Before starting this section of the update, I'd like to mention that the wheels and tires are Nitto Ridge Grapplers in a 35x12.50-18 around Pro Comp 1069 alloy 18x9 wheels. Okay, continue.
The next couple things that happened with the truck were aesthetic and cosmetic. My current plan (as it has been for about 3 years now) is to transform the truck from a "kid" truck into an "adult" truck. Basically, a clean and simple truck on the exterior with tasteful modifications.
Before getting to the exterior stuff, I'll mention that I did add an Edge CTS2 monitor. Not a necessity by any means, but they were on sale, can you blame me? I figure being able to monitor IAT would be cool, as well as have a code reader on board at all times. Once the Duramax starts to take shape, the CTS2 will be a very welcome item to have.
Eventually I would like to body swap the whole truck and paint it. However, that is not in the budget so I can either leave it alone or swap panels as they become available. I'm not interested in have a multicolored truck (no disrespect to the guys that do) so I had to play the waiting game for a lot of my panels. One that was high up on the list to be replaced was the bed. Finding a clean, straight, 8' green bed with flares is a tall order, especially in New England. However, I found one! It was listed for $300 with a gate and drop-in Duraliner. Only about an hour away. I messaged the guy and set up a time to go look at it. When I arrived, it was still on the truck: a regular cab, 8 lug gasser in surprisingly good condition. The truck was missing doors to my chagrin, I need a set of doors for the truck as well, and the interior was gutted. But the bed was nice. .... The rear bumper was also nice, nicer than mine. How much for the bumper? Guy said $50. Then I looked at the fenders, they were nice... nicer than mine. How much for the fenders? Guy said $500 takes the whole truck. Good deal, but I didn't want another parts truck. I had already bought and sold 2 this year. So, I offered $400 for the whole truck and took it home. $400 bought me a bed, gate, rear bumper, and good fenders. I was able to give the rest to Brent who salvaged a couple drivetrain components off it before sending the rest to scrap.
The bed is an 8/10. Very clean, good crossmembers underneath, a dent in the passenger side that should pop easily, and IMMACULATE under the liner. I think the liner has been in it since day 1, and it shows. Eventually, I will have the "4x4" painted blue to match the pinstriping on the other parts of the truck, like my old bed was. Got the bed swapped on and moved onto the next part of the facelift.
Ever since riding down to Numidia, PA to go racing last summer with a friend, I have wanted to add a Tonneau cover to my truck. I never realized how much utility it adds to the truck, especially on long drives when the bed can be used to store luggage, tools, etc. My local go-to guy for parts is Sean at Street Diesel Performance in Chaplin, CT. Sean builds SEMA trucks for Fusion bumpers and American Force wheels. But he's a down-to-earth guy that helps me out with all my silly 6.5 projects. Almost any part is 1-2 days away. Summit who? Never heard of her. Anyway, I reached out to Sean to ask what Tonneau he recommended, and he sold me an Extang Trifecta 2.0. Fit and finish is nice, fits the bed well. Not a difficult item to add by any means, but I feel like its really cleans up the truck and gives it a good look.
Next up was something that I had thought of doing but never gotten around to: a good cut and buff. Let's just take a moment to say thank you to GM for using some darn good paint in the 90's. With the help of my father (who is very experienced in the field of auto detailing) we washed, claybarred, buffed, and waxed the truck. I will let the pictures speak for themselves.
The truck had a pretty easy month or so following the cleanup. It was mid November and I had a 700mi round trip to PA on the horizon. One thing that I had not taken care of was my front driveshaft. I had ordered it from Chris at CT Driveshaft Service in East Hartford, CT and hadn't picked it up yet. With snow in the forecast, I figured it was as good a time as any to pick up and install the driveshaft. I was concerned about clearance with the crossover pipe, so I ordered a new Diamond Eye unit from Quadstar Tuning - yet to be installed. Anyway, I fired the driveshaft in and drove down my street to a nearby dirt road for eh, er, "testing".
