Egt issue with my setup

Jpscustoms

Jpscustoms

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Feb 17, 2008
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fresh rebuild, .030 pistons, 181/210 cam, 5x.012 sdx injectors, balanced/benched pump, stock dvs, 16.5 timing, he351cw ported gate over s472...damn thing runs great and spools awesome but egts when towing are crazy pull any kind of grade and it hit 1300-1400 instantly and cruises at 1000-1100.....thoughts?
 
Do you downshift when pulling grades? What rearend gears?
 
3:73 gears and yes i tried down shifting but it will only reduce temps 100degress say 1200-1300ish but that will climb to 1400 still if you try to maintain speed. i used to be able to pull same grade no prob with the hx35/40 hybrid single and 5x.010 injectors.... figured twins and 5x.012 wouldnt be a prob
 
have you adjusted the afc spring any? just curious cause mine runs great unloaded but unless i tighten the spring it is a turd and runs hot while pulling a load
 
Try giving it a little more timing. The pop pressure on the injectors might be a bit different. That's the only other thing I can think of off hand. What were the EGTs at the same grade and speed before?
 
Which afc spring are you running?

How much boost are you currently making?
 
100 plate, rack plug, im going to mess with the afc today. The timing has been up to 22 degress with no change really. Its making 25 to 30lbs pulling grade.
 
Tighten the star wheel so it delays the fueling a bit. While towing your gonna make more boost obviously. So limiting the fueling it has midrange by tightening the star wheel will help. how much I don't know, you just need a good Half a day to play with the plate and figure out what works.

Good luck on the new build, hopefully this one will last way longer than your other one.
 
I'm still learning about these 12v's but, where's your plate at? Can you pull it back some? I was having something similar when I had my AFC full forward. After pulling it back and spending some time tuning it my egts came down.

As for it not being a lot of fuel, depending on the pump isn't it enough for 500+? And that's being done on a 351.
 
I had the same turbo setup but with the internal gate permanently shut with a 50mm E.D. external gate, same cam, 5x.014's, no plate, 18* timing and 024 DV's. For me, dropping to 4th was usually enough to keep things in the 1150* area on 6% grades making 32-34 psi boost. When I got on it really hard I could still get the EGT's to climb though.
 
What did your pump put out, cc-wise when it was benched?
 
Jpscustoms said:
fresh rebuild, .030 pistons, 181/210 cam, 5x.012 sdx injectors, balanced/benched pump, stock dvs, 16.5 timing, he351cw ported gate over s472...damn thing runs great and spools awesome but egts when towing are crazy pull any kind of grade and it hit 1300-1400 instantly and cruises at 1000-1100.....thoughts?
Click to expand...

The cruising temps are way too high to be normal, there is definitely something wrong.

Are there any exhaust leaks between the exhaust outlet ports on the head and inlet flange on the He351? (Check exhaust manifold for cracks, leaky gaskets, etc) Even small ones that only leave a faint soot trail?

If I were you, I'd pull the He351 exhaust housing and inspect the wastegate to make sure it's sealing properly, your problem sounds like a partially stuck open wastegate, overported wastegate that's leaking, or exhaust leak before the He351 inlet.

Just for more information, what is the cruising total boost pressure, and what is the boost pressure between turbo stages?

Also, if you have the info, what is the total boost on the hills vs boost pressure between turbo stages?


In my experience a small boost leak can cause 100* higher EGT's, an exhaust leak can cause 200-300* higher EGT's. Your cruising temps are so high, I'd really check into the exhaust side of the system.
 
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well I pulled the plate back and tightened the afc and that helped...it maxs out at 1300 now. still seems to have a little higher than normal crusing temps.... going to keep playing with it to see what I can figure out...but it getting better atleast.
 
Keep tuning the AFC. When I had my AFC FF the EGT's would climb faster than the boost and peak EGT's would be 1500+. Now, my AFCis less than half forward and pretty close to tuned. EGT's climb normal and peak are down to a little over 1200.

And like BB24 said look for leaks.
 
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