sloweh3

I recently picked up a 92 si hatch w/ an obd0 b16 swap. The car acts really sluggish up until around 4-5k. I was wondering if the intake manifold and throttle body combo was too big for the motor.

Currently it has a BDL 68mm throttle body and an aebs intake manifold, port matched to the throttle body. The intake manifold has also been cut open and ported more, then re-welded back. I'm not sure how much was ported though. I was wondering if this combo was too big for just a stock b16. Thanks.

BlackoutVTi

You sound like you may benefit from portmatched intake ports on your head, and a polish job inside. Do you have an intake that will allow the increased flow of the IM and throttle body?

The sudden steps between diameters that your intake air flows past may be causing critical turbulence.

Also, you may want to check your TPS, as that can be a cause for your engine to attempt to pull timing at innappropriate times, causing the engine to seem suspiciously sluggish.

sloweh3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlackoutVTi &raquo;</TD></TR><TR><TD CLASS="quote">You sound like you may benefit from portmatched intake ports on your head, and a polish job inside. Do you have an intake that will allow the increased flow of the IM and throttle body?

The sudden steps between diameters that your intake air flows past may be causing critical turbulence.

Also, you may want to check your TPS, as that can be a cause for your engine to attempt to pull timing at innappropriate times, causing the engine to seem suspiciously sluggish.</TD></TR></TABLE>

I'm running a j's racing intake (the big whale *****)

ddd4114

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlackoutVTi &raquo;</TD></TR><TR><TD CLASS="quote">The sudden steps between diameters that your intake air flows past may be causing critical turbulence.</TD></TR></TABLE>
Who said that's bad?

68mm is probably too big. What intake manifold and cams are you using?

Also, port-matching the throttle body to the intake manifold without an anti-reversion step will extend the intake manifold plenum into the intake piping. This eliminates the possibility of taking advantage of captured pressure waves. As a result, you will lose potential power.

sloweh3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ddd4114 &raquo;</TD></TR><TR><TD CLASS="quote">
Who said that's bad?

68mm is probably too big. What intake manifold and cams are you using?

Also, port-matching the throttle body to the intake manifold without an anti-reversion step will extend the intake manifold plenum into the intake piping. This eliminates the possibility of taking advantage of captured pressure waves. As a result, you will lose potential power.</TD></TR></TABLE>

AEBS intake manifold and stock cams. Internally, the motor is stock, it's just bolt ons that were put on before I bought the car.

ddd4114

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sloweh3 &raquo;</TD></TR><TR><TD CLASS="quote">AEBS intake manifold and stock cams. Internally, the motor is stock, it's just bolt ons that were put on before I bought the car.</TD></TR></TABLE>
How does the intake manifold compare to stock?

I'm almost certain that the throttle body is too big, but I'm not familiar with the intake manifold.

sloweh3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ddd4114 &raquo;</TD></TR><TR><TD CLASS="quote">
How does the intake manifold compare to stock?

I'm almost certain that the throttle body is too big, but I'm not familiar with the intake manifold.</TD></TR></TABLE>

I believe that intake manifold is just a little bigger than an itr intake manifold, but since it has been ported more, the ports are bigger than one you would buy from kteller.

ddd4114

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sloweh3 &raquo;</TD></TR><TR><TD CLASS="quote">I believe that intake manifold is just a little bigger than an itr intake manifold, but since it has been ported more, the ports are bigger than one you would buy from kteller.</TD></TR></TABLE>
I would call them to see what they recommend.

sloweh3

ok, thanks for the help

Redbone

I thought that PNP the head without upping the compression would actually be detrimental to making more power? What else have you got done to the motor?

sloweh3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redbone &raquo;</TD></TR><TR><TD CLASS="quote">I thought that PNP the head without upping the compression would actually be detrimental to making more power? What else have you got done to the motor?</TD></TR></TABLE>

just a stock internal obd0 b16. DC Sports 4-1 2.5" header, Omnipower 2.5" test pipe, Apexi NOIR catback, AEM Fuel Rail and regulator, J's Racing Intake, and a street tune on chrome

ddd4114

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redbone &raquo;</TD></TR><TR><TD CLASS="quote">I thought that PNP the head without upping the compression would actually be detrimental to making more power?</TD></TR></TABLE>
It depends on the port job.

You can gain or lose power with porting/polishing no matter what setup you have. It depends who's doing it and how good of a job they do.

sloweh3

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ddd4114 &raquo;</TD></TR><TR><TD CLASS="quote">
It depends on the port job.

You can gain or lose power with porting/polishing no matter what setup you have. It depends who's doing it and how good of a job they do.</TD></TR></TABLE>

yea, i just found an itr intake manifold and tb for a pretty good price, so i'm gonna pick that up now and sell my old setup. hopefully after a retune i'll have much better results