Civic EG

I've heard rumors about people using the bigger B series throttle bodies on D series motors. Has anyone done this? If so, did you notice any difference in power?
This is my first time owning a D series so I apologize if this is a dumb question.

No such think as a dumb question if you are trying to learn. I own a b18 and a d15 and I was fixen to ask how to do the diy on that but you beat me to it in a way. I heard from other people that they could tell a lil diff but might as well it cant be that hard or hurt it.

i think itd be better for a more forced induction motor or one that will need more air to go through its a pretty much simple swap just make sure you get or make the correct sized tb gasket as well as you will have to port out the intake to get the maximum benifits of doing the swap

I had it on my cx with a z6 motor in it i did feel more pull towards the top end but bottom end lost some power and gas mileage i lost a couple miles but idk if it was my lead foot or not lol...

Classiccarsrule85 wrote:i think itd be better for a more forced induction motor or one that will need more air to go through its a pretty much simple swap just make sure you get or make the correct sized tb gasket as well as you will have to port out the intake to get the maximum benifits of doing the swap

I had it on my cx with a z6 motor in it i did feel more pull towards the top end but bottom end lost some power and gas mileage i lost a couple miles but idk if it was my lead foot or not lol...

Thanks for the information. A friend of mine has a bored out gsr throttle body that I want to pick up but I'm not sure if it is worth it since the rest of the motor is stock. If I have to match port the i/m as it is, I'm not sure if it will be good or bad that the throttle body is bored out.

definately if the tb is bored out its best for forced induction now the ls b18b1 tb is bigger than the stock z6 and probaly as big as you want to go if you where to keep the motor stock. thats the tb i used

If I just swapped my Tb and didn't modify my intake would I still see a difference?

no since if you look at it the tb and intake manifold have a different size hole you would just get the same flow into the intake as you would if you had the stock intake.

We get this question here a lot. It will bolt right on (sometimes you have to swap the studs around), though there are some differences with FITV's with certain throttle bodies.

Yes, there is a power difference. A negative difference. You lose power by putting too large of a throttle body on your engine. It turns out that the best size is the stock size. If your engine is boosted and/or making up and around 300+ hp then I suggest you use a little bit of dyno time and try a larger throttle body.

The engine is only pulling so much air. If you make a bigger passage, you don't increase the amount of air going in. You simply slow the air flow down. Try sucking down a soda with a pvc pipe vs a straw. It requires much more force.

As for the step between the throttle body and the intake manifold, that is INTENTIONAL and very important!! Don't remove it!!! This is an anti-reversion step having to do with the pulse wave tuning of the engine. You lose power w/out it. With this step, you actually achieve some boost pressure at the intake valves at particular RPM.

Pulse wave tuning is a big topic and if you're interested it, you can research it.