Pettit Super Charger Owners
11-13-2010, 04:51 PM
#8129
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A few setbacks today, looks like a little more fab work on the IC tank is needed, not a big deal. OMP bracket needs some fine tuning, no biggie. Its looking like the airbox needs some work also. No big hurdles as of yet.
11-14-2010, 07:46 AM
#8131
11-14-2010, 08:49 PM
#8133
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I think I finally found what kept my engine temps high for the last year or so. No matter what I did (mazmart water pump/thermostat combo, 90% water/antifreeze, water weter additive, aditional rail/pettit radiator, BHR aluminumk radiator, extra electric push fan and 180 degrees oem fans switch) my car ran 195+ under high rev/boost. I decided to move my BHR prototype heat exchanger from the normal radiator angle to a straight flush with the front bumper opening.
To my surprised it made a world of difference. Took the car for a very spirited drive a/c on and a/c off mode and temps never pass over 185 with 174 while cruizing at 70 mph at ambient temps 78 to 80.
To my surprised it made a world of difference. Took the car for a very spirited drive a/c on and a/c off mode and temps never pass over 185 with 174 while cruizing at 70 mph at ambient temps 78 to 80.
Last edited by marsredr100; 11-14-2010 at 08:57 PM.
11-14-2010, 10:28 PM
#8134
a) 195° is, essentially, just warmed up; and
b) 180° or less is too cold to run at full load safely.
A perfect operating temperature (if you could maintain it without fluctuation) would be right at 205° or slightly less in both your oil and water.
11-15-2010, 09:47 AM
#8135
Way to go Juan----i wonder when someone would do this.
Now you can go back with the oem thermostat and take the rail cooler off.
Please do a diy--and tell us what is needed--hoses and mounts?
How are you venting the radiator heat?
I disagree that 185F is to cool to place a full load on the engine.
170 or so is borderline and 160 is too cool, but 185 is sweet. measuring from the hot radiator hose.
Yes you may get better efficentcy at a higher temp, but the lower temp is not neccesarily unsafe.
OD
Now you can go back with the oem thermostat and take the rail cooler off.
Please do a diy--and tell us what is needed--hoses and mounts?
How are you venting the radiator heat?
I disagree that 185F is to cool to place a full load on the engine.
170 or so is borderline and 160 is too cool, but 185 is sweet. measuring from the hot radiator hose.
Yes you may get better efficentcy at a higher temp, but the lower temp is not neccesarily unsafe.
OD
11-15-2010, 05:14 PM
#8136
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Way to go Juan----i wonder when someone would do this.
Now you can go back with the oem thermostat and take the rail cooler off.
Please do a diy--and tell us what is needed--hoses and mounts?
How are you venting the radiator heat?
I disagree that 185F is to cool to place a full load on the engine.
170 or so is borderline and 160 is too cool, but 185 is sweet. measuring from the hot radiator hose.
Yes you may get better efficentcy at a higher temp, but the lower temp is not neccesarily unsafe.
OD
Now you can go back with the oem thermostat and take the rail cooler off.
Please do a diy--and tell us what is needed--hoses and mounts?
How are you venting the radiator heat?
I disagree that 185F is to cool to place a full load on the engine.
170 or so is borderline and 160 is too cool, but 185 is sweet. measuring from the hot radiator hose.
Yes you may get better efficentcy at a higher temp, but the lower temp is not neccesarily unsafe.
OD
The prototype BHR heat exchanger is held at the bottom with one 10mm bolt on each side going thru the plastic of the bottom shroud into two already fabricated bolt holes of the heat exchanger. The top part is held in place by about 1/2 inch top part of the heat exchanger leaning against the opening of the radiator/ac condenser opening. It doesn't move at all but I will add a bracket next week just to be safe.
Radiator heat is vented OEM. I did not use my vented hood during my drive test yesterday but I will at Palm Beach next month.
11-15-2010, 07:13 PM
#8138
Gasoline engines, iron blocks, and aluminum heads. If the "danger to manifold" threshhold is crossed by a mere 15 degree coolant operating temperature difference, something else is awry.
11-15-2010, 07:38 PM
#8140
It isn't the absolute temperature that is the issue. It is the delta and the differential in the thermal expansion.
