Significant improvement in towing performance!

[rjschoolcraft]

I am presently sitting in Las Vegas, NV in attendance at the SEMA Show 2003. I towed my travel trailer to Las Vegas from Martinsville for the show. The route is I-70 to I-15...some very mountainous terrain.

Thanks to information gleaned from this resource and products from Kennedy Diesel, my Suburban is finally a respectable towing machine...and I sense there is more in there. Having traveled the exact same route (and farther) in June with the family on vacation, I have a good comparison test established. At the time of the summer trip, I had Kennedy's TD Max chip, the HO water pump and dual t-stats, the K&N air filter and Banks exhaust installed. I suffered from overheating problems and low power in western Colorado and Utah.

This trip, I have the Kennedy intercooler, Kennedy fan clutch and 9-blade steel fan. From Indiana through Kansas I set the cruise on 70 mph and drove...the most speed loss was 5 mph on some grades in Missouri. In the summer I had to down shift on most any grade to keep from losing more than 5 mph.

In Colorado, I set the cruise on 75 mph (speed limit) and just drove. It was amazing. Previously, I could not sustain 75 mph on level ground...I could only do that on down grades.

Late Monday night as I was approaching Denver, I lost boost. Turns out, the waste gate actuator failed...the rod broke where it connects to the piston in the canister. I lost two thirds of a day while rounding up the part in Denver, replaced it in a K-Mart parking lot, then moved on.

Climbing out of Denver on I-70 up to the Eisenhower Tunnel under the Great Divide was my first real test. Last summer, I struggled with overheating (had to stop twice to cool down) and low power (it was hot). I actually dropped into first gear at less than 35 mph when approaching the tunnel at 11,000+ elevation. This time, I hit the tunnel at 50 mph and only briefly dropped into second gear. At no other time on the east side of the divide did I drop below 55 mph.

The down grades were managed much more easily with the TorqLoc engaged. The rig felt much more secure and it was much easier to maintain safe speeds.

Last summer, the tow through Utah was a struggle. At several spots, I had to crawl in first gear at about 25-30 mph. This time, I never dropped below 50 mph and only used second gear a couple of times. I actually got into a bit of a contest with a Dodge Cummins 3500 dually towing a 5th-wheel. He could pull me slightly on some of the grades...Then he decided to really out run me. I fell in behind and stayed with him (the draft helped). We ran at over 80 mph for several miles, then I got a good jump on an upgrade, passed him and went on. Cool

This truck really has me excited now. Overheating seems to be a thing of the past. Now I am just beginning to tap the real power potential.

I now have the return trip to do, starting tomorrow and hope to be home by Saturday night. As for the water mist injection issue, I can't see how it would provide the performance that the intercooler did for that sustained effort. Running 70 - 75 mph towing the trailer requires sustained boost levels of 10-13 psi...that's over 1800 miles at high boost levels. In the systems I've seen described here, the water would be on all the time and I don't see how I could keep the tank full. Just my opinion.

So far, the intercooler and the fan clutch are the two most significant changes that I have made...but they all work together.

What fun! [img]smile.gif[/img]

[ 06-25-2004, 07:37 AM: Message edited by: ronniejoe ]

[moondoggie]

Good Day!

Thanks for sharing your story. With a little added detail, this could make a VERY good article.....

Blessings!

Brian Johnson, #5044

[jspringator]

I have pretty much everything you have except the intercooler, and the torque loc, which won't work on the 99. I wonder how much difference the intercooler alone would make? My last trip was down I-75 to Florida, and it would be hard to imagine much improvement. I estimate my weight around 6000 lbs.,loaded.

[dslpwr]

THE ONLY REGRET I HAVE ABOUT MY INTERCOOLER IS THAT I WAITED SO LONG TO BY ONE.
I DO NOT THINK IT WILL WORK BEST ON A STOCK ENGINE. NEED MORE BOOST AND FUEL
WHEN MY TRUCK WAS STOCK IT WOULD DOWN SHIFT BIG HILLS ABOUT 55 MPH.
WITH EXHAUST AND CHIP ABOUT 65 ON SAME HILL WITH HIGH EGT.
WITH INTERCOOLER IT WILL RUN 72 MPH ON SAME HILL IN OVERDRIVE AND UNDER 1000 DEGRESS ON EGT.

