Reading the thread title almost gave me an aneurysm because to me Holley and Dominator is this:
Photography by J.G. Pasterjak
In our previous update, we regaled you with tails of our 2004 Corvette Z06 that ran great at the kickoff event of the SCCA ProSolo season–until it didn’t.
Reflashing our Holley Dominator’s tune seemingly solved the problem, so we were excited to load the car onto the trailer for our next event, this past weekend’s Tire Rack Red Hills National Tour in Adel, Georgia.
[Bringing Our LS3-Powered C5 Corvette to Life | Project C5 Corvette Z06]
Then, just as we yanked the handbrake once the car was on the trailer, it happened again: The car took a 2300 rpm idle with no response from the throttle. Reflashing the tune again fixed things, but clearly there was still a caper afoot.
Luckily this happened on Thursday, and Holley’s tech department was responsive and eager to help. After a bit of back and forth, we had no 100% conclusion, but their expert analysis pointed to the throttle body. The throttle body on our LS3 was an early LS3 design from the late-oughts that wasn’t officially supported by the Holley Dominator drive-by-wire software.
As Holley explained it, there are really only two things in that circuit that could trigger the issue: the throttle pedal and the throttle body.
When the ECU senses too great of a discrepancy between the position of the two, it triggers the fault mode. Between our throttle body not being fully supported and Holley’s hands-on experience with faulty throttle bodies from that generation, they suggested a fully compatible throttle body as the first step to a solution. They sent us a list of fully supported throttle bodies that would work with our ECU.
So we yanked off our old throttle body–thankfully it’s a quick, four-bolt process, even with the car strapped to the trailer–and headed to our local Chevy dealer.
“Year, make and model,” was the request from the nice lady behind the parts counter. “Yeah I’mma stop you right there,” we replied, before explaining the situation as best we could in between apologies for being a complete pain in the butt.
Luckily–and here’s where we give a huge shout-out to the parts department at Jon Hall Chevrolet in Daytona Beach for being super accommodating–she was down to clown and joined our detective mission.
Basically, we needed whichever throttle body from Holley’s approved list most closely matched our original piece in physical configuration–and was also in stock.
The dealer had three from the list, and all were close, but one perfectly matched our throttle body in intake and outlet diameter, bolt pattern and connector location. The closest match turned out to be part No. 12629992, the OEM unit on a bunch of high-performance, V8-powered GM machinery from around 2012 through 2017. The list covers vehicles like the Cadillac CTS-V and Camaro ZL-1 as well as lots of 6.2-liter, LS-powered trucks and SUVs.
We grabbed the new throttle body, bolted it on, and entered the part number via a drop-down menu in the Holley tuning software.
The engine fired right up.
So far, so good, but we haven’t rally given it a fair test yet. Just to be on the safe side, we spent the weekend reflashing the tune and resynching the throttle body on nearly every startup. We also ordered a spare throttle pedal which met us back in Florida, so we’ll resume actual durability testing when the stakes aren’t so high.
Speaking of stakes, there was also an event to be run, and things went fairly well in that regard despite a bit of back luck of the draw on the first day of competition.
On Saturday, our CAM-S class ran in the first heat, and we were greeted with a wet course, temps in the high 40s, and 20-plus mph winds. So the course was drying, but the conditions handed a serious advantage to whoever ran last and whoever had a co-driver, since they would have dryer conditions and whatever miniscule amount of heat was allowed to build in the tires. And, just as we expected, we finished Day 1 in third behind two cars with two drivers who ran after us.
Sunday was dry, but also ridiculously cold. A bomb cyclone in the upper south was pushing temperatures in the Valdosta area well below freezing–it was 26 degrees when we arrived at South Georgia Motorsports Park–and it never rose above 32 degrees for our entire first heat.
Still, our Yokohama A052s performed admirably in the frozen conditions. The first run was a bit sketchy, but subsequent runs felt shockingly “normal” given the ambient temps.
Still, we didn’t have the speed to undig the hole we had dug ourselves into the previous day. Even though we managed times at the front of the class, we remained third, just 0.037 second behind Kenny Lee in an LS2-powered C5 and just a few tenths off Joshua Sightler, who was driving a former national championship-winning CAM-S C5 Corvette.
Of course, the entire CAM-S field also got to watch as temps rose quickly and steadily throughout the day, and stock Honda Civics started outrunning us as the pavement warmed up, but we had a warm, friendly competition in our class despite the frigid temps.
Next up, we’ll head to the FIRM for some longer runs to see if indeed we have fixed our throttle issue. In either case, we’ll probably install the new pedal and keep our existing one as a backup.
Reading the thread title almost gave me an aneurysm because to me Holley and Dominator is this:
Appleseed said:Reading the thread title almost gave me an aneurysm because to me Holley and Dominator is this:
Where do you plug the tuning slide rule in?
In reply to JG Pasterjak :
Everywhere you see a + or a -
Interesting as I have used all those GM tb with at least the DBWX2 boxes and haven't really seen differences. Likely you had an early one from a TAC setup vs the later integrated ECU ones that Holley is expecting. Maybe it's just in bad shape causing a dbw fault intermittently, which with some systems are hard to clear out.
Appleseed said:Reading the thread title almost gave me an aneurysm because to me Holley and Dominator is this:
Me too.
Holley shouldn't be recycling names, Chevy style. They should have called it the Eliminator.
Appleseed said:Holley shouldn't be recycling names, Chevy style. They should have called it the Eliminator.
This would have been epic. Missed opportunity.
So just for reference, were you running one of the earlier 90mm Gold blade units like #12605109 before?
deaconblue said:So just for reference, were you running one of the earlier 90mm Gold blade units like #12605109 before?
Yeah the first pic of the TB in the story is the old one. 90mm gold blade top-rearward swing.
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