Vacuum operation under boost..
 

As soon as I convince myself that D15B3 (B2 w/ carb) will keep running I'll plant my GT15 under the hood but I got some questions in mind, hope you can help.

1st; has anyone boosted a carburated D series engine? Are there common problems to be solved or known and accepted?

2nd problem is kinda tricky; as you know carburators run using low pressure - high pressure flow dynamics, i.e. my motor has 2 main vacuum centers and lots of tiny lines connected to those low pressure centers and running to auto choke system, 2nd barrel vacuum etc. All those stuff works when there exists enough low pressure (vacuum). One of the vacuum centers (that provide low pressure to above mentined lines) is located behind the intake manifold. Question is that, when I apply the boost, there's gonna be high pressure instead of low, my shity vacuum operated 2nd barrel (or whatever else stuff) won't work! Damn I wanna be wrong, please someone come out and say that there will be enough pressure drop when engine sucks the damn boosted air.

This thing has been bothering me for over a year, I've asked whoever I could and of course could not get a satisfactory answer.

All your expriences and opinions will be greatly appreciated.

Thnx..

Re:Vacuum operation under boost..
 

why don't you swap a si head onto it and change ecu's to go with it. That way you can have efi. fuelinjection is sweet compared to carbs. I think depending on what year or setup is, that you would haev to get a electric fuel pump. Your setup is so foreign I don't really have any advice other than swap to fuel injection to give you. just buy a b18c and turbo that. might be a first from where you are.

Re:Vacuum operation under boost..
 

For the carb setup all you need to do is box out the carb. Basically you place the entire carb under pressure just like it normally is(atmospheric).



Mike

Re:Vacuum operation under boost..
 

Do that, or go EFI. you can get the intake manifold from any 1.6 DOHC CRX or Mpfi 1.5 vtec engine that comes in the 92-95 civic LSi or the 4th gen 1.6 16v SOHC civic's. those or the common cars in europe with MPFI