What is the size of the throttle body opening on the skunk2 intake manifold for a 1990 B18a1? I want to upgrade to a throttle body with the same bore as the skunk2 manifold has and can't seem to find the measurements for it. I know it has to be bigger than 58mm which I am pretty sure is the stock throttle body size.

 

The gsr one is 64mm so I'd be willing to bet money the ls one is also.

 

O I heard the GSR LS and RS integras came with 58 and the type R had a 62 and the b20 had a 60...the reason I think this is true is because skunk2 sells throttle bodies starting at 60 and going up and I don't see any reason for replacing a stock 64mm for a skunk2 60mm...I'll do some more research on stock sizes and thanks for bringing that up.

 

KJ was refering to your question about IM opening diameter not TB butterfly size.

 

Yeah I was referring to the opening on the manifold. They are at least 64, might be 66 but I know they are at least 64mm. As far as the TB's a stock gsr is 60mm, stock b18b ls is 60mm also. The old b18a and b16a1 were 58mm, I heard the h22a was 62mm but I measured 61mm with a digital caliper.

 

Alright then when I was researching I must have misread. So I'm guessing that the skunk2 throttle body must be measuring the butterfly size as in the smallest area in the throttle body opening. Is there any stock easy to find throttle bodies that would show a little gain on the dyno without hurting the wallet as much as skunk2 would like to do? I know it wouldn't be much but if I can get like 3 whp on the dyno thats 3 more than I had before I put the part on. My goal though is to get a throttle body that is matched with the skunk2 manifold as closely as possible.

 

You can take a stock gsr throttle body and have it bored to 64mm for about $100-$150. I remember a company called Maxbore that was somewhat local and had a decent turnaround time. Try Honda-Tech.com: Main and searc for maxbore.

 

Ok thanks for the correct info. So realistically if I do obtain a very close match to my skunk2 manifold what kind of power would I expect? I know its low but since it would be easy for me to just throw on a throttle body I figured that it would be and easy gain. I'm talking just whp and tq.

 

ls skunk2 tb flage is 78mm edit intake manifold flange

 

Just make sure the opening on the manifold side of the throttlebody is as big or smaller than the manifold and you are good to go. If the throttlebody is bigger than the manifold then a gasket match with a dremel/grinder and you are good to go.