Drag racing the GMT360 with the LL8

[Mooseman]

If there's no cooling system there's no fan clutch. No fan clutch, no 5V reference signal. This could be the source of the 5V reference issue.

Well no. Many times we advise to disconnect the fan clutch to diagnose issues with the throttle system. The problem lies in the fan clutch or the wiring leading to it. A missing fan clutch will not cause this. I have driven lots without an EV clutch, using a thermal instead, and didn't cause any issues (with the relevant fan codes tuned out).

 

[rchalmers3]

If there's no cooling system there's no fan clutch. No fan clutch, no 5V reference signal. This could be the source of the 5V reference issue.

Thanks for your interest and suggestion. I tested and confirmed the hi and lo reference signals were present before posting. For some reason I ended up with an APP pedal harness connector that was pinned differently. That's what I get by building a car in the manner of country singer Johnny Cash did back when he worked for Cadillac.

Rick

 

[FloMaxSS]

Hey Rick, Congrats on getting it moving! The Braille battery relocation looks great.. got to love that short zero-voltage-drop cable run!
Suspension: I see you already have djm dropped UCA's, check! You'll still need the bell-tech front drop spring mount/shock kit or the kw coilovers. Tie-rod alignment and lower control arm alignment will inevitably be off after lowering. Wait until you finish installing rest of front suspension pieces and no longer need to unbolt front crossmember, then get alignment done at shop that knows how to do lowered alignments.
For the rear, you just need belltech 31.5" springs and their shocks or kw adj shocks. I recommend installing adj. "helper" air bags inside the springs, allowing you to stiffen pass side rear suspension to perfect your launch. You don't need sway bars front or rear for pure drag so you can ditch all that if not already done so.
A more "radical" idea for rear-mount rad would be to remove hatch and mount rad vertically in rear cargo area. With all 4 windows down this would provide decent airflow and allow the most efficient vertical orientation. Are you even keeping 4 operable windows? lol
Also curious to see how you are mounting front bumper cover back on.. a bumper-gap-delete kit solves the top bumper cover mounting, but all the lower mount points stem from having un-shortened front frame rails and having intact steel front bumper.

 

[rchalmers3]

Suspension: I see you already have djm dropped UCA's, check! You'll still need the bell-tech front drop spring mount/shock kit or the kw coilovers. Tie-rod alignment and lower control arm alignment will inevitably be off after lowering. Wait until you finish installing rest of front suspension pieces and no longer need to unbolt front crossmember, then get alignment done at shop that knows how to do lowered alignments.
For the rear, you just need belltech 31.5" springs and their shocks or kw adj shocks. I recommend installing adj. "helper" air bags inside the springs, allowing you to stiffen pass side rear suspension to perfect your launch. You don't need sway bars front or rear for pure drag so you can ditch all that if not already done so.
A more "radical" idea for rear-mount rad would be to remove hatch and mount rad vertically in rear cargo area. With all 4 windows down this would provide decent airflow and allow the most efficient vertical orientation. Are you even keeping 4 operable windows? lol
Also curious to see how you are mounting front bumper cover back on.. a bumper-gap-delete kit solves the top bumper cover mounting, but all the lower mount points stem from having un-shortened front frame rails and having intact steel front bumper.

Hiya FloMaxSS,
Unfortunately I won't be able to utilize any of the pre-made, kitted suspension components that are offered for the GMT360. I have carved way too much weight out of the car to use an off-the-shelf lowering spring. I spoke with an engineer at Eibach, and he agreed to assist me with spec'ing a set of springs once I get it weighed. If I'm lucky, he may find springs in their catalog that will work, saving me the trouble and cost of ordering a custom set.

I eliminated the front sway bar early on, and retained the rear sway bar, as I have no idea on just how much induced torque roll I'll be encountering, so I'll leave it there until proven otherwise. I'm not sure an air bag is a better option. What are you running?

