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.

 

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?!?!

 

Same tires. I've tried multiple times recently in all different kinds of wind, and still, only 120.

 

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?

 

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.