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Why did my top speed go down?

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Old 12-29-01, 05:53 AM
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Why did my top speed go down?

Last year, a couple months after I got my car, all I had done to it was a cone intake and a ghetto cold air box and I got it to go 132 before I let off. Now it seems it won't go any faster than 120. My coolant seals are starting to go, but I wouldn't think that would affect it by 12 or more MPH in the top end. I no longer have the cold air box, but I wouldn't think that would affect it that much either. Is my engine just tired? The plan is to get a rebuild with a street port, so that should fix it, but is there anything I might do to restore some power until I get my rebuild? Thanks.
Old 12-29-01, 11:14 AM
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have you recently switched to different tires?

also, sometimes it just depends on the weather. was it more windy that day? i remember one day i got up to 127 in my n/a...then another day i went all out going the other direction on the same highway stretch...only hit 117...oh well...

...when can we EVER explain the way RX-7's act?!?!
Old 12-29-01, 02:38 PM
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Same tires. I've tried multiple times recently in all different kinds of wind, and still, only 120.
Old 12-30-01, 04:03 AM
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Well, I saw an airpump in the pics, but it says 6ports wired open (you do that when you remove airpump on 89+, right?) Is it possible you have clogged your catalytic (like by running w/ out airpump) and this is cooking your seals and lowering performance due to backpressure? BTW, are those speeds in 4th or 5th gear?
Old 12-30-01, 11:12 AM
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Airpump has been on the whole time, auxillary ports have been tied open the whole time, and the cats should not be clogged but I suppose it is very possible. I'm hoping to get a race pipe real soon here, so I guess I will see how that works. Those speeds are in 4th gear. I read on the big list when I first got my car about using JB Radiator Stop Leak to slow the coolant seals from going bad, and I put some of that in about a week ago when I got my oil changed. So far, the radiator is staying full, and no more coolant in the oil.
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