Dial in and intake manifold temperature

shurite44 · 09-17-2006, 11:38 PM

Last night at dragway 42 a father and son team with two trans ams LS1's were using a laser thermometer to get the temperature of the intake manifold. They were using this for dial in predictions.

They were both on the money. Anyone have any info on this technique?

_twisted_ · 09-17-2006, 11:45 PM

That would require a lot of runs, data collection (log book). It could be beneficial if your hot lapping.

If you can get that temp damn near the same each run, you'll only need to worry about the DA.

shurite44 · 09-17-2006, 11:47 PM

Well that is the thing, they did not worry about DA. They dialed in off intake manifold temp. Was quite easy, I would like to find out more about it.

mackeyred96 · 09-18-2006, 01:12 AM

You can do the samething by just using your temp gage. We all know these LT/LS motors run better the cooler you get them. The problem is keeping them cold if that how you figured your dial. That's why alot of bracket racers will run their car at the same temp all the time, let say 180 deg at the line only because it's easer to maintain. While others like Panuzzo (he's the best at this) will cool his car as low as he can get it for every round, and never want to hit the line higher than 160 deg . Another problem with this is if you go round your motor will heat soak and then you'll have to dial up and that could be as much as .1 for every 10 deg above you best runs at 160 deg.

shurite44 · 09-18-2006, 01:22 AM

Nope, fellows I am not talking about improving the consistency of the car by launching at a certain coolant temp. I do that. I rarely have more than 3 degrees fluctuation of coolant temps.

I am talking about calculating the dial in based on intake manifold pressure just prior to staging using a laser thermometer on the intake manifold. This is done instead of not in addition to taking weather readings for the DA or HP conversion factors.

I am curious if anyone else has info on this. They claim more accuracy than using DA.

Any thoughts or links to this technique?

shurite44 · 09-18-2006, 01:24 AM

Quote:

Originally Posted by jd_v3tt3

It could be beneficial if your hot lapping.

.

By the way, they left both cars running while setting in the staging lanes. I never saw them turn them off.

Face · 09-18-2006, 02:37 AM

I guess they were trying to keep all fluids the same temp, pass after pass. Pretty good idea measuring the intake manifold temp though.

As for hot lapping, my E.T.'s usual decrease, not increase.

REDGAR · 09-18-2006, 11:55 AM

Are you sure they were predicting based on the that or just checking it for logging?

shurite44 · 09-18-2006, 01:01 PM

Well I think at a certain point they were logging some numbers. But they continued to open the hood even when we were slowly moving up to stage.

I talked to the Father and he said this, "We use this to dial in our ET, it is more accurate than taking the weather."

But they did have an ambient wx temp gauge on the pillar also. It worked basically like the vettes temp gauge for outside air temp. But their focus was on the intake manifold.

They ran well, that is why I would like to know more about it. I guess I could just start logging these temps myself and see how they correspond to ET.

Just thought I would mention it here because I have never seen this technique. I was an aviator for 22 years so I really enjoy the performance calculation side of racing.

ralph · 09-18-2006, 03:48 PM

I would think DA would be more important than manifold temp. It's a good idea to try to maintain consistent conditions, incl manifold temp, but a 5 tenths drop in the barometer, is going to make a difference regardless of the manifold temps.

shurite44 · 09-18-2006, 03:54 PM

It would seem so to me also.

But these guys were no dummies, so I would guess they have some sort of wx back up or something.

What I liked about it was the simplicity.

I know for a fact these guys were in the money a couple times, once they walked off with the first place 3K prize this summer. So like I said it is probably worth some investigation.

kazman · 09-18-2006, 04:21 PM

I think they are playing head games with you and everyone else with ears shot. Intake temp is important but you can't just forget about air temp, bar pressure, wind, clouds, dew point, etc. I not only keep the water temp the same for every run but the oil and trans temps too. I never cool it down but keep it running to come up to racing temps.

shurite44 · 09-18-2006, 08:07 PM

No, that is not what was going on.

Anyway, nevermind.

mackeyred96 · 09-18-2006, 08:36 PM

Quote:

Originally Posted by kazman

I think they are playing head games with you and everyone else with ears shot.

Ya, I was going to mention that also. That’s one of my favorite things to do.
I would add switches under the hood, extra hoses, wires ect. Anything to make people think I was doing something special, and it was all for show. I’ve even once before a final round laid under my car in the staging lanes looking at the rear, just laying there. Didn’t open the hood, just made out like there was a problem with the rear. I just want to get into my opponents head I may have a problem. Why, if he thought I had a problem he might not try to cut a tight light not wanting to foul , knowing I might not make it down the track and it was all bogus.
There are 100s of things like that you can do to get into your opponent head.

shurite44 · 09-18-2006, 08:47 PM

Holy sh!t, I should have known better than to start a thread in here.

Ok, fellows I am going to jump back on my turnip wagon and go home.

Please let the thread die.