L28 Engine Build and Triple Webers vs FI ITBS? Is the Price difference justified?

[Ownallday]

Wanted some insight for my future build with the L28, I plan on getting another P79 Head (Previous owner practically screwed the studs for the exhaust manifold closest to the thermostat so I have produced a lovely leak overtime with the annoying clicking sound that sounds like valve slap)

The head will be sent out to be rebuilt and built by topendperformance, I do not plan on building the block (I park the car on the street, don't have tools to pull the block) but I do have the N42 Block for reference

I want to get the new head fully built as possible as I want to push the most power out of building it.

Also will be getting new MSA 6-1 TBC coated headers (will header wrap them) I am sure my pacesetter headers are warped (They look beat up too and recommend to not add header wrap, I want less heat)

MSD ignition system and Ignition upgrade, radiator upgrade, trans rebuild with a lighter flywheel

And last but not least the part I am unsure the route I want to go. topendperformance sells both Triple Webers and Fuel Injection ITB systems (they even tune both systems and have a dyno) The Webers is a little above 2k for everything, while the ITB setup goes for around the 4k-5k mark. My question is how big is the difference between the two systems in terms of power and reliability? Is the almost 3k price difference really worth it? I have a friend who has many issues with his home built 2.9L 45 weber setup and another friend who has not had a single issue in over 6 years with his stock L28 40 weber setup (his webers were tuned by topendperformance also)

Also how much power should I expect from this build? I really want to achieve 250hp at the crank

[Zed Head]

I don't think that your choice is as simple as EFI/ITB or carbs.  If you go with EFI you won't need the MSD igntion, for example.  The EFI will use a crank signal.  If you keep carbs then you'll need to get the right distributor for your timing advance curves.  

EFI will be easier to tune, and will probably be cleaner.  But it has more parts, like the crank sensor, injectors, O2 sensors, etc.

If you go with TEP's system you'll probably need to stay in touch with TEP if there are issues to deal with.  If you go with Webers there are probably more people out there that know how to work on them.  You're planning a big jump from where you're at now.

https://www.racetep.com/automaker/datsun-z/z-car-triple-sidedraft-weber-carb-and-fuel-injection-conversions.html

https://www.borlainduction.com/

[Ownallday]

1 hour ago, Zed Head said:

I don't think that your choice is as simple as EFI/ITB or carbs.  If you go with EFI you won't need the MSD igntion, for example.  The EFI will use a crank signal.  If you keep carbs then you'll need to get the right distributor for your timing advance curves.  

EFI will be easier to tune, and will probably be cleaner.  But it has more parts, like the crank sensor, injectors, O2 sensors, etc.

If you go with TEP's system you'll probably need to stay in touch with TEP if there are issues to deal with.  If you go with Webers there are probably more people out there that know how to work on them.  You're planning a big jump from where you're at now.

https://www.racetep.com/automaker/datsun-z/z-car-triple-sidedraft-weber-carb-and-fuel-injection-conversions.html

https://www.borlainduction.com/

Did not know that. I was going towards MSD everything in terms of the ignition system however in general. My big question is how much of a power jump difference will there be between webers and efi itb setup and without a doubt the efi will probably be more reliable overall but by how much?

 

My plan was either TEP or Datsun Spirits setup. TEP is nice because they are 20 minutes from my house so as long as they don't go out of business I think I should be good. And yeah I know it's a big jump, I figured better to just finish everything in the engine bay rather than work one by one constantly taking things off like I have been for the last two years.

[jonbill]

both EFI and carbs will produce the same power assuming both setup well. As ZH said, the big difference is the EFI can be much easier to setup.

You would need to give more detail on the build specs to be able to talk about how much power it might make.

[240260280]

EFI will work more consistently over a wider barometric and temperature range.

EFI will be easier to tune for most engine load and rpm ranges.

EFI has more parts to purchase, install, and risk of failure.

[crayZlair]

I have the TEP EFI setup on my autocross Z, and I absolutely love it. I started with the Electromotive TEC-GT management system for distributorless Ignition capabilities(crank trigger) along with triple Mikuni sidedraft carbs that I got for cheap. I could not get the carbs to run right under the extreme cornering of autocross (kept wanting to bog, probably float issue). I switched over to the TWM/Borla side draft throttle bodies and everything is so much better! The TEC-GT gave me the option to run carbs or EFI, all had to do was wire the injectors, change the fuel pump and add a few more sensors.

Edited August 5, 2020 by crayZlair
added more for clarity

[conedodger]

Your info says "Canyon Country." I live in an area that could  be called that. I live at 4500' and if I go West, I can get to 8900' within 20 miles. EFI wouldn't care about the elevation but when I had triple Webers, it did get a little dicey. Carbs are often pig-rich to cover up the bad tune. Programmable EFI has a steep learning curve but once you are proficient, you wouldn't want to go back. Imagine driving a 50 year old car with reliability and clean running along with excellent power...