Reducing bump steer effect is proving difficult. I have collected the components for fabricating heim joint tie rods, but I am not able to locate an adapter stud with the correct taper dimensions at the spindle. If you have any recommendations or resources for this detail, please do share!

For this weeks update, I have created a fixture for the fuel tank and routed the power supply for the pump. I need to weld in a bung into the tank for draining, then I can fit the tank, replace the fuel rail and injectors with the two hose model, then build out the hose assemblies.

I am assembling a water to air inter-cooler system that I wish to fit. My intention is to have this system in place and proven before I fit a built motor. At the moment I have the water side (tank, submersible pump and plumbing) all ready. I need to purchase a suitable inter-cooler, mount it and then route the inlet and outlets.

@MRRSM I remember you mentioning the idea of fitting some skinny front wheels. I bought and fitted new front brake rotors, wheel adapters (6x5 to 5x4.75) and a set of 2006 GTO spare wheels. The wheels are spiffy looking, if I do say. I'll use the improvement in looks to spur me onward.

A radiator purchase is on hold while my credit card cools down. However I am able to prepare some of the hose routing details that will allow for the radiator relocation. More on that later.

Yeah, the front clip.... I need to look at some tilt front end assemblies to get my head around the tilt action, pieces and fitment. Then I need to devise a frame that holds the grill, backing, lamps, bumper and so on to the fenders and hood. I'm looking forward to having that project be my focus!

 

[FloMaxSS]

Hey Rick, Hope you have fared this summer well! Hope Eibach has some de-rated springs that fit! I recommend getting helper bags installed inside the springs... allows you pump up pass side more, allowing better weight transfer and traction off the line. I have had no issues with bump-steer and I'm lighter than almost all the modified v8 TB's out there. I just used upper control arms made for lowering, KW v3 front coilovers and rear shocks, 31.5" lowering springs out back.. Wish I had more to contribute for potential bump-steer causes. How is the project going??

 

[rchalmers3]

Hey Rick, Hope you have fared this summer well! Hope Eibach has some de-rated springs that fit! I recommend getting helper bags installed inside the springs... allows you pump up pass side more, allowing better weight transfer and traction off the line. I have had no issues with bump-steer and I'm lighter than almost all the modified v8 TB's out there. I just used upper control arms made for lowering, KW v3 front coilovers and rear shocks, 31.5" lowering springs out back.. Wish I had more to contribute for potential bump-steer causes. How is the project going??

Hey! @FloMaxSS Thanks for your continued interest in my project. You were gone awhile!

I spent most the summer working on other people's projects, but I'm getting back to the car.
It's a running, driving vehicle. I drove it around the block a few times, enjoying the open exhaust sound. I then gutted the interior for finishing the roll cage. That task is complete, so this weekend I will re-install all the interior pieces and post up some glam shots of the current status. Meanwhile, I have eplies, and a few questions for you:

Re: helper bags.... I thought it would be simpler to build one adjustable sway bar link to use the sway bar to load the passenger side rear corner. Would you agree or dis-agree with this method over a helper air bag?

Re: Bump steer... I had a machinist fashion some 3/4" shouldered bolts to pass through the spindles, and replaced the ball joints with heim joints. The total cost was equivalent to an off-the-shelf kit and while I have not yet had it aligned, I am confident the tie rod angles can now be optimized to the lowered front suspension.

Re: KW coil overs... Wow! Thanks for the opportunity to source adjustable front coil overs! I went to their website, but was unable to locate ANY products for the Trailblazer. If you don't mind, please share here the part numbers or custom build specs on the units you are running. This intel would be greatly appreciated, as I have not been able to uncover any resources on my own.

The current remaining project tasks are to get the car weighed, fit the suspension pieces, have it dyno tuned for E85 and install the front clip. The list is getting shorter, and I feel the goal of taking it to the track is becoming realistic.

Cheers,
Rick

 

[rchalmers3]

Ok fellas, here is what I have created thus far.

