I've heard different things about the GSR manifold.

1) If you get an ITR ecu, the secondary butterflies will not operate.

2) The butterflies will work fine, it is vacuum controlled.

Can anyone help me out here? I'm interested in an ITR ecu just for temporary use.

 

from what i've heard they are run by the ecu so NO they will not work.

 

Well, the secondaries are physically opened by vacuum (or actually a lack of vacuum), but the signal that controls the vacuum comes from the ECU. The ITR ECU has no provision for this signal, and the secondaries will not operate unless some other method of sending a signal is installed (e.g. an RPM controlled switch).

 

what he said

 

I have some interesting thoughts on this GSR manifold secondary butterfly thing.

Keep in mind this was in my car with my particular mods (ITR cams, etc.) Your mileage may vary!!!!

After installing my DC JDM header I incurred a flat spot at 4400 or where vtec kicks in.

While I was tinkering with cam gear settings I decided to disconnect the secondary butterflies and see how she did. What I felt...no loss in low rpm power (say before 4400) from 4400 to about 5000 dead spot like before, then from about 5100 and up to 6000 it simply rips. The GSR butterflies normally don’t open until 5750. My car really responded to the secondary’s opening up in that 750 rpm range.

Remember this is on my vehicle so your mileage will vary. As far as it being fact that you will lose 10 ftlbs from having the secondary butterflies open all the time, that may be true with GSR cams but the ITR cams on my car liked more air all around.

After talking to several people (including Erick himself from EricksRacing) he told me my vtec needs to be raised to 5100. I am having my GSR P72 chipped by EricksRacing. They have a chip that works well for ITR cams in a GSR with GSR intake. He said the best solution would be a skunk2 intake manifold and vtec set around 5700-5800. That will be a future project (probably when I build the 2.0 liter)

As for now I'm just going to chip the ECU for 5100 vtec x-over and keep the GSR intake. I will make sure to test the new ECU chip with the secondary's connected and disabled.