I wasn't sure how the electronic t-case was going to like with the new axle. I was concerned that with the truck not "seeing" the thermal actuator for the front diff anymore that it wouldn't want to engage 4wd. That fear was quickly erased. I locked the hubs, pressed the button on the dash, and instantly had 4wd. In order to confirm that 4wd was working, I climbed a 6' dirt pile. Cool, 4wd works. So the only logical thing to do at this point was launch the thing at 7psi and see what happens. I mean, its a brand new axle, new shaft, what could possibly go wrong? Right? So I launched the truck at about 7psi and it ate. Its a narrow road, so I was more concerned about going straight than I was with my speed. I don't know how fast I went, felt like about 50mph or so. I stopped the truck, put it in 2wd, unlocked the hubs, and got back in with intentions of driving the half mile back to my house. Upon acceleration, the turbo sounded like a slide whistle. Great. Got it home no problem, with it still making 12-15psi under acceleration (normally 20) - I figured I had a boost leak. So I got home and popped the hood with the truck still running. I sprayed soapy water around some of the intake boots looking for bubbles. No bubbles. So, fearing the worst, I shut the truck down. On shut down, my fears were confirmed: the turbo sounded, how you say, "no bueno". I pulled the intake boot off it to find a chewed up wheel and scoring on the inside of the compressor housing. The old HX40 hybrid thing was down for the count.
So, with the PA trip 3 weeks away and not wanting to have the truck down for too long, I began evaluating my turbo options. My thoughts as follows:
-S300 box turbo: only available T4, will need additional work to fit, not a lot of data on a 6.5, but $699 new and a proven turbo
-Quadstar Super 54: designed to fit, I know it will work and run well, basically drop-in, but $1200+
-eBay: cheap, but hit or miss quality
-rebuild my HX40: not a project I wanted to take on
-used Holset
Initially, I went looking for a used Holset. I figured it would drop in to my current setup, and save me a couple bucks over going with a new turbo, and I could sleep at night knowing I still had a name brand turbo as opposed to a chinese unit. So I found a tight H1C locally for $100 that I picked up. 300,000 miles off an 89 Dodge but no shaft play and spun nice and smooth. Long story short, the CHRA didn't want to come apart, and I cracked the compressor bearing housing. My fault, but frustrating nonetheless. So I was out $100, and back to the drawing board.
I wound up going with the S300. Ideally, my truck is studded and I go with a Quadstar 60, but I wasn't able to spend the money, and my truck isn't studded so I didn't go that route.
Details on the S300: 60/68/0.91 T4 divided, non-gated. It runs pretty well all things considered. Being the that the truck is an auto, I can kind of get away with a bigger turbo than if it were a stick. However, the 3.73's and 35's do not work in my favor. Going from a 60mm hot side to a 68mm and from the 16mm housing to the 0.91 which visually appears to be bigger meant that it was going to be laggier. And it was. Basically, the turbo spools well if you kick the truck in the nads a little, but if you roll into it on a hill and it doesn't downshift, I see about 10psi and 1000* and climbing. Hottest I've had it is 1200, that was on the highway pulling a hill at about 7200/2000rpm. The key to keeping the turbo happy is rpm. Over 2200 and its a happy camper. My setup, unsurprisingly, does not yield good lugging. No big deal, just give it more skinny pedal and get more smiles per gallon.
I've put probably 2500 miles on the S300 so far and its a decent option. I haven't run a Quadstar turbo, but I would imagine the S300 is inferior as it has not been optimized to work on a 6.5 platform. Based on the turbos I have run, I would rank them best to worst: 60/60/16 Holset, S300, HX35, ATT.
To return to the timeline briefly, the truck made it to PA and back without a hiccup. I got it on the graffiti highway in Centralia - which is really cool if you've never been. Averaged about 14mpg on the trip, some backroads driving and probably 3/4 highway going 75-80. Par for the course as far as I am concerned.
Okay, back to the turbo. In an effort to see what I can do with this thing to make it better for a 6.5, I have ordered and now received a new exhaust housing for it. I went with an 0.81 T4 open scroll non gated housing from Boost Lab. I opted to stay T4 because of the increased flow over a T3, but the tighter 0.81 A/R for hopefully a quicker spool up. Again, I know that cm2 and A/R are apples and oranges, but for what its worth, the 0.81 its externally smaller than the 16cm2 housing that came off the HX40.
Short term plans include installing a drive pressure gauge through the EAS system on the Edge monitor, and swapping the new exhaust housing on.
That's my long-winded update on the 6.5 side of things. Not sure where/when I will update on the Duramax; there's not a ton to report yet. Thanks for reading this much, I will now go look for some good pictures to upload from the last year.
