Running Dinan throttle bodies on stock tune?

[bigjae46]

Guys, if I'm planning on returning the car back to stock and installing a set of used stock ITBs, is the BMW procedure to calibrate the ITBs critical or is this something that can just be swapped into place without much issue?

I think that's if you replace the actuator and the arm...I could be wrong.

[E46_M3_ZCP]

Guys, if I'm planning on returning the car back to stock and installing a set of used stock ITBs, is the BMW procedure to calibrate the ITBs critical or is this something that can just be swapped into place without much issue?

[Obioban]

..👍🏻

That's the first thing I said. But he was under a strict contract and wasn't allowed to advertise he did the work much less do any on the side. This was over 15 years ago.

Dinan's old engine builder is building engines to their old specs, Steve Dinan himself started a new company that is offering many of the same services as before... I suspect he'd be okay at this point.

[old///MFanatic]

Sweet inside info!

..👍🏻

He could offer this as a service, where you mail in your existing TBs, and make a fair penny I’d imagine.

That's the first thing I said. But he was under a strict contract and wasn't allowed to advertise he did the work much less do any on the side. This was over 15 years ago.

[Obioban]

Well Yes and No.
They machine and bore out using the stock throttle bodies. But since it's internal diameter is then wider being bored out the butterfly plate won't be big enough to fit anymore. So they machine and make precise fitting new throttle plates (with D on them). Earlier model Dinan BB throttle bodies would also have the throttle arm profiled down so it's overall flow sideways (mostly at WOT) would have less obstruction. But I think they stopped the arm "profiling" for cost reasons. I knew the machinist who used to make these.

He could offer this as a service, where you mail in your existing TBs, and make a fair penny I’d imagine.

[Tbonem3]

Sweet inside info!

[old///MFanatic]

Are Dinans stock parts with material removed (and a D etched in)?

Well Yes and No.
They machine and bore out using the stock throttle bodies. But since it's internal diameter is then wider being bored out the butterfly plate won't be big enough to fit anymore. So they machine and make precise fitting new throttle plates (with D on them). Earlier model Dinan BB throttle bodies would also have the throttle arm profiled down so it's overall flow sideways (mostly at WOT) would have less obstruction. But I think they stopped the arm "profiling" for cost reasons. I knew the machinist who used to make these.

[old///MFanatic]

Can oversized Dinan throttle bodies be run with a stock tune? Probably for a few months before other parts show up. I would use the stock airbox.

I agree, don't see any reason why not. They're not really "over sized" per se, but internally bored out larger for flow.

[pawa_k2001]

Are dinans stock parts with material removed (and a D etched in)? .35lbs of material to be exact

🤣 Yes. I was hoping for 0.50lbs but 0.35lbs is it.

Maybe I should have Lang Racing lighten the cylinder head by port matching the runners.


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[Obioban]

^ that is how they're made, yes.

[Tbonem3]

Are dinans stock parts with material removed (and a D etched in)? .35lbs of material to be exact

[pawa_k2001]

Installing the Dinan throttle bodies, found that they are 0.35lbs lighter than stock. 😀

[pawa_k2001]

Yep - no reason they won't run on the stock tune. You will require a custom tune to get the most out of them but I believe they are also pretty pointless on their own... if you are slowly building up to Cams and Airbox etc then I probably wouldn't bother tuning after installing them, just run them on stock tune until you install something more substantial like cams/airbox/headers to make your tuning $ go further...

Thanks. They just fell into my lap, as in equal trade for my stock ITBs.

[Obioban]

How much did they run you? I’ve been thinking about power upgrades...trying to resist...

Throttlebodies should be the last upgrade you do. They make no power on a stockish engine and not very much over a narrow rpm band on a fully modified engine, while not being cheap and make tuning good drivability in harder... and kind of being a pita to properly install.

last bolt on power mod, after you’ve done EVERYTHING else, imo.

[bigjae46]

How much did they run you? I’ve been thinking about power upgrades...trying to resist...