Author Topic: Exhaust temp questions  (Read 7800 times)

Offline Supercat

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Exhaust temp questions
« on: August 07, 2014, 03:46:08 PM »
We are still running rich with our car ,injected alcohol.
What is a ball park temp for the exhaust using a thermal gun to check temp.
We were at 214F. at the elbow( 3" from the flange) after a good warm-up in the pits this past week in Ohio.
Car ran well but as I said still rich.
Thanks for any info.
John

Offline masracingtd1167

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Re: Exhaust temp questions
« Reply #1 on: August 07, 2014, 04:06:49 PM »
How hot the pipes get when warming it up is really not much help for tuning . If you were taking egt's going down track I would say around 1100 ish but I don't really pay much attention to them . If it's not building heat during a run it's too fat !

Offline GlennLever

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Re: Exhaust temp questions
« Reply #2 on: August 07, 2014, 04:38:27 PM »
EGT's are hard to tune by, to fat and you are burning fuel in the pipe. It is better to read the plug after a run.
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Offline Supercat

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Re: Exhaust temp questions
« Reply #3 on: August 07, 2014, 05:50:52 PM »
Before the racepak stopped working properly we were around 375-425F on the pass.
The reason I made the comment about the idle is, we are use to warming up the car when we had the smaller Nailhead in the car,it was much hotter at the pipes during the warm up.
We have the car ready to run at Orlando this week if the weather cooperates.

Offline wideopen231

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Re: Exhaust temp questions
« Reply #4 on: August 07, 2014, 05:57:49 PM »
mpt sure where you are reading but sounds funny.425 is way beyond fat. I would thing raw fuel coming out pipes fat. Like Bill said normally 1000 to 1100 depending on where you read and how setup is.

Maybe a call to Spud is in order here.If nothing else go to his site sign up and use his calculator,Maybe not dead perfect but it will get you real close. When get back from weekend call him about having system flowed.
« Last Edit: August 07, 2014, 06:00:36 PM by wideopen231 »
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Offline Supercat

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Re: Exhaust temp questions
« Reply #5 on: August 07, 2014, 06:29:18 PM »
Spud has been in contact with me on the base tune up for the car.
Being that this is a Buick that exceeds the normal flow for them, we are just playing it safe as we narrow down the tune. We make 2 passes before we make each adjustment and record the info.
Last week we ran 3 passes at 8.229-8.250 @ 167-168.1 with 1.21-1.23 60'
Going through the lights at 6400rpm
We will be changing to a 31" x13 tire trying to get the rpm up.

Again trying to learn the tuning variances used as ways to double check things.
Thanks everyone for the info.
I had ordered another box of plugs earlier today.

Offline Cajuninjector

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Re: Exhaust temp questions
« Reply #6 on: August 08, 2014, 05:02:52 AM »
We read egt's in each pipe and launch close to 1000 deg.
By the end of a quarter mile run they're about 1300.
We have the air bleeds  that install under each butterfly so it's easy to tweak the temps so they're all equal at launch.
 
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Offline JrFuel Hayden

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Re: Exhaust temp questions
« Reply #7 on: August 23, 2014, 09:35:45 AM »
I have found when using my infared temp gun, the zoomie temps vary depending on the coatings on the pipes. I have had my pipes, chromed, VHT painted, High Temp ceramic coated, and even raw. I use the temp gun during warm-up to adjust the injectors to get them even temps. The EGT temps will vary depending on cam timing and yes tune-up. 1300° is too high for my combo, but some cams with more overlap can put too much fuel in the pipes and burn the alky in the pipes, so you can get higher EGT's. That's why it's hard to compare different racers EGT.
The best is to read your spark plugs, I use NGK because they are cad plated, and will burn off showing me how much heat I'm getting on the plugs/ in the motor. I have recommended to other racers that when they are working on their tune-up to install at least one new plug for each run so you can see what's going on. Example 1'st run of the day put a new plug in # 1 hole, 2'nd run new plug in # 2, etc. Just keep track of which cylinder has the new plug, I have a tool tray with S-plug holders, I just keep the run plug in the tray to remind me which has the new plug.

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