Just to make it clear, I did not get my throttle body from Milspec. But I will talk to him about getting the right paint.

 

dsevo - to clarify, you should NOT use RTV on the butterfly and from my experience the OEM butterfly should seal fine...there are several ways to adjust idle and I would recommend going that route over paint / other....

 

I understand that, but I have a ported throttle body which doesn't have the OEM butterfly. The butterfly is slightly too small which is allowing too much air passed the butterfly, making the idle settings and idle control stepper worthless. When my tuner was tuning my car he told me that was likely the issue, then when I took the throttle body off, sure enough he was right. He lowered the idle settings and the idle screw as much as possible, and it didn't change the idle at all, meaning that air is getting into the motor some other way. He also showed me a stock throttle body, and the throttle plate let almost no light through, where mine shows light all the way around it. Furthermore, the stock throttle bodies are sealed with this paint that I speak of, and mine doesn't have any.

 

When I opened my throttle body I was under the impression the black was carbon build up from blow by entering the intake. Particulates are bound to deposit themselves in turbulent and slow moving areas. It would make sense the throttle body would be such a spot. To the OP why don't you ask the vendor to supply a properly sized butterfly? Maybe irrelevant but every butterfly I've seen has an intentional gap (flat spot) at the bottom to supply a base amount of idle air which is then added to and fine tuned by the idle circuit or throttle stop.

 

The deposit thing is a misconception, it is in fact applied at the factory. I have PM'd the vendor, I'm waiting for a response. The evo tb does not have a flat spot on the butterfly.

 

dow produces a moly spray. i forget the actual name / product code.

i have been using this now for about the last 40-50 tb's.

it allows me to run a slightly larger blade to housing gap, then i make up the difference with the spray.....the tb bodies get distorted a bit my t-bolt clamps, bolting onto the int mani, distortion when relasing the bolted housing from the machining fixture, etc.....

GL

 

i got my tb from buschur , and had no paint , and u cant see anylight either , im i ok ??

 

^ some are fine, some are not.....everyone is trying to hold such a tight tolerance between the body & blade in attempts to gain idle speed control....but yet, not have them bind / hang-up from the closed position.....

I've experienced a few issues as well...you just correct them to your best ability & learn from it.

 

Aby, Is it possible to purchase a 65mm tb plate from you?

 

Good info. Any chance you can find out the name of the Dow spray? I looked on their website, but I couldn't find anything. Where do you buy it?

 

so this is only done to tb , that u can see the light thru the butterfly ???

do u have a pic on a comparison after fixed ???

 

Just close the biss to compensate. Or you can run in open loop and lean it till idle comes down to where you want

 

The biss is closed all the way, and the car still idles at 2k rpm. The weird thing to me is the car idled at 1k rpm before switching out the injectors and getting it tuned. I think the gap on the butterfly is too big, but I also think there must be another issue because the idle is so high. This is driving me crazy, and I gotta figure something out in the next couple days.

 

321 you can get it at Earl's Indy on Gasoline Alley

 

Awesome thanks.