 

[rchalmers3]

More...
Apologies to those of you who know how to build a car properly. I am aware of many details I could do better. I'll listen to your observations and ideas about things I may not know of or may not have considered. This has been an educational and fulfilling project.
The remaining details include fitting the front clip, installing a windshield, fitting customized suspension and final tuning.

 

[rchalmers3]

I stitched together the front clip. Now I need to figure out how to mount it.

 

[Mooseman]

What will be interesting is the final weigh-in without all the extras.

You may have already talked about it but what is the purpose of the duct going in and out of the firewall? An intercooler?

 

[Blckshdw]

You may have already talked about it but what is the purpose of the duct going in and out of the firewall? An intercooler?

That's what I thought the box and tubing in the passenger seat area was for, an ice box

Very cool to see how this is progressing.

 

[rchalmers3]

What will be interesting is the final weigh-in without all the extras.

I have no idea of what the thing will end up weighing. I hope to be pleased and surprised, but because these trucks are so heavily constructed, I am attempting to curb my optimism.

Why don't we start a guessing pool? Wikipedia says these trucks have a curb weight of 4400 lbs.

I'll start by guessing I have removed 1000 lbs, so 3400 lbs is my guess. What's your estimate?

Rick

 

[rchalmers3]

That's what I thought the box and tubing in the passenger seat area was for, an ice box

Very cool to see how this is progressing.

Thanks for the props. Yes to an inter-cooler. Here are a few details: The cooler hangs from the roll bar. I put flanges on the inlet and outlet to seal the pipes against the firewall. An unrelated detail is the dual OBD ports: one for a dash and the other for diagnostics.

The ice box has an immersion pump inside. The orange hose is a simple vent curled around the roll cage cross bar. The sealed hatch on the ice box may look familiar to those of you who enjoy kayaking.
I fitted a hose bib connection to the return hose. I'll disconnect the return hose and run the pump to purge the tank.

Thanks to all.
Rick

 

[FloMaxSS]

Hey! @FloMaxSS Thanks for your continued interest in my project. You were gone awhile!

I spent most the summer working on other people's projects, but I'm getting back to the car.
It's a running, driving vehicle. I drove it around the block a few times, enjoying the open exhaust sound. I then gutted the interior for finishing the roll cage. That task is complete, so this weekend I will re-install all the interior pieces and post up some glam shots of the current status. Meanwhile, I have eplies, and a few questions for you:

Re: helper bags.... I thought it would be simpler to build one adjustable sway bar link to use the sway bar to load the passenger side rear corner. Would you agree or dis-agree with this method over a helper air bag?

Re: Bump steer... I had a machinist fashion some 3/4" shouldered bolts to pass through the spindles, and replaced the ball joints with heim joints. The total cost was equivalent to an off-the-shelf kit and while I have not yet had it aligned, I am confident the tie rod angles can now be optimized to the lowered front suspension.

Re: KW coil overs... Wow! Thanks for the opportunity to source adjustable front coil overs! I went to their website, but was unable to locate ANY products for the Trailblazer. If you don't mind, please share here the part numbers or custom build specs on the units you are running. This intel would be greatly appreciated, as I have not been able to uncover any resources on my own.

The current remaining project tasks are to get the car weighed, fit the suspension pieces, have it dyno tuned for E85 and install the front clip. The list is getting shorter, and I feel the goal of taking it to the track is becoming realistic.

Cheers,
Rick

Glad to see all the progress and that you're seeing this through!

Suspension - Driven Speed Performance

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The Viking coilovers are phenomenal or so I've heard.
Can't wait to hear how your bump-steer soulution works out.
It's been awhile since I've heard of using adj swaybar tierods to preload. I think most just rely on rear adj shocks, I went a step farther with the bags. I'm not sure why more people haven't experimented with adj tie rods though..
You still had something left in the interior to gut?

 

[rchalmers3]

Fellas,
It's been three years in the making. This spring and summer I completed the car, then had it aligned and tuned. Last night I took it to the local 1/8th mile track. I will make this the final chapter of this thread and share with you the results of this project. Here are images of the car at the track yesterday evening. It was over 90 degrees and humid as heck.