And it isn't quite the same thing as "iron block, aluminum head". Rather, it is like having a split block with half aluminum and half iron. Nobody does that - except Mazda.
And it isn't quite the same thing as "iron block, aluminum head". Rather, it is like having a split block with half aluminum and half iron. Nobody does that - except Mazda.
11-15-2010, 07:50 PM
#8141
In that case I know of some pretty stellar rotary Mazda engine builders that disagree with your assessment since mid 180s is a fairly standard coolant/oil temp range. If anything the higher temps would be a bigger issue or it could come down to the torque specs used
I did misunderstand your angle though, in my line of work corrosion is my immediate thought when discussing dissimilar metals
.
I did misunderstand your angle though, in my line of work corrosion is my immediate thought when discussing dissimilar metals
.
Last edited by TeamRX8; 11-15-2010 at 07:53 PM.
11-15-2010, 08:01 PM
#8143
ok, guess I misunderstood again, this is straight out of the Mazda racing literature for temperatures
which it sort of disagrees with your coolant/oil temp equality recommendation, they generally recommend bias towards the oil temp
.
which it sort of disagrees with your coolant/oil temp equality recommendation, they generally recommend bias towards the oil temp
.
Last edited by TeamRX8; 11-15-2010 at 08:03 PM.
11-15-2010, 08:17 PM
#8144
could be relevant - maybe ...
https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/cool-vs-hot-acceleration-test-results-101595/
see also post#8
https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/cool-vs-hot-acceleration-test-results-101595/
see also post#8
Last edited by Brettus; 11-15-2010 at 08:21 PM.
11-15-2010, 09:17 PM
#8146
It was definitely written pre-renesis , but is generally used just the same, and it is also strictly racing oriented. Not saying you're wrong, but as we often know even the most experienced experts can often disagree on what is best based on their own knowledge base.
11-16-2010, 08:07 AM
#8147
So Juan---did I misunderstand that this was the oem radiator you vertically mounted?
185-200F for coolant is the generally accepted range here in this area that everyone shoots for. By everyone I mean Racing teams, major rotary engine rebuilders etc. Spikes to 210-215 are acceptable but not to be done repetively. We measure from the hot hose or the ob11 site.
Oil temps that we consider too high is in the 240F max range measured from the pan. We want to measure from the engine to the 1st cooler but we havent fabbed a way to do that yet.
What a number of people dont realize is that if you are measuring oil temps at the oil filter site, that is post both coolers and a 240F reading there is unacceptable. I really dont know the efficentcy of our oem coolers but I try not to go over 210F measured from that site. Its a guess.
By the way --what does the coolant temp in the range we are speaking off have to do with boost versus na? Wouldnt the charge temp be the more important one at these levels?
Now if you are doing repeatively runs to 9K+ rpms the temps are even more critical. Thats a new ball game. We (most of us) are keeping ours to 8-8.2K
OD
185-200F for coolant is the generally accepted range here in this area that everyone shoots for. By everyone I mean Racing teams, major rotary engine rebuilders etc. Spikes to 210-215 are acceptable but not to be done repetively. We measure from the hot hose or the ob11 site.
Oil temps that we consider too high is in the 240F max range measured from the pan. We want to measure from the engine to the 1st cooler but we havent fabbed a way to do that yet.
What a number of people dont realize is that if you are measuring oil temps at the oil filter site, that is post both coolers and a 240F reading there is unacceptable. I really dont know the efficentcy of our oem coolers but I try not to go over 210F measured from that site. Its a guess.
By the way --what does the coolant temp in the range we are speaking off have to do with boost versus na? Wouldnt the charge temp be the more important one at these levels?
Now if you are doing repeatively runs to 9K+ rpms the temps are even more critical. Thats a new ball game. We (most of us) are keeping ours to 8-8.2K
OD
Last edited by olddragger; 11-16-2010 at 08:17 AM.
11-16-2010, 08:22 AM
#8148
11-16-2010, 08:52 AM
#8149
Original Turbo 'd Auto !!
11-16-2010, 09:41 AM
#8150
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As you can see from the first pic the new grounding setup they got serios about it. Heres a few other pics. I should have finished fitting the IC tank before welding but I forgot about that little detail over the past year. Not a big deal though.