as the title says...how do you do it? i took out my upper half of the manifold off today and i couldnt figure out how to remove te secondaries....can any1 please help? thanx

 

You have an h23 right?

Why would you want to remove the secondaries?

 

Take the upper part off. Then its just a plate that you pull up on and it should slide off. It might be a little tuff bc the gasket usually sticks.

 

just take out the plate and bolt the upper half right onto the lower half? damn...thats easy i thought you took the butterflies out...dumb me...thanks anyways....and im removing them just to try thing out

 

bump for more anwsers

 

The diaphram might get stuck on the FPR depending on what fuel rail you're using... mine did. A new gasket might be a good idea, I belive they're the same part (top and bottom gasket) so you only need one.

Also, the lost plenum volume might have a negative impact on head flow.

Adi

 

so head flow would be decreased? i thought it would increase since there is less **** disturbing it....

im using oem fuel rail will it clear it? i have an aem coming in anyways...

 

you just remove th plate and then put the top part of the intake mani back on,

i can deffinatlye say this is going to hurt your bottom end, and any gains up top are going to be small if any.

honda put the butterflies in for a reason.. just remember that

 

you just pull it off like everyone said, however removing the plate shortens your runner length which leads to less volume which is equal to less mass which is less force which means your intake charge has less force coming into the combustion chamber so after BDC it will not continue to force as much air into the cylinder, I also removed my butterflys but i would not recommend it for most people especially with an h23, the only reason I have mine removed(which i might not even keep it that way) is to see if there are any gains to be made on a highly modified setup on the top end

 

I don't know much about intake manifold sizing except that it's very complex, and that small changes runner or plenum shape/length/volume can have tremendous effects on engine output characteristics.

In theory though, the lack of butterflies should cause for less restriction and some top end gains. BUT what if that same restriction causes a kind of turbulance that results in more efficient filling of the combustion chamber and better fuel atomization?

Still though, you spend less than 1% of you time above 6000rpm and a lot more under 3500rpm, so why sacrifice city driving? Just my two cents.

Adi

 

good point, but i just wanna try it and see....

 

I removed my butterflies but I did not remove the plate, just the individual flaps so that I would not lose plenum volume...

 

^^^ thats what i thought was supposed to happen...how did you remove the butterflies?

 

horrible idea. you say you just want to 'see' ....gonna dyno that?

 

no......not gonna dyno....

 

https://honda-tech.com/zerothread?id=1089260

 

we did this to my boys accord with a 22. we got a little bit more top end, no effect on the bottom end. it does suck up more gas though. not needed really just port and polish the head and port match the manifold to the head. get your throttle body bored this is more money but bigger gains.