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Well, finally hit the limit and it's egt's....

G

great white

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Canada's Ocean Playground
Hauling the 35 footer back from a camping trip today I found the limit of my 98 and it's pretty disappointing.

Tooling around back roads and up smalls hills, she's ok.

But, I hit the highway on the way back. here's what I was looking at:

Speed - 100 KPH (62 mph)

Boost - steady at 6M on flat runs, up to 10 psi on climbs

Oil press - 35-40 psi

ECT - Never got above 85-90 C (185 - 194 F) no matter how hard I worked it.

EGT - 950-1000 on the flats, spike 1200 on cruise with small uphills.

Long uphill runs - Had to drive the EGT's or risk overtemping. Dropped down to 80 KPH (49 MPH) on very small hills. I have no idea how I'm going to climb over the rockies with this thing.....

But the most disappointing thing was, the truck was a total DOG! I had to get into the throttle very hard and the truck took forever to get up to speed. There was a noticeable drivetrain shudder if I got on it too hard, maybe the transmission protesting a bit.

It's not exactly running a stock tune but nothing hot either. Just the tiniest whisp of black on accell.

It's running a K47 with a K&N. I've got a devils own water injection kit, but not istalled yet.

I've been running the stock exhaust and now I'm making plans to source a stainless 4" exhaust in an attempt to get the EGT's down a bit.

Walt's is Hearthrob right? Anyone have experience with this system? It's the only one I've seen that's complete and in stainless. I'll just have to eat the UPS shipping costs I guess...

Not sure what else to do to get those EGT's down. More boost is out or the question, my 350,000 km block and rings isn't going to deal with more.

That coast to coast trip I have to do this summer is gettting more and more scary.....:mad2:

A new optimizer or P400 is just out of the question right now. My Planned LB7 swap is right out of the ballpark....


Suggestions?


Am I screwed?

:nonod:
 
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you need to get that 4 inch exhaust installed. Lower back pressure and more power, and should lower egt some. Also get that water injection put on. It'll take care of the high exhaust temps. You will need a good sized reservoir for your water supply or you'll be filling the tank frequently on that towing trip.
BTW, I got a wmi from Heath to install on mine this spring.
 
Give the exh. a try, I have Walt's aluminized exh. I like it, didn't like the UPS thing though.
 
NVW said:
Give the exh. a try, I have Walt's aluminized exh. I like it, didn't like the UPS thing though.
Click to expand...

How much did UPS bilk you for Leo?

Walts site says around 150 bucks on top of shipping charges IIRC.

I've gotten fleeced by them once, didn't like it either.

I just don't see any other way to get a stainless system.

I'm going to Newfoundland where they salt the roads like crazy. It's a stainless system or get used to changing it ever 2-3 years....
 
Oh, and if you want ss 4" exhaust, I bought mine from SS Diesel supply; it is a very nice system and very reasonably priced for ss. I added some better, heavier hangers and band clamps for easier removal. Some here don't like that company, but I was satisfied with the exhaust. Louder than stock, but sounds great and mine came with oval muffler.
 
chessie 6.5 said:
Oh, and if you want ss 4" exhaust, I bought mine from SS Diesel supply; it is a very nice system and very reasonably priced for ss. I added some better, heavier hangers and band clamps for easier removal. Some here don't like that company, but I was satisfied with the exhaust. Louder than stock, but sounds great and mine came with oval muffler.
Click to expand...

That's "walt", the guy I'm talking about....;)
 
great white said:
How much did UPS bilk you for Leo?

Walts site says around 150 bucks on top of shipping charges IIRC.

I've gotten fleeced by them once, didn't like it either.

I just don't see any other way to get a stainless system.

I'm going to Newfoundland where they salt the roads like crazy. It's a stainless system or get used to changing it ever 2-3 years....
Click to expand...

Darned if I can remember BJ, I think it was about $100 shipping then $50-$75 brokerage?
 
NVW said:
Darned if I can remember BJ, I think it was about $100 shipping then $50-$75 brokerage?
Click to expand...

Just checked Walts site. Looks like 110 brokerage, 163 shipping and 475 for the stainless turbo back.

I figure anywhere around 725-750 USD....


Ouch.


I can bite off about a grand, but I can't suck up the 5-10,000 for a new block.

Lordy, it better drop my EGT's and get me over the rocks or I'm screwed...
 
robzombie4551 said:
It will help but WMI will give about 150* in reduction of egts along with the 50*/100* the exh will give you.

You will be tested on the hills for sure no matter what you do.
Click to expand...

That might work out.

I'd hit 1200 on uphill grades (not serious grades) with a 20-25 knot headwind and accelerating or holding speed at 55 mph.

A 200 degree drop would have me at 1000, which should be liveable.

I could roll some more fuel out of the curve, but I'm pretty much at the lower limit already. No smoke at my boost levels.

Crank more fuel out and I'll probably loose too much power. Dial up more boost, risk the rings more than the huge blowby I've already got....

