the work myself. It fired up first crank. There's a ton of information on the web, and it's really dead simple to troubleshoot in a parking lot, as there's only a handful of super cheap sensors you can find in nearly any auto parts store.

My car is my daily driver here in the UK, started up this morning in the mid 20s (F) first try, no fancy idle valve or hand throttle, just 20 seconds of me giving it some gas after it fired up and some creativity in the tuning. 30k miles on it with the only hiccups being things that were my fault. Small port 3.0 with 964 cams and stock exhaust, dyno'd just shy of 190hp to the wheels, tuned by myself.

Anyways, long story short, if you want to put some effort in, EFI is hard to beat and can be relatively affordable. If you can manage the quirks of CIS, it's very much proven and people still swear by it, but the dwindling knowledge base and parts availability shouldn't be ignored. Carbs are carbs, lots of cool factor and look the part, but I never even considered them.

That’s what my plan is (hand throttle) no idle air control needed with this route.

These fueling debates always make me laugh. The range in prices people mention is huge. It is also true. You really can spend $30-$40K on a setup. Or you can spend $4k:

EFI w/ ITBs can be done for ~$4k. Probably not with new PMO parts or new RHD parts for that matter but i've got 15K miles on my setup. I sourced every part individually and saved a fair amount doing it that way. This isn't the easiest way to do it but might be the cheapest.

Sensors
GM 1bar map sensor
GM intake temp sensor
Subaru knock sensor
3.2 Carrera CHT sensor
wideband O2 that I think was direct replacement for a 350z??? Been a long time...
100psi fuel pressure sensor

Fuel supply
Tomei fuel pressure reg
Used injectors and fuel rail from the used Triumph T595 throttles

Computer/Eng timing/Ignition
AEM Infinity 506
AEM Flying Lead harness starter
AEM EPM (cam and crank sensor in one
Rassant EPM adaptor for dist housing
6 Audi smart coils

ITB's
Closed Course manifolds
used Triumph T595 throttle bodies from eBay
Closed Course throttle linkage setup
PMS Rainhat kit adapted to fit Triumph ITBs with velocity stacks

All of this was around $4000. Got it running pretty well and then spend another $1000 on a dyno tuning for about 8 hours.

This project was the most satisfying automotive adventure of my life. Learned an enormous amount and gained so much confidence and troubleshooting ability.

No. The factory harness remains stock. My car is a 1977 so there was no ECU. Maybe on newer cars this is different... I don't know.
I tuned it with the help of a few Pelicans. Pretty simple to get to 90-95% perfect in a few days. I'm confident I can get close to 100% without a tuner or dyno but if I want, I can go that route for $500 as that's the price I was quoted.
TunerStudio. My timing is controlled by the dizzy but with an aftermarket solution crating a timing map ins't that hard (there are literally dozens listed here on the forums). Fuel Map only needs to get the engine running and then you tune it to your motor; no two engines take the same VE Table.
Sucks for him.
Again, sucks for him.


Honestly, if anyone pays $30k for an EFI/ITB setup, I have a bridge to sell them. The tech had democratized since the big names started offering these kits. All of the prices I listed were accurate as of yesterday and for brand new parts.

Just as there's a wealth of information here and people willing to help when CIS breaks or when carbs need tuning, the same goes for EFI/ITB.... Ask the question and answers will come. I've had several people (Jamie, Ian And Al) all help me along the way and in turn I've helped a bunch of others with their setups. It's not that complicated and aside from the ITB part, literally every other new car on the streets is running EFI and they all seem to work well and have no problem being serviced.

I get the appeal of CIS and carbs. I debated a long time about the switch even after I fixed and tuned my CIS to work perfectly but I wanted something else and the idea of ditching one 45 year old tech (CIS) for another 45 year old tech (carbs) seemed silly.

Each system has its pros and cons, debating them is kind of a waste of time because for each individual there's a different weight to that list of pros and cons; someone may prioritize winter start up more than induction sound... who cares.

But the facts remain that you CAN build a very awesome EFI/ITB system for under $4K.

Agreed. I had a wonderful 3.2 ss in the past I used MS on and it ran wonderfully. Now my plan is to use my fresh webers(relished by performance oriented) as itbs and use the MFI ports for injector ports. If all goes as planned 2500 in parts and my time to tune. That said I will have base maps already as a starting point. BTDT over the years

What're you going to use for a throttle position sensor? Is there something out there that'll bolt on to a Weber? Does the same thing work on PMOs? (Or are you going speed-density or similar instead?)

What to do, keep Cis or go with Pmo’s
 

You can get away without a TPS, yeah it’s helpful for acceleration enrichment but even then if you have a good vacuum signal you can get away without the TPS. Of course if you’re planning on alpha-n or a hybrid ITB mode the TPS is critical.

TPS needed to activate idle tables and for decel fuel cut. I would consider it a required sensor.

Street: CIS
Track car: ITB+Standalone

Carbs look cool but the MPG seems terrible and the performance just isn't that much better unless crazy cam or something. Seems inferior for streetability to CIS, and inferior for performance to ITB + standalone. Very pretty, just..... meh

This is one of those arguments that I just don't understand: with EFI you have comprehensive engine control so you can set whatever tune you want. You can even have different tunes for different situations: one for modest and fuel efficient driving to the track and one for the track that chugs gas. That flexibility just isn't available with CIS (Unless your Ian and have a trick on-the-fly adjustable WUR) or carbs and for that reason, objectively, they are inferior systems.

I'm not crapping on CIS or carbs but there's just no way to have the level of control available with EFI.

But for a street car, that doesn't really matter.

Street car perspective: CIS is reliable, gets decent MPG.

If it's a car that sees the track where metrics are important, sure, go standalone. But I don't really give a care about tuning for HP in a street car. Can't have fun for more than 10 seconds without the fun n*z*s writing you a $275 ticket, minimum.

You tune for more than raw HP, and that just not really possible with CIS unless you’re changing cams and pistons which is major engine surgery.

Look, I’m not saying that CIS is bad, it’s totally fine, there’s just a lot it cannot do and that is leaving performance on the table. And performance isn’t just about raw HP, it’s about fuel economy, throttle response, cold starts, reliability, and scalability; getting the car to perform how you want.

I agree that for most people, including the overwhelming majority here, as long as their CIS is in perfect working order, there’s no reason at all to change; none. That said, there’s really very little that’s logical about using a 45 year old sports car as a daily street car and this coming from someone who does.

To the OP: evaluate what you want out of your car and then be open to the answer borne out of those desires and limitations. You may find one meets your needs more than another.

Everyone here will preach their own gospel and none of that really matters to you.

My main point was to refute the idea that you need $30k for an efi/ITB setup

/out