Test Pull and EGTs

[Spindrift]

Some background is important here.

We've been looking and looking and looking for a new TT. With five kids and two Bernese Mountain dogs, size has been an issue. Finally, my wife and I see the Cougar 304BHS. She falls in love with the floorplan and the amount of storage space that's available. We have yet to find another TT with a floorplan that compares to it. However, I'm lukewarm on the quality of the construction details but I know how long we've been looking...and looking...and looking...and LOOKING. So we put down a deposit. The Burb has been my vehicle of choice given our family's size, so I decided to schedule a test pull with the TT in order to see how the truck performs.

Just got back from my test pull. Unfortunately, the dealer didn't have time to pull out the Cougar so we hooked up to a Prowler 300 FQS. This was my first time with the truck pulling anything of substantial weight so I'm starting from a point at which I can't compare the truck's performance to any other TT in this size range.

Here are the specs on the two trailers:
Cougar: Gross Dry Wt. 7,300#, Carrying Capacity 2,340#, GVWR 9,640#, Hitch Wt. 840#.
Prowler: Gross Dry Wt. 6,625#, Carrying Capacity 2,975#, GVWR 9,600#, Hitch Wt. 937#.

Therefore, my test pull used a TT that was approx. 675# less than our intended purchase. Important point...both the truck and the trailer were empty, except for a full tank of fuel in the Burb.

The truck had absolutely no problems with the Prowler on straights or moderate grades. It was easy. But then we ran some very steep grades. I can't say what % grade they were, but you wouldn't see them on any Eastern U.S. interstate, which is where we'll probably do 90% of our driving. There were four short climbs (1/2 to 3/4 miles in length although I'm going to need to confirm this distance). On three of the climbs my pyro hit 1200 degrees for a few seconds (thermocouple is installed in the crossover pipe, just below the flange, driver's side). On the fourth hill, the pyro hit 1300 for a few seconds just before I made the crest of the hill. On all four hills I was running in 3rd gear at roughly 45MPH at the crest. I forgot to make a note of the RPM readings. The truck has a 4.10 rear.

So...what do you think? Could the Cougar be too much TT for my truck? I think the number of times I'm ever going to see hills like this are few and far between.

Would appreciate your thoughts and questions, especially if I've left out any vital info for you.

[ 03-27-2004, 01:48 PM: Message edited by: Spindrift ]

[tanker]

Hi spindrift, As a fellow suburban lover since 1975, I'll give you my thoughts. As you can see below I'm towing more than what you will be towing with the Cougar. I was pulling a 90 Jayco 30FK for several years without a problem. What you "Must" do is keep the EGT's in check. Don't ever go to 1200 degrees pre-turbo, or you will be asking for a disaster. Head cracks, blown head gaskets etc. So back off when the pyro hits 1100+ degrees if its still climbing. One thing that would improve your ability to reduce EGT's would be the addition of an intercooler. It made a big differance on mine when towing. You should do well with the 4:10 axle ratio. Plus you mentioned you are pulling on the East Coast. Although there are some good long pulls in the East through New England, Pa. Va. Wv. etc. Just use common sense, and don't try and race a Powerstroke, Dodge/Cummins or Dura Max up some hill, you will get there just fine a few minutes behind, but so what, you still got there.
I'd go for the cougar you and wife fell in love with, I know a few satisfied owners of Cougars.
Good luck with your choice.

[FisHn2DMax]

I would go with the Cougar and not even think twice. Keep in mind, by the time you add the family gear, and water, your total weight will exceed your test tow by 1500-2000lbs. I own a 5'er made by the same company that weighs 9500lbs loaded with water and gear. I pull 6-8% grades all the time and had to learn to back off the throttle a bit when the EGT's started to climb. The keystone ( cougar) is a good value for the money! Make sure you go get a load leveling -equalizer- weight distributing hitch with sway control. Keep the Burb and the trailer level with each other (loaded) and Enjoy! smile.gif

[Spindrift]

The good news here is that I'll now be able to say to my wife, "But honey, if I don't make this mod..."

We looked at other TTs in the under 8,500# GVWR class: Fleetwood Terry Dakota (very mixed consumer reviews related to quality), Jayco Jay Flight (sorry, can't get past the aluminum skin, and the bathroom set-up), Aerolite (if I was in slightly better shape I think I could probably bend the frame with my own two hands).
I'm still aggravated because Keystone could have made some rather simple design alterations to come up with a significantly better TT but I guess the accountants and the marketing folks put the cabash on it.

Tanker...the intercooler is a good idea, but I sure am interested in looking at a meth/water mist injection system. Cost, space considerations and effect on EGTs could make the system a viable option to intercooling.

[TMS]

Spindrift,

Just got a Jayco Eagle .... not aluminum skin ...fiberglass.... 6750# MT and 8500# loaded ....278 FBS ....lotsa room. Take a look. I'm towing (just a newbie) with a '03 2500HD Crew D/A. No gauges, but will probably look into some as I listen to other posts on this site.

[rjschoolcraft]

I have over 130,000 miles on the engine in my Suburban, over 195,000 miles on the truck. I have towed my trailer that weighs at or over 8600 lb. when loaded (probably 9000 on our recent trip). In stock trim (except for gages), I ran up to 1450 F pre-turbo (probe in same location as yours) for short durations regularly. I used to run 1350 F steady state in headwinds. Not the first problem with the engine from that perspective. With the intercooler, my egt's are much lower and feel much more secure. However, climbing mountains in the western US, I still have hit 1400 F for very short periods.

Based on my direct experience, I think the 1200 F limit that gets tossed around here is very conservative. Mine has lived with 1350 F sustained for years (not with intercooler) and short duration spikes above that.

It's up to you to decide from your experience and any other information sources you can find (this page for example) what you think is safe. I can just tell you what has worked in my experience.

[tanker]

Yikes! :D 1400 degrees pre-turbo. I think I would count my blessings, or check the gauge calibration. I thought my 1200+ degrees is what caused my head to crack, and head gaskets to leak. :rolleyes:

[rjschoolcraft]

I've had two different gages and probes (both from Banks) and both read similarly, so I believe the calibration is right. I think the key is that the 1400+ F was not a sustained temperature. Now I have run sustained at 1350 F with no problems.

I know a guy, who will remain unidentified, that has run much higher temperatures on both 6.5's and Duramaxes.

Several years ago, my uncle had a 4020 diesel that needed an overhaul. While it was in, he had a turbo charger system installed. It had a 3" chrome straight stack and really sounded cool. What a difference it made. I recall running that tractor with an eye on the egt gage. Our established limit for sustained operation was 1350 F. So maybe I have incorrectly applied the same limits here, but so far so good.

[MikeC]

Spindrift,

We have a 31' bunkhouse slide from Cardinal, made by Forest River. The bunks are in a separate bedroom with it's own wardrobe and entertainment center. Might want to take a look.

Mike