V8 Throttle body manifolds

Do those throttle bodies have fuel injectors built in? Or will there be a boss on the adapter?

 

Ambitious project. Good luck, I will follow

 

What injectors where you thinking of using?

 

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Kev,

Just as a SWAG (Scientific Wild Ass Guess), what is your anticipated 'Price Target?'

 

Having done this type of conversion recently on our 4L build, my hats off to you on this. It should pick up decent power on a stock engine, the bigger issue you'll run into is off-idle tip in and idle itself. Large TB's on these small engines result in very hard to control air flow dynamics.

Also just as a friendly heads up, it looks as though you're a business, nice restoration work BTW, love the use of 3D scanning tech. Anyway just tread careful on posts offering sales when you're a business and also not a subscribed member.

 

I can't speak for the OP but I would hazard a ballpark in the ~5k USD range to also cover EFI at the very least. Having done this exact setup on our 4L build I have a really good handle on the costs and all the little details to make it a 'swap' over. It's not cheap. It really cleans up the engine bay but there is a lot of parts that get removed and a lot of parts needed to make it fully functional.

The real bugger is that 3D printing is cheap for prototyping, we use it a lot. Final machining on a 5-axis mill is expensive. There are now materials for 3D printing that would work for final product in an engine bay environment but the costs of them are just as much if not greater then machined metals unless it's a really complex part. 3D printing is the future and it's frustrating that it's not developing faster to make it more cost sensible for small run custom work.

 

Do you think 40mm DCNF TB's would be appropriate for the 3.2L (328)?

 

Carbs are a bit different then EFI TB's. If you're talking about the weber carbs then no, the 40mm is not big enough, 42 minimum or 44 preferred.

For EFI TB's a 40mm throat is just fine. It'll come down to the idle circuit and progression holes if any for controlling off-idle response.

The more common EFI TB's like found on German marques is 50mm that's a massive TB's and the only reason it works just fine on the small displacement engines like BMW and Audi etc.. that they use drive by wire throttle control and variable valve timing.

 

Yes, was referring to Borla/TWM DCNF TB's, specifically.

Gracias

 

were u running a idle circuit on your 4L built motor?

you can print 3D adapter parts to use as a casting pattern, it would save dramatically on milling time and do without a 5 axis. the bonus would be a period correct look without a shinny billet look for those who care about aesthetics.

I too i prefer focusing on high charge velocity with smaller TB's rather than high volume flow at peak rpm for the last few ponies with large tbs. i stop monkeying around with DCNF 40, 42, DCOE 40 45 and IDF, IDA 40 46 for nearly 2 decades now

im not sure if the if the drive by wire and the variable valve timing is the ONLY reason you can get away with large TB's. plenty of kids are running smoothly with 51mm tb's on sk2's without fly by wire or variable advance/retard valve timing. mapping and idle circuit are the key.

folks are also removing the throttle by wire on their e46 s54 motors for a cable system. some are doing it to save on cost of repairs while others want do away with the soft factory programed tip-in throttle response and to run a stand alone. they say e46 ecus are notoriously difficult to piggy back though i have no personal experience with this.

 

Hi Kev,

Those pistons. Custom?

 

splendid looking motor and facility! thanks for sharing. can we get some numbers off of the dyno before and after?

 

interested in that too! You Plan to do a small batch in the future? or offer as a set maybe. Would be very tempting..

 

Just to follow... looks very nice.