Turbo upgrade?

[jaluhn83]

I'm running a full moose pump with mine and it seems to be a good combo - only time I really worry about egts is full throttle if she starts to lug - over 2k rpm it seems to burn clean & stay under about 1200* (pre turbo)

Also worth noting that there's a ton of different HX35W variants - mine is a 98 manual, I think. There's a 8 blade and 7 blade version, 7 is the later and is supposed to flow more air but possibly at the expense of low end performance.

 

[racer30]

Hey Jaluhn83....Where is your Thermocouple for your gauge mounted? Do you run it to 1200 very often...seems a bit high to me....How much boost are you running when you get those temps...Just poking you for info....

 

[Joejohn]

What are normal unloaded cruising egt's at 70mph?

 

[cpdenton]

Normal is a direct result of each different setup.

I have a moose junior pump, 80 cc's or so, with a banks sidewinder. 5 speed manual with 4.10 rear end. 235/85 16 tires

70 mph= about 2500-2600 rpm or so and about 475 degrees on the exhaust. Unloaded.

 

[Joejohn]

Wow I'm at 800! I must have to small of a turbine.

 

[cpdenton]

I haven't seen anything about your timing. What do you have it set at?

At 70 unloaded, I am hitting 5-6 psi boost with no intercooler.

 

[Joejohn]

I can't recall what the timing was at. I just had it set at an injection shop and it runs better. I played with the timing allot without the timing meter and my egt's ranged from 700-850 and that was about all it would change. At 70 it's at 7psi with a psd intercooler. It getting good mileage too. I don't get it. The only thing I can think is that it's the turbo not flowing enough. I just don't see what else could cause it to be so high without being way out of tune.

 

[jaluhn83]

My thermalcouple is in the up pipe just before the turbo inlet.

I'm comfortable running up to about 1200 intermittently and I've hit 1250 a few times - I prefer to stay around 1100 though. I used similar numbers on the last setup and had 30-40k miles on the motor when I pulled it apart (damage due to overheating) and saw no evidence of damage caused by high exhaust temps. I'm also running 0.015" decked pistons with ceramic coating now so that should give a bit more wiggle room.

I only see that high of temps under full throttle pulling though, and only if I'm into it for a few minutes. Most of the time she'll run about 1000-1100 at 20 psi on hills and pulls well. I'm getting enough air to burn clean and keep temps down up until that last bit of fuel which is just about perfect. Could probably bump the wastegate up a bit and get lower full throttle egts, but maybe actually higher cylinder temps.

Cruising unloaded I'm running ~5 psi & 5-600* on the pryo.

I've got timing set pretty much right dead center on spec (luminosity).

The intercooler on my rig isn't fully setup yet, (air to water, water side isn't done yet) so I think that will help some. Even without it she behaves pretty well.

Under full throttle the coolant temps will creep up but not bad. My normal load is around 15k gcw and I'll usually be able to pull hills (cajon pass, I8 east from san diego, etc - max of 5-6%) at 50-60 with coolant temps up to about 210-215 and oil sump temps 10-20* higher. I took 2 heavy loads recently (20-21k gcw) up from san diego recently and with those I was down to 35-45 on the hills and saw coolant temps up to 225-230, but even then they took a while to get there. I'm running a 3 row aluminum radiator and some sort of a heavy duty stock fan clutch.

 

[racer30]

OK 1200 at the turbo inlet would be (IMO) to high for stock uncoated pistons because the temp would be even higher at the cylinder head. But now that you have coated pistons I think your better protected from High EGTs. It seems like your water and oil temps are lower than some Guys report on stock engines under heavy loads....This I believe is a benefit of coated pistons not passing as much heat to the oil through the oil sprayed on the bottoms of the pistons... My rig has not been tested on a long pull like a mountain pass yet, But my temps are 1000EGT's at WOT measured at the port of one cylinders flow, 625 with 5 psi at 3000 rpm cruise, about 190 on my water temp gauge with 10 gallons coolant and I haven't got my engine oil temps over 180 yet with 18 quarts of oil (running the big international pan and 1 gallon oil filter) (measured at the midland Air compressor oil drain line) My 7.3 is in a 21000lb Motor Home running 90cc of fuel with .030 decompressed coated pistons, HX40w Turbo running 20psi waste gate getting 18psi at the manifold after the 06 dodge 3" Intercooler J2 cam, lightened NA rods (100 grams) ported heads 4" exhaust no muffler 5' long. I'm real happy with the performance so far but I want to set the timing before really pulling a long hill (more than 2 miles). Its nice to get some numbers from a guy that's pulling big loads on a regular basis.

 

[Joejohn]

I have never hurt pistons and rings due to high egt's but I have wollard out valve guides and burnt exhuast valves.

 

[jaluhn83]

I've seen pistons where the edges of the flame trough have melted a bit likely from high egts.

For me 1200-1250 is a reasonable max - it's really not going to cool that much between the manifold and turbo inlet, not when you're flowing that much gas through there.

I used similar numbers with the last setup (banks wg turbo) and had nothing that looks to have been damaged by it when i pulled the motor apart.

I think the main reason I'm seeing good cooling is cause I've got a very good clutch fan - it seems to fully lock up by about 205*. For a bit I had a new clutch on there and it would get distinctly hotter - up to 230-ish with just the horse trailer, probably cause the stupid clutch didn't even start to do anything till 210*....

Admittedly I'm still only around 10k miles on this rig - I like the performance but it's way too early to say for sure that it'll last.

 

[racer30]

Well if you have seen them after 1250 and be ok then that makes me even more happy....I purchased 5 engines, opened up 3 myself in my search for a good block and 18 out of the 24 pistons where cracked in the center... 3 of the engines were Turbo engines 2 had spun bearings one had a broken piston and had run with the rod just slapping around in the cylinder bashing it with the rist pin until it grooved the cylinder wall real Bad. The PO said it still ran when He pulled it... So maybe I'm being extra carful not to overheat mine...