The completed car weighs 3088lb, W/O driver weight. The weight bias front to rear is 55.5% to 44.5%. The stock, normally aspirated 2006 engine running on E85 race gas produces 262 horsepower at the wheels.

The completed tilt front clip is made of 90% factory pieces cut up, stitched together and hinges on a removable hinge/brace.

I'm using an Autometer gauge product that uses a Bluetooth connection. It is a dongle that plugs into the ALDL, and sends a signal to the cheap tablet mounted on the roll bar cross brace. Honestly, having gauges is kinda useless. That big red light will inform me if the oil pressure drops below 20PSI. That's all that really matters, isn't it?

I decorated the car by covering it with stickers and by drilling holes in the rear bumper cover. My excuse for doing this was to prevent the bumper cover from blowing off at mach speeds....
The performance results were a disappointment. According to one of the online calculators, I should have a sub 14 second car, given the car weight and power produced. The calculator also indicates a 60' time of 2 seconds. The best I could do was 2.3 seconds. The stock street tires and open differential would not allow me to mash the throttle. It would spin up the rear tires anytime I floored it within the first 200 feet. On a prepped track!

Despite the lackluster results, I am pleased. To have finally driven this creation at a track is a personal victory in itself. Of course, I will look for a way to lock the differential and purchase a set of drag radial tires. I remind myself that this was the plan: sort out the car and make it ready for adding power through forced induction.

I recognized at the beginning this forum serves TB owners who want to keep their trucks on the road, while here I am taking this one off the road and onto the track. I acknowledge the divergent purpose my project is to the forum, and I am grateful to all of you who have contributed an interest and/or commentary. This thread has been a welcome form of expression, and I hope I have lent value to others. Thank you.
Rick

@FloMaxSS @limequat @Mooseman @mrrsm @Tankcruiser @azswiss @TJBaker57 @Reprise
@efi-diy

 

[Blckshdw]

That's awesome, glad you were able to get it done, and test it out. Had to be an amazing feeling to get to take it down the track after putting in so much time and effort.

 

[Mooseman]

We've had a few over the years that modded them for racing so it's not entirely foreign to us here. That front clip is awesome!

I'm kinda surprised at the HP numbers you got as this engine in stock form produced north of 290 HP. Just needs some more tweaking. The weight savings were amazing going down from the stock 5500 lbs.

 

[mrrsm]

I know that Rick ( @rchalmers3) has pretty much completed this Novel GMT360 Drag Racing Machine... but I would be remiss for not mentioning a decade old Thread from another site that featured a Q&A about GM Atlas Vortec 4200 Engine Swaps into certain Vehicles. By the second page in that Thread... One particular Member there cranked out THESE Very Cool images (AND HIS UNIQUE SPECS) of his Custom Welded Aluminum Crank-Case Oil-Pan for his JEEP that is well worth dropping into THIS Thread ...for the sake of Drag Racing Posterity:

4200 Vortec, but is it worth it?

First time poster, did not see anything regarding rebuilding the 4200 LL8 engine. . . Please don't flame me if I missed something!Anyhoo, I found this 4200. Looks like it would need some serious work on the bottom end, but for less than $200, I find myself very tempted.Anyone done any ...

www.inliners.org

 

[rchalmers3]

I know that Rick ( @rchalmers3) has pretty much completed this Novel GMT360 Drag Racing Machine... but I would be remiss for not mentioning a decade old Thread from another site that featured a Q&A about GM Atlas Vortec 4200 Engine Swaps into certain Vehicles. By the second page in that Thread... One particular Member there cranked out THESE Very Cool images (AND HIS UNIQUE SPECS) of his Custom Welded Aluminum Crank-Case Oil-Pan for his JEEP that is well worth dropping into THIS Thread ...for the sake of Drag Racing Posterity:

Thanks for the bump.
I wish I could agree with you that I have nearly completed this project. It appears to be the opposite: After fitting drag slicks and welding the differential, I tested the car and found the transmission has weak holding power in second gear. I am in the process of building a 2008 year model 4L60E transmission using extensive Sonnax performance parts and a Rossler trans brake. Here is the assembled back half:

The front half is waiting for delivery of a heavier spring compressor, as my Chinese spring compressor cannot compress the Rossler springs and billet cap for the reverse piston (seen on bottom left).