[rjschoolcraft]

In all honesty, the intercooler was huge! As I said earlier, the chip was in when I did this in June...The intercooler is the only performance improver since that time. Before, the high intake temps and coolant temps were causing the PCM to draw back on fuel. Now it just rolls on. For what it's worth, I towed down through the hills of Kentucky just after installing the intercooler, fan and fan clutch back in July on a 95+ degree day...A/C running. It was incredible how much better it did.

Kennedy has a "hotter" chip than the one I have. I'm probably sold on it now and will have to acquire it soon.

My rig, fully loaded, weighs in at over 16,300 lb. combined weight. Roughly 8100 lbs. each. I wasn't as heavily loaded on this trip...minus the wife and kids and associated gear. However, I would guess that I am around 14,000 lb. combined.

Another point... Through Kansas, running 70 mph, the egt gage ran between 850 and 900F Previously (with only exhaust and air filter mods), I struggled to run 65 with egt's in the 1300 to 1350F range. Last summer, I could run 70 in Kansas in most areas (with chip), but my egt readings were between 1100 and 1200F. Granted it's cooler outside now than last summer, but I've run out this way in the spring before (this past spring and the one previous) and that's when I registered the 1300+ egt's...the ambient temps were similar to now. So the intercooler has made a tremendous difference.

In Utah, running 75 in most areas, the egt was between 900 and 1100F. I hit over 1400F a few times on some of the big mountain climbs, but I used to run that all the time when the truck was stock except for gages. That's where I think a turbo charger upgrade will help. I think I'm blowing the waste gate open at higher engine speeds. My boost falls off (to about 8-9 psi) and the egt's really climb. This engine seems to like boost to keep it cool.

[ 11-06-2003, 04:57 PM: Message edited by: ronniejoe ]

[patrick m.]

i would have to agree that the 6.5 LOVES boost.

[catmandoo]

i have a 92 1/2 ton 2wd that i just put my banks on and was lucky to get 1/2 lb cruisin at 60 empty and after the mandrel downpipe and full exhaust(no muffler) and getting that air chamber to seal 95% i can run 2-3 lbs at 60-65 and can get 5lbs like that and power from hell jeez feels like a v-12,used to struggle up good grades now i can pick up speed. all this talk of intercoolers will they be worth the trouble in my situation i usually don't tow anything and usually empty i know just how i could run one and i have to pull my front end off anyway(damn pheasants)i guess question is would it be worth the trouble.

[patrick m.]

if your max boost is 5psi, the intercooler wont be a benefit to you.
When the charge air is compressed to 10psi and more, the tempurature rises too high and is less dense. When i installed mine, i noticed a 2psi loss in total boost, partially due to the cooling affect, and partially due to the added distance and resistance.
im more curious why you only get 5psi from your "Banks" turbo. I read in one of your posts that it is an "early" stlye kit, and was non-wastegated".
My Garrett is from a "banks" kit and is also n/w, but i get 16psi max.
do you have any measurements?(turbine wheel dia, comp wheel dia, a/r ratio)etc

[KrisHull]

Patrick,
Where did you buy your turbo, and how much was it?

[jspringator]

Under what conditions will the computer cut fuel because it senses boost is too high? Is this a concern with the JK Boost controller?

[Bobbie Martin]

Ronniejoe,
Did you notice any increase in fuel economy? Did the intercooler make any difference in everyday (unloaded) driving?
Thanks, Bobbie

[catmandoo]

well i also have an 82 gmc 3/4 ton suburban with a banks on it and the most i have ever seen out of it was 7 lbs pulling pretty hard. i figured this was normal for these.i could prbably get 7 out of this one if i was pulling something but empty by the time i get up to 5 lbs i'm doing over 60 mph 1st gear i don't get any boost 2nd just before shift it will come up to maybe 1 lb 3rd 31/2 to 4 lbs before shift to 4th then like i say time i get to 5 if i don't want to chance a ticket i have to back off.i could probably get more if i turned the pump up to spec. i turned it up like said here in other posts and when on it hard it just billowed smoke so i turned the pump down just a hair and it really helped the smoke and it seemed to gain a little power. now i really have to be pullin hard to see smoke,one other weird thing i noticed is i thought my cold advance quit after i turned up the pump and when i started it yesterday it still didn't idle high like it should but after running for about 5 mins it made a definate switch in idle sound(got quieter) so i kinda assume it is working,just doesn't hammer like before.

[LanduytG]

I have to agree with Ronnie that the big IC had a very big gain. I did this about 3 or so years ago and the first trip was do to the Smokies and I never was under 60 mph and never had to worry about EGT's or water temp. The truck is a joy to drive when you don't have to worry about those two things. I have the BD rv chip I might have to try JK's big chip.

