BlacktopSR

Overheating FC3s Rx7 turbo
i have a 1987 mazda rx7 turbo...I have the following enigne mods..
Street ported 13B
TO4E turbo with S5 exhaust side
corksport 3" wide front mount
mazdatrix intercooler piping
hks bov
Rtek 2.1 standalone system
Full turboback apexi exhaust
550cc primary injectors and 1600cc secondary
etc....

now this is my issue...about 2 weeks after i purchased the car it started overheating...the guy who had it before me told me the radiator was bad and it didnt have a shroud fan or belt driven fan but instead was powered by an electrical fan...i hardly ever drive the car and i have never pushed it past 3/4 temp...The following stats are 50psi of oil pressure at idle and around 75psi at full boost, 12.1 across the wideband at full boost and no misfire condition that could make be believe its heating up from leaning out...the overflow tank does boil over and results in an aftermarket overflow tank cap to blow off...the car doesn't overheat at idle and i have even left it running for almost 20mins and still no overheating...its only when i put the car is first gear and drive the car for over 10mins and even if i do a hard pull you can see the temp actually go down until i come to a complete stop and the cars temp gradually starts to clime..i replaced the following parts
installed new OEM radiator
new thermostat
installed fan clutch and fan shroud
brand new electric universal fan 16inches
also p/s and a/c have been eliminated
also turbo exhaust side has been wrapped for heat reduction and charge pipes are about 2 1/2 inches wide
car is running a universal coolant temp sensor which controls the electric fan only and works very effectively

The car won't overheat at idle but starts overheating when i start driving it...The car dynoed 386rwhp and 311 torque which i no is much more than stock oem...I have noticed the follow symtoms which make be have about 4 theories...

1. water pump can be turned by hand even with the belt...now when i pinched the belt and take out some of the slack the water pump cant be turned by hand, so maybe the belt is slipping at high rpms which isn't rotating the water pump fast enough...But i dont hear a belt squeal...theres is now only one belt on the car and it runs the water pump, altenator, and rotor shaft pully..

2. Water pump could be bad but i see no leaks of any sort...which could maybe go back to my original theory...

3. Radiator cant support the amount of power that im putting down and the heat cant disperse fast enough...i currently am running the belt driven clutch fan, fan shroud, and an electric fan at the same time...the radiator that i installed in the rx7 came with another cap which was rated at .9psi which turns the stock one cap housing system into a 2 cap same bar system...i eliminated the radiator cap by installing a sealed cap and ever since i did that the aftermarket overflow tank cap keeps blowing off...the aftermarket overflow tank cap isnt a screw on type....
4. and the worst of them all...Blown coolant seal...There is absolutely no water in the oil and the car does not smoke unless for sitting for a long period of time...and when it smokes it only smokes for about 45 seconds and its not even alot then clears up...






eliminated it down to the water pump and the fact that theirs only one belt system left the alternator belt....so it might not be turning the water pump
we did a flush and the first half of the coolant wasnt boiling but the second half was so im guessing its not circulating like it should..its not blown or anything did a compression test and it came out fine 101 psi....so i completely stump and would greatly appreciate all the help i can get

jackhild59

iTrader: (7)

Damn, now you have three (3) threads on the same thing. I don't understand how you can buy such a nice car, someone else's work, and can't spend the 45$ to put on the double alt pulley that will FIX your trouble. Don't keep asking the same question hoping to get different answers.

Are you ADHD?


You know, you are going to burn this engine up if you haven't already.

You should have bought a stock Honda Civic.

JunpoweR

iTrader: (1)

with a handle like BLACKTOPSR you need to part the car out and build yourself a shitty 240sx!

Turbo II Rotor

iTrader: (2)

Fan is too small, shroud doesn't cover the whole rad, stock rad, stock rad with fmic, needs dual alt pulley and the return hose has a kink in it.