Eventually I'll get the vehicle sorted and get to building a few engines for receiving forced induction.

Regarding engine modifications and performance, I located a Facebook group focused on the 4200.

Log into Facebook

Log into Facebook to start sharing and connecting with your friends, family, and people you know.

www.facebook.com

As you find everywhere in life, there are a handful of experienced and helpful contributors, .... and a bunch of other people. This resource is the place to visit for anything that is LL8 performance related, which is not all that much, really. But yeah, custom oil pans and intake manifolds are common within the group, and there is now a production cast turbo manifold being offered. If anybody is seeking performance related ideas and parts, this is the current source. I'll just add here that I'm not a fan of social media. A fellas gotta go where the stuff is.

Thanks to all,
Rick

 

[mrrsm]

Ouch... But... Your work is that One Shining Project of its Kind anywhere in North America that is very likely to "Break New Ground" along the lines of "Breakage". It these Links will help... Drop by and Download these for your Project Library Research:

The ATSG Comprehensive OBD2 Diagnostic Guide for The 4L60E,65E,70E & 4l80E,85E Trans

This is a VERY comprehensive 185 Page PDF Service Guide covering the OBD2 Diagnostics for The GM 4L60E, 4L65E, 4L70E, 4L80E and 4L85E Transmissions. It contains a great many contributions from the Members of the GM Automatic Transmission Service Group (ATSG) imparting arcane knowledge, tips and...

gmtnation.com

ATSG Resources: HP-Tuners Transmission "How-To" PDF

ATSG has produced an excellent "One Over The World" PDF Resources Page...and WAY down at the bottom of THIS Link is the one for using HP-Tuners on How to Set Up your Transmission conditions within for Shift Adjustments coordinated with your particular Tunes. Download, SAVE and Use This Bad Boy...

gmtnation.com

https://atsgmembers.com/memarea/bulletins/bulletins/21/21-01.pdf

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atsg.com

 

[mrrsm]

Just touching Base again, Rick...

Calvin (NIVLAC57) produced THIS Video on the implications of Dry vs. Wet Oil Pans and Dry Sump Racing Applications...the primary one right in reach of Calvin...might also interest you:

Forged vs. Cast - What's the Difference? - Milwaukee Forge

Differences Between Forging and Casting Metal Forging and casting are two very different manufacturing processes used to manipulate the shape of metal. In the casting process, metal is heated until molten. Then it is poured into a mold or vessel to create a desired shape. In the forging process...

www.milwaukeeforge.com

Best way to compare the differences between a Cast Crank (THIN Casting Parting Line from the Sand Mold) and Forged Crank (WIDE Drop Forging Impact Space along the Center Line) and the differences in the SOUNDS when struck with a Brass Hammer... Cast = A Dull THUD vs. Forged = It WILL Ring Like a BELL:

So WTF am I mentioning THIS information for?

Well... HERE is an Interesting Development... Am I CRAZY...or is THIS a Genuine Forged Crankshaft for the GM Atlas LL8 4.2L (Early Model 7 Notched) Motors. I'm very suspicious because they use the word "Forging" in this Advert Image....but it displays a THIN Sand Casting Mold Line...so WTF?

2006 Chevrolet Trailblazer 4.2L Engine Crankshaft Kit 105110 -2

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proenginerebuilders.com

Is this REAL... Or REALLY JUST A "SINTERED POWDERED IRON" HEAD FAKE?

Sintering - Wikipedia

en.wikipedia.org