Interesting pic: Carbon and oil in LIM, also comments on polishing the UIM runners
#1
Original Gangster/Rotary!
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Interesting pic: Carbon and oil in LIM, also comments on polishing the UIM runners
I swapped UIMs last night, and noticed an interesting trend in my intake runners. The UIM mirrors what you see in this pic, and where the TB bolts to the UIM the entire surface area of the runners is the light brown 'oily' color with no evidence of carbon.
Something else very interesting......on the old UIM I had opened up and smoothed out the runners (I did the same to the LIM as you can see in the pic, but I am NOT removing that sob, lol). The new UIM has the stock roughened surface on the inner area of the runners. The car is *much* smoother below 3k rpms now. Previously it has been jerky and bucked on/off throttle at rpms below 3k or so. I attributed this to my portwork/overlap and/or my spec 6 puck clutch. Now I can lug the motor if needed and accelerate smoothly from off idle . Very happy. I assume this has to do with increased turbulence and laminar flow.
Comments, suggestions?
Something else very interesting......on the old UIM I had opened up and smoothed out the runners (I did the same to the LIM as you can see in the pic, but I am NOT removing that sob, lol). The new UIM has the stock roughened surface on the inner area of the runners. The car is *much* smoother below 3k rpms now. Previously it has been jerky and bucked on/off throttle at rpms below 3k or so. I attributed this to my portwork/overlap and/or my spec 6 puck clutch. Now I can lug the motor if needed and accelerate smoothly from off idle . Very happy. I assume this has to do with increased turbulence and laminar flow.
Comments, suggestions?
Last edited by GoodfellaFD3S; 04-07-05 at 11:33 PM.
#6
RX-7 Bad Ass
iTrader: (55)
Easy. You have two sets of throttle plates - primary and secondary. The primary plate goes to the two center "tubes" in the UIM/LIM, and to the two intake ports in the middle iron housing. 90% of your driving on the street will be just on the primary throttle plate - the secondaries will be closed. With the secondaries closed, their intake tract is basically dead space, and gets reversion of oil and gas fumes and other crap.
It's normal, and there's really nothing much you can do about it.
Dale
It's normal, and there's really nothing much you can do about it.
Dale
#7
2/4 wheel cornering fiend
Originally Posted by GoodfellaFD3S
Something else very interesting......on the old UIM I had opened up and smoothed out the runners (I did the same to the LIM as you can see in the pic, but I am NOT removing that sob, lol). The new UIM has the stock roughened surface on the inner area of the runners. The car is *much* smoother below 3k rpms now. Previously it has been jerky and bucked on/off throttle at rpms below 3k or so. I attributed this to my portwork/overlap and/or my spec 6 puck clutch. Now I can lug the motor if needed and accelerate smoothly from off idle . Very happy. I assume this has to do with increased turbulence and laminar flow.
Comments, suggestions?
Comments, suggestions?
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