NEED MORE BOOST

[BioFarmer93]

One last issue with any 7.3 engine. We just don't have the cooling passages like the 6.9 does. The engineers plugged off 2 places on the heads and the block. So naturally we run a little hotter. The easy fix is run the 6.9 head gaskets and punch holes in the plugs of the cooling passages. Its been done and it works.

No thread-jack intended, but this is something I read about here quite a while back and would like to do since the engine is coming out next weekend for head gaskets, studs, F&R seals and whatever else needs attending to.. Is it something I can do at home or do I need to take the heads back to the shop? I'll bump my older post in a minute for any response. Apologies to Racin460 for the intrusion!

 

[rhkcommander]

How fast to 1100 egt,
Rolling coal too?

You could have boost leaks occuring at the top of your levels, this isnt something you can test in the driveway. My advice - flashlight and video camera, soapy suds on pressure side and go for a hard fast drive till you get your max psi.

Clogged , old airfilters can choke the engine out too. Try a run without one and see. Clogged exhaust can hurt performance too.


As for cams, ive heard plenty of great reviews of the typ4 cam, on turbo too. But it was developed as a N/A logger cam IIRC...

 

[C_Luft]

Look on Google for the smogie build it's the owner of R&D idi performance , he would usually hit 34 psi on his idi

 

[typ4]

I see 14-18 pulling hard regularly , same cam, modded turbo does make a difference. I roll black under load, egts get to 1000, boost starts climing , levels out at 900* 15 ish psi. little smoke.

 

[Black dawg]

im sorry I didn't post in the beginning that I have a intercooler on it, and cold air intake. and yes mel timed the truck for me and drove it. let me see... gears sounds like im still going to get 7-9psi out of the turbo, right? I know there has been a lot of discussion on here about making 20psi, but know one has said what turbo they have. I get about 2-5psi around 1700rpm-60mph, when I get to a hill that just is not enough air for the fuel, and the smoke begins.....

You really should be making more boost. How big is this hill, how many miles? That turbo will do 20psi (with that cam I dont know). what intercooler are you using? not having coolant temp problems?

 

[77f250diesel]

I'll vouch for the typ4 compressor mod, I can peg my 15 psi boost gauge with ease.

Dennis

 

[F350camper]

something is leaking, or your wastegate isnt properly adjusted.

 

[racin460]

coolant problems? don't have any running stock radiator (cleaned the heck out of it with strait clr) and the heads are fully ceramic coated so the heat don't get throw to fast.
intercooler is of a dt466 school bus with modified inlet and outlet all tubing is 3" cutom intake hat with 3" inlet
turbo outlet machined down to except a 3" flange / 3" down pipe to beside trans 5" from there back over the axle and out behind rear tire, no muffler
gears are 355
trans is zf5
like said "power not a problem" this thing runs (ask mel next time you got him on the phone) he said he never had an idi put him in the seat like this thing does)
I'm not doing 35mph at the top of a hill because of power, im doing this because im hitting 12,000 egt and don't want to see how much farther I can push it.
as far as hijacking the thread your not at all, and ill comment back with I pulled the core pugs out of the heads and the block, **** a step drill to the 7.3 gaskets and made the passage in the gasket about 1/2" (it dose make cooling a lot nicer)
something else iv seen running ac, the fan stays locked up all the time from the heat off the condenser and the engine temp drops down to 140 quickly
what this thread was meant for was what type4/russ posted I wanted to know if that mod helps and or what guys have done to achieve more efichant boost. I don't run the engine over 2-2200rpm I cruse around 15-1,700rpm and im only making 2-5 cruising. Id like more boost at that rpm, so with that said. If hitting 15psi@2000rpm, dose that give me 7-10@15-1700rpm? thank you for all the help to all that have posted im sorry I could not make it to the rally (even thow it was as close as it can get to me) I just didn't have the time.

 

[laserjock]

It might be the intercooler and piping. Remember if the intercooler is working, the manifold pressure should drop a little because of the reduction in temperature. At the same time, you should see an egt reduction with that much intercooler. If the turbo you have is healthy and you don't have any leaks, it may just not be enough turbo for the fuel you have. .

 

[towcat]

you've identified your problem. it's the gearing. 3.55 gears are meant for economy running. not pulling.
you needa minimum of 4.10 gears at 11k gvw trailer weight and a minimum of 4.56 gears for 15k trailer weight
if your motor can't spin, it can't build boost.
it's that simple.

 

[laserjock]

Do the temps drop if you downshift? You may need to spin it more like 2700-3000 on the hills. I'm putting 3.55s in mine because it will be light load most of the time with the understanding I'll be spending time in 4th with a load going through the mountains. It may suck a little more fuel at that rpm but I would hope she won't melt down either. Just some thoughts.

 

[typ4]

I , FWIW agree with towcat, 2200 is way to low to work these engines. When I hit my stated boost its at 2800.

 

[kuskoal]

It's called "lugging". You aren't spinning the engine fast enough to spin the turbo faster to build more booat to blah blah blah blah. Drop her down a gear and get the rpm's up and try it. You have the expanding gas portion of 1200 egt, now get the rpm up to push MORE exhaust through the turbine wheel.

 

[FarmerFrank]

It's called "lugging". You aren't spinning the engine fast enough to spin the turbo faster to build more booat to blah blah blah blah. Drop her down a gear and get the rpm's up and try it. You have the expanding gas portion of 1200 egt, now get the rpm up to push MORE exhaust through the turbine wheel.

Im not much of an expert, but i know mine sure wont hold a hill at those weights at that low of an RPM. i run 3:55's too and when i see a hill i drop it a gear and let it scream to the top. a V8 diesel is not made to lug. They are made to run higher RPMs and hold them. if you want 2200 RPMs go with a cummins, they are made to lug and hold

 

[racin460]

I have a trip this coming week end to a place iv been about 4 times before. So ill get a chance to try some things and ill let post back with results and concerns. thanks guys I don't like hearing things scream. I cant even mow my grass with the mower wide open. so im going to look as some and let you know. thanks again