Greg

[joed]

I also agree that the intercooler was the most noticeable peformance gainer. Since I live in Colorado, I give my truck the I 70 workout several times a year.

This is my 3rd year with the intercooler, and while towing, I picked up 5-10 mph on most climbs, about a 10 degree average drop in coolant temp, and 200 or so degree drop in EGTs.

As far as the boost "dumping", my truck has always done that over a certain rpm. I talked to JK about that and he felt the they were designed that way because of the added stress to the engine a higher rpms. The intercooler does seem to like boost though, 13-14 psi seems to be yield the most noticeable difference. But to me, even at lower boost levels, the added power is noticeable.

As for fuel economy, I haven't really noticed any change, loaded or unloaded.

After having it, I wouldn't be without it. It's just too bad they didn't come stock with one.

Joe.

[patrick m.]

Kris, i bought the turbo from a friend, used.
James, Kennedy's boost controller will "hide" the added pressure so the computer does not open the wastegate.
Without an intercooler, the high charge air temp detected by the "IAT- intake air temp sensor, will cause the computer to open the wastegate, and reduce fuel. In some cases the computer seems to just reduce fuel,which will affect boost.
IMHO, any boost pressure over 10psi will benefit from an intercooler, and probably should have one.

[d.h.]

Hi there I have a 98 6.5t.d c/c dually and tow a 30ft 5er.Combined weight is 18500lbs.Before I upgraded the truck had a hard tine pulling on level ground,never mind a hill.I dealt with diesel auto in Vancouver.I installed their 4" exaust and downpipe an i/c, boch high flow injectors high flow air and a little boost box I then installed ispro boost and pyro guages. This year I travelled accros B.C and I was truly impressed with the differance. The boost would go right off the guage if I let it. I crested a few 3-4 thousand foot passes and the truck never dropped below 50mph.I think i would have needed a tow over before.It has put my faith in the engine up a few pegs,as far as power.The cooling I think would be the next area to deal with as with all the boost and 90deg weather that was the only thing I had to moniter a little more carefully.I think one could do a little piston melting if not watched
Dave

[rjschoolcraft]

I'm back home.

On Friday, November 7, 2003, I left Las Vegas at 6:00 am PST (9:00 am EST) and headed for home. At 11:00 pm PST (2:00 am EST), I pulled into a rest area near Colby, KS...nearly 1,000 miles away.

The Suburban performed well on this drive. I had good power and could run whatever speed I wanted within reason.

On Saturday, I left the rest area at 6:00 am EST... Something changed. The boost had fallen back to nearly stock levels and power was way down.

After studying the gages for the nearly 900 miles remaining, it is clear that the PCM is commanding the boost level. I suspect that the BARO sensor may have failed. I had an extra Boost Sensor at home. Today, I installed it, but no difference. I will try the new BARO sensor as soon as I can acquire one.

Does anyone know if the BARO signal fails, will the PCM revert to a default (low) boost schedule?

[LanduytG]

Ronnie
What are you using to control the boost? How far down did it drop? Yes the boro has a effect on boost. I control the boost with one of JK's adjustable boost controllers that on the map sensor. I had boost problems and founf the pot to be bad in the controller.


Greg

[moedog]

THATS THE PROBLEM WITH THESE SCREWY 6.5S, THEY ARE LIKE A LINCOLN I HAD ONCE UPON A TIME AND NEVER AGAIN. ABOUT THE TIME YOU THINK THEY ARE FINALLY FIXED ON LOUSY POWER AND HIGH TEMPS. SOMETHING ELSE BREAKS OR GOES HAYWIRE.
MY NEIGHBOR HAS A NEW 6.0 LITRE FORD DIESEL AND THEY ARE BUYING IT BACK ON THE LEMON LAW FOR FAILED INJECTORS ONE AFTER ANOTHER.
I,M STILL SAVING MY PENNIES TO DO THE CUMMINS CONVERSION. I HAVE EVERYTHING BUT THE TRANNY AND THE HYBRED TURBO FOR THE ENGINE.SHOULD GET IT IN THE CHEVY NEXT YEAR AND ILL DO A FULL REPORT FOR THE PAGE AND ALL YOU DISGRUNTLED DETROIT DIESEL OWNERS!!!!

[Ralph Fichtl]

Where did you get your TorqLoc and how much?