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I just finished the last bits of the Mishimoto radiator install this morning. See pics below. I'm pretty happy with the first results. I may have finally ended my 7-year battle with excessive engine temperatures, on my '96 Cobra.
Some relevant details:
-All temperature measurements were taken with my full-sweep Autometer temp gauge, as well as via datalog on my SCT tuner.
-My Autometer gauge, with the sender mounted in the stock crossover location, always reads 4-6 degrees hotter than the PCM datalog readings. I actually just replaced the original ECT sensor this morning, and that delta remained the same. So for example, when the ECU commands the low speed fan on at 208, my Autometer gauge reads 212. (I suspect this may reflect the actual difference in running temperatures between the two heads).
-I recently removed my "performance" chip, which returned my fan on/off speeds to stock (low speed on at 208 degrees, and high speed on at 228, I believe). For years, I'd had them programmed to come on about 13 degrees cooler--mainly as a band-aid. Also, I was happy to find that the car seems to run better without the chip--pulls harder, and runs more consistently.
-Years ago, I'd swapped out the dense '96 AC condenser, for a less restrictive 97+ unit. This did very little to improve my operating temps.
-A week ago, I replaced the original fan with a stock replacement unit--just because I thought I should. This made no difference in engine temps.
The results so far:
After getting the last of the air out of the system, I drove the car for about 40 minutes, in 85 degree weather. Driving around town, with no AC, and some stoplights, per the gauge, I ran anywhere between 198 and 213 degrees (so 194 to 209, according to the computer). This was about how it ran before--which seems normal, I'd say, with the stock thermostat and fan settings. Around town, the biggest difference I noticed with the new radiator was in how quickly the engine would cool itself back down--either from the fan turning on, or from getting the car moving again. Also, if I could keep moving, the motor ran at around 203, and the fans would never run at all. This was never the case with the old radiator.
Then I turned the AC on, and took the car on the freeway in 80mph traffic. This is where it gets good. With the old radiator, under these conditions, within just a few miles, I'd see temperatures of 230 degrees on the gauge (or 225 according to the computer). That's about as hot as I'd ever let it get, before I'd always turn the AC off, and just suffer (and even then, the temperature would only slowly drop several degrees). Mind you, I'd see these temperatures even driving gently/carefully.
With the Mishimoto radiator however, under the same conditions, the temperature rose to about 211 as I blasted onto the highway, but then within a mile or two, rather than just getting hotter and hotter, actually began to decrease. This was unheard of, with the old radiator.
In short, when I would have normally been running at 230 degrees (per the gauge), I stabilized at right around 208 degrees (or 204 according to the computer). That's 22 degrees cooler than with the old radiator, under similar conditions. Even when I'd downshift into 3rd and hammer it a bit, the temperature still stayed under 210. I'm very pleased so far. I'll give more updates on the performance this week, during the heatwave.
By the way, the install wasn't bad at all. The one thing nobody told me though, was that you have to cut a notch in the lower beam of the radiator, so it will clear the overflow tank prop-rod mount. (Wish I took a picture of the notch I cut, but it didn't occur to me. I used a small cutting wheel, and cut an inch and a half rectangle out of the sheet metal on the bottom of the radiator). Anyhow, once I figured that out, the install went pretty quickly.
Edit: I recently learned that there may be two different styles of prop-rod mount, used on these cars. Mine is a big round cylinder, with a bushing in the center, and the rod through that. I saw one online the other day, that is supposedly OEM, where the rod just mounts on a flat plate. I guess if you have that kind, you might not need to notch the bottom of the radiator. Not sure though.
Thanks again.
Tom
With stabilizers
With fan
Old vs. new
Thickness comparison
Old radiator thickness. (The Mishimoto is spec'd at 1.57" thick).
Mishimoto mounts.
I just finished the last bits of the Mishimoto radiator install this morning. See pics below. I'm pretty happy with the first results. I may have finally ended my 7-year battle with excessive engine temperatures, on my '96 Cobra.
Some relevant details:
-All temperature measurements were taken with my full-sweep Autometer temp gauge, as well as via datalog on my SCT tuner.
-My Autometer gauge, with the sender mounted in the stock crossover location, always reads 4-6 degrees hotter than the PCM datalog readings. I actually just replaced the original ECT sensor this morning, and that delta remained the same. So for example, when the ECU commands the low speed fan on at 208, my Autometer gauge reads 212. (I suspect this may reflect the actual difference in running temperatures between the two heads).
-I recently removed my "performance" chip, which returned my fan on/off speeds to stock (low speed on at 208 degrees, and high speed on at 228, I believe). For years, I'd had them programmed to come on about 13 degrees cooler--mainly as a band-aid. Also, I was happy to find that the car seems to run better without the chip--pulls harder, and runs more consistently.
-Years ago, I'd swapped out the dense '96 AC condenser, for a less restrictive 97+ unit. This did very little to improve my operating temps.
-A week ago, I replaced the original fan with a stock replacement unit--just because I thought I should. This made no difference in engine temps.
The results so far:
After getting the last of the air out of the system, I drove the car for about 40 minutes, in 85 degree weather. Driving around town, with no AC, and some stoplights, per the gauge, I ran anywhere between 198 and 213 degrees (so 194 to 209, according to the computer). This was about how it ran before--which seems normal, I'd say, with the stock thermostat and fan settings. Around town, the biggest difference I noticed with the new radiator was in how quickly the engine would cool itself back down--either from the fan turning on, or from getting the car moving again. Also, if I could keep moving, the motor ran at around 203, and the fans would never run at all. This was never the case with the old radiator.
Then I turned the AC on, and took the car on the freeway in 80mph traffic. This is where it gets good. With the old radiator, under these conditions, within just a few miles, I'd see temperatures of 230 degrees on the gauge (or 225 according to the computer). That's about as hot as I'd ever let it get, before I'd always turn the AC off, and just suffer (and even then, the temperature would only slowly drop several degrees). Mind you, I'd see these temperatures even driving gently/carefully.
With the Mishimoto radiator however, under the same conditions, the temperature rose to about 211 as I blasted onto the highway, but then within a mile or two, rather than just getting hotter and hotter, actually began to decrease. This was unheard of, with the old radiator.
In short, when I would have normally been running at 230 degrees (per the gauge), I stabilized at right around 208 degrees (or 204 according to the computer). That's 22 degrees cooler than with the old radiator, under similar conditions. Even when I'd downshift into 3rd and hammer it a bit, the temperature still stayed under 210. I'm very pleased so far. I'll give more updates on the performance this week, during the heatwave.
By the way, the install wasn't bad at all. The one thing nobody told me though, was that you have to cut a notch in the lower beam of the radiator, so it will clear the overflow tank prop-rod mount. (Wish I took a picture of the notch I cut, but it didn't occur to me. I used a small cutting wheel, and cut an inch and a half rectangle out of the sheet metal on the bottom of the radiator). Anyhow, once I figured that out, the install went pretty quickly.
Edit: I recently learned that there may be two different styles of prop-rod mount, used on these cars. Mine is a big round cylinder, with a bushing in the center, and the rod through that. I saw one online the other day, that is supposedly OEM, where the rod just mounts on a flat plate. I guess if you have that kind, you might not need to notch the bottom of the radiator. Not sure though.
Thanks again.
Tom
With stabilizers
With fan
Old vs. new
Thickness comparison
Old radiator thickness. (The Mishimoto is spec'd at 1.57" thick).
Mishimoto mounts.
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