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View Full Version : EGT And the "Hot Juice" question



Duke
05-22-2003, 13:20
I am about ready to order the Hot Juice and some guages from JK. To be honest I have neven even ridden in a Dmax that has been chipped but all the recomendations I have heard here and the ET numbers guys are seeing at the track pretty much speak for themselves.
My question is this: I keep reading and hearing you shouldn't run the hot juice without gauges but I am am curious of how hard you can typically push the truck before these dangerous exhaust temps are reached. Can you typically "stand on it" from 0 to speed limiter, run a complete quarter mile, 5 city block stop lights ? In other words in a non-tow mode, what scenario puts you into a potential heat danger zone??

CanadaKev
05-22-2003, 14:10
Duke,
JMHO
It would be almost immpossible to reach dangerous EGT levels in non-towing situations.
But I would still recommend increasing air flow.
(intake & exhaust). Talk to JK about this.

The last two loads of heifers I have hauled(27,000 CGVW), I ran in level 4 HOT.(I know, not recommended but I was curious about EGT's). I only had two short hills to pull(both approx. 2 miles long, 11% grade) but I had my foot into it. Max EGT 950(post turbo). I think airflow must have a lot to do with keeping EGT's down.

A real test would be a 15 mile 7% grade.

Kev

Duke
05-22-2003, 15:06
Thanks for the input Kev. If you can pull all that on a 11% grade for two miles I would agree it would be virtually impossible to run into a heat problem with the truck hauling only itself around.

Kennedy
05-22-2003, 15:29
My observations have been that if you tow with the torque of the engine you'll be fine. If you tow with the HP (foot on floor above 2700 RPM) it will get a bit warm.

I run a very fast acting probe, and can see some pretty high numbers (over 1400

TST Tech
05-22-2003, 15:43
Hey guys!
We've had a lot Duramaxes on the dyno here that run amazing cool for the amount of power they put out. The only problems we've encountered is with the turbo's. We've had two let go at about 40 psi pretty consistantly. Gauges are a great ideal for any disel truck, even if you don't do much towing. Keep on truckin! Greg

car of the week
05-22-2003, 16:24
Question for all:

You all seem to have relatively low EGT's. I have the Autometer gauges with the probe in the exhaust manifold and under hard acceleration i can see temps to 1600* unloaded. Is this normal? if i were to do a quarter mile, i would easily read 1600+. Should i worry?

Regards,
Ryan

imported_
05-22-2003, 16:36
Duke,

I rarely tow, I installed gauges before my other mods. It gave me a base line of what the stock truck did and what it is doing now. I have my probe in the exhaust manifold, commonly known as the "hoot" position.

Before any mods I had a hard time hitting 1200 in the 1/4 or 0-WOT runs. And if I did they were very short. I cruised at 120km/h around 700-900 degrees.

With the hot juice, Amsoil filter and swiss cheesed air box and straight pie, I can get 1450 for short bursts (3-5 secs)in the 1/4 mile and at WOT. My cruising temps are 600-800 at 120km/h

Gauges gave me an apreciation of what I am doing to my truck. At 90mph I run at 1000 degrees. I have often said to myself that's 400 degrees hotter then at 70mph and backed off. 400 degrees difference has to do things to the longevity of the turbo, oil etc. It might be in the safe range, but it does get you thinking about what is going on to get those 1000+ numbers.

[ 05-22-2003: Message edited by: Big Blue ]</p>

mackin
05-22-2003, 17:59
Ryan

Them are some HIGH numbers .... Definitely not normal, down right NFG .... I have to believe it is a faulty gauge and or probe .... Or something went wrong during the install ....

If your Max was really experiencing them temps I think you would have a whole lot to tell us ...

I would try a new gauge or probe,for sure .... Unless your running some fancy stuff like JK .... But even he hasn't reported them high numbers just with Hot OJ ...

Mac ;)

[ 05-22-2003: Message edited by: mackin ]</p>

CanadaKev
05-22-2003, 21:55
Greg,
How the heck do you get 40 lbs o' boost.
Mine max's out at about 25 psi :confused:

Kev

mackin
05-23-2003, 04:59
CanadaKev

You don't want to know ... :eek:

Are you wastegated ?? Go plug it and get a free cell intake,oh ya you have one ....Go climb a hill with your foot in it ,maximum performance setting ....
Scatter ..... Scary... But like I told "Mr Mopar" (Amianthus ) my gauge doesen't go that high so I have nothing to worry about ....We agreed .. LOL

Mac

Mac :D :D :D :D :D :D

[ 05-23-2003: Message edited by: mackin ]</p>

TST Tech
05-23-2003, 07:25
CanadaKev,
The 40 psi that we saw was when the truck was straped to the dyno under full load with the pulse width extension turned up way to high. We basically wanted to see what the breaking point was. 25 psi on the road is good boost! We had two turbos basically explode right at 40 psi on two different trucks. Our comp version will take it up to around 32 psi, but at that point we allow the waste gate to open up. Anything over 34 to 35 psi we felt that the turbo was out of it's range and we could actually see h.p start to decrease on the dyno. Not to mention that the egt's were gettin up there also. We are extremely happy with the power that can be made with this engine. Can't wait to get our hands on a 2004 model! Have a great day! Greg

GMCTRUCK
05-23-2003, 08:10
Greg, I've seen 35psi on 6th gear highway blasts at level 9. Are you saying I need to adjust boost elbow?

TST Tech
05-23-2003, 09:44
GMCTRUCK
Absolutely not! It's ok for it go that high for a short blast. If it stays up there for more than 60seconds, I'd say we need to back it off some. Our brass elbow is set to open up at 32 psi, but it's not uncommon for it to spike above that during a big pull or when really lugging it.How's that clutch holding up for you? Greg

GMCTRUCK
05-23-2003, 09:51
Clutch is still fine (don't know for how long). It should be okay for an empty truck. 4x4 lauches, full power towing, or a couple dyno pulls would probably lunch the stock clutch though. How's your joint venture on the clutch upgrade coming along? BTW, welcome to the site, I'm sure you'll be able to answer alot of our questions and straighten some people out. Jesse.

sdaver
05-23-2003, 09:57
some of us need it :D dave

TST Tech
05-23-2003, 10:18
Thanks Jesse, Glad to be here!We are currently working with SouthBend on an graded clutch. We sent them a complete stock clutch last week that they plan on modifing for us. We also are working with another company out of Maryland that has lots of experience with the over road trucks. They have a full line of ceramic pads that work real well on the Dodges and Fords, so we're hoping we put together the same type of set up for the over powered Duramaxes. BTW I spoke with Clint at ATS this moring and he informed me that he ran 1/4 mile last night in 12.90@ 104.9 m.p.h. No drugs, PowerMax comp ( same version that you have) Duramaximizer, stock injectors, and of course twin turbos! I actually have an updated comp version if you interested. I've got two people with them right now that absolutly love them. Instead of level 5 being equal to 9 on a standard program, level 2 is equal to 9! It is very agressive! Exhaust temps are higher and it will be harder on drive trains, but it will definatly hall the mail! The two that I have out there are trucks with level 2 ATS upgrades. So far so good. Keep on truckin ,Have a great day! Greg