egt & boost #'s seem off

[wraney]

installed boost and pyro (before turbo) awhile back and from reading other posts numbers seem off. truck is 91 inter-cooled w/automatic haven't done any mod's except turn fuel screw about 3/8 of a turn without removing the collar from screw. OK here's the #'s,loaded WOT max boost is 14 psi. pulling 2 horse trailer 70-75mph egt 1000*-1100*. up hill WOT 1200* with the max i've seen is 1250*. seems not enough boost and too much heat? truck has 165000 miles.

 

[wraney]

was wondering if my questions are inappropriate,cause i've had 0 replies. thanks,wade raney.

 

[BCaldwell]

numbers

wraney right question just no one who knows the answers has seen it yet. I have not hooked up my pyro yet so can't compare #s Bill

 

[BushWakr - RIP]

wraney,



For my way of thinking, the first thing I'd look at is "air in, air out"

Your air filter needs to be upgraded to a higher flowing type, thats one thing.

Second, you really do need to consider a free-flow exhaust system. The stock one's ... well, basically they really bite.

I think that these things will really help contribute to moving more air and help with temps,and allow you to achieve more boost.

Your only adjustment of 3/8ths turn of fuel screw is not enough to make a huge difference in boost (assuming that was starting at "stock" setting to begin with).

It will help a bit. My truck stock only maxed at about 12-13 psi with the 18cm housing.

The stock turbo housing on the truck, depending on the year is as follows (credit to another TDR member for this. )... .



89-91. 5 had 18. 5 housings WH1 turbo

91. 5-92 had 21 housings WH1 turbo



Either way they both do not spoolup very quick. They do however provide lots of air at the upper end so that leads me to think you are restricted in your air in/out.

Next, if you are hauling a fair bit of weight and working it hard in OD then you are really loading it up and that will also contribute to high temps.

What would you guess your total max weight to be with trailer/horses/fuel/cargo etc ??

Do you find that at the speeds your running, you are primarily in OD?

If so, the only way to reduce your temps is to drop to 3rd (direct drive 1:1) this will bring up the RPM's, and move more air as well as lower temps.

Now having said all that, you can safely run all day at 1200*F - 1250*F EGT's without any real problems, but NO MORE.

If you do this, you will need to watch engine coolant temps closely though.

OH, do you have a transmission temp guage????? NO? GET ONE !!!

You could well be running that trans. up into the 230*F - 250*F range and that is just plain nasty !!!!

Again, dropping to 3rd will help with that too. (auxilary cooler maybe?)

Well that's all I can come up with at this time of night. Hope there is some help in there somewere.



Regards, Bob.

 

[Case500D]

Sounds About Right

Wraney,



I can tell you on my '92 (see signature)with a 21 cm housing only produced 13 lb of boost and 1050 to 1100*F EGT. This is all with a stock fuel setting, K&N air filter, straight pipe. The 3/8 of a turn on fuel may be contributing to the higher EGT, especially if you aren't getting the air to it to burn the fuel. A better air filter and opened up exhaust would provide lower EGT and higher boost. I would start out with a free flowing air filter and at least straight piping your truck. A 16 cm hot end housing would also be a cheap investment as well as bumping your pump timing up. BushWker will be able to provide more info on what hot end housing will work, but I really like my 16cm. Let us know more about your truck and we will be able to help you get it setup. Hope I haven't confused you too much



Jeremy

 

[Midnite]

Bob and Jeremy have some great suggestions. For what it's worth, my '92 maxed out at 16 lbs. boost when it was stock (with the exception of a free-flowing muffler added on).



There are a couple of cheap/free things you can try first that should help:



1. The stock air filter actually flows pretty good, but the airbox is very restrictive--it forces all the air through a space smaller than the cross section of a 2x4. The airbox is very simple to remove, and in fact I drove mine for over 25,000 miles with mine removed, and with the stock air filter simply resting unsecured with no problems whatsoever. Easy thing to try and see if it'll change your peak EGTs or boost level.



2. Check for boost leaks. The best thing to do is to take it to a shop that's familiar with this and knows how to do it. I never even thought about boost leaks on my truck until I stopped in at Piers' shop (Piers Diesel Research, www.piersdiesel.com). It turned out I had quite a few pinhole sized leaks in all four rubber boots on the intake side (the ones that isolate the intercooler from engine vibrations).



Mike