I have read all sorts of stuff on CAI and Phenolics and I wanted to know what the real temps were under the hood. I guess this might be relative to the season of the year and exactly how hot it is outside in your neck of the woods. Here in Florida it gets.... well pretty stickin hot this time of year. The phenolics claimed to knock off 100 degrees and that sounded a bit much. So I did a test myself.

I discovered that our computer department had purchased a really nice digital infrared temperature gun, complete with laser beam and instruction book. It might help if I read the directions. It takes a series of readings over a few seconds and comes back with average temp, min, max of the spot just above where you are pointing to with the laser beam, so you can get +-2 degree accuracy readings. I was able to pick some key areas to measure under the hood.

First thing, these Crossfires generate a fair amount of heat under the hood. And they keep that heat for an awfully long time. This is the only car I know that has a button you can press that keeps the inside of the car warm for 30 minutes after the engine is turned off by pulling heat off the motor area. They could probably extend that out a few hours with no problem. The engine only looses about 10-15 degrees an hour over the first 6-8 hours at 80 degrees ambient temperature. I like to open the hood to accelerate the process a bit.

Here are some initial numbers I captured right after a nice 30 minute drive home from work at 5pm on a nice 95 degree afternoon (80mph hi-way, then some stop and go). My car has stock intakes (no CAI) with new 3mm phenolic spacers just installed.

Engine exhaust headers - +300 F
Engine block - 220 F
Air filter boxes - 140 F (standard SRT-6)
Upper Plenum - 147 F
Supercharger body - 169 F
Lower Plenum & Y-Pipes - 194 F
Plastic engine cover and air intake tubes - 140 F

The 3mm spacers caused a 47 degree difference in temperature after a 30 minute run. Amazing that there was also a 21 degree difference between the Supercharger body temp and the upper plenum, even though they are side by side.

After 6 hours in the garage, the exhaust pipes that were once over 300 F had cooled down to about 95 degrees, while the upper plenums, now isolated from the block, remained at ~110 F and the SC and block were both 10 degrees cooler at ~100 F.

More later, enjoy the ride.
Karl

 

mine is pretty hot too. I use a fan, ice, and a wall air conditioner to cool it down between rounds.. It's cools the supercharger in about 15 minutes. You can touch the sc with your hand and it's just a little warm if that. This is in over 100 degree weather, and usually I hit the track and it's over 107 degrees. For everyday driving the phenolic spacers will allow you more time to enjoy that power. It will never be at it fastest all the time. Just a downside of having a supercharged car versus all motor power. Just realize that depending on weather conditions your beast may turn into a shy monster, so pick your battles carefully when your car is at it's best. I have ran 13.30 on one pass when getting directly to the track and then cooling it off and run 12.91.

 

I know its weird, but my car runs very consistant 12.20's-12.30's every pass now whether its cold or warm. I don't have that huge variation of ET's like many of you have. I'm not sure what the deal is, but for a supercharged car, it is very consistant!

 

That actually is not to bad for a high performance car.

 

I've been measuring my intake plenum temp before each run at the track - right at the front driver's side corner by the S in the SRT-6.

When the ambient temps are in the high seventies thru low nineties, my IPT (intake plenum temp) is anywhere from 100 to 140 degrees. Last time at the track it was running hot - around 135.

At the track, I generally end up with a 1/2 hour between runs with the hood open - no ice or fans or AC - and the temp will drop 10 to 20 degrees. The temp will spike during the run, sometimes increasing as much as 25 degrees. If I sit one run out and wait an hour with the hood open, I can usually get the IPT down close to 100~110.

Before I added my CAI and the Code3 pulley, I was running very consistent 13.3 ET's. After the CAi and pulley, I ran a good 12.8, but couldn't reproduce it, and my times have dropped back to 13.3~13.5, which makes no sense. I may be going with a Johnson pump and phenolic spacers before I planned to.

I've also noticed that the NeedWings CAI tube heats up quickly, and is often hotter than other surrounding engine parts, such as the intake plenums. I may also wrap the intake tube to help get cold air in.

Distantpulse: no wonder yours is more consistent. You've got a larger heat exchanger, phenolic spacers, a faster (more reliable) coolant pump, and a cold air intake!!

 

Well, as a new owner I can't really add anything except to say that it gets hot under there quicker than anything else I've owned and stays hot for hours longer than anything I've owned. I imagine any improvement at all would result in better, more consistent times. Some of the SRT8 guys are putting thermal coatings on the underside of the intakes as well as phenolic spacer to keep temps down, or so I've read. Again, I haven't looked under the hood much yet, but perhaps thermal coatings in the right places would be an idea worth considering.

 

Distant I think you said you had a PA2 as well. What's the worst da or conditions you have ran in. Mine is a different car in the winter. I'm usually within .03 hundredths during the winter whether I cool it down or not. I don't think you have anything close to my summer conditions.

The car is consistent, don't get me wrong. If you either cool it or don't cool it each pass. It runs slower but very close. 13.30, 13.28, not cooling down. I'm just saying if your heading to the track to put down a number, then it's better to cool down your car completely. If your in warmer weather.

 

Read somewhere, maybe on this forum,that someone drove their Crossfire (SRT-6 I believe) in winter, pulled into their garage, popped the hood and heated up the whole garage.

 

Yes, I do. I believe the temps on the worst day i ran were in the high 80's with fairly humid conditions and the DA was 1800-2000. Not good air by any means, but far from the Arizona heat and altitude you are running at! I feel for ya! Haha. Im pretty sure i was running from 12.29-12.37 that day. Now what is weird is that I went back to the track after that and the weather was a whole lot better(temps-mid 70's, Low humidity, DA-600), but my times weren't that much better. I think my best time was a 12.25 that night.

 

Tom,
I still do not have my spacers, pump and HE installed.

 

My best da in the winter is around 1800-2000. I could only pray for global warming to help snow enter my region and bring my da down to 600. Enjoy that weather and that track. You put down some awesome 60's as well. I said it before and I'll say it again. It's driving. Damn good driving. I think my PA2 would be in shock if it ever reached that low of DA.

 

Haha thanks! I doubt its me, but I have been bracket racing cars for a long time. BTW, what is your best pass in those winter conditions?

 

Try that one more time... in English please.

 

LMAO!! Tom da=Density Altitude....If that is what you are talking about.