I was planning on gearing down over the rocks and settling in to 45-ish MPH in the slow lane on the interstates. Now, I'm not so sure I can pull a decent headwind...


What i really need is a P400 or an LB7. I need to win the lottery.....:mad2:
 
Trying to tow with stock exhaust is going to leave you disappointed every time, and has to be at the 4" system to get the real benefit. Thats going to free up a lot of power and lower temps.

Even on a stock PCM and the stock vacuum controller I would hold more than 10psi of boost running empty going fast up long hills. To get EGTs down you probably need more boost, which also gives better power. Not much more maybe sustain 12psi.

Another thing you might try is modifying the timing curve. If you have it very conservative, I would run the timing under load around 50-60mm3 up to about 13 degrees at 2100rpm, increasing to 19 degrees at 3300rpm. With higher timing at max fuel and more timing at low fueling. Remember horsepower rating is at 3400 rpm, so may have to get it up above 3000rpm commonly. If your timing is much more than that range may want to back it down. Advacning injection over stock wieght rated trucks drops EGTs a good amount. The LD trucks actually had more advance at load, but some had too low timing near idle. I think the 11 degrees that many OBD2 trucks use for idle timing is too much, and I actually get better throttle response between 9 and 10 degrees timing at idle. Got to realize this is cam timing, so if its 11 degrees that is 22 crank degrees advance.
 
GW, What you are experiencing in my experience is normal. I have a 4 inch ex and it made no difference. Under the exact same circumstances you report, I get the exact same results. I just back off on long grades and drive by the pyro. I am not sure an intercooler would help or not. Lower IAT's is good but the trade off will be decreased airflow to an already starved radiator unless you do a hanging one which looks weird to me and I question the effectiveness of something that small. I never got to try the WMI. It's just the way these engines are. Under those towing conditions even my Cummins ran hot but it was manageable. Don't know Dmax but have read about overheating problems in their forums as well in the at least the earlier ones. Out of all the diesels I still think the 7.3 PS is the best towing engine. Mine could not break a sweat on 105 deg day.
my .02
Alot of people don't realize how hard towing a camper is on a truck. My skidsteer weighs more but doesn't have the wind drag and the truck doesn't work nearly as hard.
Also RULE#1 when towing...No Cruise on hills !!!! You have to play around with the accelerator and the tranny to find a sweet spot. The cruise will send the motor into meltdown real quick on a hill.
4 inch ex is a GOOD upgrade but won't solve the problem, just help it a little.
 
great white said:
That might work out.

I'd hit 1200 on uphill grades (not serious grades) with a 20-25 knot headwind and accelerating or holding speed at 55 mph.

A 200 degree drop would have me at 1000, which should be liveable.

I could roll some more fuel out of the curve, but I'm pretty much at the lower limit already. No smoke at my boost levels.

Crank more fuel out and I'll probably loose too much power. Dial up more boost, risk the rings more than the huge blowby I've already got....

I was planning on gearing down over the rocks and settling in to 45-ish MPH in the slow lane on the interstates. Now, I'm not so sure I can pull a decent headwind...


What i really need is a P400 or an LB7. I need to win the lottery.....:mad2:
Click to expand...

maybe try the ATT? i hear lots of guys say that the EGT's drop alot with it, under a grand too.....
 
EGT's in your case are from lack of air or timing.
If the K&N looks dirty - they plug quick. Snorkel in fender gone?
Stock exhaust and down pipe is like breathing through a coffee stirrer straw. It has to go.
Turn the turbo up to 14 PSI. I have pics of the copper showing on the mains and enough blowby that a road draft tube made the truck look like it was on fire. The extra boost kept the EGT's in check with a 1/3 turn of the screw. The extra boost didn't hurt the engine!

Last give the timing some advance as this will drop EGT's. Possible you have a worn chain causing some retard and high EGT's with that.

As far as a dog towing - get used to it it isn't a 365 HP Duramax. maybe you can get 10 MPH more on the hills over stock and that would be 43 MPH vs 33.
 
The SSD walt exhaust sucks. Simply many better systems out there and the most important of all - hangers that work! I don't know what year the included flat blade hangers are supposed to go to but I have only seen round hangers on 1993 and 1995. You don't get round hanger brackets with this kit.

It cost me more than it should have to install this system because I had to buy hangers from the shop installing it.
 
Hmmm, part of the problem maybe?

DSC04154.jpg


Dunno, best not to take the chance. Soooo:

DSC04155.jpg


Left a little bit of the center "ring" to provide some extra rigidity for the center section. Also, you can't see it, but I eased over the sharp edge where the air enters the plenum.

It is an "F" intake, no EGR or EGR plumbing at all. The lower is wide open. Nothing but a slightly domed floor. The upper was replaced just before I bought it, so it must have gotten one of the uncommon "F" intakes with the webbing.

I've often wondered why the web was there. Thought of everything from a baffle to smooth intake pulses to directing the air more at the runners. I've seen pics of it both there and not there on factory applications.

Meh, dunno why it was there really.

Gone now.....;)
 
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