hypermax and timing

[lucky]

Hi:
Just back from a 19,000km idi trip to Alaska. 6.9 ran just fine. On the long hard hills it pulled a little hot on the pyro so I had to back off. Has anyone retarded their timing after the hypermax install as per instructions from Hypermax. Pump up 3 flats. It had an 11' slidein camper pushing a lot of wind. 3" exhaust straight thru muffler. c6 3.54

 

[Agnem]

Huff set his up so that he could control the cold idle advance manually. He then set the timing with the advance on, and then could manually retard it whenever he wanted. Get a DPS pump, and the timing comes adjusted to perform better with a turbo.

 

[jauguston]

What do you call too high on the EGT? When I installed my Hypermax turbo their tech support told me that a 6.9 could run at 1250 all day. I just got back from a 2000 mile trip and pulled some loong hills at around 1200 degrees with the propane on. I was 16,000# towing the Samurai. My pump is turned up 2 1/2 flats.

Jim

 

[MTIDI]

depends on the location of your pyro. where is yours located at?

mine is in the banks location, which is right before the turbo. the claim a safe maximum of 1050, although i have had it up to about 1125 or so.

 

[dbarilow]

Hypermax tells you to retard the timing if you live in the republic of California emission **** central. Some articles say retarding the timing could reduce lag, but it could make it hard to start especially if the pump is tired.

 

[akoldnav]

I hope you had an excellent trip to alaska and back. I can see high egt temps on some of our hills on my F350 with the Cab Over camper that I carry around. All of my trucks have Banks Turbos, but the overall effect should be the same.

I really love living here in Anchorage, except from December to March, but even that isn't too bad. I was born and raised in NE Oklahoma and it could get so darn hot that you could be setting under a shade tree, naked and still be hot. I can always put enough clothes on to get warmed up in Alaska.

Next time you come up, give me a call.

akoldnav

 

[lucky]

Thanks for the replies gents. Pyro prob is in the uppipe near the manifold. EGts on long hard hills would just climb if I let it. The odd time I wasn't watching and for a few seconds it touched 1400. On the hills I never watched the speedo just the pyro and backed off when it touched 1200. If I hit a steep but short hill doing 60mph it stayed cooler than if you hit the bottom at say 50mph. Jim: you have 4:10, I have 3.54 you can keep it spinning a little more. I may back the screw off a flat and see. However I was pushing a lot of wind and may try the truck as is toFlorida this winter pulling a 5er and pushing less wind. Try those hills in Yellowstone folks.
Alaska and the Yukon were the greatest; nice look at what things were before humans messed things up. Oh ya, took the truck and camper over the scale at the grain elevator before I left - camper and truck 9900# then add the stuff and us and fido and I figure 11000#. It has more peddle on these hills but I back off at 1200.

 

[Black dawg]

backing up the timing probably wont help with the high egts, retarded timing usually makes the egt go up. this is why it will noticeably reduce turbo lag. how much boost did you have at those temps?

 

[lucky]

Boost at 1200 egt was 7psi, maybe 8. I hear others with 10-13. Any thoughts.

 

[jauguston]

Two thoughts on the boost based on my setup. I have a E series cab MH. I chose to buy the Hypermax hood mount cool air intake system to reduce the air temp going to the turbo. That helps to control the temperature on the exhaust side and the air being cooler is denser. On the exhaust side I have a 3" Y at the end of the Hypermax down pipe that leads to dual 3" exhaust with round truck type 3" in-out mufflers from NAPA then 3" tail pipes exiting behind the duals. That exhaust setup was all ready existing from when I was NA so I left it there. It is probably as low a backpressure combination as you can get and still have a reasonably quiet rig.

I wrapped the up pipes with insulating pipe wrap from Summit and wrapped the turbo hot side with insulation to retain the heat in the system until it got through the turbo. Pump timing is stock.

My boost will run to 12 psi on a good pull and to 13 psi when I activate the propane.

1200 degrees is about as hot as it will get and most of the time not much over 1100.

In talking to Hypermax they told me my boost numbers are about as good as they have heard of for a non-pulse system and they thought the exhaust setup and the heat wrapping was a lot of the reason.

Jim

 

[lucky]

Hi Jim:
I remember your mods and thought gee I should get higher numbers for boost but I think with 4:10's your spinning pretty good at 60mph vs my 3.54. Still I think my egt's are either timing or fuel screw related. The screw can come down from 3 to two and I may try this first. If egt's are still high I may have it timed.
Any other thoughts out there?
Ken

 

[jauguston]

If you are hoping to get 12-13 psi of boost at 60 mph in high gear with 3.54 gears I am afraid you are dreaming. Pull a good hill in second gear at near governor RPM and see what you get. At 60 mph you are probably only turning 2200-2300 rpm. I doubt your engine will produce 100 horsepower at that rpm. These engines need to turn fairly high rpm to make their rated power. I don't get high boost until the engine is wound up, never in high gear at 60 mph. Your engine is lugging and that is probably why the EGT goes so high.

I'm sure you already know what you need to do but I will say it anyway--- you need to go to 4.10 gears to pull those kinds of weights.

Jim

 

[lucky]

I hear ya Jim. However, even in 2nd gear screaming up those hills in Yellowstone with just a camper on the back I can still push up the egts to the point I have to back off. I think the real cure starts with a capital D but I won't say it here.

 

[jauguston]

The "D" would be one way to cure the problem but it is not the only or cheapest cure. What you want your rig to do can be done-I am doing it. Feed it some cool air and free up the exhaust some more will sure help. For every 10 degrees you reduce the incoming air temperature to your engine you will get approximately 1 1/2% gain in horsepower. so if you can reduce the inlet temp by 50 degrees there is a power gain and the cooler the air goes in the cooler it comes out.

Jim

 

[MTIDI]

oh and another thing.

my timing was retarded a few weeks ago. I had the truck timed to 8-8.5 deg and it my egts went down, by about 200 degress or so.