Racing Q Overheats on Track

[dgoodno]

:help :help :help :help :help :help :help :help :help Ok, so we have good advice on the camshaft and rear differential. One of the major problems on the track is overheating.

I am very aggressive on track. Either the gas or brake pedal is pushed to the floor. Because of the brake problem mentioned in the last two threads, the engine is often used for braking on the hottest turns [coming off the long straight]. Besides, on most tracks I'm only out of second on the long straights.

I do have the modified chip and therefore run at higher rpm, although even before then they (all my Qs) ran hot on the track.

I have removed the air conditioning and added an air scoop lower front. I had toyed with installing an oversized flex fan along with a number of other options.

What has been done -- and has anything worked? :thinker

[EWT]

:help :help :help :help :help :help :help :help :help Ok, so we have good advice on the camshaft and rear differential. One of the major problems on the track is overheating.

I am very aggressive on track. Either the gas or brake pedal is pushed to the floor. Because of the brake problem mentioned in the last two threads, the engine is often used for braking on the hottest turns [coming off the long straight]. Besides, on most tracks I'm only out of second on the long straights.

I do have the modified chip and therefore run at higher rpm, although even before then they (all my Qs) ran hot on the track.

I have removed the air conditioning and added an air scoop lower front. I had toyed with installing an oversized flex fan along with a number of other options.

What has been done -- and has anything worked? :thinker

If you haven't already done so, run no more than 20-25% anti-freeze and add some Redline Water Wetter, which improves heat transfer. If that doesn't work you'll probably need to get a new oversized radiator, which might need to be custom built, although you might be able to find an off the shelf unit that fits. One thing to definitely not try is to replace the stock engine driven fan with electric fans. They don't move as much air as a good sized engine driven fan no matter how many million CFM they claim to move.

Another idea that is probably needed anyway (do you have an oil temperature gauge?) is to add a good sized oil cooler to provide another way for the engine to dissapate heat.

Eric

[dgoodno]

Eric,

Down to no anti-freeze and liberal use of Water Wetter.

Had considered custom radiator. Any recommended source out there?

The great thing about the Q there is lots of room to add and add . . . I have added the transcooler, but plenty of room to add more!

[EWT]

Eric,

Down to no anti-freeze and liberal use of Water Wetter.

Had considered custom radiator. Any recommended souse out there?

I'd start with Fluidyne http://www.fluidyne.com/ and Griffin http://griffinrad.com/ If you want to kill two birds with one stone, you may be able to get a radiator with an oil cooler built into the end tank, which is really the best way to do oil cooling if you have enough space.

Eric

[dgoodno]

Now that sounds like a cool idea. I have never heard of building the oil cooler into the radiator. :ylsuper There should be enough room, since the air conditioning has been pulled.

[Q451990]

Dennis had a custom radiator made for his Q, but I'm not sure when it was done. Don't forget the slot for the active fluid cooler for more coolers as well. That might be a good location for an engine oil cooler.

Heath

[911/Q45]

I'm guessing that radiator capacity isn't the problem, airflow is. The Q is pretty well sealed up under the hood, so although the air can get in through the front, it can't exit out the back of the radiator very efficiently. Short of cutting a big hole in the hood and ducting out the top, there probably isn't much you can do after the water wetter and antifreeze trick.

[Q45tech]

Just changing from a brand new oem radiator to the custom Griffin unit [all thick aluminum no plastic end tanks no integral ATF heat exchanger 1" thicker and holds another quart than oem] lowered the stabilized running temperature by 5-6F and legthened the temperature rise time at idle by about 15%.

The problem is the Q coolant capacity is nothing like say a MB 500 with is 15 quarts vs. 10 quarts...........an inline extra tank could be designed.

[AZhitman]

Oil cooler FYI:

Summit sells a remote oil filter kit for the 240SX (same mount as the Q). Add an inline cooler behind the lower front airdam, hang your DUAL filters where the battery used to be (please tell me yours has been relocated to the trunk).

[EWT]

I'm guessing that radiator capacity isn't the problem, airflow is. The Q is pretty well sealed up under the hood, so although the air can get in through the front, it can't exit out the back of the radiator very efficiently. Short of cutting a big hole in the hood and ducting out the top, there probably isn't much you can do after the water wetter and antifreeze trick.

I bet radiator size has a lot to do with it. The stock radiator is pretty wimpy. It's not very thick.

[dgoodno]

:nono :shocked2 :nono :shocked2 :nono :shocked2

Az, what can I say. No, the battery is not in the trunk.

[tonytgtr]

Does this mean you want the battery in the trunk. Should I start getting nthe things for that also? Tony

[dgoodno]

I imagine this has something to do with safety -- something that I should know and not have to ask

I have just sent you an email with several items and will get another email off to you in the next couple days with all the recommendations to date.

:ylsuper Thanks Tony, and everyone else that has commented!:ylsuper

[EWT]

I imagine this has something to do with safety -- something that I should know and not have to ask

It's done for reasons of weight distribution, and as a side benefit, it frees up space under the hood that can be used for other "stuff." I've never done it on any of the street-driven track cars I've owned because it adds one more non-OEM thing to go wrong.

Eric

[dgoodno]

I'm pondering the pros and cons. Is there any risk in putting the battery next to the gas tank, or that matter, in the same sealed space (trunk) where fumes could be released?

Would one not also want to weigh each rear wheel point to see if there is currently a weight imbalance between the two sides?

This will add a long cable back to the engine cavity along with weight that it will bring.

Tony, we need to consider all and if we do it, do it with the addition of the needed gauges and starter system.

[AZhitman]

Put it on the right, where the CD changer was (to offset driver weight).

Run a vent behind the gas filler door... Better yet, put in an Optima.

dgoodno, do you have a front strut tower brace yet?

[dgoodno]

Yes, where the CD player was makes sense.

I believe the front strut tower brace was put on with all the suspension work that I did in the beginning. If I did it would have been from Stillion. I'll have to double check. In case I have not, what is the gain -- stability on turns?